Abstract

Legumes are an important component of feeding systems in temperate zones to fix nitrogen and to produce high quality forage as a feed for livestock. However, marginal protein deficiency exists when ruminants are fed on fresh temperate forages due to high degradation rates of forage proteins in the rumen. Consequently, there is a large absorption of NH3 from the rumen, leaving absorption of essential amino acids (EAA) from the small intestine that is below animal requirements for these AA (Barry, 1982). Condensed tannins (CT) in Lotus corniculatus (Birdsfoot trefoil) reduce rumen protein degradability and increase EAA absorption from the small intestine (Waghorn et al., 1987). Separate feeding experiments with sheep have shown that CT in lotus increased wool production and milk secretion (Wang et al., 1996a&b) and both ovulation rate during mating, and lambing percentage (Min et al., 1999: Min et al., 2001), all with no increase in voluntary feed intake (VFI). In addition, lambs fed lotus accumulated fewer dags than lambs grazed on perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) pasture (Leathwick & Atkinson, 1995). Each of these effects was measured in separate specific experiments. The objective of this study was to assess the effect of feeding Lotus corniculatus upon wool production and lamb weaning weight under commercial dryland farming conditions without anthelmintic drench input, using a systems approach, where effects upon animal productivity and parasites were measured in the same experiment.

CA, Ramirez-Restrepo, TN Barry, N Lopez-Villalobos, PD Kemp, WB Pomroy, WC McNabb, TG Harvey, and NM Shadbolt

Proceedings of the New Zealand Society of Animal Production, Volume 62, Palmerston North, 177-178, 2002