The effect of varicocele on semen quality in boars exposed to heat stress.

Semen quality has a dramatic impact on reproductive efficiency in the swine industry, influencing both conception rate and litter size. The objective of this study was to assess whether the presence of varicocele hinders semen quality in both thermoneutral and heat stress (HS) conditions. At approximately 6 mo of age, ultrasonography was used to measure left and right pampiniform plexus area in order to detect varicocele in maternal line boars at the University of Nebraska-Lincoln.

Genetic relationships among sperm quality traits of Duroc boars collected during the summer season.

The goals of the study were to estimate the heritability and repeatability of boar sperm quality traits during the summer season, estimate phenotypic and genetic correlations between sperm quality traits, and assess the effect of these traits on total number born (TNB). Semen samples were collected and individually processed from Duroc boars (n = 363) from May through October 2017. Single sire litter information was available for 121 of the boars.

The heritability of pampiniform plexus vessel size and varicocoele in boars.

Ultrasonography was used to capture a coronal-sagittal image of the veins of the pampiniform plexus (PP) and the testicular artery of 327 maternal-line boars at approximately 6 months of age at the University of Nebraska-Lincoln. Varicocoele was diagnosed by two methods. Method 1 diagnosed varicocoele when the average vessel area on one side of the scrotum was 1.

Longitudinal analysis of weight showed little relationship with age at puberty in gilts.

Continued selection for increased gilt body weight could negatively impact selection for age at puberty (AP) in gilts. The purpose of this study was to compare the genetic potential for growth to that for reducing age of puberty in swine. Females utilized (n = 1,079) were produced over a 6-yr period from a population developed to determine the impact of energy restrictions and genetic influences on sow development and longevity.