RESUMO Objetivou-se com este estudo avaliar os efeitos da substituição total do farelo de soja por milho e ureia sobre consumo e digestibilidade aparente da matéria seca, perfil metabólico proteico e balanço de nitrogênio de vacas mestiças em lactação em pastejo, com lotação intermitente de capim-mombaça (Panicum maximum). Foram utilizadas 12 vacas mestiças em lactação, com peso corporal médio inicial de 473,0+45,0kg, período de lactação médio de 95,0+42,2 dias e produção de leite de média inicial de 14,1+1,9kg/dia. As vacas eram primíparas e multíparas, mestiças de Girolando, Pardo-Suíço e Jersey. Os tratamentos consistiram em quatro níveis de substituição do farelo de soja por milho e ureia (0; 33; 66; 100% na matéria seca - MS). O capim-mombaça apresentou teor médio de proteína bruta e fibra em detergente neutro de 19 e 59% na MS, respectivamente. A substituição do farelo de soja por milho e ureia não alterou o consumo e a digestibilidade aparente da MS. As concentrações de ureia e N-ureico plasmáticos foram alteradas pela substituição do farelo de soja por milho e ureia. O balanço de nitrogênio foi positivo e não foi alterado com as substituições. Para vacas mestiças produzindo, em média, 12,5kg/dia e mantidas em pasto de qualidade, pode se substituir totalmente o farelo de soja por milho e ureia.

The objective of this research was to evaluate the influence of procedures for hygienic milking and cleaning of dairy equipment and milk cooling tanks on the levels of total bacterial count (TBC). Mixed-effect models were used in order to model the structure of dependence between and within dairy farms. To this end, four bulk samples of milk were collected from each tank in eight properties for TBC analysis, employing the flow cytometry method. A questionnaire was applied in each property to assess the current situation of milking procedures on each production system that took part on this research, followed by training of employees in good agricultural practices in the production of milk and monitoring of the TBC measurements. Analysis of longitudinal data was the method employed, which focused on random effects models. The results showed that the handling procedures for milking and the cleanliness of the cooling tanks contributed to a further reduction in the levels of total bacterial count in raw milk cooling tanks.

This research article aims to evaluate the effect of total replacement of corn by soybean meal and urea on intake and apparent digestibility of dry matter and its components, production and composition of milk and feeding behavior of lactating cows grazing, with intermittent stocking Mombaça grass (Megathyrsus maximus cv. Mombaça). Twelve milking cows were distributed in a triple 4 x 4 latin square. Experimental treatments consisted of four soybean meal replacement levels by corn more urea (0; 33; 66; 100%). The grass has an average content of crude protein and neutral detergent fiber of 19% and 59%, respectively. The replacement of soybean meal by corn and urea did not affect the intake and digestibility of nutrients. A linear reduction of milk production was observed, but there was no change in milk production corrected to 4.0% of fat. The milk components (g/kg) of fat, protein, lactose, and total solids were not altered, as well as feeding behavior. Under the conditions of this study, the replacement of the diets is suitable for crossbred dairy cows in lactation third medium, producing in average of 12.5 kg/day-1 when kept in quality pastures.