Feed intake, liveweight and wool growth rate in Merino sheep with different responsiveness to low- and high-quality feed

A previous field trial using 30 sheep from each of 3 strains of Merino sheep (designated F, M and B) found that wool growth rate in strain B changed less throughout the year, compared with the other 2 strains. The present study examined components of liveweight loss on dry pasture with low protein and low digestibility to detect underlying relationships with the subsequent responsiveness of wool growth rate to young green pasture. Strain B lost less liveweight when grazed on dry (poor-quality) pasture, but lost more liveweight on sparse green pasture, than the other 2 strains. The rate of liveweight loss was not related to fatness on dry pasture, but was related to fatness on green pasture. The plasma concentration of leptin at the start of winter was related to clean-fleece weight (P