Big financial impact of late pregnancy feeding in sheep
Getting nutrition right in the last six weeks of pregnancy will have a huge impact on a flock’s financial performance.
This is according to NWF technical co-ordinator, Carolyne Barringer, who says: “About 70 per cent of lamb growth takes place in the last six weeks, and late pregnancy feeding will influence both ewe and lamb survival.
“Energy requirement increases significantly while appetite is reduced by around 30 per cent. Underfeeding can result is thin ewes; small, weak lambs and poor milk yields, while over-feeding increases the risk of dystocia.”
Miss Barringer advises condition scoring all ewes as soon as possible and grouping animals based on condition score and the number of lambs being carried. This allows a step feeding approach, closely matching the energy and protein supply to the needs of the ewe and the lambs.
“Condition scoring is a quick and easy way to assess ewes and treat them as individuals. This year we have seen some ewes coming in over-fit, while others are in very poor condition, usually a consequence of variable grass supply in the late autumn.
“Ewes that are either over fat or in poor condition and carrying multiple lambs are most at risk of pregnancy toxaemia, due to inadequate levels of available energy.
Miss Barringer says a 50kg ewe carrying a single lamb will require 7.5MJ/day, six weeks before lambing, rising to 11.3MJ/day in the week before lambing.
A 70kg ewe carrying twins requires 11.8MJ/day at six weeks out, increasing to 19.2MJ/day in the week before she lambs.
“Unless ewes are grouped accordingly, there is no way of ensuring they get the energy they require, resulting in a mixture of over- and under-feeding, but the consequence will be the same with poorer flock performance.
“The feeding regime prior to lambing will also influence udder development and the quality of colostrum. Thin, pale colostrum is indicative of poor feeding, while thick, yellow colostrum is suggestive of a well-fed ewe.”
“Grouping ewes and increasing the feed level weekly is the best way to improve performance and keep feed costs under control.
“Remember to increase the energy density to compensate for reduced appetite. For a small single-bearing ewe, look to feed 0.2kg of concentrate six weeks pre-lambing, rising to 0.5kg/day, while for a larger twin-bearing ewe, expect to feed 0.2kg/day, building to 1kg/day in the week pre-lambing.”
She also stresses the importance of feeding good quality protein. Ewes carrying twins, in particular, require additional rumen bypass protein to support the demands of the lambs from four weeks pre-lambing.
The consequence of failing to feed sufficient, high quality protein is poor foetal development, reduced udder development and lower milk yields.
“A ewe carrying twins requires around 34 per cent more protein than a single bearing ewe.
“Grouping ewes is the only way to target the correct level of protein. Look to include ingredients high in bypass protein to match the ewes’ requirements.
“The extra attention possible from grouping ewes will be more than repaid in terms of healthier lambs, reduced lambing problems and better milk yields.”