Feeding value of grass/white clover swards

Abstract

Forage legumes are able to improve pasture systems and decrease their cost. Thus white clover could provide an effective N source for mixed grazing swards. Two grasses/white clover awards - ryegrass and cocksfoot/clover - compared with pure grass awards as control, were studied using sheep in metabolism crates to know the feeding value of these grazed or conserved mixed swards. During the first growth cycle of each year, white clover DM content did not exceed 30 % in the sward. So, the effect of clover on OM digestibility and DM intake was low. The clover DM content of regrowths was higher (30 - 50 %) so that OM and CP digestibility and DM intake were improved respectively by 10 % and 5 - 15 %. Also high clover content increased feeding value which is more constant than with pure swards. Consequently, interval between grazings could be used with 4 or 6 weeks of regrowth period. Conserved as silage ensiled from the first growth, conservation quality and nutritive value of mixed swards are not influenced by mean clover content. As hay, cut on second growth of the season (30 - 40 % clover), nitrogen quality (+ 15 %), OM digestibility (+ 5 / 10 %) and DM intake (+ 10 / 20 %) of mixed swards were improved greatly. It is concluded that white clover could be viewed as a secure corrective of grass feeding value variations.