The Influence of Genetic Merit For Milk Production on the Response to Complete Diet Feeding

Abstract

In two previous studies at this Institute, premixing of the silage and concentrate elements of the diet prior to feeding (complete diet feeding) produced either no increase in intake and milk production (Agnew and Mayne, 1992) or a slight increase in intake with no response in milk production (Agnew and Mayne, 1990). However the maximum proportions of concentrate dry matter intake (DMI) in the diets used in these experiments were 0.54 and 0.51 respectively. With the present rapid increases in cow genetic merit, across the industry, coupled with possible changes in the relative costs of feed grains and ensiled grass, there is a need to explore the response to complete diet feeding with animals of high genetic merit receiving higher proportions of concentrates. The current study therefore examined the response to complete diet feeding and its interaction with genetic merit of the cow, when using high concentrate diets.