Relation between bovine milk quality, production volume, and environmental variables in dairy farms

Abstract

The objective of this study was to evaluate the relation between dairy farms with different volumes of milk production (L milk/day) and milk quality in the Western region of Santa Catarina State, as well as to identify environmental characteristics that could be associated with milk quality. Twenty-nine dairy farms were surveyed and categorized into three groups according to the volume of milk produced daily: S1, less than 200 L/day; S2, from 201 to 500 L/day; and S3, more than 500 L/day. Milk samples were collected from the bulk tank and analyzed for fat, protein, and lactose, somatic cell count (SCC), and total bacterial count (TBC). A questionnaire was applied to dairy farmers in order to obtain a set of twenty explanatory variables that may influence milk quality such as farmer profile, farm structure, and management. Outcome variables were evaluated by Principal Component Analysis (PCA) and Redundancy Analysis (RA). Low values of SCC, TBC and fat content were found to be strongly associated with greater volumes of production (S3). Type of milking and feeding program were the variables that most interfered with milk quality, followed by the average production per cow and type of grazing.