Early lactation milk yield and interrelationships between milk constituents of free grazing prepartum supplemented Bunaji cows.

Abstract

A study was conducted to investigate effect of prepartum supplementary feeding of free grazing Bunaji cows on the early lactation milk yield (MY) and interrelationships between the resulting milk constituents. Twenty cows, balanced for their weight and parity, were allocated to a completely randomized design, with five animals per treatment. The treatments were: A, range grazing (RG); B, RG + 100% corn bran (CB); C, RG + 60% CB + 40% palm kernel cake (PKC), and D, RG + 60% CB + 40% dried brewer's grains (DBG). W hereas milk yield was significantly (P 0.05) correlated to total solid (TS) and crude protein (CP) (r = -0.885; - 0.6989). Contrarily, insignificant (P > 0.05) but positive correlations existed between TS and CP (r = 0.8607), TS and lactose (r = 0.8554), CP and solids-not-fat (SNF) (r = 0.7677), lactose and CP (r = 0.6210) and MY and CP (= 0.560). There was a negative and highly significant (P < 0.01) correlation between MF and SNF (r = -0.9893) and MF and lactose (r = 0.9944). The relationships between TS and SNF and MF and gross energy were positive and highly significant (P < 0.01, r = 0.9962; 0.9459). However, MY and MF were significantly negatively related (P < 0.05, -0.9840). Prepartum supplementary feeding improved the milk yield of the grazing cows in the early lactation while both positive and negative relationships existed between milk constituents of the cows suggesting that the regression equations can be used to predict one milk constituent from the other.