Acta Scientiarum: Animal Sciences (Jul 2010)
Fatores ambientais e de manejo sobre a composição química do leite em granjas leiteiras do Estado do Paraná, Brasil = Environmental and handling factors on the chemical composition of milk in dairy farms of Paraná State, Brazil
Abstract
O objetivo do trabalho foi avaliar a influência da composição químicobromatológica da dieta total e os fatores ambientais das estações do ano sobre a composição química do leite. As granjas leiteiras estudadas foram identificadas como Granja 1 (G1) e Granja 2 (G2). Definiram-se como tratamento as quatro estações do ano e os dois sistemas de produção leiteira (G1 e G2). Foram coletadas 34 amostras da dieta total fornecida aos animais em lactação para a análise da composição químico-bromatológica, e 20 amostras de leite cru diretamente dos tetos dos animais para avaliar a composição química do leite, durante as quatro estações ano. Para as análises estatísticas dos dados, foi empregado o método dos quadrados mínimos. Constatou-se que houve diferença (p The objective of this research study was to evaluate the influence of total diet chemical composition and environment factors of thedifferent seasons of the year on the chemical composition of milk. The milk farms evaluated were classified as Farm 1 (G1) and Farm 2 (G2). The study defined as treatments the four seasons of the year and the milk production system (G1 and G2). A total of 34 diet samples were collected, fed to lactating animals in order to analyze the chemicalbromatological composition, and 20 samples of raw milk straight from cows in order to evaluate the chemical composition of milk during the four seasons. For data statistical analyses, the method of least squares was used. There was a difference (p 0.05) in lactose and total solids percentage between the studied farms. On the other hand, it was observed that the production (kg day-1) and all analyzed milk components were different (p < 0.05) during the four seasons of the year. The results demonstrate that the total diet chemical composition, lactation phases and environments factors of seasons of the year may cause variation in milk production and chemical composition.
