Reproductive performance of Santa Inês ewes fed protected fat diet

Abstract

-The objective of this work was to evaluate the reproductive performance of Santa Inês ewes fed a diet supplemented with protected fat. Intervals from lambing to first clinical estrus and to conception, conception rate, prolificacy, live weight and body condition were determined. After lambing, 60 ewes and their offsprings were weighted and randomly assigned to three treatments, based on age, body weight and number of born lambs. Treatments consisted of: control diet, or control diet plus 30 g of protected fat, from lambing to day 25 of post-lambing (Sup25), or to day 60 of post-lambing (Sup60). Out of 60 evaluated ewes, 93.3% returned to estrus, and 74.5% got pregnant, with 73.53% lambing rate and 196.5 days lambing interval. The average periods from lambing to first estrus were 32.4, 27.2 and 35.5 days for ewes fed the control diet, Sup25, and Sup60, respectively. The intervals from lambing to conception were 45.2, 46.5 and 45.2 days, and the supplemented diets did not show differences in comparison to the control diet. Supplementation with protected fat to well-nourished Santa Inês ewes does not improve their reproductive performance.Index terms: Ovis aries, conception rate, estrus, lambing interval, nutrition. Desempenho reprodutivo de ovelhas Santa Inês alimentadas com dieta com gordura protegidaResumo -O objetivo deste trabalho foi avaliar o desempenho reprodutivo de ovelhas Santa Inês alimentadas com dieta suplementada com gordura protegida. Os intervalos do parto ao primeiro estro clínico e à concepção, a taxa de gestação, a prolificidade, o peso vivo e a condição corporal foram determinados. Depois do parto, 60 ovelhas e seus cordeiros foram pesados e distribuídos aleatoriamente em três tratamentos com base na idade, peso corporal e número de cordeiros nascidos. Os tratamentos consistiram de dieta controle ou da dieta controle mais 30 g de gordura protegida, do parto aos 25 dias pós-parto (Sup25), ou aos 60 dias pós-parto (Sup60). Das 60 ovelhas avaliadas, 93,3% retornaram ao estro, e 74,5% ficaram prenhes, com taxa de parição de 73,53% e intervalo de parto de 196,5 dias. O período médio do parto até o primeiro estro foi de 32,4, 27,2 e 35,5 dias, para as ovelhas alimentadas com a dieta controle, Sup25 e Sup60, respectivamente. Os intervalos do parto até a concepção foram de 45,2, 46,5 e 45,2 dias, e as dietas com suplementação não apresentaram diferenças em comparação ao tratamento controle. A suplementação com gordura protegida para ovelhas da raça Santa Inês, bem nutridas, não melhora seu desempenho reprodutivo.Termos para indexação: Ovis aries, taxa de concepção, estro, intervalo de parto, nutrição.

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