Exigências nutricionais em macroelementos minerais de cordeiros Santa Inês e F1 (Dooper x Santa Inês) em pastejo no Semiárido.

Abstract

This study aimed to estimate body composition and requirements for maintenance and weight gain in Ca, P, Mg, and Na Santa Inês lambs, and F1 (Dorper x Santa Inês) growing, reared at pasture in the semiarid. We used 36 lambs, male, not neutered, Santa Inês was 18 and 18 F1 (Dorper x Santa Inês), these, twelve animals were used as reference, six from each racial group and the remaining 24 were divided into three treatment, presenting initial weight of 15 kg. Treatments consisted of three levels of food intake adjusted in accordance with grazing time (nine, six and three hours of grazing) and their level of supplementation. The distribution of animals in treatments occurred with the formation of homogeneous batches of three animals one of each treatment, as they gained the same weight. When a batch of animals reached 30 kg body weight, their lot was slaughtered. The values of body composition in minerals of lambs grazing, 15 to 35 kg bodyweight, Santa Ines, varied 10,36 to 18,61 g Ca, 6,74 to 10,60 g P, 0,32 to 0,35 g Mg, 1,17 to 1,36 and 3,94 g K to 4, 20 g per kg of EBW. The body composition of minerals in F1 animals (Dorper x Santa Inês) of the same weight range, Ca, P, Mg, Na, K, ranged from 10,06 to 15,42 g, 5,93 to 9,18 g, 0,28 to 0,34 g, 1,20 to 1,29 g and 3,87 to 3,93 g per kg EBW, respectively. The net requirements for daily weight gain per kg, animals Santa Ines was estimated at 12,2 to 21,8 g Ca, 7,2 to 11,4 g P, 0,27 to 0,30 g Mg, 0,99 to 1,16 g K and 3,10 to 3,30 g Na; and the F1 lambs (Dorper x Santa Inês) were 10,5 to 16,1 g Ca, 6,2 to 9,7 g P, 0,26 to 0,30 g Mg, 0,87 to 0,81 g K and 2,83 to 2,79 g of Na, animals for 15 to 35 kg body weight. Net requirements for maintenance of sheep grazing in the Semiarid, weighing 15-35 kg, estimates were 6,7 mg/kg/day of Ca, 13,6 mg/kg/day of P, 3,5 mg/kg/day of Mg, 25,7 mg/kg/day of K and 7,0 mg/kg/day of Na.