The use of a combined wheat or beet pulp and maize silage diet in dairy cattle

Abstract

Two complete diets based on maize silage including an iso-energetic contribution (0.33 UFL/kg MS) in the form of either wheat (28 % of the mixture) or dry beet pulp (33 %) were compared. For two periods of six weeks, two groups of 13 cows each, in the declining phase of lactation, were observed. One group received the wheat diet and the other the beet pulp diet. Ingestion levels increased and were comparable for the two diets (3.20 kg MS/100 kg live weight, on average), wheat (5.2 kg MS/ cow/day) and beet pulp (6.0 kg MS), representing, respectively, 27 and 32 % of the total diet. Starch content in the diets were respectively 39.6 and 20.2 % and that of crude cellulose 14.3 and 18.8 % for wheat and beet pulp diets. The total energetic values (17 UFL on average) were in excess of this for both diets (+ 1.6 UFL on average), but mainly for the cereal (+ 2.3 UFL). With both wheat and beet pulp diets, milk production, fat content and protein content were comparable, respectively, 23.6 and 24.0 kg, 943 and 953 g, 730 and 735 g per day. The fat content was not affected by the nature of the complementary feed (40.4 and 40.1 g/kg), but the protein content of the milk significantly increased with the wheat diet (31.3 compared to 31.0 g/kg). Technologically, this represents a better cheese yield and improved the coagulation properties. For both treatments the animals gained about 250 g/day throughout the experimental trial and the diets were correctly estimated (0.86 UFL/kg MS). Despite the fact that the two diets were very different chemically, their effect on production was limited. The slight increase with the wheat diet, was probably due to the greater energy content of the cereal.