Performance and ingestive behavior of lactating ewes fed diets containing different levels of neutral detergent fiber

Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe study was carried out the Department of Animal Science of the Federal University of Santa Maria, with the objective to investigate the effect of the supply of diets with different levels of neutral detergent fiber (NDF) on the nutrients intake, daily milk yield (MP), milk composition (MC) and ingestive behavior of lactating ewes. Eighteen ewes, proceeding from the alternated crossing between Texel and Ile de France breeds were used, housed indoors in individual cages. The animals were distributed on three treatments: 34, 43 and 52% NDF in the diet, in dry matter basis (DM) to consist in the treatments. Equal protein diets, with 13% of PB (crude protein) content, in DM basis, was composed of total mixed ration of corn ensilage (Zea mays L.), and a concentrate mixture based on fragmented corn, soybean bran (Glycine max L.) and mineral mixing. The food supply was ad libtum, done twice a day, in set up times at 8:30 AM and 4:30 PM. An entirely randomized design was used, with three treatments and six repetitions each. The results were submit of the analysis of variance and regression study. The addition of increasing in NDF levels result in quadratic effect (P0.05) of the diets on the variations of average weight daily gain (GMD). The body score condition (CC) presented quadratic behavior (P0,05) das dietas sobre as variações de peso vivo (GMD). A condição corporal final (CC2) evoluiu quadraticamente (P<0,05). Verificou-se efeito quadrático (P<0,05) da produção de leite em função dos tratamentos, que foi máxima com um nível de 39,8% de FDN na dieta. Os teores de PB do leite variaram quadraticamente (P<0,05). O teor de gordura do leite (Gord), expresso em g/dia, e a densidade, diminuíram linearmente (P<0,05) com o incremento de FDN na dieta. Os teores de sólidos totais (ST), expressos em g/dia, densidade (DENS), leite corrigido para 3,5% de gordura (LCG3,5) e 4% de gordura (LCG4) e leite corrigido para sólidos totais (LCST) variaram de modo quadrático (P<0,05), em função dos tratamentos. O estágio da lactação influenciou a produção de leite dos animais (P<0,05), resultando efeito quadrático para os níveis 34% e 43% de FDN, e linear para o nível de 52% de FDN na dieta. Houve efeito quadrático (P