Kc. Curry et al., SELECTION FOR REPRODUCTIVE RATE IN FEMALES AND FEEDING REGIMEN ON TESTICULAR TRAITS AND EPIDIDYMAL SPERM RESERVES IN RAMBOUILLET RAMS, Small ruminant research, 11(3), 1993, pp. 257-265
The objectives of this study were to evaluate whether selection for or
against reproductive rate in Rambouillet ewes altered testicular and
epididymal characteristics in male offspring, and to examine the inter
action of post-weaning feeding regimen and selection line on body weig
hts and testicular and epididymal characteristics. Rams were from line
s selected for either low or high reproductive rate and from a random-
bred control line. At 10 months of age, rams from each line were assig
ned to one of two feeding regimens, (i) placed on pasture and fed gras
s hay for duration of experiment (normal plane; NP) or (ii) continued
on a pelleted diet for 7 months then combined with NP rams for the dur
ation of experiment (high plane; HP). Testicular and epididymal traits
and epididymal sperm reserves were evaluated at the end of the feedin
g period. Rams on the HP gained weight more rapidly (P<0.05) and were
heavier (P<0.05) at the end of the experiment than rams on the NP. Sel
ection line or interactions of line with feeding regimen did not affec
t (P>0.10) body weights. Selection line, feeding regimen or their inte
ractions did not affect (P>0.10) scrotal circumference, testicular or
epididymal characteristics or epididymal sperm reserves, except that t
here was a line by feeding regimen interaction (P<0.05) for caput/corp
us epididymal weight. These results indicate that selecting for low or
high reproductive rate in Rambouillet ewes or feeding a high plane of
nutrition after weaning did not alter testicular or epididymal charac
teristics of mature male offspring.