Thursday, 16 December 2010

Lambs and Corkscrew Grass Don’t Mix

We recently experienced significant lamb losses to the extent that we engaged the veterinarian from the Lachlan Livestock Health and Pest Authority to come out and take a look. It transpired that the root cause of the losses was our decision (made in hindsight out of ignorance and inexperience) to put the ewes and lambs post shearing of the ewes into paddocks that had a heavy load of Corkscrew Grass seed. The deciding factors at the time were that the paddocks had not been grazed for quite some time, were next in the grazing rotation plan, contained a solid stand of fresh diverse pasture which would give good nutrition, and we were keen to reduce the herbage mass to reduce fire risk.

With the benefit of hindsight what follows are the key factors that contributed to the lambs losses (no ewes were lost):

  • The Corkscrew Grass seeds penetrated the wool and skin of both the ewes and lambs
  • The resultant pain and stress on the ewes triggered many of them to wean their lambs as an automatic mechanism. Presumably being larger and older the ewes were still able to seek feed and water although many did lose condition.
  • The pain and stress on the lambs was such that many ‘hunched up’ and found it difficult to walk and feed
  • The weaning from their mother’s created a simultaneous reduction in nutrition intake for the lambs
  • The height and density of the Corkscrew Grass stand coupled with the severing of the coaching relationship with the mothers meant that the lambs either found it difficult to go to the water or were not at all able to go to the water. NB: In all of the paddocks there was a plentiful supply of good quality drinking water. There was also plenty of green feed in the paddock which will have provided for the majority of an animals hydration needs – especially given that the daily maximum ambient temperatures have not been extreme.

The veterinarian who came to our place asked the night before for us to have a couple of affected lambs close to the house – preferably one that had died a short time ago and another that was exhibiting classic symptoms of the problem. Due to the extreme wet conditions the best we could do was bring back two that were still alive but were in an advanced stage of ill-health. She took the temperature of one of the lambs and checked its mouth and eyes. This showed that the animal was not suffering from infection and had good pink colour meaning it was not anaemic. The other significant diagnostic action taken by the vet (with our permission) was to humanely slaughter one of the lambs and conduct a simple autopsy. Some of the specific attributes checked and what each indicated are:

  • Inspection of the underside of skin (visible in this photo) to see how much seed had penetrated and how far it had gone. The attached photograph shows a section of the area examined. We found it upsetting and disturbing to see what the lamb was dealing with. Seed numbers were high and in some cases they had completely penetrated, rather than just the sharp seed tip.
  • Inspection of the main lymph gland at the shoulder. This was huge in relative terms compared to what would normally be the case indicating the level of stress on the animal from the seed load
  • Inspection of the fat around the kidneys and one of the kidneys. Whilst the kidney was in excellent order there was little to no fat around it – proof that the lamb was in poor condition.
  • Inspection of the stomach and intestines. This revealed a very low level of worm infestation - nothing that would suggest parasites are causing animal losses.

Last year we had no problems with Corkscrew Grass and lambs but on the other hand seasonal conditions were dry until December. Discussions with our wool broker, shearing contractor and neighbours suggest that this year’s wet conditions really are extraordinary and ‘perfect’ for the proliferation of this species. One neighbour has also had problems with impact of Corkscrew Grass on his lambs and commented that this is the first time this has happened and that he has never experienced a season like this one.

Yesterday we had all of our lambs shorn and have drenched them for worms. This, combined with our intent to keep them on paddocks with little to no Corkscrew Grass, should reduce the risk of further losses. That said we have noticed that the seeding period for this grass now seems to be over i.e. the bulk of the plants have now ‘shed’ their seed which will make it safe for the sheep.

To the future … we will do further research on whether Corkscrew Grass can be managed better through grazing and other management techniques. It may also be time for us to look at acquiring cattle which we know are more effective at enhancing soil conditions and they naturally ‘shed’ seed like Corkscrew. What we do know with absolute certainty is that lambs and Corkscrew grass just don’t mix.

Monday, 1 November 2010

How to make a Worm Tower

I am a big fan of what Nick Ritar and Kirsten Bradley are doing - spreading knowledge of sustainable living (Permaculture) - through their business near Mudgee, Milkwood Permaculture. Anyone with an interest in this subject can sign up to receive their free monthly email distributed newsletters. It's a simple as going to the Milkwood Permaculture website homepage and inserting your name and email address in the registration section and clicking on the 'Subscribe' button.
In this month's newsletter Nick and Kirsten provide step by step instruction on how to make a Worm Tower. Here's a link to the full article for those who would like to know more. Jan and I have decided to give it a go!

Wednesday, 27 October 2010

Air Conditioner Installed

Yesterday we had an air conditioner installed in readiness for summer. We selected a unit manufactured by Mitsubishi Heavy Industries given its products have (one of) the highest energy efficiency ratings and were strongly recommended as best in the market by two trusted contacts ... one of which works in the industry for a competing manufacturer and the other in the solar energy supply industry.

Here are some of the key details:
Model #: SRK71ZEA-S1
Supplier: Coles Hardware & Glass, Cnr Flint & Bathurst Sts, Forbes Phone (02) 6852 1955
Installers: Michael Coles from the above business did the gas fitting work ( and the electrician was Colin Mayo also from Forbes phone 0419 697 168.

We were impressed with the overall supply and installation and are happy to give both Michael and Col a plug.

The first step in the installation is locating the best place for both the 'head' (inside unit) and 'compressor' (outside unit). The head is located in a position in the living room that will allow for the cool air to reach into the two bedrooms. This photo shows the backing plate and hole through the wall for the wiring and pipes.

This photo shows Colin (L) and Mike (R) putting the head on the backing plate. The head is a tad under 1100 mm wide.

Here you can see the compressor unit on the concrete pad supplied as part of the installation. Sitting on top of the unit is a high pressure vacuum unit ... used to basically extract all moisture from the copper pipes prior to releasing the refrigerant (stored in the unit). Most of the compressor units are placed on wall brackets but in our case we opted for a concrete pad on the ground given concerns that being an old weather board home the noise from the compressor would go straight through the wall. It's the way to go for us ... and we also learned that with houses like ours the vibrations can also trigger rattles from windows.
The compressor has to be installed (and is) at least 1500 mm from any gas tanks to comply with regulations.

Here you can see Mike and Col doing the last bit of the installation. There was a reasonable amount of pipe fitting and electrical work involved ... all carried out without fuss. Col was able to source power using one of two spare cables that our local electrician (Alf Zammit) left for this purpose when he originally wired the cottage for us.

In terms of trends we learned that the majority of people locally are now tending to buy evaporative air conditioning units in response to escalating electricity costs. This is turn places pressure on water supplies ... but at least water is a renewable resource. Given we have a stand alone power supply system we don't have power bills ... so a refrigerated unit suits us and we don't also have to muck around connecting water to the unit. During peak usage our air conditioning unit is expected to produce around 3 to 3.5 litres of water per hour.

A comment Mike made that I found enlightening was that one way to determine the quality of a product (such as air conditioners) is by going onto e-Bay and seeing how many spare parts sellers there are. The more spare parts sellers there are the poorer the product quality!

Sunday, 24 October 2010

Location of Ochre Arch

The following Google Maps link shows the location of Ochre Arch. Included in the map are the directions to the farm from the towns of Grenfell, Forbes and West Wyalong via the roads we tend to use. The farm area is also marked on the map.

View Ochre Arch, Grenfell, NSW, Australia in a larger map

Saturday, 23 October 2010

Solar Panels ... Setting the Angle

In November 2009 I posted an article containing information about our remote power supply setup. Systems such as ours are more commonly known as Stand Alone Power Systems or SAPS.

When Central West Solar installed our system they set the angle of the fixed solar panels on the shed at approximately 43 degrees ... being latitude (34 degrees south of the equator) plus 10 degrees. From this I assumed that the ideal 'rule of thumb' for all solar panels would be the same as ours i.e. latitude plus 10 degrees.

A farming family we know who live south of Grenfell recently had a 10 kW grid-connect solar system installed, with the panels attached to the roof of one of their sheds. The panels have been attached directly to the roof without angle-adjustment frames and thus are at the same angle as the roof pitch. The pitch of this roof is very low ... at a guess around 5 degrees. My initial reaction was that they would most likely be missing out on quite a bit of potential energy capture at this angle.

I've been in contact with Robert at Central West Solar to get some clarification on the solar panel angle conventions and now understand that the angle can and should be set differently depending on the goal of the solar panel installation. Robert advises that "Generally peoples power consumption in this region over winter is approx the same as summer. If you dont take bias of array to suit loads in different seasons then the rule of thumb is: 
  • For the best all year round yield: Angle should be equal to the latitude
  • For the best summer yield: Angle should be latitude MINUS 10 to 15 degrees
  • For the best winter yield: Angle should be latitude PLUS 10 to 15 degrees"
In our own case, given we have a SAPS (and cannot sell surplus or externally source shortfalls), our goal is to maximise the winter yield as this is naturally a low capture part of the year due to shorter day length, less intense light, and higher probability of cloud and fog cover. Thus 43 degrees is spot on for us.

For those who are on grid connect systems where the primarily goal is to reduce the year round power bill (or maximise year round revenue) then the appropriate angle would be equal to latitude. Letting the mind wander creatively for a moment (and assuming all things being equal ... which they are not) people with this goal:
  • Living on the equator could install panels directly on to flat roofs
  • Living on the south pole could install panels directly on to north facing walls
  • With a 20 degree north facing pitch roof living at one of the following places in Australia could affix panels directly to their roof: Camooweal, Charters Towers or Bowen in Queensland; Tanumi or Avon Downs in the Northern Territory; or Port Hedland in Western Australia
What I have not investigated and thus don't have a feel for is what the yield reduction is for each degree the panels are not at the ideal setting. This is the type of information I reckon anyone with a grid connect system should find out as it would allow for cost benefit analysis to be carried out to assess the return from spending money on frames and structures that alter the angle of the panels from the pitch of the roof or for 'follow the sun' moving solar panel support structures.

Sunday, 3 October 2010

UBank losing its gloss

On 31st October 2009 I posted an article on Ochre Archives explaining how in rising rate economic climates financial institutions have a tendency of releasing new variable rate savings based products offering rates that are at the time of release competitive, whilst at the same time either capping or slowing the rate of rises on existing savings based products. In this way they are able to attract ‘new’ money (to the new higher rate accounts) but at the same time broaden the overall margin between lending rates (interest rates on variable rate loans almost always increase in line with market movements) and deposit rates leading to even greater profitability. I also explained how we had moved our main deposit funds to UBank which is part of the National Australia Bank (nab) group in an attempt to keep pace with changes.

When we opened our UBank USaver account they were offering two types of USaver accounts. The ‘standard’ one was for those who did not want or need a regular savings program and the second was for those who were prepared to commit to a regular savings plan. UBank offered a premium of about 0.1 % above the rate payable on the standard product to those who selected the regular savings option.

This morning I decided to have a close look at what UBank/nab had been ‘up to’ since we transferred funds to them in the context of the above and subsequent movements in the ‘official cash rate’ approved and determined by the Reserve Bank of Australia (RBA) Board.

On the ‘rate changes’ front from early December 2009 to end June 2010 the following has occurred:
  • The RBA made 4 upward / increase rate adjustments totalling 1.0 % in the official cash rate taking the total rate to 4.5 %
  • UBank (nab) made 5 upward adjustments totalling 0.55 % (55 % of the increase in the RBA adjustments) in the UBank standard USaver account rate making the current total rate 6.01 %
  • UBank (nab) has broadened the margin premium for the regular savings USaver account by about 0.4 % to take the total rate to 6.51 %. Thus the rate on this product has risen roughly in line with the RBA official cash rate.

Thus based on the above anyone who has a standard USaver account has been ‘left behind’ the rise in official cash rates announced by the RBA to the tune of 0.45 % which roughly equates to a $45 opportunity loss for every $10,000 invested over a 12 month period. What I'd suggested normally happens in rising rate environments has been confirmed.

I’ve observed a couple of other changes in the UBank experience and general offering:
  1. The complexity of what UBank does has increased. When you call the main switch number you now get an auto message offering superannuation product offerings
  2. The nab has re-enforced the ‘right of set-off’ clause with UBank deposits. Essentially and simplistically what this means is that the Bank has the legal right to report in its figures to the regulators the net balances (loans less deposit funds) of ‘same customer’ arrangements. The advantages to the banks are that in some circumstances they can reduce the amount of capital shareholders need to provide to support the balance sheet gearing and they can also physically transfer funds from a customer’s deposit account to the same customer’s loan account/s clear or reduce loans should they choose to do so. The advantage to some customers is that they can opt to only pay interest on the net loan, rather than pay interest on the gross loan balance and receive credit interest on the deposit account/s. Because of the right of set-off clause some customers choose have their deposit funds in a different financial institution to the one they get loans from.

The moral of the above story with variable deposit rate products is basically that as far as the financial services industry goes (or at least some of the players) the saying “If you are on a good thing stick to it” does not apply and we need to regularly check to see that we are being offered competitive deals.

For those who love micro detail below is what has happened with RBA official cash and UBank standard USaver account rate movements during the period I have referred to above.

2-Dec-09 RBA increased the official cash rate by 0.25 % to 3.75 %
9-Dec-09 NAB increased the UBank standard USaver account rate by 0.05 % to 5.51 %
22-Jan-10 NAB increased the UBank standard USaver account rate by 0.11 % to 5.62 %
3-Mar-10 RBA increased the official cash rate by 0.25 % to 4 %
12-Mar-10 NAB increased the UBank standard USaver account rate by 0.13 % to 5.75 %
19-Mar-10 NAB increased the UBank standard USaver account rate by 0.1 % to 5.85 %
7-Apr-10 RBA increased the official cash rate by 0.25 % to 4.25 %
5-May-10 RBA increased the official cash rate by 0.25 % to 4.5 %
24-Jun-10 NAB increased the UBank standard USaver account rate by 0.16 % to 6.01 %

Friday, 17 September 2010

Moving the RA Lister Motor in the Shearing Shed

When we were shearing the weaner lambs at the end of March it became apparent that it would be necessary for us move the old R A Lister petrol engine that used to power the old overhead gear to allow sufficient room for the large fleeces when we shear the older ewes.
Given we are now only a month or two off shearing the ewes I'd been mulling over the best way to move the motor and had been considering hiring some form of heavy lifting device. I then recalled a conversation I'd had a few years ago with David Byrne who owns and runs the Tasmania-based business Solutions for Sustainable Living. During that discussion David mentioned how he at one point was installing and removing fuel (wood) stoves on his own without using any heavy machinery. Basically the technique involved the use of steel pipes (as rollers), ramps and pulleys. Off the back of this knowledge we decided to give it a go with our old motor. Yes ... whilst it did take us quite a while due to lack of experience we found the whole process simple, safe and effective.
The accompanying photo shows the motor after we'd managed to move it from the concrete base it used to be on down a timber ramp and across some steel plating. Since then I've moved the motor to another part of the shed where I suspect it will stay for quite a while.
Moving the motor has had another benefit in that we found the old specification plates that were not previously visible. The single cylinder petrol motor was manufactured by R A Lister & Co Ltd, Dursley, United Kingdom. The engine number is 77599 / Spec 83 J. It is rated at 4 1/2 horse power and runs at 525 revolutions per minute. We are most curious to ascertain the year of manufacture. A bloke who works at Lister Petter Limited in the UK thinks it may have been manufactured in the 1920's but is not sure. We'll keep researching and see what we come up with.
Getting back to the main intent of this post ... the technique we used to move the motor has made us think of possibly how the Egyptians might have constructed the pyramids. Slow and steady but very effective.

Friday, 20 August 2010

Sheep Yards on Ochre Arch

In response to the recent article published in The Grenfell Record titled “Shearing with Sunshine at Ochre Arch” we received a fabulous letter from David and Jenny Johnson who now live at and farm using Permaculture techniques near Woolgoolga on the north coast of New South Wales. David’s father Clarrie at one point owned the property “Rutland” located about 5 km from us further along and to the east on Goodes Lane. David’s sister Marie and her husband Don Hampton owned “Ochre Arch” (“Cleveland” as it was then known) from around 1965 to 1977.

The sheep yards on our place are quite unusual as far as materials go, with the main steel pipes having originally been manufactured for and used as steam engine pipes. The accompanying photograph was taken 15th June 2010 and shows the pipes quite clearly, as well as some of our wether lambs prior to them being transported for sale at Forbes. Our shearing shed can be seen in the background.

In David and Jenny’s letter they explained that the steam pipes Don Hampton used when constructing the yards in came from a large batch that Clarrie Johnson had procured from the railway workshops in Sydney in about 1963 when David owned neighbouring property (to the north of us) “Pinnacle”. “They came as four pipes about 12 foot long in a continuous session with two open ends along side each other with a double flange and three of the joiners like shown in the yard picture”. David used pipes from the same batch for manufacturing cattle yards at the property he owned at that time “Braeside” near Bogolong towards Grenfell. He slipped the pipes over the top of the weldmesh and cemented them in as the corrosion from prior use made the material extremely difficult to weld.

Friday, 13 August 2010

Batteries for Our Remote Power System

Yesterday I re-read the ‘Operating Instructions’ for the batteries that are installed as part of our remote power system and was reminded of quite a few important things to keep in mind about them. To be specific we have 24 X 2 volt ‘valve regulated lead-acid’ “type 8 PVV 1200” batteries manufactured by the German company BAE Batterien GmbH. The purpose of our batteries is to store and provide direct current for conversion to 240 ac volt via the inverter.

The valves on the top of the batteries allow for release of hydrogen and must not be opened as doing so permits the access of oxygen which discharges the energy in the battery cells. Adequate ventilation is essential.

The batteries have to be kept out of direct sunlight and need to be installed and operated such that the ambient temperature difference between the cells or blocks within individual batteries is very small (less than ‘3 K’ … whatever that means!). The strings of batteries are best to be installed in specially designed cabinets for temperature evenness control and the connectors between the cells all need to be the same diameter and length.

During discharge (supply of an electrical current) the active materials in the batteries are converted to lead, sulphate and water. Curiously, the faster the rate of discharge the less amount of aggregate current ends up being available.

For long life the batteries need to be returned to full charge within a period not exceeding 4 weeks. Our batteries are classed as ‘deep discharge’ which means they can be totally discharged from time to time, however it is not our intention to do this. We have our back-up generator set up to auto recharge the batteries by 20 % from 65 % as and when this reduced charge level occurs (as mentioned in a previous blog post). I’m assured that the 65 % minimum is about optimal but have not seen any empirical data supporting this. Car batteries are not at all ‘deep discharge’ and will deteriorate rapidly if this occurs regularly.

If the battery voltage is permanently less than full it will discharge by itself resulting in ‘loss of capacity and possible sulphation of the electrodes’.

What I found particularly interesting is that when a battery is classed as ‘fully discharged’ this does not mean that it has zero voltage. By way of example, each of our ‘2 volt’ batteries are considered fully discharged (called the ‘final’ voltage) when their voltage falls to 1.8. Conversely a ‘full’ battery holds more than 2 volts … and for us this generally occurs when the voltage is 2.4.

The ideal operating temperature range for our batteries is 10 to 30 degrees Celsius. The rated maximum is 45 degrees C however they will handle temperatures for very short periods of up to 55 degrees C. High temperatures have the affect of reducing the operational life of a battery. I was unable to find information on the absolute minimum temperature batteries can handle and have noticed that cold nights do seem to reduce battery voltage more. Cold temperatures have the long term impact of reducing battery storage capacity.

As far as maintenance goes, during the whole life (estimated at 15 years) our batteries do not need to be refilled with water. “The electrolyte is diluted sulphuric acid and fixed as GEL made with micro porous SiO2.” It is recommended that every 6 months the voltage and surface temperature of a sample of batteries be checked and recorded together with the room temperature. Every 12 months the voltages and surface temperature of all batteries are to be measured and recorded.

If the batteries ever need to be stored for extended periods they should be left fully charged and in a dry frost-free room.

So … what does all this mean in the context of how our batteries are presently installed? In short our location and set-up augers well for good extended life and performance of the batteries. We experience very few frosts each year and having the batteries off ground level within a cabinet within a closed room means that they should never reach zero degrees C … especially given that each one weighs 70 kg and they are installed side-by-side effectively creating a 1680 kg block. Whilst our summers are hot it is not common for temperatures to exceed 45 degrees C and since climate records have been kept in the district the hottest day on record was 48 degrees C … well within the 55 degree C maximum. Added to this we do have an additional roof over the container where we keep the batteries, virtually eliminating the chance of temperatures getting higher than the external ambient within the storage room due to heating by sunlight on the roof and walls. The set-up of our back-up generator means that the batteries should never be discharged to high risk levels and the sunlight patterns are such that I’m confident the batteries will get to fully charged levels for short periods at least once every 4 weeks regardless of season.

Wednesday, 11 August 2010

Dew Quantity Variations

We’ve yet to connect the guttering on the solar-panel shed to one of our new tanks. Consequently each morning when dew has formed on the roof the resultant water runs out of the guttering onto the ground. I decided to measure the quantity of water generated by the dew process over 3 nights by placing a 200 litre drum under one of the gutters.

The shed dimensions are 12.2 metres width and 17 metres in length giving a total roof area of 207.4 square metres. The roof is peaked in the middle with gutters along both of the long edges. This means that the roof area feeding into a single gutter is half of 207.4 square metres = 103.7 square metres. The quantity of water captured from ‘normal’ overnight dew was 3 litres; on a ‘light frost’ night 8.5 litres water was measured and on a ‘heavy frost’ night 22 litres resulted.

22 litres from 103.7 square metres equates to receiving 0.21 litres (210 millilitres) of water per square metre of roof area … or the same as receiving 0.21 mm of rain. This is just less than a cup of water (250 millilitres) per square metre … quite a bit of water in the scheme of things.

Thursday, 5 August 2010

Rain Water On Tap

Yesterday we finalised connection of rain water (cold only at this point) into the pipes in the cottage on Ochre Arch. The set-up for rain water supply was described in broad terms in the blog article we posted on 28th May 2010 titled “Planning Our House Water Supply”. We ended up using 63 mm outside diameter polythene pipe in the ground, meaning that there is virtually zero friction loss. The pump is a Grundfos model CH 2 60. After correct priming the flow rate to the top (balance) tank was 22 litres per minute and the pressure was 450 kPa. Both of these figures were / are spot-on with what we were hoping for.

In this photograph you can see the actual connection from the poly pipe into the copper cold water pipe at the rear of the cottage. The internal diameter of the flexible connecting hose is very small at about 4 mm but the pressure generated from the balance tank located 45 metres in elevation above the house ensures adequate volume.

It is worth recording what having the water connection means in practical terms. In the accompanying photograph are the items we can now retire. What we did routinely was:
• Use the 2 X 10 litre containers to carry drinking water from the concrete tank at the shearing shed to the house. The distance is about 75 metres and on average we used 20 litres a day for drinking and hand washing
• From these containers we’d fill on a needs basis the blue 5 litre plastic drink bottle (kept on the bench in the kitchen), the green with white spots jug (kept on the wash-basin in the bathroom) and direct-fill other water bottles, hot water kettles and jugs, and drinking glasses
• Use plastic buckets and 20 litre containers to source washing water for the washing machine from the galvanised iron tank at the house

Right at this minute Jan has a load of washing underway via the washing machine. Not only does the new set-up save a lot of physical energy but it also avoids water inadvertently spilling on the bathroom floor and requiring subsequent clean-up.

Saturday, 3 July 2010

A Tale of Two Whistles

Last week I found the whistle seen in the accompanying photograph on the ground about 2 metres to the east of the car shed here on the farm. I was impressed with the quality of the item, which still works superbly, and figured it was likely that previous owners who lived on the farm between around 1935 to 1965 were likely to remember … had any of their members owned and lost it.
With the above in mind my first approach was to Don Bokeyar … whose family owned our place from around 1935 through 1950 and built the house we now live in … around 1940. I sent him an email without an accompanying photo (I’ve only taken the photo this morning). His reply read in part as follows: “That whistle got me into big trouble one day. I was riding my pushbike home from the Feeney’s where I had been dropped after school. Mrs Feeney was the teacher at the Pinnacle school. I was riding up the then dirt track from the mailbox quite happy blowing the whistle all the way home. Not a good idea at the time because Mum thought I had hurt myself or worse. On arriving home Mum found I was all OK, that was when the strap that hung behind the kitchen door was put to very effective use. Needless to say I did not see that whistle again. I recall the incident very clearly.”
There were several aspects of Don’s reply that really hit home for me:
  • A mother’s concern for the safety of her children
  • The innocence and excitement of youth
  • The toughness of justice in days gone by
  • The richness of the (real and rarely known) stories behind artefacts
  • How well sound travels in the country
  • How asking one question leads to a myriad of more questions
  • The reason why a whistle is generally considered to be one of the top 10 items to have in any safety kit
I called Don to thank him for his feedback and discuss the incident a bit more. The Feeneys lived on a property on Hoctors Road called ‘Talbalba’; about 1 km to the west of where the Pinnacle Guinea Pig Races are held. The house at ‘Talbalba’ has been unoccupied for about 40 years and is now in total disrepair. It would be about 6 km in all from ‘Talbalba’ to where we live. The distance from the mailbox Don refers to to our own house is a tad over 2 km. At the time Don had a “21” pushbike and recalls the toughest bit of the ride home as being over Simpsons Hill … the property on the north side of this hill is called Milroy (where the Guinea Pig races are held) and was owned by the Heathcote family when I was growing up. Once Don arrived at the Feeneys in the morning they would then travel via horse and sulky to the Pinnacle School … no longer in existence but the site was located not far from the present-day Pinnacle Hall. Don cannot recall a specific occasion for receiving the whistle (e.g. birthday) but knows that he did not have it for longer than a couple of days in total! As we talked further it became clear that the whistle I’d found was not the one he’d been given. His was similar to a referees whistle … complete with a ‘pea’ that meant it was capable of generating even more noise than the one I’d found. After I described the whistle to Don he expressed the view that it was most likely a 'dog whistle'. From a ‘life experiences’ perspective Don looks on the event as a positive learning on the need to be aware of how sound travels in the country and the role sound can play in warning of danger.
This morning I contacted the Causers (Lindsay ... lived here from 1950 to 1965), the Hamptons (Don who owned our farm from 1965 to 1977 and his sons David and Paul) and the Pitts (Ian ... lived on the farm from 1981 to 1987). Lindsay commented that the only whistles they ever had while here were ‘fox’ whistles … round in shape with a hole in the centre. The Hamptons and Ian Pitt have no recollection of the whistle. Ian's daughter Jenny thinks that she once had a necklace that had a whistle on it as a pendant but is not certain.
So … it seems there may have been at least two whistles ‘lost’ on our place … and the story behind the one we have is uncertain. Don’s story will not go to waste … and I’ll likely use the whistle we now have and extracts from his story as education for the school excursions we aim to host here from time to time.
(My thanks go to Don Bokeyar for permitting me to share the above story)

Monday, 21 June 2010

Pregnancy Testing the Ewes

On Thursday 10th June 2010 Andrew Naylor from Canowindra came and pregnancy-tested our older ewes. There were several reasons why we wanted this done:
  1. It would provide us with an indication of how well the ewes were travelling health-wise under our management.
  2. It enables us to identify those that are not pregnant. We see little point in carrying 'breeding' ewes that don't in fact breed. Culling them sooner rather than later is in our view better all round in that we realise the cash from the sale, have less animals to manage, and have more grass available for the rest of the mob.
  3. By identifying single and multiple embryos we can forecast how many lambs are likely to be 'on-ground' when it comes time to do the marking.
  4. Had we decided to brand those with multiple embryos we then would have had the option of separating them out and giving them access to better feed which in turn increases their prospects for taking the multiple lambs through to weaning. We did not do this because our flock size is not large and our intent is to give all of the ewes access to the best of our feed.
  5. Our joining period was the bare minimum at 35 days (2 full cycles) and if the pregnancy percentage proved to be very low we would have the option of putting the rams back in with the ewes or maybe even getting other rams for the job.
The pregnancy test involves placing an ultra-sound device just near the front of the udder area and identifying from the connected display screen whether the ewe is pregnant or has multiple embryos. In the photo you can see the mini-tent that Andrew places over himself and the equipment. It is positioned at the end of the drafting race enabling us to more easily run the sheep up the ramp and into the crush where each ewe is individually held while the scanning is carried out. The process is very quick at in excess of 200 per hour, although we understand the throughput rate may have been 300 an hour had we been better at pushing up the ewes into the scanning structure i.e. the weak-link was our ability to herd the sheep.

We were pleased with the results (3% 'empty', 37% singles and 60% multiple) and found Andrew great to deal with. No fuss - and his system for setting up, using and removing his equipment was excellent.

Sunday, 20 June 2010

Seasonal Sheep Price Variations

Tonight we had a call from our stock agent to de-brief us on the sale of our weaner wethers at Forbes on Tuesday 15th June 2010.

Whilst the wethers were on the light side they apparently looked excellent when penned up into the 3 lots - larger, main line and small. The agent commented that we should stick with what we are producing as they are the type of sheep the market is looking for.

We asked the agent whether there are any specific seasonal trends we should be aware of in the context of best time to buy and sell sheep. Some of the main points included:

  • 50 years ago prices used to peak in January / February as this was when the croppers were cashed up post harvest coupled with crop stubble to put the animals onto
  • In very recent times mixed farmers tend to sell stock so that they can fund cropping inputs such as fertiliser, seed and chemicals
  • Best time to buy stock in this region is when Victoria is in drought conditions and the local area is not
  • Lower prices are generally from March through May
  • Peak prices are January / February and August / September

Friday, 28 May 2010

Planning Our House Water Supply

“Ochre Arch” is not located near a town or town water supply and consequently it’s important to try and make sure we have sufficient drinking quality water captured on the farm. Given that we have a remote energy power supply system we also want to optimise available energy sources for moving and heating when needed the house water.

Not long after buying the farm we installed a 22,700 concrete tank at the shearing shed. This has been our primary house water supply since that time. About 12 months ago we installed a new 13,600 litre galvanised iron tank at the house to replace one of the same size that had rusted out but discovered during last winter that the water running off the house roof absorbed smoke from the wood fire making it taste ‘not-so-nice’. Having constructed the new shed for the solar panels last year we recently purchased but have yet to have installed a new 22,700 poly tank. Once this is in place we will then have 59,000 litres of tank storage connected to the main roof areas on the farm.

The location of the above roof areas is such that it is necessary to have some form of pumping in place in order to create sufficient pressure for the house water to run through the pipes producing the appropriate volumes for our needs. Most farms in our situation that are on mains power simply opt for pressure pump/s that run/s virtually every time demand for the water is created via the turning on of a tap. We are not keen on this type of set-up as with many of them the pressure varies to an uncomfortable extent whilst showering and if we had one of these pumps it would use a considerable amount of power.

Six months or so ago we had a visitor (Stafford W) who is an engineer by background and put to us the concept of locating a holding tank up on the hill to the south east of the house into which we could pump the house water … with it then gravity feeding back to the house. We were wrapped with this idea and have been pursuing it – one of the reasons being that we would always have constant water pressure – similar to what people in the towns and cities are used to. Hopefully in the next two months this will be in place via a contractor we have engaged. Another 22,700 poly tank has been purchased to be the holding tank. When this is in place and if it and the other tanks are full we will then have as much as 81,700 litres available to us at any one time. With only two of us living here it is highly unlikely (baring something unforeseen) that we would ever need to bring in water i.e. we should be comfortably self-sufficient.

We identified a suitable location for the holding tank – located approximately 700 metres from the house and sheds and some 29 metres higher in elevation above the house. 29 ‘metres of head’ would, leaving friction loss aside, create 284 kilopascals (kpa) of pressure … more than enough we thought.

The holding tank will have a capacity gauge that can be seen from the house. Whenever the holding tank level falls to, say, half full, we’d then fill it via an electric pump (to be located in to shed that houses the remote energy system) and connecting 50 mm outside diameter (ODI) poly pipe. Our intention was to also install a split solar hot water system at the house that had a LPG booster, meaning we would rarely run out of hot water.

All of the above ‘looked good’ so we had the tank manufacturer place the holding tank at the chosen location … still there at the moment pending the contractor calling to do the installation and connecting. It was then that we contacted a supplier of split solar hot water systems. He suggested that we purchase an electric (rather than gas) boost split system and also informed us that all split systems require a minimum of 375 kpa to function properly.

We are comfortable with the suggestion about the electric boost system as apparently they are extremely effective, our remote energy system can handle it AND it will mean that we will then not have to pay for gas for the booster; although on rare occasions the diesel back-up generator may be required. The need for 375 kpa was a potential problem, though. After a bit of a cooling off period, some lateral thinking and some GPS and other measurements we have managed to locate an alternate site for the holding tank. This will be 45 metres higher in elevation than the house (on the same hill as the one we were going to use but in a different paddock) but involve probably another 100 extra metres of poly pipe AND some very rugged terrain over which the ploy pipe will need to be laid. The contractor was contacted and is comfortable with the change, including relocating the holding tank.

What we needed to do, though, was reach a comfort level that the altered set-up would in fact deliver water at a minimum of 375 kpa. It was then that we contacted our ‘water guru’, Phil W, for advice. He did some calculations and advised us that:

* As a ‘Rule of thumb’ water flow rates for various outlets in houses are generally:

  • 0.25 litres per second for bath, basin or shower
  • 0.2 litres per second for a kitchen sink
  • 0.1 litres per second for a toilet

* Given the set-up of our house water / plumbing here the maximum flow required would be 0.5 litres per second, assuming that say the kitchen sink tap was running at the same time as the shower

* Friction loss, expressed in metres of head, through 800 metres of 50 mm outside diameter PN8 grade poly pipe from a gross height/head of 45 metres would be:

  • 2.96 (roughly 3) metres of head assuming a volume rate of 0.5 litres per second
  • 10 metres of head assuming a volume rate of 1.0 litres per second
  • 35 metres of head assuming a volume rate of 2.0 litres per second

This would then mean that we would have a clear 42 metres of head to work with (45 minus 3). 42 metres of head produces 411 kilopascals of pressure. This is well in excess of the required 375 kpa to run the split solar system.

The critical assumption we are making is that the requirement of 375 kpa is based on INFLOW to the hot water system and not OUTFLOW from the system. Under normal circumstances the outflow through a hot water system would be around 275 kpa where the inflow was 413 kpa.

The investigation process continues but the above provides an insight into factors to be considered. We have decided not to directly connect the tank at the house to the pump given the taste of the water and will only pump directly from the shearing and renewable energy shed tanks.

Thursday, 15 April 2010

Curious Wind Turbine Facts & Observations

In response to The Grenfell Record article mentioned in our last blogsite post several people have contacted us for more information, mainly about the wind turbine. I thought there may be others who are interested in this as well and provide below some of the more curious learnings we’ve had to date.

Our battery set-up is 48 volts, made up of 24 X 2 volt batteries. The actual voltage has varied so far from around 49 to 56 which is quite normal. The wind turbine does not add any current to the batteries until and unless the voltage it generates exceeds what is currently in the batteries. So whilst the blades of the turbine (which span 1.8 metres) might be spinning this does not necessarily mean that usable power is being generated. The Weddin Shire does not theoretically experience wind patterns that support reliable wind turbine based power generation however it is amazing to us how often the wind speed is sufficient to see our turbine adding power to the batteries.

When the batteries are fully charged and there is sunshine the solar panel system goes into ‘float’ mode which basically means that it ceases to generate power, a bit like going into neutral in a car. The wind turbine controller acts differently. When the voltage from the wind turbine exceeds what’s in the batteries and the batteries are fully charged the controller literally burns off the surplus power via heating of resisters in the back of the control unit, a bit like a mini bread toaster. NB: The controller design, its location in the control room and installation arrangement is such that it is completely safe from a potential fire risk perspective.

At various stages when the turbine is gathering speed in response to increasing air movement (wind) there is considerable vibration. The tower arrangement in place is specifically designed to account for this. Some others who have purchased and installed small turbines have placed them on the end of sheds or houses and found that the units literally send tremors / shakes through the entire structure.

Wind turbines do not handle wind turbulence (disturbed air flow) at all well. This is why large wind turbines are generally on high towers with no trees or other structures nearby. In our case, we do have a large tree not far from the turbine to the west, and when we receive westerly winds the whole turbine unit on top of the tower at times actually rotates.

The guy rope tower arrangement is ingeniously simple and the turbine can be easily lowered to the ground and resurrected. The whole unit can handle very strong wind speeds; however the manual does suggest that the unit be lowered if it is known that wind speeds are likely to exceed 130 km per hour. The controller unit does have an ‘off’ switch and when this is flicked the turbine stops spinning courtesy of a non-moving-part breaking system that works electromagnetically.

Wednesday, 7 April 2010

Shearing with Sunshine at Ochre Arch

Ochre Arch featured on page 1 of The Grenfell Record today. Here's a link to the online copy of the article.

Thursday, 11 March 2010

Ooma (Community) Water Scheme Underway

Ochre Arch is a member / participant of what is known locally as the Ooma Water Scheme (the Scheme). In broad terms 34 farming families have signed up to receive high quality bore water from a new water bore located near the village of Garema, located between the larger towns of Forbes and Grenfell.

The Scheme was initiated by a few local landholders in response to the stresses of carting stock and domestic water during the past 7 or so dry years. Some of the key facts behind the scheme include:
  • Number of farms: 44
  • Number of water delivery points: 50
  • Water will be delivered into tanks or troughs and NOT dams, ensuring minimal water loss
  • Total maximum combined daily water delivery: 600,000 litres per day (about 0.6 of a standard Olympic swimming pool
  • Pipe type: polythene
  • Number of pumps: 3 - main one at the bore plus one each at the two transfer points
  • Total pipe length: Approximately 124 km, delivered in approximately 86 semi trailer loads
  • Cost of the scheme: Approximately $1.2 M
  • Funding: All except for $25,000 (State Government grant to cover the cost of the main pump at the bore) is being provided by the individual landholders (including us!) with the share determined based on daily usage request.
Here, courtesy of scheme members Adam and Claire Nicholson, are two photographs showing the amount of polythene pipe currently on their place pending completion of the scheme. What you can see represents about one third of the total pipe being used in the scheme.

Here on Ochre Arch we've 'signed up' for 10,000 litres per day, which is guaranteed to be delivered over an 18 hour period. This will be sufficient for approximately 2,000 sheep during hot conditions, or 200 cattle.
Installation has commenced, with Ochre Arch being 'first cab off the rank' in terms of pipe laying. It will be several months before the whole scheme is operational. We are pretty excited about being involved in the Scheme as it provided us with not only permanent water, but also high quality water for our stock.

Monday, 15 February 2010

Drenching Sheep and Weaning Lambs

On 7th February we herded the sheep from the Yabby Paddock into the yards, drafted the lambs from the ewes, drenched the ewes, released the ewes into the Deep Gully Paddock and retained the lambs in the yards overnight. On 8th February we drenched the lambs and released them into the Saddle Paddock. What follows is some of the background, observations and learnings from the overall exercise.

The Decision to Wean the Lambs

I conducted research to ascertain the best approach to separate ewes from their lambs (wean) to ensure that both were not checked. The range of recommendations was in the end mystifying due to the strength of diversity of views, which included:

  • Apply ‘weaning rings’ to the lambs and put the animals back with the ewes. These are small rubberised spiked clips that are placed into the nose of lambs (and calves). When the lamb attempts to drink from the ewe the latter finds the experience most uncomfortable and pushes the lamb away and in time weaning occurs. Advantage: No separation stress on either the ewe or lamb. Disadvantage: Cost of the rings, time and effort in applying them to the animals, failure rates and waste. Plus they don’t seem to be something that either the lamb or the ewe would appreciate experiencing!
  • Separate the whole mob into two halves, ensuring that each ewe / lamb set/s remain intact. Take the first half and draft off the lambs from the ewes. Then take the second half and do the same thing. Mix the lambs from the first half with the ewes from the second. Mix the lambs from the second half with the ewes from the first. Put both resultant mobs into separate paddocks. Advantage: Whilst the lambs no longer have access to their mothers to source milk (and are thus weaned) they are still able to receive education and increased survival rates by being with mature ewes. Disadvantage: Time and effort in sorting the mob, with a risk that the initial dividing of the mob into two halves is not ‘clean’ with not all lambs being separated from their mothers and are not weaned.
  • Separate the lambs from the ewes and put both (new) mobs in adjoining paddocks. Advantage: Reduced stress on both lambs and ewes as they can still interact indirectly along the common fence-line. Disadvantage: High risk that some lambs will get through the fence and re-unite with their mothers.
  • Separate the lambs from the ewes and put both (new) mobs in paddocks located a long way from each other. Advantage: Certainty of weaning occurring. Disadvantages: Separation stress and absence of mature sheep in the lamb mob to guide the lambs.

We selected the last option above based on our desire to reduce the possibility of having lambs reunite with their mothers. Some of the ewes had already weaned their lambs. The timing of our weaning was also some 3 to 8 weeks later than the industry norm; thus all of the lambs have had more coaching by mature sheep than might otherwise be the case.

I also sought information on how long lambs need to be separated from their mothers before the mother’s milk ‘dries up’ and the lambs on return can no longer receive milk. The answers varied widely, with some suggesting that the mother’s can still permit lambs to suckle (and will receive some milk) as long as 3 months after separation! We will want the ewe lamb portion to return to the ewes so that we can maintain a single mob after the wether portion has been sold.

We’ve been contemplating weaning the lambs from the ewes since before the end of 2009 but deferred taking this action given the benefits of maintaining one mob on the farm (time management, water management and maximising pasture production) and the rain we received over Christmas provided us with the bonus of certainty of having sufficient feed such that it was not necessary to reduce stock numbers. Against this, we do need to make sure that the ewes have sufficient time to increase body condition or fat score post weaning to either score 3 or score 2 on a rising plane of nutrition. Weaning removes the physiological drain on the ewes from producing milk allows them a better chance of gaining condition. This in turn increases the conception rate at joining provided they are not then over-weight. Added to this it really was time to wean the lambs as best practice suggests that having the lambs on their mother’s milk past 12-16 weeks adds little value to either the lambs as they get most of their nutrition requirements from the pasture. We are also getting close to the point of selling some lambs and having the lambs as a separate mob will mean we have fewer animals to work on during the selection process.

Fact Sheets on Fat Scoring and Conception Rates

Clink on the following link for a fact sheet on determining the fat scores of sheep and lambs:

Clink on the following link for a fact sheet on animal nutrition and fat score and the impact of conception rate:

The Decision to Drench

Part of the research I did on the subject of drenching sheep included whether it was possible / practical to incorporate a drench into the stock water; saving the time and physical effort of physically drenching each animal. We have been using a temporary water set-up including troughs and know roughly how much the mob drinks per day (especially on very hot and dry days). The basic logic of mixing drench in the water seemed sound in that as a rule of thumb the drench dosage rate/s and the amount of drinking water per day are both a (different) percentage of an animal’s body weight. I decided against such an approach on advice from a NSW DPI sheep internal parasites guru given several factors:

  • It is actually illegal, breaching labelling and product use requirements
  • It is impossible to control how much drench each animal receives
  • Following on from the above, animals that don’t drink on the chosen day (when the drench is mixed in with the water) may be the ones who need it the most, some might over-dose, and others may get such a low dose that it accelerates the rate of resistance in the parasites themselves
  • It is impossible to know whether the drench will react adversely to the tank, piping, trough or exposure to the elements

Given the impact of internal parasites (mainly worms of various sorts) can have on sheep generally we made the decision to drench all of the sheep (ewes and lambs) at the same time as weaning given we’d not drenched before and many people warned us that many lambs can be lost if not drenched at weaning. Ideally the drenching decision should be based on analysis of worm counts in faeces. Next time, maybe! It way well have been that the long rest periods we give our paddocks are such that there was no need to drench at all … but we figure it was ‘better to be safe than sorry’ – especially in the early stages of our sheep management learning journey.

Purchasing drench

When buying drench (and vaccines) it is necessary to have an idea of the body weight of the heavier animals in the mob. It is from this that the dosage rate is determined … and from this the volume of liquid that has to be purchased. Giving the animals a dose that exceeds the recommended ratio of drench / vaccine is less critical than applying a low dose. The latter fosters more rapid development of resistance (to the treatment) by the parasites.

In consultation with staff at our local rural merchant in Grenfell we bought two types of drench: both broad spectrum but the one for the lambs has added chemicals to address tape worms. Both (in our case) came in 5 litre containers which have a strap such that they become pack packs for the drenching. The set-up is slightly different to what I remember from my growing up days on the farm in that the pack is the opposite way up on ones back to what we used to do and this is facilitated through a tube that goes from the cap to the bottom of the container. From an OH&S perspective the ‘new way’ is no doubt safer as there is no risk of the cap coming off and releasing chemical down the back of the person doing the drenching.

We purchased a new drench gun to reduce the risk of equipment malfunction.

Herding the mob into the sheep yards

On Ochre Arch we do not have or use sheep dogs for a variety or reasons, the main one being that we practice both Low Stress Stock-handling and holistic planned grazing. It is very simple to move the animals from one paddock to another on foot; with Jan and me working together.

Getting the animals into the sheep yards proved to be not so simple and we’ve still much to learn. We got to a point where about ¾ of the mob went into the large holding pen on the eastern side of the yards but we just couldn’t get the remaining ¼ or so to go through the gate and given the length of time we continued our efforts it transpired that the whole mob came back out into the paddock releasing the pressure on the animals. (For those not familiar with Low Stress Stock-handling one of the ‘golden rules’ is that with herding animals under pressure is ‘the pressure will always be released’. Pressure is defined simplistically as an animal having something or someone within its ‘flight zone’ – which in human terms is very similar to ‘personal space’). It was then that I decided to try applying increased pressure to the mob at the entrance to the yards by using the 2-wheel motor bike. After quite some time and effort it became clear that this approach was simply not going to work. The mob was milling around outside the gate to the holding pen and none of the animals showed signs of going near the gate itself. We opted to revert to herding them on foot and after some patient effort involving actually reducing the pressure on the mob we got to a point where 2/3rds of the mob were in the holding yard. At that point we decided to shut the gate behind them and allow the other 1/3rd to stay in the paddock. We then moved those that were in the holding pen further into the main yards, and once that was done we then went back into the paddock, succeeded in herding the remainder into the holding pen (they could see the rest of the mob in the yards) and then moved them forward to be with the others in the main yard.

Lesson: Be both patient, not too ambitious and remember that increased pressure on the sheep is not necessarily the way to go. It did help us in getting the mob into the holding pen that it was well grassed.

Drafting the lambs from the ewes

I did the actual drafting given that at times this can be quite a physical exercise when two sheep come through together or in such quick succession that it proves necessary to stop them coming through to avoid animals ending up going into the unintended pen. Having said that, it’s not a big deal if a couple go the wrong way through the race as they can be individually caught and put where they belong once all of the drafting has been done.

Jan took on the task of hunting the mob into the drafting pen. This is not an easy task either and requires more patience and a more constant but reduced intensity of physical activity. Our drafting pen has two entry gates and thus can be accessed from two different pens in the yards. To begin with we were herding the animals from the northern / down-slope pen into the drafting pen but it was proving very slow. My instincts made me feel that the mob would flow better through the process if they were brought in from the southern / up-slope pen. We tried this and it made a huge difference, and substantially accelerated the process.

One curious observation was that it in the vast majority of cases the ewes were first to enter the drafting race itself, and very rare for a lamb to do so. Maybe this is because they have had several years of going through drafting races and know that the process itself actually leads to reduced stress once through the race.

Drenching the ewes

Our ewes are seriously big sheep making it a bit of a challenge for me to reach the heads of some in the drenching race. They are also strong and were fresh from the paddock. That said, we took our time and found that 25 or so fitted into the drenching race at a go. We were pleased to note that the ewes were in better condition than they looked from a distance.

One ewe was losing her wool. It was not due to lice and the wool was coming away in chunks from the skin. Subsequent discussion with a local long term sheep man suggests that this is not unusual and it is likely the animal at some point suffered a high fever but is now fully recovered.

One ewe was in absolutely prime condition. We assume that she may have lost her lamb/s at or shortly after birth. Its condition demonstrated both that sheep can do very well on our place and that the process of raising a lamb is physically very demanding.

An unexpected, annoying and in hindsight obvious learning was that as the drench level fell below about 1/3rd full air started being drawn into the drench gun. This was caused by the pack going from vertical to horizontal and beyond as I at times had to reach down low to the ground to lift the heads of some sheep that had found there way underneath others to reduce the stress levels. When this started occurring I took the pack off my back and Jan held it from the side of the pen. The good news was that no further problems with air getting into the gun occurred but the bad news was that it made it more awkward for me to do the drenching as the risk of an animal getting caught up in the tube from the pack to the drench gun increased. Lesson: If drenching on one’s own it may be necessary to set up some type of rig adjacent to the pen to hang the pack on to ensure that the number of doses calculated can in fact be dispensed.

One of Jan’s roles during the drenching process was to act as ‘spotter’ for me. When drenching it can be very difficult to remember which sheep have been drenched and which have not. Having a spotter is important to prevent no-dosing, and over-dosing and chemical wasting. Jan did a superb job of keeping track of drenched and to-be-drenched sheep.

The drench gun nozzle came loose at one point and had to be tightened. The drench given to the ewes was very milky in colour and quite thick. During cleaning (essentially flushing firstly water with detergent then just water through the gun) the flow through the gun ceased and I found it necessary to dismantle and separately clean the intake valve. It took a long time for the residual drench to be completely flushed from the gun.

We counted the ewes as each batch came out of the drenching race.

Releasing the ewes

Our experience at lamb marking was that ewes lingered near the yards (their lambs) when we let them out of the yards to gain access to feed while the remaining lambs were being progressively marked. We expected the same when we released the ewes into the Airstrip Paddock at weaning … before we took them on to the Deep Gully paddock. The reality was the total opposite. The ewes ‘took off’ and it is not an exaggeration to say that ‘not one of the ewes looked back’, even though the lambs were still within earshot and sight.

Leaving the lambs in the sheep yards overnight

It was never our intention to leave the lambs in the yards overnight but in the end we did so for several reasons: the activities we’d carried out to that point took longer than expected and we would not have had time to drench all the lambs before dark, we were unsure how difficult it would be to re-muster the lambs the next morning if we did let them out and we did want all of the drenching to be completed as soon as possible, I was tired and needed a rest, and we had heard that lambs in their own mob have a tendency to get over-excited and can trample each other … and by keeping them in overnight they might be less energetic than their mothers had been!

Drenching the lambs

It’s a bit hard to be certain but we think the lambs were less energetic as a result of being detained in the yards overnight than the ewes had been the day before. In any case, they worked well through the yards and we had no issues with trampling. Being smaller than the ewes we were able to fit around 60 in the drenching race each time.

The drench itself was clear. We had no equipment issues but did notice that the plastic barrel of the drench gun is now very slightly translucent rather than transparent from friction. Once again we experienced air being sucked into the gun when the container level was about 1/3rd full and resolved the issue in the same way as for the ewes.

We were curious to know the weight of the larger lambs as this information is a great help in the decision of when to sell – especially if we want to sell them as fat lambs rather than just for wool production. There are no sheep scales on Ochre Arch so we’d purchased a cheap set of bathroom scales for $10. The process for determining the weight of a lamb using these is simple but physical:

  • The person weighing the lamb/s finds his or her own current weight by stepping on the scales
  • Lamb is then caught and carried to the scales
  • The person with the lamb steps on the scales and the total weight is noted
  • It is then a simple calculation to determine the lamb’s weight, being weight at step 3 minus weight at step 1.

The lambs we weighed were in excess of 35 kg so we have subsequently decided to have a stock agent visit to develop a selling plan / program for the wethers and any other culls.

Jan counted the lambs as they came out of the drenching pen. From this we were then able to calculate the weaning percentage. Total number of lambs weaned divided by original number of ewes purchased as a percentage came in at 130 %. This was down from the 140 % marking percentage reflecting subsequent losses but is still very acceptable.

From a definition percentage: fertility is the ability of the ewes to get in lamb, and fecundity is the ability to rear the lambs. Both percentages need to be calculated based off the total number of ewes originally joined before we bought them rather than just the ones we purchased (which were all in lamb, with any non-pregnant ones having been sold post scanning). The revised figures then come in at:

  • Fertility rate = 97.4 %
  • Fecundity rate (to weaning) = 128.4 %

A small percentage of the ear tags applied during lamb marking was gone and a couple of lambs have had adverse reactions to their tags. More tags are now on order and will be applied at time of sale of the animals.

Additional treatment of some lambs

We noticed that several of the lambs had wool stain at the top and down the sides of their shoulders. The colour of the wool staple at that point was a bright oxidised copper. We’d not seen this before but deduced that the cause was moisture retention, and a possibly pre-cursor to fly strike. To reduce the risk of fly strike we separated these and the one or two others that had fly strike and treated them for fly strike after all of the lambs had been drenched. It has subsequently been confirmed to us that these wool stained lambs will be prone to fly strike and need to be culled from the mob.

Releasing the lambs

We released the lambs after treatment into the Saddle Paddock without incident.

Observations since the weaning took place

None of the lambs have found their way back to the ewes. Both the ewes and the lamb mobs have been silent; quite different to when they were together. When we drove the ute around the lambs we were particularly pleased to note how quiet they were … not stressed and with small flight zones reflecting the benefits of being handled in a low stress environment.

Wednesday, 13 January 2010

Some Brief and Pertinent Information on Mosquitoes

The three most common creatures that cause the most discomfort to humans in Australia are flies, ants and mosquitoes. Here's a link to an article on the latter that I thought was a good read and worth sharing: