Androstenone and testosterone levels and testicular morphology of Duroc boars related to estimated breeding value for androstenone

Androstenone and testosterone levels in Duroc boars with an estimated breeding value for androstenone (EBVandrostenone) were followed in the period from birth to sexual maturity. The breeding value for androstenone had been estimated based on androstenone levels in 1202 Duroc boars at an age of 24 weeks. Testosterone and androstenone levels in plasma were recorded in 19 boars at 1 week of age and in their 15 respective litter-siblings at 3 weeks of age. Between 12 and 27 weeks of age, plasma levels were recorded weekly in a third set of 16 litter-siblings. In the last group, histomorphology was performed at 12, 16, 20, and 27 weeks of age to determine sexual maturity status. The EBVandrostenone was positively related to plasma androstenone in animals 12 to 27 weeks of age and to plasma testosterone levels in 1- and 3-week-old animals. The EBVandrostenone was not related to testis morphology. The concentration of fat androstenone was positively correlated to the percentage of immature seminiferous tubules and negatively correlated to the percentage of mature seminiferous tubules at 20 weeks. Testosterone in plasma showed no relationship with testis morphology. Most individuals reached puberty at 20 weeks of age, which indicates that Duroc mature later than crossbred boars. The results indicated that breeding value based on the single trait boar taint parameter EBVandrostenone was not related to testicular development.