Milk quality from dairy farms divided in five levels of production

Abstract Text: This study aimed to characterize the physicochemical properties of milk from different production scales. A databank with 21,917 analyses, from January 2005 to December 2012, of 409 producers was used. Milk samples were collected twice a month and placed directly into milk cooling tanks. The properties were divided according to monthly average of daily milk yield in the following levels: 10 to 100 liters of milk per day (N = 7,858); 100 to 200 liters (N = 6,494), 200 to 500 liters (N = 5,085), 500 to 1,000 liters (N = 1,725), 1,000 to 5,000 liters (N = 755). Years and months were analyzed in a completely randomized split-plot design repeated in a time scheme, with years as plots and months as sub-plots. Within the reported period, 11.32% of the samples were from producers who account for 44.25% of production. Moreover, the great majority of the samples (88.68%) are from producers representing 55.75% of the supplied milk. An urgent need of improvement in management of total bacterial count (TBC) was observed throughout the year, and only August and September presented results below 100,000 CFU/mL. Somatic cell count (SCC), decreases in dry period, where June is the month with the lowest rate, and there is an increase in this SCC in the rainy season. This characterization is important so the industry can establish a protocol for mastitis control and mammary gland health throughout the year. No significant difference was found when correlating levels of production and SCC. However, TBC was affected by levels of production (P < 0.05), which mean that greater producers, in general, have a better management of this item. Protein was not affected by production levels (P > 0.05), and it increases in early dry period, with a subsequent decrease until the beginning of the rainy season. For small producers (up to 500 liters, including the first three levels) June had the highest fat production. The data obtained in the study shows that dairy farming in the region is predominantly developed in small properties. However, higher volumes are produced by fewer producers. The quality of milk produced deserves attention from the entire production chain of milk, and it still presents problems as high TBC, high SCC and low total solids, requiring more efficient management techniques. 

Keywords: fat, milk, protein