Sexual Preference of Crossbreed Ewes for Rams Medicated with Naloxone

Ewe sexual preference depends on several factors; ram attractiveness is important. This work was carried out in the first week of September 2020 and repeated November 2021. For trial two rams were treated with 0.5 mg naloxone im for 15 days, control saline injections. Sexual studied synchronized ewes (n 0 12) displaying estrus at end treatment rams. Ewe’s proceptive receptive behavior noted. Plasma testosterone levels monitored through duration experiment second 4 same as 1, number increased to 24. It observed that treatment, not significantly different between rams; but beginning plasma until values reached ng/mL compared 6 When exposed untreated during trial, 11 showed high proceptivity receptivity (p<0.01) they mated, only one ewe complete preference. In it 19 also (p < .001). Hormone behaved following pattern trial. concluded facilitated secretion concentration this androgen motivated prefer mating ram.