The effect of long-chain polyunsaturated fatty acid and vitamin E supplementation of ewes on neonatal lamb behaviour and performance

Capper, Judith Louise (2005). The effect of long-chain polyunsaturated fatty acid and vitamin E supplementation of ewes on neonatal lamb behaviour and performance. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.0000e8c5

Abstract

Three experiments investigated the effect of long-chain polyunsaturated fatty acid (PUFA) and vitamin E supplementation of ewes upon lamb vigour and performance. In Experiment One, four diets were fed to 48 ewes in a two-by-two factorial design. Each diet contained either fish oil (high in C20:5n-3 and C22:6n-3) or Megalac^® (control fat, C16:0) and a basal (50 mg/kg) or supranutritional (500 mg/kg) concentration of vitamin E. Fish oil supplementation significantly increased ewe gestation length, deposition of C22:6n-3 in lamb brain tissue and neonatal lamb vigour. It also had significant detrimental effects upon milk composition and lamb growth. Vitamin E supplementation of the ewe increased the concentration of the vitamin in lamb brain and muscle tissue, and improved lamb birthweight. Within Experiment Two, three treatment diets based on algae (high in C22:6n-3), linseed (high in C18:3n-3) or Megalac^® were fed to sixty pregnant ewes. After parturition, thirty ewes were changed onto diets containing either linseed or Megalac^®. Gestation length and brain C22:6n-3 content were unaffected by diet, although lamb vigour was improved by maternal PUFA supplementation. The use of strategic supplementation abrogated the effects of PUFA supplementation upon lamb growth rate. Nevertheless, significant effects of algal supplementation were observed upon milk composition after a 28-day change-over period. Experiment Three employed three diets, each containing either fish oil or Megalac^® plus basal or supranutritional vitamin E, followed by Megalac^® supplementation during lactation. Gestation length and lamb behaviour were unaffected by treatment diet. Differences in milk composition were observed 28 days after the diet change. Long-chain PUFA supplementation of the pregnant ewe appears to improve neonatal lamb vigour, although effects upon milk composition cannot be negated by changing the dietary fat source during lactation. The vitamin E status of the neonatal lamb may be manipulated by maternal supplementation.