The relationship of teat number to seven measures of female reproduction was evaluated in the University of Nebraska Gene Pool population. Teat number was recorded for 7,513 pigs, ovulation rate for 2,794 gilts and litter size and weight at birth and weaning (42 days) for 789 gilts. Paternal half-sib and full-sib analyses were used to estimate heritabilities for each trait and to estimate the g...

Ovulation rate is an important phenotypic trait that is a critical component of litter size in pigs. Despite being moderately heritable in pigs, selection for increased ovulation rate is difficult because it is difficult to measure and is a sex-limited trait. A QTL for ovulation rate residing on the p-terminal end of pig chromosome 8 has been detected in a Meishan-cross resource population. Com...

The rate of ovulation of the domestic fowl may be expressed by the equation of an autocatalytic chemical reaction. This is not surprising in view of the fact that the rate of growth may also be expressed by such an equation, and that the rate of ovulation is probably an index of the growth of the eggs. This brings the phenomenon of ovulation in the hen under the general subject of growth, and s...

We previously reported that ovulation rate, but not pregnancy rate or litter size at d 30 post-mating, was enhanced by gonadotropin treatment (P.G. 600; Intervet America Inc., Millsboro, DE) in gilts fed a progestin (Regu-mate; Intervet America Inc.) compared with gilts receiving progestin alone. We hypothesized that P.G. 600 altered the timing of ovulation, therefore mating gilts 12 and 24 h a...

Half-sib daughters sired by a bull believed to be a carrier of a major gene for high ovulation rate were evaluated for ovulation rate and genotyped in an effort to both test the hypothesis of segregation of a major gene and to map the gene's location. A total of 131 daughters were produced over four consecutive years at a University of Wisconsin-Madison research farm. All were evaluated for ovu...

Inhibin is released during late prophase by suppressing the FSH secretion without affecting LH secretion. Immunization against inhibin will increase FSH synthesis leading to ovulation rate. As both immunization against inhibin and FSH injection could increase ovulation rate, therefore, an interaction of both treatment should act synergically or addively. Immunized group (n=10) were immunized wi...

Results: Average ovulation rate for all sows in the study was 14.58 +/0.32 ova and for the parity-two sows was 14.0 +/0.23 ova. The mean weaning-to-breeding interval for the parity-two sows was 5.87 +/0.14 days. Ovulation rate in the parity-two sows increased by 0.25 +/0.09 ova as the number of piglets weaned in the sow’s previous parity increased by one piglet (P <.05). The parity-two sow’s po...

Ovulation rate in gilts maintained under continuous light (daylight plus 118 to 130 lux of artificial light at night) for a complete oestrous cycle during the spring months was not significantly different from that in gilts maintained under normal daylight. Average ovulation rates were 13\m=.\4for controls and 13\m=.\1for treated gilts. A significant (P<0\m=.\01)difference in ovulation rate was...

Selection for litter size may result in an increase in uterine crowding due to a faster increase in ovulation rate than in litter size. Increased ovulation rate does not result in a proportionally increased number of piglets born alive. In this study, the effect of ovulation rate on vitality characteristics of fetal-placental units at d 40 of pregnancy was investigated. For this, 43 Large White...