The effect of cottonseed components on testicular development in pubescent rams

The effect of gossypol on testicular development in rams was examined using 2 experimental approaches. Trial I utilized direct ruminal deposition of gossypol acetic acid (GAA; 95% purity), whereas Trial II compared 2 types of dietary cottonseed, regular and glandless. For Trial I, 18 Polypay or Polypay x Dorset ram lambs, aged 4 to 6 mo, were surgically fitted with rumen cannulae. These 18 ram lambs were divided into groups of 6 which were given either 0, 2.2 or 6.6 mg of GAA/kg body weight daily via gelatin capsules directly into the rumen. All rams in Trial I were slaughtered after 4 or 8 w of treatment to allow recovery of their scrotal contents. The mean testicular weight for the group of rams given 6.6 mg GAA/kg/d was 8% (p less than .05) less than for the rams given 0 mg GAA/kg/d. The caudal epididymal sperm were examined microscopically for percentage of progressively motile sperm and flow cytometrically for mitochondrial function using rhodamine 123 (R123). Differences in sperm motility were not evident among the treatment groups, nor were differences detectable in the 2 major sperm populations, B and C, that were identified by flow cytometry. In Trial II, 21 Polypay and Polypay-Dorset ram lambs, aged 10 mo, were randomly assigned into 3 groups (n = 7) and fed either glandless fuzzy cottonseed (GFC), glandless flake cottonseed (GFL) or regular fuzzy cottonseed (RFC). All rams were fed for 5 w a total daily ration (TDR) equivalent to 3.5% of their body weight daily with 25% being cottonseed. After 8 w the scrotal contents were recovered by castration.(ABSTRACT TRUNCATED AT 250 WORDS)