Across the country flocks are gearing up in preparation for another critical period in the shepherd's calendar; lambing. Particular care of the ewes should be undertaken in the last trimester to help reduce the mortality rate of neonatal lambs and maximise flock profitability, advises James Brinicombe, R & D Director of the Denis Brinicombe Group.
In the last 8 weeks of pregnancy the unborn lamb(s) completes 70% of foetal development, together with mammary development in the ewes. Milk production and colostrum quality can be positively influenced during this period therefore supplying a correctly balanced diet to the ewe is crucial, suggests Mr Brinicombe.
Alongside increased protein and energy requirements, the ewe will have a greater demand for vitamins, minerals and trace elements which will need to be met. Two nutrients that have a particularly important function at this stage are selenium and vitamin E, having a vital role to play in both the health of the ewe and the health of the lamb, before and after birth. Both of these vital nutrients have been shown to be essential for the optimal funtioning of the reproductive, muscular, circulatory, nervous and immune systems.
Selenium and vitamin E work synergistically together but have very independent roles and whilst they may have a sparing effect in cases of very minor deficiencies, there is a limit to this exchange. Therefore a constant plentiful supply of both should be maintained, explains Mr Brinicombe.
Deficiencies in selenium and vitamin E in-utero can lead to heart, lung or skeletal problems prior to birth and can contribute to abortions, stillbirths and weak lambs, which may die shortly after birth. Surviving lambs will likely be slow to stand and suckle, lambs get the majority of their requirement for selenium and vitamin E from the first colostrum, which is said to contain approximately four to five times more of these nutrients than milk, so it is essential that they are up and feeding quickly.
Affected lambs will often have a compromised immune system and be susceptible to infections and the onset of White Muscle Disease, a degenerative muscle disease which if untreated could prove fatal if the cardiac muscle is affected. The disease typically affects rapidly growing two to six week old lambs.
Ewes do not escape from problems of a selenium and vitamin E deficient diet; suffering from depressed immune systems which can leave them at risk of uterine infections, meaning more costs are likely to be incurred by the farmer.
Providing late gestation ewes with 100iu vitamin E and 1mg selenium per head per day has been shown to improve lamb vigour and survivability at birth and higher growth rates long-term, concludes Mr Brinicombe.