Influence of body condition on ovulatory response to lupin (Lupinus angustifolius) supplementation of sheep

Fifteen mature Merino ewes were fattened with a maize grain/alfalfa chaff diet while an equal-sized group of similar ewes were maintained in store (score 2) condition (mean BW difference 11 kg). All sheep were then fed a maintenance diet of oat chaff. Following synchronization of all sheep with intravaginal sponges containing 40 mg progestagen, half of each group were fed a lupin (Lupinus angustifolius) grain supplement of 750 g/head/d from d 8 onwards of progestagen treatment. Ovulation rate following removal of the sponges was 64% higher (P<0.05) in the lupin-supplemented group but was not affected (P>0.05) by the condition score of the ewes. Plasma glucose, plasma urea nitrogen and some plasma amino acids were higher (P<0.05) in the lupin-supplemented group. These results indicate that nutritional flushing may increase ovulation rate of ewes regardless of their body condition.