Blood meal as a protein supplement for dairy cows

Abstract

Proc. Aust. Soc. Anim. Prod. I996 Vol. 21 BLOOD MEAL AS A PROTEIN SUPPLEMENT FOR DAIRY COWS S.C. VALENTINE and B. D. BARTSCH Primary Industries (South Australia), Flaxley Agricultural Centre, Box 157 1, Flaxley, S.A. 5 153 Replacing part of the lupin grain in a barley/lupin grain concentrate mixture with blood meal, as a source of rumen undegradable dietary protein (UDP), increased milk and milk protein yield in high producing dairy cows in early lactation fed poor quality pasture silage (Valentine and Bartsch 1995). However, the production response by dairy cows to UDP supplements may depend on the quality and type of roughage (Thomas and Rae 1988). Two experiments were carried out to compare milk production by high producing cows fed iso-nitrogenous concentrate mixtures of either barley and lupins or barley, lupins and blood meal as supplements to high quality pasture silage or hay diets. Twenty-six Holstein-Friesian cows in experiment 1 and 32 cows in experiment 2, all in early lactation, were allocated to groups of 2 based on similarity in calving date and milk fat yield recorded during a 7-day covariance period. In experiment 1, cows within each group were allocated at random to be fed 9 kg/day of iso-nitrogenous rolled grain mixtures comprising either 50% barley and 50% lupins (11.3 MJ ME/kg DM, 22.3% CP) or 70% barley, 24% lupins and 6% blood meal (11.6 MJ ME/kg DM, 22.3% CP). In experiment 2, the cows received 9 kg/day of iso-nitrogenous grain mixtures comprising either 34% barley and 66% lupins (11.2 MJ ME/kg DM, 25.2 % CP) or 54% barley, 40% lupins and 6% blood meal (11.5 MJ ME/kg DM, 25.2 % CP). The grain mixtures were fed with a mineral/vitamin supplement in equal amounts twice daily at milking for a 7-day adaptation period and 56-day test period. Cows within each experiment were managed as a single herd. Wilted, round bale pasture silage (8.7 MJ ME/kg DM, 14.9% CP) was available ad Z&turn in experiment 1 and round bale pasture hay (10.0 MJ ME/kg DM, 18.2% CP) in experiment 2. Milk yield and composition were recorded 3 times each week and liveweight once each week. Table 1. Covariance-corrected mean daily yields of milk and milk components, milk composition and liveweight change of cows fed lupins or a mixture of lupins and . blood meal Using blood meal as a source of UDP in rations based on a barley/lupin grain concentrate mixture and high quality silage or hay is unlikely to increase production in dairy cows producing around 30 L/day in early lactation. VALENTINE, S.C. and BARTSCH, B.D. (1995). Amt. J. Exp. Agric. 35: 325-9. THOMAS, C. and RAE, R.C. (1988). 'Nutrition and Lactation in the Dairy Cow.' pp. 327-54. (Butterworths: London). 349