Desempenho reprodutivo de ovelhas submetidas a diferentes formas de suplementação alimentar antes e durante a estação de monta

Abstract

RESUMO -Objetivou-se com este estudo analisar o desempenho reprodutivo de ovelhas submetidas a diferentes formas de suplementação alimentar antes e durante o período de acasalamento. Utilizaram-se 112 ovelhas (63 no primeiro ano e 49 no segundo) dos grupos raciais Hampshire Down, Ile de France, Suffolk e Corriedale. Os animais foram separados em três grupos: T1 (sem suplementação), T2 (suplementação com 600 g/dia de milho triturado) e T3 (suplementação com 600 g/dia de concentrado constituído de 75% de milho triturado e 25% de farelo de soja). As ovelhas sob suplementação (T2 e T3) apresentaram maiores pesos e ganhos de peso até o final da estação de monta. Os escores da condição corporal também foram maiores ao final da estação de acasalamento nas ovelhas sob suplementação, implicando maior deposição de tecidos (músculo e gordura) no corpo do animal. O flushing não resultou em maior taxa de parição nem em aumento de partos gemelares, porém, Reproductive performance of ewes submitted to different feeding managements before and during the breeding period ABSTRACT -The objective of this study was to investigate the reproductive performance of ewes submitted to different feeding management before and during the breeding period. A total of 112 ewes, 63 in year one and 49 in year two of the study, from the genetic groups Hampshire Down, Ile de France, Suffolk and Corriedale, were used. The ewes were separated in three groups: T1 (without supplementation), T2 (supplemented with 600 g/day of ground corn) and T3 (supplemented with 600 g/day of a concentrate containing 75% of ground corn and 25% of soybean meal). Supplemented ewes (T2 and T3) had higher body weight and more weight gain until the end of the breeding period than those not supplemented. Body condition scores were also greater at the end of the breeding period for supplemented ewes, indicating a greater fat and muscle deposition.Supplementation did not improve fertility rate and twins birth rate, but increased birth rate in ewes supplemented with corn. Age and genetic group both affected birth rate. It was concluded that feeding corn to ewes improved the number of lambs per ewe.

Reproductive performance of Ile de France ewes under dietary supplementation before and during the breeding season

“…The greater ADG of supplemented ewes might have resulted from their higher nutrient intake. The results of this study are similar to those reported by Mori et al (2006) and Veloso (2008), who, evaluating the reproductive performance of ewes at the beginning and during the breeding season, observed higher ADG in the supplemented ones; and by Chaturvedi et al (2003), who studied the effect of supplementation on performance and production of Malpura and Kheri ewes on a natural pasture during the end of gestation and in early lactation, and observed a higher ADG in the supplemented animals.…”

“…The average birth rate of 113.83% was similar to the 118.20% reported by Mori et al (2006), who studied the reproductive performance of Ile de France ewes supplemented before and during the breeding season; and close to the 120.84% found by Sabra and Hassan (2008), evaluating the reproductive performance of Barki ewes subjected to flushing.…”

“…The average prolificacy of 1.25 was similar to the 1.30 described by Veloso (2008), who evaluated the productive and reproductive performance of ewes subjected to different flushing systems. The average prolificacy of 1.40 of the supplemented ewes was similar to the 1.37 obtained in Corriedale ewes by Mori et al (2006). Prolificacy rates are important in the production system because, as they relate the number of lambs born per ewe, they contribute to improving the reproductive efficiency (SOUZA, 2007), increasing the scale of production of animals for reproduction and slaughter.…”

“…This result agrees with those reported by Leal et al (2010), who evaluated the reproductive performance of Santa Inês ewes receiving dietary supplementation and found a rapid return to estrus; by Sabra and Hassan (2008), who found an extension of estrus in animals when studying the reproductive performance of Barki ewes subjected to flushing; and by Islam et al (2007), who reported an improvement in the reproductive efficiency of Corriedale ewes also subjected to flushing. Regarding the fertility, calving, and birth rates, as well as the type of birth, no influences (P>0.05) of flushing and shearing (Table 6) were found on these variables, probably as a result of the good body condition score of the ewes (Table 4), which was above 3.0, considered good according to Mori et al (2006). The best results with flushing are obtained in animals that have undergone some nutritional deficiency before the breeding season, whose nutritional requirement was not met (negative energy balance), with body condition scores of 2.0 to 2.5 (FREITAS, 2008).…”

“…Two to three weeks before the beginning of the breeding season, and over its course, the nutritional level should be improved so as to provide better efficiency and reproductive performance by increasing the fertility rate and consequently birth rate (MORI et al, 2006;VELOSO, 2008). Flushing is a practice aimed at increasing the number of ovulations, improving fertility in the herd by obtaining a larger number of multiple births (CHAGAS et al, 2007).…”