Reproductive performance of sows treated with a combination of pregnant mare's serum gonadotropin and human chorionic gonadotropin at weaning in the summer.

Abstract

During the summer and fall of 1987, sows from eight herds in three states were assigned randomly to receive either a combination of 400 IU of pregnant mare's serum gonadotropin with 200 IU of hCG (P.G. 600) or no treatment at weaning. A treatment x parity interaction was observed for days to first estrus after treatment and percentage anestrus (percentage of sows not achieving estrus within 10 d after weaning). Relative to primiparous control sows, primiparous sows given P.G. 600 expressed estrus sooner (P less than .02) after weaning (6.0 vs 7.8 +/- .6 d) and exhibited less (P less than .02) postweaning anestrus (15.6 vs 29.2 +/- 4.0%). Second parity sows that received P.G. 600 showed estrus sooner (P less than .06) than second-parity control sows (4.7 vs 6.4 +/- .7 d). Days to first estrus after treatment did not differ between groups for parity-three and older sows, and percentage anestrus was not different between treatments for parity-two and older sows. The herd X treatment interaction was significant for percentage recycled (percentage of successfully mated sows that returned to estrus), subsequent farrowing rate, and subsequent number of pigs born dead. Number of pigs born alive was lower for sows treated with P.G. 600 than for control sows (10.55 vs 10.10 +/- .18; P less than .02). In summary, treatment of sows weaned in the summer and fall with P.G. 600 had decreased days to postweaning estrus in parity-one and -two sows and reduced frequency of postweaning anestrus in primiparous sows.

032 Use of Triptorelin Acetate for Inducing Ovulation and Facilitating Fixed Time Artificial Insemination of Sows Weaned on Small-Scale and Niche Market Pig Farms

“…600 increased subsequent litter size. These findings conflict with previous reports from Bates et al (1991) who found that treatment with P.G. 600 did not change farrowing percentage in six out of eight herds that were studied.…”

“…These findings are similar to those found in a study by Bates et al (1991) in which the use of P.G. 600 for first and second litter sows during periods of seasonal anestrus decreased days to estrus after weaning.…”

“…600 did not change farrowing percentage in six out of eight herds that were studied. Bates et al (1991) conducted their study during summer months when farrowing rates are lower than for sows weaned in the fall and winter (Koketsu et al, 1997). This could explain the differences of farrowing rates as sows weaned in the fall and winter may be able to respond more effectively to P.G.…”

“…Use of P.G. 600 for this purpose has proven effective even in months when ambient temperatures can delay the onset of estrus and ovulation (Bates et al, 1991;Bates et al, 2000). Additionally, found that administering P.G.…”

“…600® (Merck Animal Health, Inc., De Sota, KS) is a combination of 400 IU of equine chorionic gonadotropin (eCG) and 200 IU of human chorionic gonadotropin (hCG) administered to sows at weaning and to prepubertal gilts. Its use has resulted in accelerated onset of estrus and ovulation in weaned sows (Estienne and Hartsock, 1998) even in months when high ambient temperatures can delay the onset of estrus and ovulation (Bates et al, 1991;Bates et al, 2000). OvuGel® (JBS Animal Health, LLC; Sheridan, IN) is a synthetic gonadotropin releasing hormone (GnRH) agonist in the form of triptorelin acetate used to facilitate a single fixed time artificial insemination (FTAI) protocol by inducing ovulation.…”