Physicochemical characterization of milk in 5/8 Holstein × 3/8 Zebu crossbred cows in tropical Mexico

Abstract

Background: Milk price depends on the concentration of milk components, which are influenced by several factors. Objective: To determine the effect of cow intrinsic variables on the physicochemical composition of raw milk in a dualpurpose production system. Methods: Twenty-five 5/8 Holstein-Friesian × 3/8 Zebu (5/8H3/8Z) lactating cows aged 5-10 years and 1-6 births were selected. Body condition score (BCS) and milk production were recorded. Milk samples were taken throughout lactation from each cow at mid-milking every eight days. Milk composition analysis was carried out using an automatic Lacticheck equipment. Results: Average daily milk production per cow was 4.10 L, with 1.03 g/cm3 density, 32.70 g/L fat, 34.50 g/L protein, 50.20 g/L lactose, 91.30 g/L non-fat solids, and 127.00 g/L total solids. The BCS influenced milk composition (p<0.01). Cows with higher BCS (>3.25) showed greater density, protein and lactose, while BCS between 2.00 to 2.50 positively affected fat content (39.20 g/L). Elder cows had increased milk production. In early lactation, milk production was the highest with less fat percentage. Conclusion: Although cow production per day is low, milk composition from 5/8H3/8Z cows complies with the standards established in the Mexican norm and is considered to be of good quality.