New Zealand shearing sheds - plans and construction details

By Lindsay Galloway

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NZ Shearing Sheds Construction or Renovation 1981

Introduction by Dr Clive Dalton

Getting information to farmers that they could understand and use to improve their profits, was the main driving force for all of us who worked for the New Zealand Ministry of Agriculture & Fisheries (MAF) in the 1970s to 1990. Our ‘Information Services' section was staffed by top agricultural journalists, and we had radio and TV producers the equal of any in the commercial world.

The core for the printed information flow to farmers was a series of fact sheets called 'AgLinks' developed by Geoffrey Moss, a former Farm Adviser, especially well respected in Taranaki, who headed MAF Information Services.

Geoff was awarded an Eisenhower Fellowship to visit America and came back with the AgLink idea, to get research information from scientists to farmers, horticulturalists and their advisers, in brief ‘fact sheets’ that were easy to read, easy to file – and were free! The were an 'information link'.

Geoff appointed Colin Gardner as the first editor – a kiwi Sheep and Wool Instructor who had come back from working in Australia. Other top agricultural journalists, editors and people like me in the different MAF regions, joined the team, which started work in 1969.

We sourced topics for AgLinks and did the first drafts, which our Head Office editors fixed up and got printed for distribution either from the Wellington Head Office or through each MAF local office.

We ended up with well over 1000 topics, and we printed and gave away thousands, from which farmers could build up into sets on different topics. The sheets were colour coded to make this easy.

The aim was that if a farmer had a question – MAF needed to have an AgLink to answer it - and we did. We were farming’s Google before Google! Clearly the concept was well ahead of its time.

Shearing Sheds - plans and construction details

A classic example of the value of AgLinks was the series on Shearing Sheds written

by Lindsay Galloway, who was the highly respected Sheep & Wool officer in the MAF Christchurch office. Lindsay drew all the plans himself and had them checked by building inspectors from the Ministry of Works.

Lindsay says that as he travels around Canterbury and beyond in his retirement, he can see the results of his 40 year's service to the New Zealand sheep and wool industry still standing proudly on farms, many of which don't run sheep now and have been adapted for calf rearing with the change to dairying.

Lindsay also worked to help sheep farmers on the Chatham Islands where many of his sheds were built, and have withstood the challenging climate there.

Linsday Galloway’s Shearing Shed AgLinks are still as relevant today as they were when produced, and are invaluable for anyone wanting to build a new shearing shed, or to repair or modify a facility that has fallen into disrepair.

The death of AgLinks

AgLinks were dumped in 1989 after a failed attempt to charge for them by the ‘new MAF business managers’ who saw the end of MAF’s dedicated service to farmers. All Head Office copies had to go to the Wellington landfill, but some of us in the regions pirated a set. The National Library holds an incomplete set.

Sheep husbandry - Castrating lambs with rubber rings

By Dr Clive Dalton

Castrating lambs with rubber rings
Using rubber rings is the best way to castrate lambs in both large and small flocks. It is bloodless and research has shown that the intense pain only lasts a short time. Lambs should be castrated using rings before they are 6 weeks old - the younger the better.

The main concern is to make sure the ring is placed in the correct position, so the ram will become a proper wether.

If the testicles are missed, then the lamb will be a 'cryptorchid' where one or both testicles can be felt under the skin along the belly, or squeezed back up into the body cavity. These sheep are usually infertile, but there is always the risk of an odd animal being an effective ram.

Cryptorchids grow faster than wethers due to the testosterone produced by the testicles.

Objective
The procedure must be done so that the scrotum, along with both testicles, is captured when the ring is released. The ring must be above scrotum and testicles, and below the rudimentary teats.

Method

1. Get an assistant to catch the lamb and sit it on its rear end on a board or rail at standing height.



2. Grab the end of the scrotum and pull it through the open ring.



3. With the ring fully open and resting on the lamb's body, use your fingers and thumb to locate the testicles and press down to squeeze them through the ring. Hold them there and release the ring.


4. Before flicking the pliers off the ring, make sure there are two testicles now in the scrotum.


5. Double check - testicles in - teats out!

Sheep husbandry - docking lambs' tails

By Dr Clive Dalton


Docking lambs' tails
Removing lambs' tails has been a standard part of sheep husbandry from early times, mainly to prevent the formation of soiled wool or 'dags' sticking to the wool of sheep eating lush pasture. Removing soiled wool or dagging has always been one of the least popular jobs on a sheep farm.

Hill and mountain sheep in Britain for example, and sheep in dry desert areas do not need docking, as their normal diet is made up of dry herbage which does not produce soft faeces which then stick to the wool around the britch.

The other important reason for not docking hill and mountain sheep breeds in cold climates is that the tail protects the udder and rear end and is a said to be a source of fat which the sheep can use in times of poor nutrition.

It is done for these reasons:

• First to prevent blowflies laying their eggs among the dung and the maggots hatching out and eating into the sheep's flesh. In the worst cases flyblown sheep can die very quickly.
• Lambs sucking daggy ewes get dung on their heads and this makes them prone to blowfly attack.
  
• To prevent the soiled wool from contaminating the clean wool of the sheep with green dung stain which then costs money to scour out.
• The NZ Shearer's Union requires all sheep put up for shearing to have been dagged. This is to prevent shearers picking up bacterial diseases such as campylobacter and salmonella from the dung.
• For cosmetic reasons - there's nothing worse than looking at a flock of sheep with rear ends caked with dags.

Consumer concerns
An ever increasing number of people these days think food comes from supermarkets. They have no reason to believe anything else, as they are totally ignorant of what goes on in the production end of the agricultural or horticulture industry.

But they are concerned about animal welfare issues, which they learn about via television - usually when there is a crisis which has good media attraction. The docking of lambs' tails is one of those issues, highlighted by an inquiry I had from a researcher at a major UK supermarket chain, about the tails of New Zealand lambs being too short and causing concern.

NZ Code of Welfare:

Fortunately in New Zealand we’re well covered in the new Animal Welfare (Painful Husbandry Procedures) Code of Welfare 2005 as part of the Animal Welfare Act 1999. Here’s some key points from it.

Minimum Standard No. 4 – Tail docking of sheep

(a) Tail docking of sheep must only be undertaken where there is significant risk of faecal and urine contamination, and/or flystrike, that leads to poor hygiene, health and welfare and/or failing to do so adds a significant cost to the system.

(b) While complying with Minimum Standard 2(a), tail docking without pain relief must be performed when sheep are as young as possible, and not greater than six months of age.

(c). When tail docking a sheep over the age of six months, pain relief must be used.

Minimum Standard 2a says that:

‘Painful procedures must not be performed on newborn animals less than 12 hours old where handling, pain and post-operative complications are likely to compromise survival through impairing maternal bonding and/or colostrum intake.’

Minimum Standards will stand up in a court of law but the Codes also have ‘Recommended Best Practice’ which do not have the legal power of a Minimum Standard. But they are meant to be followed as part of ‘Best Practice’.

Recommended Minimum Standard

For tail docking of lambs, the Recommended Minimum Standard says that ‘when sheep are tail docked, their tails (excluding any wool) should be left long enough to cover the vulva in females and at a similar length in males.’

Why Kiwis dock too short?

If you have ever been in a docking gang on a big farm, you know why. When lambs are coming at you at great speed, you have to hit the right spot on the tail with the hot cauterising iron or the ring pliers without delay. You are not allowed much time to decide which is the correct spot. The greater concern is that you may leave the tail too long, (which will upset shearers later on), rather than dock the lamb too short.

Consumers's concerns must be recognised

But from now on ‘getting it right’ has become an important priority from what folk are thinking and clearly dictating as they push their trolleys around the supermarkets of the world.

It’s no good us thinking shoppers don’t know anything about sheep farming. They don’t. But this is no reason to ignore the messages about buying lamb they are sending via the supermarket checkout.

Stud breeders

These in my view are the worst offenders at docking too short, as it seems that a very short dock, or none at all does a better job of showing off a ram’s meaty rear end.

Damage caused by short docking

Short docking damages the tissues around the anus and can affect the sheep’s ability to defaecate properly hence causing more dags. A lambs tail needs to be long enough to wag!

Lamb tail docks
In your photos you can clearly see the caudal folds with ligaments that run alongside the anus and under the rectum, so when the tail is lifted the rectum is lifted and poo (even runny poo) is directed away from the body. Short tails can't do that and the poo slitters down the back end.

What is the correct length?

Tail ring in correct position on female lamb's tail.
The dock should be long enough to cover the vulva.

Tail ring in correct position on male lamb's tail.
It dock should be a similar length as in the female.

NZ Sheep Husbandry - Lifting a sheep over a fence

By Dr Clive Dalton

Back industries
Many back injuries occur when handling sheep, especially when lifting a sheep over a fence.

This is often done to save time, rather than pushing the sheep to a gate when the pen is full. Or you may be in a paddock where there is no gate to drag the sheep to to put into the next paddock.

 Use these advice to minimise the risk of injury:

• Never try to lift a heavy sheep over a fence on your own. Get someone to lift the hind legs while you lift it’s front end.
• For a small sheep, lift it up backwards by holding it around the neck and by a front leg.

• Then grab both front legs, lean back to raise the sheep's back legs off the ground, and at the same time, use your knee to give it a heave up and over the fence.
  

• Your knee acts as a fulcrum to get some leverage and help reduce the weight of the lift.

Breeding sheep to eliminate dags and worms. 3.

By Dr Clive Dalton

PART 3





Getting started

• To keep focused when reading further, have your own flock in mind to see what’s possible for you to do.
• First: Have a slogan on a big card in the woolshed or in the sheep yards for all to see. It should say: ‘We breed sheep that are Dag-Free, Worm-Free & Sustainable’.
• Keep quoting it and telling everybody you meet what you are doing, especially the stud breeder you have been getting rams from, your stock agent and especially your vet as your drench account will take a massive drop!
• You’ll need a flock of at least 1000 – 1500 ewes to fast track initial improvement, and it probably wouldn’t be worth starting with fewer than 500 because of the selection pressure needed.
  
• But give it a try with a smaller flock, and see how far you get; you may be surprised!
  

Essential features

First: To keep the job simple and avoid getting bogged in paper.
Second: To keep costs to a bare minimum.


Genetic theory
Thomas Bakewell in the 1700s used the principles used in this exercise to improve Longhorn cattle and Leicester sheep, so they’ve been well tested! He did it by ‘breeding the best to the best’. The challenge is to sort out what’s best. There are four basic ‘pathways’ to do this.


The four pathways to improvement
Text books show these in different orders but they're listed below in the best order to get started:

Pathway 1: Selecting females to breed females.
Pathway 2: Selecting females to breed males.
Pathway 3: Selecting males to breed females.
Pathway 4: Selecting males to breed males.

• Pathways 1 and 2 put pressure on the females, and 3 and 4 on the males.
  
• To maximise overall genetic gain, you must do both.
  
• So often the only selection pressure is put on the rams, which is not good enough to see any great change in human years.

Forming an ‘A’ team of females (mothers)

• To start on Pathways 1 and 2, find the best ewes in the flock as mothers of the next generation of female replacements, and to also breed males from them for use as sires.
• These ewes need to be identified and kept as a separate ‘A team’ or ‘nucleus’ flock which will get intense selection pressure for traits that keep you in business.
• Being Dag-Free and Worm-Free will top the list and so will their ‘easy care’ traits.
• All A team ewes have to keep on performing to stay in the team, because as things progress, there will be plenty top prospects waiting to gain entry.
  

When to start looking for A team members?
You can start the programme at a number of times through the year, but it’s best when there are no lambs around to get in the way. Mid pregnancy is an ideal time to start.

Top commercial flock of Perendale ewes - a wonderful starting point
for a genetic improvement programme.

Ewes at scanning

• Identify (ID) the twin-scanned (TS) ewes. Mark them with a raddle that will last till at least lambing, run them separately, and feed them well.
• Whichever is easiest, select the TS ewes out of the mixed age (MA) flock, or screen the two-tooths to find them.
  
• The 5-year-olds are also a great starting point to find some as they have stood the test of time. Don’t be worried about the size of the nucleus at this stage; just get started.
• Once you’ve got all the TS ewes drafted off, go through and throw out any you don’t like for anything you consider important.
• Do NOT drench any A team ewes, or any ewes for that matter in the rest of the flock from now on. They shouldn’t need it and it only confuses the picture. Avoid any long-acting drenches like the plague.
• f there is a health/welfare crisis (confirmed by your vet), only drench individual sheep in the A team, and mark them for culling later. Don’t be persuaded to drench the whole lot even if the drench specials are appealing!
  

Ewes between scanning and lambing

• Cull any A team ewes that ‘pack up’, grow dags or have any health/welfare problems.
  
• Be ruthless and ‘if in doubt – throw them out’ to tighten the selection pressure on them. To stay into the A team they have to measure up!
• However, if the whole A team suddenly becomes daggy, don’t panic as that’s an environmental (feed quality) problem and it’s a good ‘challenge’.
  
• Use it to ID any ewes that stayed clean during this ‘dag storm’, or got daggy and soon cleaned up. Give them a special mark. The ones that fail to dry up need a special mark too – for culling.
  

Ewes at lambing

• Lamb the A team ewes separately and with normal commercial care. If this is ‘easy-care’– then carry on with your normal routine.
• If you go around the ewes and see any that had trouble – try to remember them, or mark them for culling if you can catch them. If you can catch their lambs, mark them for culling too.
  
• Again, be ruthless. Carry the raddle or ear markers at all times!
  

Ewes at docking of their lambs

• Do NOT drench any A team ewes, or any others on the farm at docking. They should not need it, regardless of current drench promotions.
• Mark for culling any TS ewe that didn’t lamb, was wet/dry or that had any other problem. Be ruthless!
• If there’s a chance that these TS ewes may get mixed with the main flock after docking, and their scanning raddle may have faded, ID them with a numbered plastic tag. The cost is justified at this stage as you don’t want to lose them.
  

Ewes at weaning of their lambs

• Mark for culling any A team ewes that have developed physical defects or failed to meet your standards.
  
• Check udders, as you’ll be able to find any that went dry early or had mastitis. Teeth are also an obvious feature.
• Be ruthless, especially on real dirty backsides that never dried up. How dirty is dirty, you’ll have to decide and set your own standards.
• If you didn’t tag these ewes at docking, then give them a good permanent numbered tag now that you can read from a distance, as you cannot afford to lose these girls after all the work you’ve put into them.
  

Maintaining the A team nucleus flock

• You need to decide how big the A team flock should be to provide the number of replacements needed to keep up the pressure on dags and worms.
• A rough rule of thumb is to have about 7-10% of your total ewe flock in the nucleus. But be flexible at this stage.
• Keep culling these ewes hard for physical defects and health problems, especially any that get daggy, have flystrike, are lame or have simply packed up.
  
• Their problems won’t be all genetic, but be ruthless, as there will a genetic component to their ills somewhere, even if it’s not strong.
• The target is structurally sound robust ewes with ‘constitution’ that can stand up to your management. If you have any doubts about a sheep, cull it.
• YOU need to have great confidence in these sheep, as they’ll be great motivators for you and your staff as the programme proceeds.
• In your doubting moments, go and walk through them and see if you’ve seen any better ones anywhere in the district.
  

What does it take to stay in the nucleus flock?

• This is a vitally important part of the exercise. Apply the same simple rules used at the start of the programme.
  
• To gain entry into the elite flock in the first place, or to stay there at any subsequent lambing, then a sheep must have completed all of the following:

Scanned twins.

• Not been wet/dry at docking.
• To have weaned lambs – judged by udder.
• To have survived all the culling on constitution, health and structural soundness – and not caused any extra work or cost you money!
• To have stayed free of dags, or dried up quickly after a ‘dag storm’ caused by feed changes.
• Have consistently produced marbles or hand grenades.
• Have had a FEC in the low hundreds.
  

Where’s the best place to find A team replacements?

• If because of intense selection and culling, the numbers of ewes in the A team nucleus are now not enough, you may need to do another screening like was done to start the nucleus.
  
• Two good age groups to screen for A team replacements to supplement the nucleus are

1. The 5-year-olds as they have stood the test of time.
2. The two-tooths as they have a long life ahead, and have already been subject to intense selection pressure.
   

Breeding sheep to eliminate dags and worms. 4.

By Dr Clive Dalton

PART 4

Selecting female replacements from the A team

Docking ewe lambs

• Do NOT drench any ewe (or ram) lambs at docking - and this means both the A team and commercials. At this stage, the lambs’ immunity is starting to develop and anthelmintic drenching will damage it.
• Vets will not agree but we don’t know enough about the complex immune system, and until we do, don’t drench. The only exception would be a major animal health crisis, confirmed by a veterinarian.
• Mark all the ewe lambs with ear-markers to cut a bit out of the ear or punch a hole. Hopefully they will all be twins, but don’t worry about any singles in the mob.
  

Weaning ewe lambs

Polled Dorset weaned lambs being picked for slaughter

• Barring obvious culls, all the A team ewe lambs should be keepers and need priority.
• You’ll need to keep more of them as replacements than normal to apply intense selection pressure and cull heavily from weaning on.
• Hopefully you won’t need to go too deeply into the ewe lambs from the single scanned (SS) ewes to make up numbers. But this will depend on twinning rate, the season and the size of the nucleus you want. Don’t be too ambitious at this stage.
• As a target, plan to cull around 30% of the ewe lamb crop, but this will depend on the final numbers needed. There’s a fair way to go before they reach two-tooths and their final selection.
  

Drenching

NO drenching at weaning, unless you have a crisis confirmed by a veterinarian.

• Do NOT drench any A team ewe lambs at weaning.
• If any pack up around weaning, then cull them.
  
• The exception would be an outbreak of Barber’s Pole worms in the whole lot, but make sure you seek veterinary advice for a correct diagnosis (after Faecal Egg Counts) before drenching. Use a specific Barbers Pole drench and not a broad spectrum one.
• Any ewe lambs for sale from the remainder of the flock can be drenched with a conventional combination drench if they look wormy, and this is confirmed by a FEC on a sample. Decide if this will improve their sale prospects.
• Before sale and after conventional drenching, run these sale ewe lambs separately from the A team ewe lambs. You don’t want any cross-contamination of worms.
• But don’t run the A team ewe lambs on clean pasture. Put them on pasture that has had sheep on it to challenge their immunity.
  

Tapeworms

• Seeing tapeworms can panic people as they look so big.
  
• Don’t drench unless you have clear evidence of ill thrift, or if their scouring is attracting blowfly.
• If a drench is justified because the lambs look poor, use a product specific to tapes and not a broad spectrum one.
• Mark for culling any ewe lambs from the A team that have physical defects or fail to meet your standards.
  

Developing natural immunity

It's an easy enough job running hoggets through the yards and drafting off the dirties, even if some are keen to escape!

• By weaning, all lambs should be well on their way to developing natural immunity, so expect great variation in the number of daggy backsides you’ll see.
  
• You’ll see these ‘dag storms’ with feed changes, which are great to challenge immune development. Be ruthless, especially on dirty backsides that never clear up.
• It’s good to see those that go through a daggy stage and then permanently dry up. It’s the ones that don’t that you need to mark for culling.
• So make your final decision in early autumn when they are hoggets (see below).
• Nutrition of young growing animals is critical so make sure there are well fed in this.
• Minerals and trace elements are well known to enhance immunity so give these a boost.
  

Ewe hoggets

• Now the top ewe lambs from the A team ewes have grown into hoggets, they should be looking good, and it’s time to put more Dag-Free and Worm-Free selection pressure on them.
• Do NOT drench them.

These ewe hoggets have never had an anthelmintic drench in their lives. They have only had a nutritional supplement containing minerals to boost immunity.

• Keep going through the hoggets every 2-3 weeks (a month is too long), for the first three months after weaning, and draft off any tail-enders for culling.
• Mark for culling any hoggets that are regularly daggy. Any that get daggy and dry up quickly are OK as they’re still be developing their immunity under the natural worm challenge, and the ‘autumn rise’ of worm larvae is an ideal time for this.
• The tail end culls. If you think any of these need a drench, then use a conventional combination drench and finish them for sale.
• After drenching, don’t mix the drenched hoggets with the replacements.
  
• They should be run under your normal farming conditions on paddocks that have been regularly grazed by sheep.
• Don’t run these ewe hoggets on clean pasture. They need a worm challenge all the time.
  

Ewe hoggets -initial check for worms

Hoggets intensively selected for Dag-Free and Worm-Free traits.

March/April

• This is a good time to do an initial FEC to see what kind of parasite load the hoggets are carrying.
• It’s the ‘autumn rise’ of worm larvae which will give the hoggets’ immune system a really good challenge.
• January/February is too early to do this in my view, but many WormFEC™ breeders do it at this time, arguing that they want to find sheep with early immune development. It’s too ambitious in my view.
• Do a FEC from a composite sample mixed from 10 fresh droppings from the paddock. Send the sample to a recognised lab through your vet.
• Use a trigger level of 500 epg to see how things are going.
  
• If the sample is way up in the thousands, then don’t panic, as this would suggest that little immunity to worms had developed yet.
• Don’t be tempted to drench if the hoggets are looking healthy and growing well.
• The only reason to drench would be if their health and welfare were at risk, confirmed by FECs and your veterinarian.
  
• Barber’s Pole worms would be a classical reason to drench, making sure you used a drench specific to that parasite and not a broad spectrum one.
• If the sample is below 500 then that’s good news, but again don’t get excited, as it’s only one sample, and look at the animals to see how they are doing.
• Veterinarians use 500 epg as a trigger to drench the whole mob. Don’t be tempted as you are involved in a ‘breeding project’ and you’ll need to point this out to your vet.
• Again, keep a note of any hoggets that get dirty and mark for culling any that don’t dry up, as their immune systems are not coping.
  

Ewe hoggets - Serious check for worms


May/June

• After the initial check in March/April during the ‘autumn rise’, early winter (May/June) is the ideal time to put more selection pressure on these replacement hoggets for dags and worms, as worm burdens are a big challenge to these young sheep in winter.
• Get an individual FEC done on each hogget.
• This will cost around $5/sample. This must be corrected for Faecal Consistency Score (FCS) so remember to record this at the time of sampling, and build the score number into the sample ID number.
• See Part 8 for details of how to do this.
• If the cost of the FEC is going to be a major issue, just do a FCS on them.
• Ewe hoggets producing marbles need to be marked as the top group, followed by hand grenaders. Then anything below this with sloppy dung needs to be given a separate mark as potential culls.
• Keep the drench gun locked away unless there is a worm blow-out (e.g. Barber’s pole) and animal welfare is compromised and confirmed by your vet.
• Good feeding is vital during this winter period so don’t confuse worms with under nutrition.
• If you haven’t put a good permanent ID tag (numbered and readable from a distance) into these hoggets, then do it now. They are your top genetics.
  
• It would pay to put a duplicate tag (eg a numbered brass tag) in them to be doubly sure of ID incase the initial plastic tag comes out. This cost is well worthwhile.
  

Ewe hogget weight

Clean hoggets that could be further culled on weight.

• If you have more hoggets than you need and have to find a reason for reducing numbers, you can always use weight.
• Find the range by weighing a few of the smallest then a few of the biggest, and then decide a cut-off ‘target’ weight.
  

Ewe hogget fleece weight

• In the past it would have been worthwhile recording fleece weight and culling the lowest – but don’t bother. Just cull hoggets with the ‘off-type’ fleeces.
• Hoggets with high liveweight will also have the genes for high fleece weight (the genetic and phenotypic correlations between the two traits are highly positive).
• If you breed fine wool, then it would certainly be worth culling on hogget fleece weight and quality.
  

Breeding sheep to eliminate dags and worms. 5.

By Dr Clive Dalton

PART 5

Two-tooth ewes from the A team nucleus

• Now as two-tooths bred from the A team nucleus ewes, they should look a picture due to the intense selection pressure put on them up to now.
• Apart from the odd sample to monitor progress, it’s not worth doing any more FECs, but keep on ruthlessly culling any that get daggy and don’t clear up quickly.
• There would be no harm in doing a FCS now and again to check on any that are not measuring up, especially those getting daggy and not drying up fast.
• Cull any that develop problems like footrot.
  

Planning the two-tooths’ mating
Decision needed: What rams are you going to join with these top two-tooths? They deserve very special consideration after all the work you’ve put into them.

Ram options

Option 1:

Stud breeders rams at pubic auction but few FEC records and no dag data.

• Contact your nearest consultant from Sheep Improvement Ltd (SIL) by phoning 0800-745-435, or Email "mailto:help@sheepimprovement.co.nz" help@sheepimprovement.co.nz
• Ask which breeders have rams for sale with WormFEC™ and Dag Score BVs.
• Take care to check the records and ask the breeder how many rams have been tested and how this was done, as despite the SIL WormFEC™ protocol in the Breeders’ Manual (1994), some breeders have developed a few variations of their own.
• FCS is not accepted by SIL as a correction for FEC. And in any case, the rams will all have been drenched regularly and recently, so you won’t be able to get a true ‘drug-free’ FCS assessment.
• Beware that breeders may advertise that they are breeding for worm resistance or even worm resilience, but their programmes will need questioning.

Lab FEC raw data on rams at a sale - a very rare feature.
The FECs were not being used in an index.

Option 2:

• Failing any success with SIL breeders, the next option is to look at any old sires you have on the farm purchased previously from SIL breeders.
• This could surprise you or shock you - to see what you have spent money on (in all innocence) in previous seasons.
  
• Their mature (genetic) immunity against dags and worms should have been fully developed – if they have any. It would be worthwhile having a look.
• Make sure they have not been drenched for at least two months (preferably three) and first check their FCS. It’s not worth wasting $5 on a FEC if a ram is a scourer.
• Any like this need to be used as terminal sires as you’ll be dagging their progeny for the next five years at least.
• For the marblers or hand grenaders, get a FEC done.
• Don’t contemplate using any animal with a FEC over 500 epg and zero should be a better target.
  

Option 3:
This is the obvious choice - to use your own rams, bred in the A team nucleus flock, and Pathway 2 describes this.

Breeding sheep to eliminate dags and worms. 8.

By Dr Clive Dalton

PART 8

Life cycle of main species of sheep worms

• The main species are 'roundworms', but there are also tape worms, lung worms and liver flukes. Below are Barber's Pole worms (Haemonchus contortus)
  

• Mature worms live in the sheep's gut where they mate and produce eggs.
• These eggs then pass out in dung on to the pasture.
• When conditions are right (warm and moist), they hatch into larvae and go through three main stages - L1 to L3.
• The L3 stage is the critical one as they crawl up the pasture plants to be eaten by another sheep to continue the cycle as mature worms inside the sheep.
• It takes about 21 days for ingested larvae to develop into adults capable of laying eggs.
• These larvae are aquatic creatures and need moisture to survive and travel. Dessication kills them.
• Larvae need a minimum of 2-6 weeks of warm moist conditions to develop successfully.
• Some larvae can live for 6-8 months in cooler temperatures (surviving frosts) and in warmer conditions can die after 2-3 months.
• They can survive droughts by going down 10-20cm.

• KEY POINT: Around 90% of the worm cycle is on the pasture where you can't do much about them - other than get other species of animals to eat them with no ill effects.
• If you want to kill any worms, you have to do it with chemicals when they are inside the sheep. Some drenches only kill the worms and others kill both worms and eggs.

Faecal Egg Counting (FEC)

• A FEC is a good general indicator of a worm burden is the number of eggs passing out of the animal in the faeces.
• This is the basis of a ‘Faecal Egg Count’ that can be done through a vet clinic or on the farm if you have a microscope and the equipment.
  
• Ask your vet for details, or you can buy a commercially available kit with everything you require plus technical support when needed from FECPAK International Ltd, Box 5057, Dunedin, New Zealand.
• The costs through a veterinary clinic can vary depending on quantity.
• To check the quality control of the veterinary laboratory, split some samples and send them in with different numbers. The sub-samples should not vary more than a few hundred eggs per gram.

• Some farmers with a FEC kit share the work and cost with neighbours.
• A FEC shows the number of eggs per gram of faeces (epg) and there are accepted ‘trigger levels’ after which you should take action by drenching – or do nothing.
• You cannot tell the worm species from their eggs, so to identify species the eggs have to be incubated in the lab which takes about 10 days and consequently costs more.

Larvae being incubated in lab

• However the eggs of Nematodirus are larger and very distinctive compared to all other strongyloides worm eggs.
  
• They are always counted separately as Nematodirus worms are not great egg producers so animals can harbour heavy worm burdens and have low (less than 500) epg. This often occurs in lambs.
  

Limitations of a FEC

• A FEC can only be a snapshot of the animal’s worm burden judged by egg output at that time of sampling.
• It’s really a measure of what was going on inside the sheep 3 weeks beforehand.
• With the standard FEC used in the past, the biggest limitation was that samples were not corrected for the Dry Matter intake of the animal or the moisture content of the faeces.
• Despite the limitations of FEC (and still some academic criticism of its interpretations) it’s a very cost-effective tool and in any case it’s the best we have at the moment.
• Whatever its many shortcomings, it's the most cost effective at this time.
  

FEC sampling tips

Paddock (composite) samples

• The easiest way to get a dung sample for FEC is to pick up fresh faeces from the paddock.
• Follow a few sheep around for a while, or go where they have been camping, and make up a composite sample from at least 5 heaps and better still 10.
  
• Mix them well.
• Using composite samples keeps the lab costs down.
• When the lab gets a composite sample, it should give it a further good mix before sub sampling, but check that this will be done.
• The more accurate way for the lab to do a composite FEC is for individual samples to be sent to the lab and an equal weight of sample is taken from each, and a special composite FEC carried out to a sensitivity of 10 epg per pooled sample.
  

Finger sampling

• Use your index finger to draw a sample of faeces from the rectum.
• Rubber gloves are recommended.
  
• The sheep will not like this, and it can take a good push to gain entry if the animal has not been scouring.
  
• You need at least 5 g of faeces so it usually needs a second finger insertion. The sheep won't like this either.
• With many sheep to do, this can be tiring on your fingers so you may have to change hands occasionally.
  

Probe rectal sampling

• You can use a probe made from half inch plastic water pipe to draw out the sample.
• The probe is carefully inserted, and given a 180 degree twist before removal.
  
• You will normally get more than the 5g needed by one insertion of the probe.

Faecal Consistency Score (FCS)

• Australian research from Armidale in NSW has shown that when you get the FEC, you should correct it for moisture content. They showed that the easiest way to judge this was from the form of the faeces.
• The more liquid the faeces, the quicker they pass through the digestive system, and hence the more diluted the 'eggs per gram of faeces' will be when they come out the rear end.
• A healthy sheep with an efficient digestive system passes round ‘marbles’ – even when on lush pasture and crops.
  
• These are formed in the hind gut where water is removed, and the movement of the gut wall (peristalsis) produces the marbles. It’s an amazing bit of physiology!

When to do it?

• It should always be done when collecting a FEC sample and the score built into the animal ID number.
• Or it can be done at any other time.

Scores used

• The Australian researchers used numerical scores but the following descriptions are used below as they are easier to remember:

Photo 1: ‘Marbles’

Photo 2: ‘Hand grenades’


Photo 3: ‘Plops’


Photo 4: ‘Slops’



Photo 5: ‘Scour’



Corrections
The corrections used are very simple and again are easy to remember. Multiply the FEC by 1 to 5 as shown below:

• Marbles x 1
• Hand grenades x 2
• Plops x 3
• Slops x 4
• Scour x 5
  

A quick and easy method
If you don't want to pull out a sample of faeces from the rectum, then all you do is insert your finger and feel what's in there.

• Marbles - you will feel these easily
• Hand grenades - you will feel an empty gut as the handgrenade has just been voided.
• Plops - you will see just a green stain on the end of your finger.
• Slops - your finger will come out quite green.
• Scour- your finger will be covered in green soup!
  

Advantages of marbles

An overnight pile of marbles from a sheep that has defeacated 2-3 times without getting up.
She has got up and no dung has stuck to her wool causing dags.

Faecal marbles have big advantages for sheep, and big disadvantages for larvae:

• Marbles don’t stick to wool and produce dags.
• They fall to the ground and many separate and spread out.
• If the lamb’s tail has not been docked too short, causing damage to the supporting tissue around the anus, when the sheep wags it’s tail during defaecation the marbles are projected away from the body.
• Single marbles or small clusters dry out quickly on the ground leading to larval death through desiccation.
• The surface area of marbles is about six times greater than if the same volume of dung was in a large wet heap.
• The dark green to black colour of the marbles absorbs more UV radiation adding to larval death.
  

Conclusion: Having sheep that pass marbles will be a practical and effective way to reduce the larval population on the paddock.

Breeding implications of FCS correction
Correcting a FEC for FCS has major implications to improve the accuracy of FEC interpretation, when selecting individual animals in breeding programmes.

Example:

• When selecting ram hoggets or two tooths as future sires, if you decided to keep a ram with a FEC of less than 500 epg, you would be fairly happy that he was resistant to worms.
  
• But that would only be correct if he was passing marbles (FCS 1).
• If he was scouring (FCS 5), then multiplying his FEC of 500 x 5 would give a 2,500 epg count and you would certainly not want to keep him as a future sire – even though he may be classed as resistant using FEC alone.
  
• He should be on his way to the dog tucker freezer. The FCS has changed the decision drastically – and for the better.
• So not correcting for faecal moisture can lead to a very wrong genetic assessment of replacements (especially rams) for the flock.
  
• You could easily end up with high-index daggy sheep that will pass those genes on to their progeny, and you would be bending over their rear end and removing dags for the next five years.. That’s not progress!
  

Drench resistant worms in sheep – drenching to control worms

Sheep, farming, husbandry, animal health, worms, internal parasites, drenches, anthelmintics.

By Dr Clive Dalton

Well, which one are you going to buy? Will the store assistant know enough to help you?
Beware of being told that 'this one's a good seller at the moment'! Or this one has the free jerkin'.

Drenches on the market
It is mind boggling to see the enormous range of products (anthelmintics) on the market to treat internal parasites in sheep.

Anthelmintics are any products that kill internal parasites, and past annual surveys in farming press show the following:

• There were around 40 different brands on the market.
• These were made by 5 companies.
• 15 were sold by vets only, and 16 were available from all outlets.
• Concentration of the chemicals ranged from 1g/Litre to 40g/Litre.
• Ingredient dose rate ranged from 0.2mg/kg LW to 10mg/kg LW.
• Formulated dose rate ranged from 1ml/5kg LW to 1ml/20kg LW.
• Withholding periods for meat ranged from 3 to 91 days.
• Safety margins ranged from 3x the dose to 100x.
• 15 of the products were ovicidal (killed worm eggs) and 16 did not.
• All of them killed both mature and immature parasites.
• 17 products included minerals, 1 had vitamins and 2 included vaccines
  

Ways to deliver

• Products can be given as an oral drench, as an oral bolus or capsule that stays in the rumen, or they can be injected.
• Check the label about the injection method (it’s usually subcutaneous) and for the best site (in the neck).
• There are no straight pouron ‘anthelmintics’ for sheep.
• Other products are called ‘endectocides’ as they kill both internal and external parasites and can be administered by mouth or injection in sheep. Pouron endectocides are not used in sheep.
• Some products are ‘ovicidal’ which means they also kill worm eggs in the sheep, as well as the worms.
• When checking the survey table of drench brands on the market, remember the ‘active ingredient’ column is much more important than the brand.
• And when you buy, don’t let the promotional ‘giveaways’ bias your decision.
  

Key questions:

• Is it any wonder that we get confused when buying drench? Have sympathy for the shop assistant too having to give advice and make recommendations when customers have no knowledge of the subject.
  
• Is it any wonder the customer buys a product with the lowest price and the best promotional give-away?

The drench chemical families

• Only a few years ago we didn’t need to know much about the chemicals used in drenches, but things have now changed.
• The key issue is that all the different products on the market are based on only three chemical ‘action families’ or ‘actives’. Active ingredients have long names that are hard to remember.
• We’ve got to get over this as it’s now very important to be able to ‘talk chemicals’ to your veterinarian or consultant.
• Calling them ‘white’ and ‘clear’ drench families was once helpful, but now not all white drenches are white and not all clear drenches are clear!
• Labeling does not always tell you clearly which family the product belongs to. You have to know your chemicals to find this out with far too many products.
• The printing on the labels is very small to fit in all that legally has to be presented. So it’s hard to read and no company has provided a small cheap lens to help the ‘average’ farmer who at over 50 years old needs some visual assistance!
• Current knowledge is that each chemical family kills worms the same way – thank goodness for that! So if a worm is not killed by one type of white drench then it won’t be killed by any other chemical in the white drench family.
• The unfortunate result of all this is that farmers now need to be more aware of the active ingredients in the specific brands of drench within each chemical family.
• This is now especially important when buying a branded product. You’ll have to recognise which chemical family the drench belongs to and know what species of worms it is expected to kill.
• Use the Table below as a check list to show which active ingredient is in which chemical drench family. You’ll need to check this when buying branded products. The table doesn’t list the chemicals used in double- or triple-combination products – so check the label. Don’t buy the product if you are not sure what’s in it and you cannot find out.
  

Key point:
Once your sheep have drench resistance to some or all three families of actives, flock management and your life will be a lot more complicated.


How anthelmintics work

• After drenching, the active ingredient is absorbed from the gut and circulates through the blood stream throughout the body, and is then resecreted back into the gut to do its work.
• Some active ingredients can also kill worms through direct contact with the parasite in the gut.
• When blood levels of the chemical drop below an ‘active’ level, then the drench loses its power.
• The length of activity of a drench depends on a range of factors related to the formulation and the worm species in the host.
• ‘Persistence’ is the term used to describe how long after administration a chemical in the drench will still work. For example the chemical in control-release capsules lasts a long time so is very persistent.
  

The gut trigger

• This is a clever bit of engineering in ruminants called the ‘oesophageal groove’.
• It is nature’s way of making sure milk when swallowed by the young lamb goes straight into the 4th stomach or abomasum for gastric digestion where it can clot.
• You don’t want milk going into the other three fore-stomachs (rumen, reticulum and omasum) where bacteria and other micro-organisms are developing to digest fibre.
• In the adult animal certain minerals and chemicals can close the groove so the drench will bypass the rumen where you want it to go.
• Large volume drenches are more likely to trigger the groove than low-volume drenches – so low volume products are a feature you should also look for and check with your veterinarian.
  

Disclaimer This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.

Sheep Farm Husbandry- breeding methods

Sheep, husbandry, breeding, genetics, selection, breeding methods, pure breeding, pedigree breeding, cross breeding, strains, heterosis & hybrid vigour, grading up, interbreeding, inbreeding & linebreeding

By Dr Clive Dalton

Pure breeding

• The earlier list of breeds would be considered as “pure breeds” or purebreds.
  
• This does not mean that they are “genetically pure” as some breeders in the past would have had us believe. It just means that they have easily-recognised common features that persist when rams of that breed are mated to ewes of that breed.
• Genetically, all breeds have similar genes, the exception being the Merino with some genes that are a bit different such as the genes for superfine wool and wrinkles.
  
• When you look at DNA, then even different species of animal share the same DNA and even with humans!
  

Pedigree breeding
This is the same as pure breeding but the pedigrees of all purebred animals are registered in the breed organisations flock book.

Strains within breeds
Within breeds there are different “strains” of sheep that may have different physical traits or may perform a bit differently. But again, their genes do not differ much. The Rare Breeds in the list above would be good examples of different strains, and the different wool types in the Merino (superfine and fine) are different strains.

Crossbreeding
“Crossbreds” come from mating rams and the ewes of different breeds. Here are some basic principles:

• When you crossbreed, then genetic variation is increased.
• Crossbreds are generally more productive than purebreds, and generally (but not always) exhibit “hybrid vigour” or “heterosis”. Hybrid vigour is where performance is better than the average of both parents. This is “positive heterosis” but it can be also be “negative” and worse than the average. Nobody talks about negative heterosis and always assumes it is positive which they call hybrid vigour.
• Don’t expect the crossbred to be better than both parents. It happens in plants when crossing highly inbred lines of maize for example which you cannot achieve with animals.
  

• Hybrid vigour is seen mostly in “fitness traits” like litter size, survival and growth rate, and crossbreds are often better than purebreds in environments where conditions are tough.

• This hybrid vigour is usually higher (as much as 10-13% extra) production in the first cross (called the F1), but then it declines more in the F2 and is all but gone by the F3 unless you take steps to maintain it.

• If you keep bringing in outside breeds to cross with your ewes which are different genetically, then you can keep a fair amount of the hybrid vigour going.
• The wider the genetic differences between the breeds crossed, the greater is the hybrid vigour. So if you cross two breeds that are very similar, don’t expect much hybrid vigour. You’ll end up with offspring that are an average of both parent breeds.
  

Where do you go after the first cross?
This is the main concern with crossbreeding. It’s easy to produce the first cross – then what? Here are some options:

• Keep re-mating the purebred parent breeds, and slaughter all the first-cross lambs.
  
• When you want to replace the purebred parents, then buy them in. This is the simplest thing to do.
• Or produce replacement parents yourself, but you’ll need flocks of each parent breed – a large flock to breed the purebred ewes and a small flock to breed purebred rams. This can be a lot of work and is a big-farm operation if you want to do the job properly, as you only get good crossbreds by mating good purebreds. That is worth remembering.
• Slaughter all the F1 male lambs for meat, but keep the F1 females as dams for further breeding. These F1 females are generally great sheep and make fertile and good milking ewes so their lambs grow well to weaning.
• Mate these F1 females to a specialist meat breed sire called a “terminal sire” as all the progeny go for slaughter.
  

Grading up
This is using crossbreeding to change from one breed to another. Here’s the usual process:

• Start off with “foundation” animals of one breed or type. Usually there are no rules about what they look like, but it would pay to check if they need to be inspected and approved by the breed organisation of your choice.
• Mate them with a purebred pedigree registered ram of the breed you want to change to, and this will produce F1 offspring. These will have 1/2 the genes of the new breed you want.
• Mate these F1 females to a purebred pedigree ram again. They may need to be approved by an inspector from the breed society or association before proceeding to breed from them so check this out.
• This produces the F2 that have 3/4 of the new breed.
• Carry on mating the females born each generation to produce 7/8 and 15/16 offspring.
• Some breed organisations will allow you to register 7/8 as “purebreds” but others only accept the next generation of 15/16.
• This can be a very long process as only half the lambs born each generation are females, and along with losses, some animals may not turn out to be acceptable and not meet your or the breed association’s standards.
• It’s a funny thing that when you are grading up and want ewe lambs so badly, how often you seem to have an endless run of ram lambs confounding the laws of nature. The 50/50 rule doesn’t seem to work.
• Some pedigree breeders over the years have always been concerned that these newly graded-up purebreds could have introduced some “rogue” genes that will have had bad effects on the breed. Some geneticists consider this to have been an asset to the breed by introducing genetic variation to allow better selection.
  

Interbreeding
When you get to the stage where things are becoming confusing and you don’t know what stage of cross the animal is, it’s maybe time to forget about where you are at and start “interbreeding” among the population, and ignore breed and select simply on performance. Here are a few key points:

• Note this is not inbreeding (see below).
• You will have to do some basic recording to identify good-performing animals.
• Keep the best ewes on performance and keep their female offspring as replacements. Cull heavily on performance and structural soundness.
• Keep the best ram lambs each year from the best ewes as potential flock sires– making sure they don’t mate their own daughters or grand-daughters.
• Traditional pure breeders in the past called this “mongrelising”. It’s the way new breeds were formed in the past and is the way modern commercial strains, types or “composites” are being produced by selection from a “gene pool”.
• It’s the way the New Zealand Huntaway was produced – and that’s the best example in the world of an animal selected primarily on performance as nobody cared what they looked like. Anything that did not perform was euthanased as nobody wanted them as pets.
• If you get to a stage where you are totally confused and don’t want to get involved in more basic recording, then start again by buying pure-bred stock and produce F1s or buy them in.
  

Inbreeding and linebreeding
In crossbreeding, animals are mated that are not related, so you end up producing more genetic variation in the flock. In direct contrast, inbreeding is where you mate animals that are related, i.e. have common ancestors somewhere in their pedigree. It’s sometimes called “close breeding”. Here are some of the key facts about inbreeding and linebreeding:

• If related animals are mated, their offspring will have more of their parent’s genes in common – whether they are good genes or bad ones, so genetic variation will decrease.
  
• If you mate animals that are very closely related like sons back on mothers or sires on daughters, you’ll increase relationships (called homozygosity) very rapidly indeed, and this is called “intense inbreeding”.
  
• If you do it more slowly when mating cousins, then homozygosity will build up more slowly and this is called “linebreeding”.
  
• So the difference between inbreeding and linebreeding is simply how fast you proceed towards homozygosity; or the state where everyone had the same genes as in clones.
• You don’t get very far with inbreeding in sheep compared to what’s possible in plants, as they usually become infertile or show very poor survival and die out.
  
• As inbreeding starts to build up, you see minor defects appearing like undershot jaws, extra limbs or odd colours. But then as it increases further, “inbreeding depression” takes hold and you find weak offspring at birth, poor survival and poor growth. Highly inbred animals get to breeding age they have low fertility.

New technology

• Embryo transfer is now regularly used in sheep with high genetic potential.
• Artificial insemination is not in common use yet.
• Ovine Single Nucleotide Polymorphisms (SNP) chip to make finding the genes in the sheep genome easier. Called the Ovine SNP50 Bead Chip it's a tool to characterise genetic variation to find important commercial traits.
  

Sheep's ovaries exposed to flush out embryos

Disclaimer
This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.