The effects of offering sucrose and fishmeal to dairy cows receiving different levels of concentrates on food intake and animal performance

Extract

Quota restricts the volume and butterfat content of milk at farm level. However there is no restriction on milk protein concentration. In a previous study in the present series, sucrose supplementation of cows in late lactation offered grass silage based diets increased milk protein concentration, while supplementation with sucrose and fishmeal increased protein concentration and the yields of milk, protein and fat plus protein equivalent to, or greater than, that obtained from the parent herbage. The present study was undertaken to evaluate the effects of partially replacing a concentrate supplement with sucrose and/or fishmeal, over a range of concentrate feed levels, on forage intake, milk production and composition.

Herbage was harvested from the primary growth of a predominantly perennial ryegrass sward, unwilted, precision chopped and treated with a formic acid based additive (Add-Safe, Trouw Nutrition) at 2.85 l/t. A concentrate was formulated consisting of unmolassed sugar beet pulp, barley, soyabean meal and minerals and vitamins. Four complete diets were prepared consisting of the silage and either concentrate (20 g/kg fresh silage) (SC), concentrate and sucrose (each at 10 g/kg fresh silage) (SCS) concentrate and fishmeal (each at 10 g/kg fresh silage) (SCF) or sucrose and fishmeal (each at 10 g/kg fresh silage) (SSF).