Volume 39, 112-116

Tropical Grasslands (2005) Volume 39, 112–116

Effects of a fibrolytic enzyme supplement on the performance of Holstein Friesian cows grazing kikuyu

B.C. GRANZIN

NSW Department of Primary Industries, Wollongbar Agricultural Institute, Wollongbar, New South Wales, Australia

Abstract

An experiment was conducted to examine the effects of a supplement containing fibrolytic enzymes (FE) (Promote^®, Agribrands International, St Louis, Missouri, USA) on milk production, intake and digestibility of Holstein Friesian cows in mid-lactation and grazing kikuyu pastures. Cows (24 primiparous, 24 multiparous) were fed either 0 or 4 g/cow/d of Promote^® which was incorporated into a grain-based supplement [6.3 kg dry matter (DM)/cow/d].
Positive effects of FE on yields of milk and milk protein were recorded in primiparous cows (P = 0.055, 17.7 vs 18.8 L/cow/d; P = 0.056, 579 vs 622 g/cow/d, respectively), but not in multiparous cows (P = 0.484, 20.3 vs 20.8 L/cow/d; P = 0.427, 543 vs 608 g/cow/d). There were no effects of FE on milk fat yield, milk composition or liveweight change. No significant differences in pasture intake between treatment groups could be detected. There was a significant FE × parity group interaction (P = 0.033) for starch digestibility, with primiparous cows fed FE having a significantly higher value than the remaining groups. There were no effects of FE on digestibilities of organic matter, neutral detergent fibre or acid detergent fibre. Reasons for the differences in response to FE in the different parity groups are discussed.