ACCURACY OF SOME PUBLISHED FEED-INTAKE PREDICTION EQUATIONS FOR DAIRY-COWS IN GHANA

Voluntary feed intake (VFI) data obtained with Holstein-Friesian cows in Ghana were used to evaluate the accuracy of six VFI prediction equations drawn from the literature for their simplicity and ease of use. The dry matter (DM) intake and production data were collected during experiments on the feeding of dairy cows at the University of Science and Technology Dairy/Beef Cattle Project, Boadi, from 1977-1982. Equation 1 of Vadiveloo and Holmes generally gave the lowest (1.7 - 4.5 kg DM2) mean square error of prediction (MSPE) across all stages of lactation. However, equation 2 (5.2 - 10.6 kg DM2) of Vadiveloo and Holmes, the Ministry of Agriculture, Fisheries and Food equation and modified forms of this equation (3.9 - 9.6 kg DM2, and the equation (2.8 - 6.8 kg DM2) of McCullough gave very large MSPE. It is, however, possible to improve the accuracy of prediction of equations 1 and 2 of Vadiveloo and Holmes by the addition of a locality constant term.