Effects of Nutritional Plane at Breeding on Feed Intake, Body Weight, Condition Score, Mass Indexes, and Chemical Composition, and Reproductive Performance of Hair Sheep.

This study was conducted to assess effects of the nutritional plane before and during breeding on feed intake, body weight (BW) change, reproductive performance, body condition score (BCS), body mass indexes (BMI), and body composition of three breeds of hair sheep. Twenty-five Dorper, 27 Katahdin, and 33 St. Croix ewes were allocated to groups and treatments based on initial BW and age. Supplementation treatments were soybean meal fed at 0.16% BW (LS) and a mixture of 25% soybean meal and 75% ground corn given at 0.8% BW (HS; dry matter basis) for 88 to 102 days including 17 days after breeding. Wheat straw intake (% BW) was greater (p < 0.01) for LS than for HS. Average daily gain and BCS change were similar among breeds, but both were greater for HS vs. LS. Birth rate, litter size, total litter birth weight, gestation length, and number of services were similar among breeds (p > 0.05), although individual lamb birth weight was lower for St. Croix than for Katahdin (p < 0.05). None of these reproductive variables were influenced by treatment or the breed × treatment interaction (p > 0.05). There were no breed differences in whole body concentrations of water, fat, protein, ash, or energy in week 0 or 4, but in 8 week concentrations of water, protein, and ash were greatest among breeds for St. Croix (p < 0.05) and levels of fat and energy were lower for St. Croix than for Dorper (p < 0.05). In week 8, total amounts and concentrations of fat and energy were greater for HS vs. LS and those of water, protein, and ash were less for HS (p < 0.05). There were interactions (p < 0.05) between treatment and period in blood concentrations of cholesterol and non-esterified fatty acids and between breed, treatment, and period in level of triglycerides and total antioxidant capacity. The concentration of cortisol was greater for HS vs. LS (p < 0.05). In conclusion, supplementation did not influence reproductive performance despite differences in BW and BCS change, which may be due to the initial moderate BCS and greater wheat straw intake for the LS treatment.

Carcass characteristics of Canindé goats subjected to feed restriction / Características de carcaça de caprinos Canindé submetidos à restrição alimentar

ABSTRACT: This study aimed to evaluate the effects of feed restriction on the carcass characteristics of castrated Canindé goat kids. A randomized block design was used, in which 21 goat kids with a body weight (BW) of 15.9±1.0kg were allocated to three levels of feed restriction: ad libitum, 20% and 40% restriction related to the ad libitum intake. The diet consisted of 55% forage (Tifton) and 45% concentrate. All animals were slaughtered when the kids fed ad libitum reached a BW of 25kg. After slaughter, the carcasses were chilled for 24 hours and subsequently measured. Kids fed ad libitum and subjected to 20% feed restriction showed similar morphometric carcass measurements, except for the chest circumference. Goat kids fed ad libitum exhibited greater values for warm and cold carcass yields compared with those subjected to 40% feed restriction and did not differ from the kids under 20% feed restriction. Weights of the commercial cuts showed decreasing mean values according to the intensity of feed restriction. Castrated Canindé goat kids subjected to 20% feed restriction presented similar carcass yields and proportion of commercial cuts to those fed ad libitum.

RESUMO: Objetivou-se com o presente estudo avaliar os efeitos da restrição alimentar sobre as características de carcaça de cabritos Canindé castrados. Foi utilizado um delineamento em blocos casualizados, no qual 21 cabritos com peso corporal (PC) de 15,9±1,0kg foram distribuídos por três níveis de restrição alimentar: ad libitum, 20% e 40% de restrição alimentar. A dieta consistiu de 55% de volumoso (Tifton) e 45% de concentrado. Os animais foram abatidos quando os cabritos alimentados ad libitum atingiram PC de 25kg. Após o abate, as carcaças foram resfriadas por 24 horas e, subsequentemente, mensuradas. Os cabritos alimentados ad libitum e submetidos à restrição alimentar de 20% apresentaram medidas morfométricas semelhantes, exceto para a circunferência do peito. Os cabritos alimentados ad libitum apresentaram maiores valores para rendimento de carcaça quente e fria em comparação àqueles submetidos à restrição alimentar de 40% e não diferiram entre os cabritos com restrição alimentar de 20%. Os pesos dos cortes comerciais apresentaram médias decrescentes com a intensidade da restrição alimentar. Cabritos Canindé castrados submetidos à restrição alimentar de 20% obtém rendimento de carcaça e proporção dos cortes comerciais similares aos alimentados ad libitum.