Effects of Castration and Exogenous Estradiol or Testosterone on Limb Bone Growth and Some Performance Traits in Young Male Pigs

Abstract

A total of 57 male pigs were randomly allocated at I wk of age to one of four treatments: castrated and implanted with estradiol-170; castrated and implanted with testosterone; castrated and not implanted; not castrated and not implanted. The pigs were weaned at 3 wk of age and raised under conventional commercial conditions to 2, 4 or 6 mo of age. Within age group, treatment had no effect (P>0.05) on average daily gain, feed efficiency, backfat thickness or the growth coefficients of individual organs relative to body weight. Weights, lengths and circumferences of limb bones (humerus, scapula, tibio-fibula, patella, femur and pelvis) did not differ significantly among treatments within age groups. However, the radio-ulnae were thicker (P < 0.05) in boars than in the other three groups. No significant treatment differences in the rate of radiosulfate incorporation into the tibial or radial growth plates or on the rate of linear bone growth during the last 16-26 d of the study were detected. It is concluded that neither estradiol-17B nor testosterone therapy of young castrated male pigs is likely to influence their growth or bone development up to 6 mo of age.

Fate and occurrence of steroids in swine and dairy cattle farms with different farming scales and wastes disposal systems

“…Higher estimated daily excretion masses of synthetic androgens were found in cattle feces than in swine feces. This is consistent with a previous study by Chaudhary and Price (1987), in which they pointed out that some hormonal growth promoters are primarily used in cattle rather than in swine due to their little effect in swine growth. Most synthetic androgens detected in the feces samples were from exogenous usage, such as 17a-trenbolone, 17b-trenbolone (Khan et al, 2008), 17a-boldenone, 17b-boldenone, methyl testosterone and 4-hydroxy-androst-4-ene-17-dione, while some may come from endogenous source or transformation by other steroids.…”