LUPINOSIS OF EWES AROUND THE TIME OF MATING REDUCES REPRODUCTIVE-PERFORMANCE

Lupinosis was induced in Merino ewes by subcutaneous injections of pho mopsin toxins, given for 2 weeks before and up to 2 weeks after the st art of joining, and the reproductive performance of the injected ewes was compared with untreated control ewes. Two experiments were conduct ed in consecutive years, with similar results. The liver damage and im pairment of liver function due to lupinosis were measured by increases in plasma activities of glutamate dehydrogenase and gamma glutamyl tr ansferase, plasma concentration of bilirubin, and plasma clearance of bromosulfthalein. Ovulation rate was depressed by phomopsin administra tion (1.11 v. 1.33 for the combined phomopsin-treated and control ewes , P < 0.001), and fewer phomopsin-treated ewes were pregnant (70.4% fo r the combined phomopsin-treated ewes v. 93.8% for the combined contro l ewes, P < 0.01). Thus, fewer lambs were born to the phomopsin-treate d ewes compared with the control ewes (66.0 v. 109.3% for the combined years, P < 0.01). These results indicate that there may be severe det rimental effects of phomopsin intoxication on reproductive performance of ewes.