Effects of sexed semen on fertility and sex ratio of calves in indigenous Arsi Cattle at Adami Tulu Agricultural Research Center

Abstract

An on-station study was conducted at Adami Tulu Agricultural Research Center during 2021 to 2022/23 breeding season  to evaluate the effect of sexed semen on fertility rate of cows,  number of services per conception (NSPC), conception rate, sex ratio of calves born and the economics of using sexed semen in indigenous Arsi cattle. For evaluation purpose indigenous Arsi Breed cattle were selected from nucleus herd maintained at on station based on their parity, body condition and reproductive history and assigned to one of the following treatments. Animals in Treatment 1 were inseminated with conventional semen and Treatment 2 were inseminated with sexed semen. They were synchronized for estrus by injecting PGF2α hormone, whereas, those animals exhibited the sign of heat naturally were inseminated directly. Heat was detected by herdsmen in the early morning, mid-day,   early evening and at nighttime. Standard procedure of semen handling and insemination was implemented during the study. Pregnancy diagnosis was performed by rectal palpation after 90 days of insemination. There was no significant difference (P>0.05) in NSPC between the treatments and the overall mean NSPC was 1.23±.049.  There was no significant difference (P>0.05) in pregnancy rate between treatments. The pregnancy rate was 71% and 56.4% for conventional and sexed semen, respectively. The mean conception rate was 57.9% and 44% with conventional and sexed semen, respectively. There was a significant difference (P<0.05) in sex ratio of calves born between treatments. The average female calf obtained was 50% and 85% for conventional and sexed semen, respectively. The overall advantage of using sexed semen was 769,532 ETB and 15,390.64 ETB advantage per unit of sexed semen used. Sexed semen can be used as alternative artificial insemination technology for Arsi breed cows to produce  more female calves for herd replacement. On-farm evaluation and demonstration of using sexed semen technology is important  in potential areas suitable for dairy production.