Effect of sterile service on estrus duration, fertility and prolificacy inartificially inseminated dairy goats

The effect of sterile service on estrus duration, fertility and prolificacy in artificially inseminated dairy goats during breeding season was studied . Nubian does (n=126) were divided into 2 equal groups: service and control . Estrus was synchronized with intravaginal sponges containing either fluor gestone acetate (FGA; 40 mg) or medroxiprogesterone acetate (MAP; 60 mg) fo r 12 or 14 d, respectively. Two vasectomized teaser bucks were used to dete ct estrus at 6-h intervals for 5 d after sponge removal (0600, 1200, 1800 a nd 2400 h). The teasers were fitted with aprons and permitted to mount all does in bath groups, but to penetrate only the service does within the firs t 12 h of estrus. Does in both groups were inseminated twice at 12 and 24 h after estrus was first detected, using 1 straw per insemination containing 200 million of cooled spermatozoa from 1 buck. The semen was placed in mid -cervix. Estrus duration for the service and control does was (mean +/- SD) 29.4 +/- 6.5 and 41.8 +/- 9.6 h, respectively, Fertility for the service d oes was 73.7% (46/63); for control does it was 58.7% (37/63). Prolificacy w as 2.1 (96/46) and 2.0 (74/37) for service and control does, respectively. Estrus duration (P<0.001) and fertility (P<0.05) differed between the servi ce and control group, but prolificacy was similar (P>0.05). It is concluded that sterile service reduces the duration of estrus and increases fertilit y in artificially inseminated dairy goats. (C) 2000 by Elsevier Science Inc .