Influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 2. Liveweight, body condition score, carcass yield and mortality.

摘要

The effects of animal species (AS; Angora goats, Merino sheep, mixed-grazed goats and sheep at the ratio of 1:1) and stocking rate (SR; 7.5, 10 and 12.5 animals/ha) on the liveweight, body condition score, carcass yield and mortality of goats and sheep were determined in a replicated experiment on improved annual temperate pastures in southern Australia from 1981 to 1984. The pattern of liveweight change was similar for both species with growth from pasture germination in autumn until maturation in late spring followed by weight loss. In winter, sheep grew faster than goats (65 versus 10 g/day, P<0.05). In mixed-grazed treatments between November and December goats either grew when sheep were losing weight or goats lost less weight than sheep (P<0.01). Both AS (P<0.001) and SR (P<0.001) affected liveweight of sheep and an AS x SR interaction (P<0.05) affected liveweight of goats. Mixed-grazed sheep were heavier than separately grazed sheep at all SR with a mean difference at 10 and 12.5/ha of 4.6 kg. Mixed-grazed goats at 10/ha were heavier than separately grazed goats from the end of the second year of the experiment, but at 12.5/ha, separately grazed goats maintained an advantage over mixed-grazed goats, with a 9.4-kg mean difference in December (P<0.05). Body condition scores of goats and sheep declined with increasing SR; they were highest in late spring and were highly correlated with liveweight (r2