Setting up for lambing - nutrition, management and behaviour

July 2021

Ross Kuchel – Agriculture Advisor

Nutritional management in the lead up to lambing and during the lactating period is critical for the survival and performance of the lamb and the ewe. This year, given the exceptionally good conditions of both the pasture and stock, the expectation is for high numbers of multiple births (twin, triplets etc) and for lambs with high birth weights.

To ensure adequate nutrition to meet the requirements of the ewe during this period, the following minimum herbage amounts are required.

In the lead up to lambing, one of the main issues to lookout for, especially if your ewes are over-weight with multiple foetuses is Pregnancy Toxaemia. Heavy, fat, twin bearing ewes are particularly high risk with sometimes death being the only indicator. If noticed, the first signs of the disease will be ewes not feeding, separating from the mob and walking around with their heads held high or “star-gazing”. Pregnancy toxaemia is often referred to as “Preg Tox” or is also known as Twin Lamb Disease. It is typically brought on via a stress event. Some of the main triggers are:

Foot Abscess – a bacterial infection in the foot causing lameness and stress, potentially causing pregnancy toxaemia in the ewe resulting in death. For prevention, footbath your ewes during pregnancy (and ideally again before lambing) in a solution of 10-20% zinc sulphate heptahydrate. Refer to - https://pir.sa.gov.au/__data/assets/word_doc/0017/24121

Reduced Nutrition – Fat ewes don’t have a big appetite and particularly with twin bearing ewes, a drop in nutrition in late pregnancy can result in pregnancy toxaemia. It may sound counterintuitive when there is plenty of feed bulk, but if you identify a decrease in pasture quality consider providing a concentrated energy supplement. This could be in the form of grain or pellet.

Internal parasites and Clostridial diseases – ensure ewes are clean of worms and fluke prior to lambing and are placed onto clean, worm free pastures. During lambing/lactation, a ewes’ resistance/tolerance to internal parasites and disease drops. It is good practice to drench and give a booster vaccination (5in1 or 6in1) four weeks out from the start of lambing.

Lamb survival is highly determined by the interaction between the ewe and lamb, especially during the first 1 – 24 hours post-partum. It is a common saying that a merino ewe cannot count past one. i.e., that she will happily walk away with one lamb, completely forgetting about its twin. Research has shown that in twin bearing ewes, lamb survival is increased by up to 10% by reducing mob size. The studies conducted by Birchip Cropping Group in Victoria showed that for each extra 100 ewes in a mob, twin lamb survival dropped by 3.5%. It concluded that it is best practice to aim for mob sizes of less than 250 ewes (ideally closer to or less than 100). It showed that lamb survival was determined by the actual mob size, not stocking rate (density), in that it is a matter of just how many ewes and lambs are in the group not the paddock size.

If you have any concerns or queries regarding your stock in the leadup to lambing, calving or kidding please contact:

Ross Kuchel, Ag Advisor on 0428 314 588

Lou Baskind, District Vet on 0427 422 530

Local Land services Braidwood District Office on 1300 795 299