Fontes alternativas de proteína para vacas em lactação

Abstract

It was evaluated in this work alternative sources of protein for lactation cows, about the intake, digestibility, milk yield and composition. Eight cows multiparous ¾ (Holandez / Gir) were distributed in two 4 x 4 latin squares, simultaneous. Each experimental period lasted 21 days (14 days for adaptation and seven days to collect data and samples). Were evaluated three protein sources, cottonseed meal (CM), soybean semi integral (SBSI), mazoferm and soybean meal (SBM) as witness. When mazoferm was used was observed smaller intake of dry matter, organic matter, crude protein and total digestible nutrients compared to SBM. Milk yield was lower in animals received mazoferm compared with fed SBM. The fat content in milk no differed and yield fat was lower for the animals that received CM and mazoferm compared to SBM. With respect to the percentage of milk in protein, when it was provided SBSI was observed lower content compared to SBM. Animals fed CM presented lower total solids in milk compared with those receiving SBM. Feed efficiency was greater for animals fed diets with mazoferm e nitrogen use efficiency was lower for those receiving CM compared with SBM. Nutrient digestibility was lower for animals fed diets with mazoferm, except for digestibility of non-fibrous carbohydrate which did not differ with respect to diet with SBM. Digestibility crude protein was greater for diets with CM and SBSI compared the diet with SBM. Based on dry matter intake and animal performance, is recommended the replacement of soybean meal by cottonseed meal and soybean meal semi integral.