Nutrient intake, milk yield and composition of ewes fed diet containing different neutral detergent fiber levels

The experiment was carried to evaluate the effect of different levels of fiber in the diet on the nutrients intake, daily milk yield and composition of ewes. Eighteen multiparous ewes, housed in individual cage 24 hours postpartum. were randomly assigned to three levels of dietary NDF (treatment): 34, 43 and 52%. The diets constituted by a total mixed ration of corn silage, and a concentrate mix (ground corn, soybean meal and mineral mix) were formulated to be isoproteic (13% CP). The milk yield and composition was evaluated at each week, during 42 days. The NDF levels quadratically affected the intakes of DM, OM, CP, EE, NDF, ADF, NSC and TC (kg/day, %BW and g/kgBW(0.75)). The maximum intake of DM corresponded to the 42.7% of NDF level in the diet. Quadratic effect on the milk yield was verified, which was higher with 39.8% of NDF level. Quadratic effect on CP milk contents was observed. Milk fat contents (g/day) and milk density showed linear decrease with the increment of NDF level in the diet. Total solids contents (g/day), 3.5% fat corrected milk yield and corrected for total solids showed a quadratic behavior. The stage of the lactation influenced the milk production, in way that the peak of the lactation can occurs between the first and the third week of lactation.