Influence of somatic cell count in the composition of Girolando cow's milk in tropical zone

Abstract

Bovine mastitis has been identified as the main disease affecting dairy cattle worldwide. Somatic Cell Count (SCC) in milk is one of the most important indicators to evaluate the udder health of cows due to the high direct correlation with the mammary gland's degree of infection. This study aimed to evaluate the different ranges of somatic cell count (SCC) on the composition of bovine milk as well as finding a correlation between somatic cell count and body condition score on milk production and composition of this species. The experiment was conducted on a commercial farm located in São José de Mipibu, Rio Grande do Norte, Brazil. The same cows were milked mechanically, obtaining a milk production record for the period of December 2011 to May 2012. For this, 24 Girolando breed cows (3/4 and 7/8) were used, being 50% primiparous and 50% multiparous with average production 7.51 ± 2.58 kg day-1 and 10.98 ± 2.49 kg day-1, respectively. The cows were milked mechanically, obtaining a record of milk production over a period of five months, and milk samples were collected and sent for laboratory analysis. The levels of milk composition were evaluated. Lactose, non-fat solids and milk urea nitrogen were influenced by different intervals of somatic cell count of milk. In milk samples from primiparous and multiparous cows, positive correlations between somatic cell count and some components were found. As for body condition score, significant correlations were also found for milk production and composition. It was concluded the different levels of somatic cell count influenced the percentage of lactose, non-fat solids and milk urea nitrogen. Somatic cell count and body condition score also showed significant correlations with milk production and composition.