Early lamb survivability the key to flock margins

Taking steps to increase lamb survivability in the immediate post-lambing period should be a management priority as it will have a significant impact on returns.

Ewe & LambsTaking steps to increase lamb survivability in the immediate post-lambing period should be a management priority as it will have a significant impact on returns.

According to Chantal Bryant, large animal vet with Scarsdale Vets, part of the XL Vet group, around 60% of total lamb losses occur in the first two weeks of life, with 49% of all losses happening in the 48 hours after birth.

“Although there will be breed variations, the broad objective is to produce live lambs between 4-7kg at birth which are up and sucking within 15 minutes of birth. If this is achieved then the lamb has a 90-95% chance of being weaned” she suggests. “Management pre-lambing and around lambing will greatly influence this, ensuring lambs are born within the optimum size range and that ewes are healthy with an adequate milk supply.

“The absolute essential is to manage ewes to ensure they are at the target body condition score (BCS) at lambing. Lowland ewes should be at score 3.0-3.5 while for hill ewes the target is 2.5.”

She says that if ewes are too thin at lambing they will tend to have light lambs below 4kg which will have insufficient brown fat and will struggle in the first 24 hours. If they survive they will have reduced growth rates, not least as ewe milk supply and quality will be poor due to reduced udder weight.

“This could be a problem this winter where forage stocks have been limited or poorer quality following the difficult season and the wet autumn and winter. Assess condition now and review the ration in the weeks leading up to lambing. A small increase in feed costs could have a significant impact on the number of lambs born live and their viability.”

“If ewes are too fat the problem is likely to be large lambs with an increased need for assisted lambing, affecting lamb vigour. The ewe will have reduced feed intakes immediately pre-lambing which can compromise milk production.”

She says that pregnancy toxaemia, or twin lamb disease, can be a problem with both over fat and thin ewes. Pregnancy toxaemia can lead onto other conditions such as hypocalcaemia, reduced milk production, reduced lamb growth and increased lamb mortality.

Chantal advises that managing BCS is the most effective prevention strategy and the foundation of increased lamb survival. She recommends grouping ewes at scanning based on BCS and the number of lambs carried to allow targeted pre-lambing nutrition to ensure the correct condition score is achieved at lambing.

“Scanning and BCS are the best ways to correctly group ewes allowing rations to be adjusted to maintain condition as required,” she stresses.

At lambing, the key to lamb survival is to ensure ewes and lambs get on their feet quickly so the lamb can suck and the ewe can settle into milk production.

Roxanne Winstanley, product manager with Farm-O-San says that careful supplementation can deliver a good return in pre and immediately post lambing ewes.

“Where ewe energy intakes are being compromised in the last few weeks of pregnancy, consider feeding a supplement containing the key ingredients needed to support the ewe and to ensure a good start to lactation, specifically designed to boost energy intakes and support the liver.

“Farm-O-San Ewe Keto is a dietetic feed for in-lamb ewes, based on propylene glycol and glycerine. It supports the in-lamb ewe with glycogenic energy to reduce the risk of twin lamb disease. The inclusion of niacin and vitamin B12 improves energy utilization, choline encourages proper liver function while vitamin E and zinc are added to support resistance.”

In the run-up to lambing she comments that ewes tend to go off food and water and then, when they lamb they lose large amounts of fluids, leading to dehydration. Many ewes do not drink for eight hours after lambing, making the problem worse.

“Lambing is a time of significant physiological stress and it is important ewes recover quickly so they are able to care for their lambs and settle into lactation. Key to recovery is prompt and effective rehydration to encourage ewe vigour, increase appetite and promote early lactation yields.”

She says a dehydrated ewe takes longer to recover from lambing and will have reduced milk yields which will impact on lamb performance, with the consequences continuing for several weeks after lambing. Prompt and effective rehydration can ensure ewes settle into lactation quicker.

“Effective rehydration immediately post-lambing is not just about access to plenty of clean fresh water,” she continues. “At lambing, ewes also lose electrolytes which need to be replaced. As they will have been in negative energy balance, they can also be short of rapidly available energy. Supplements which provide electrolytes and dextrose will rehydrate ewes more effectively then water alone.”

Farm-O-San Reviva Ewe is a recovery drink for freshly lambed ewes. It contains the electrolytes required for rapid rehydration, dextrose a source of energy that can be absorbed from the gut rapidly, and added vitamins. Roxanne recommends providing rehydrating solutions to ewes for at least six hours immediately post lambing.

“There is no doubt that rehydrating ewes can be a cost-effective part of post-lambing management routines, helping improve the survivability of lambs in the crucial first 48 hours,” she concludes.

For further information contact our Farm-O-San Team