Protein sources effect in the grazing cows diet on milk production

In order to find protein sources that could improve milk production and to increase the alternative foods use, this study aimed to evaluate the crossbred Holstein × Zebu cow’s milk production fed with four different protein sources. The experiment was carried out between February and May 2016, at the Paulista Agribusiness Agency (APTA), in the city of Colina /Sao Paulo/ Brazil. Twelve crossbred Holstein × Zebu cows with 20 milk liters/ day average production, between the 45th and 90th lactation days, grouped into four groups of three animals and distributed in a 4 x 4 Latin square experimental design, with four replications. Where, each group received after the morning and afternoon milks, concentrated ration with 12% CP, being distinguished only the protein source, which were; Soybean meal, peanut meal, cottonseed meal and sunflower meal. The amount of feed provided was regulated according to the individual production, for each 2.5 milk liters the animals received 1kg of feed, so, the dairy control was done every day. The pasture was fertilized and had 4 acres, divided into 24 pickets, and each picket was occupied for one day. The experiment totalized 84 days, divided in 4 cycles of 21 days, where the first 14 were destined to the diets animals adaptation and the remainder to data collections. The animals grazed on Panicum maximum cv. Tanzania in a 4 hectares area, divided into 24 pickets, and each picket was occupied for one day. According to the SAS statistical program, using the Tukey test (P> 0.05) and analysis of variance, only the treatment that consumed peanut meal had a significant difference, presenting the best production average of 21.36 l / Day, whereas the other treatments presented; 20.22 l / day for soybean meal, 20.07 l / day for sunflower meal and 19.58 l / day for cotton meal. Thus, we concluded that among the protein sources used the peanut meal provided a better milk production to the animals.