Kikuyu over-sown with ryegrass and clover: grazing capacity, milk production and milk composition

Abstract

The high dry matter yield of kikuyu (Pennisetum clandestinum) under favourable conditions supports high stocking rates and milk production per hectare. However, the quality of kikuyu is generally low and consequently the milk production per cow is also low. The aim of the study was to determine the grazing capacity, milk production and milk composition from kikuyu, kikuyu over-sown with annual ryegrass (Lolium multiflorum var. westerwoldicum), kikuyu over-sown with a mixture of perennial ryegrass (L. perenne), white clover (Trifolium repens) and red clover (T. pratense), and kikuyu over-sown with a mixture of white and red clovers. Milk production per cow was highest on pasture with high clover content and the grazing capacity of pasture increased as the grass component increased. The milk produced from kikuyu during spring (15 kg cow^–1 d^–1) and summer (14.4 kg cow^–1 d^–1) was higher than during the autumn (12.1 kg cow^–1 d^–1). The total milk production from kikuyu during spring (3 876 kg milk ha^–1) increased when kikuyu was over-sown with annual ryegrass (8 133 kg milk ha^–1) or with clover (7 370 kg milk ha^–1). The summer and autumn grazing capacity of kikuyu and kikuyu–annual ryegrass fertilised with nitrogen was higher than the kikuyu–clover pastures not receiving nitrogen. The clover content of the pastures did not affect the milk protein or butterfat content. The mean annual grazing capacity of kikuyu (6.7 cows ha^–1) and kikuyu–annual ryegrass (8 cows ha^–1) pasture was higher than the kikuyu clover (5.3 cows ha^–1) pasture. The grazing capacity and milk production per cow from kikuyu over-sown with ryegrass varied less than from kikuyu or kikuyu–clover pastures. This resulted in a similar or higher milk production per hectare from kikuyu–ryegrass compared to that of kikuyu or kikuyu–clover pastures.

Keywords: annual ryegrass, butterfat, kikuyu, milk, milk protein, perennial ryegrass, red clover, white clover

African Journal of Range & Forage Science 2008, 25(3): 103–110