NUTRITIVE-VALUE OF SUBTERRANEAN CLOVER IN A TEMPERATE ENVIRONMENT

Citation
Jg. Mulholland et al., NUTRITIVE-VALUE OF SUBTERRANEAN CLOVER IN A TEMPERATE ENVIRONMENT, Australian journal of experimental agriculture, 36(7), 1996, pp. 803-814
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Agriculture Dairy & AnumalScience",Agriculture
ISSN journal
0816-1089
Volume
36
Issue
7
Year of publication
1996
Pages
803 - 814
Database
ISI
SICI code
0816-1089(1996)36:7<803:NOSCIA>2.0.ZU;2-O
Abstract
A study was made over 2 years of the nutritive value of the subterrane an clover (Trifolium subterraneum L.) cultivars, Trikkala, Larisa and Goulburn, in grazing experiments with Border Leicester x Merino lambs. Liveweight gain was similar for all cultivars in the first year and i n the second year was higher on Larisa (153 g/day) compared with Goulb urn and Trikkala (131 and 103 g/day, respectively). Wool growth was no t significantly different between cultivars. Both the digestibility an d water-soluble carbohydrate content of the petiole and stem plant fra ction were significantly (P < 0.05) higher than those of the leaf frac tion, even though the leaf had a lower level of cell wall organic matt er. The ratio of lignin to cell wall organic matter was also higher in the leaf fraction. Samples obtained via oesophageal fistula showed th at petioles comprised most of the dry matter in the diet and, thus, we re the major contributor to energy supply. Differences were found in t he degradability characteristics of the 3 cultivars which led to signi ficant (P < 0.05) differences in the concentration of rumen degradable dry matter and effective rumen degradable protein (ERDP). During the vegetative and early flowering stages, the concentration of ERDP excee ded the supply of fermentable metabolisable energy required for microb ial protein synthesis. In mature clover, the concentration of ERDP was low and limiting microbial protein synthesis. The degradation charact eristics of protein were highly correlated with liveweight gain (r(2) = 0.90) and wool growth (r(2) = 0.70). It is suggested that increasing the petiole:leaf ratio could increase the efficiency of utilisation o f subterranean clover diets.