Balanço nutricional de ovinos Santa Inês sob regime alimentar para ganho compensatório.

Abstract

The objective of this study was to evaluate the nutritional balance of Santa Inês sheep subjected to feed restriction. The experiment was carried out from January to April 2009 The first digestibility trial during the restriction period was from 19 to 25 February and the second at the end of the period of feedback. 20 pure blood Santa Ines sheep, averaging 26.108 kg of body weight (BW) and 190 days of age were used and kept in metabolic cages equipped with individual troughs and drinkers. Water was offered at will and measured by weighing them with a calibrated scale at ten (10) grams. Restriction levels were 0, 20, 40 and 60%. The experimental design was completely randomized with four treatments and five repetitions. There was a quadratic effect (P < 0.05) for gross energy consumption (CEB), the gross energy of the faeces (EBfz) and energy balance (EB). The gross energy of urine (EBur) and gross energy absorbed (EBabs) had a linear outcome (P < 0.05). The gross energy retained (EBret) was not significant (P > 0.05). The behavior of nitrogen consumed (Ncons) and nitrogen of the faeces (Nfz) in feed restriction was quadratic (P < 0.05). Urinary Nitrogen (Nurina), absorbed nitrogen (Nabs), nitrogen retention (Nret) and nitrogen balance (BN) showed linear outcome (P < 0.05). The water excreted in the feces ( AFZ ) had a quadractric outcome ( P < 0.05 ) and water excreted in the urine (Aur) showed a linear response (P < 0.05). The retained water (Aret) and absorbed water (Aabs) were not significant (P > 0.05). The water balance (BH) showed linear increase with positive values. Dietary restriction of 40 % can be adopted as a practical nutritional management during periods of food shortage or sheep who will undergo the most severe confinement; and restrictions, such as 60%, are not recommended because they can impair the performance of animals.