ANIMAL HEALTH
Post mortems
Get your knives out
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BY: SARA SUTHERLAND n most aspects, the welfare of sheep on your average New Zealand sheep and beef farm is way better than most of our customers realise. Their physical, social and emotional needs are met. They don’t need to worry about starving or getting too fat, they aren’t frightened or abused, they live very natural lives, all they have to do is sit around eating and chatting with their best mates. In terms of animal welfare, the way we raise sheep in NZ is better in most measurable ways than just about any other animal production system anywhere in the world. One area where we may fall behind other systems is in lamb survival. Lamb wastage (conceived but not surviving to weaning) is about 15-20% on many farms, even higher with triplets. The vast majority of these losses occur around lambing time – at lambing or in the first 48 hours. Once you know what is causing these losses you can put steps into place to reduce them. The only way to know is to investigate those dead lambs. With a little bit of training and a little bit of practice, farmers or farm staff can do their own post-mortem exams of dead lambs very quickly and safely. You get over the “yuck” factor quickly and can even pretend you’re on one of those forensic TV shows. With my regular clients I am happy for them to text me photos of
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anything they are unsure of – maybe have a discussion with your vet first!
The Process First, always wear disposable gloves even if you hate the feel and never get sick. A good case of leptospirosis means six weeks off work, a bad case you can get chronic fatigue and you may never be able to farm again. If you’re pregnant, double gloves and a face mask, or delegate someone else for the job. Collect as many dead bodies as you can find – you have to get in quick before the hawks find them. If you want to save them up you can stick them in the freezer, just be aware they need a good 2 days to thaw. It is important to look at lots of bodies – finding out what is going on in one or two animals doesn’t necessarily mean that is your main issue. Have something handy to record what you find – paper and pencil or the techy people among you will be able to work out how to dictate into your cell phone without smearing blood everywhere. The most important thing you are finding out is whether the majority of your lamb losses are due to starvation/mismothering, exposure, infection/disease, dystocia (difficult births), or are these in fact late abortions and not deaths at or around birth. Having a standard protocol or way of going about it makes you more confident you haven’t missed anything. This is the way I do these and the way I teach my clients, there are other good protocols out there.
Examine the outside of the body. Is the lamb dry as though it was properly cleaned off by the ewe? Otherwise maybe mismothering is an issue. Is it fully formed and covered with hair? Otherwise this is an abortion and you should contact your veterinarian. Look at the pads on the front hooves. These are present at birth and wear off when the lamb walks around. If they have worn off then the lamb lived long enough to get up and walk. Lay the carcase on its back and cut between the front legs and the ribcage on each side. This makes the body lie reasonably stable. Cut carefully from the front of the brisket taking off the top of the chest, and the skin over the stomachs. This allows you to see the inside of the abdomen and the inside of the chest. Take a moment as you are peeling off the skin over the abdomen to look at the navel/umbilicus. If it is thicker than a pencil, contains pus or if there’s a lot of bruising around it this suggests infection (navel ill). Sometimes when you open up the body you see pus very obviously in the lungs or around the internal organs – this means infection is the issue. Have a look at the liver. White spots suggest infection (this could be before or after birth). Tan circles could be bacterial abortion, talk to your vet. Look at the stomach. You can pull it out and open it up. If it is full of clotted milk (cream cheese floating in clear liquid) then the lamb has had a good drink and starvation is not the issue. If it is completely
Country-Wide
October 2021
