Evaluation of the quality of milk according to the stages of lactation of the bovine Barroso-Salmeco, Guatemala.

Abstract

The 24 females delivered with 15 days of lactation, of second parturition were evaluated according to the stages of lactation with the physical, chemical, nutritional and sanitary characteristics such as density, freezing point, pH, fat, protein, lactose, non-fatty solids, point of freezing, somatic cells. To compare the stages, multivariate analysis was performed with the Student’s “t” test at 95% confidence. The results in the middle stage vr delayed there significant difference (P ≤ 0.05) for the protein in the mean with 3.38% and late 3.51%; lactose in the average 4.70% and late 4.90%. In the early delayed vr, there is significant difference (P ≤ 0.05), for the freezing point in the early with -0.59 ° C and late -0.63 ° C; density in the early with 1.035 g / cm3 and late 1.037 g / cm3; fat in the early with 1.59% and late with 2.12%; the protein for the early with 3.29% and late 3.51% and the lactose in the early with 4.56% and late 4.90%. The somatic cells showed an average of 104.651.67 ± 3.943.22 cel / ml. Conclusions, physical and chemical parameters were established such as pH, density and freezing point are within the ranges for dual purpose cattle, except the freezing point and density that in the three stages of lactation is relatively high. Nutritionals such as fat, protein, lactose and non-fatty solids are within normal values except fat that was low in all three stages and the amount of cel / ml normal.