Opposite variations of two epididymal components and blood plasma testosterone in two breeds of rams.
1. Testicular volume (T Vol), blood plasma testosterone (T) concentration, seminal plasma alpha-glucosidase (alpha-G) specific activity, L-carnitine (L-C) concentration as well as semen characteristics were compared in eight Finnish Landrace (F) and eight Suffolk (S) rams throughout 21 months. 2. Only T Vol and T exhibited a typical seasonal variation in both breeds, whereas L-C, alpha-G and live sperm output presented a seasonal profile only in S rams. 3. L-C and alpha-G variations were opposite to those of T in S rams, while they fluctuated in F rams throughout the entire experiment, as did live sperm output. 4. Only the number of ejaculates and T were significantly higher in F rams (3.50 +/- 0.08 in 5 min and 7.62 +/- 0.40 ng/ml) than in S rams (2.30 +/- 0.05 in 5 min and 5.5 +/- 0.30 ng/ml); these two characteristics might therefore be considered as two indexes of sexual activity in rams. 5. By contrast, among all characteristics measured, only alpha-G was significantly higher in S rams than in F rams (1.33 +/- 0.04 vs 0.77 +/- 0.03 mU/mg proteins); this result, as well as seasonal alpha-G profile present in only S rams, allowed us to conclude that alpha-G might be considered as an additional index of seasonal reproduction in rams.
Department of Didactics, Université Laval, Ste-Foy, Quebec, Canada.
J
J
Besançon
P
P
Demers
J P
JP
Lemay
R R
RR
Tremblay
D000818:Animals; D002331:Carnitine / Q000378:metabolism; D004822:Epididymis / Q000378:metabolism*; D008297:Male; D010507:Periodicity; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D012661:Semen / Q000166:cytology; D012756:Sheep / Q000502:physiology*; D013045:Species Specificity; D013737:Testis / Q000033:anatomy & histology; D013739:Testosterone / Q000097:blood*; D000520:alpha-Glucosidases / Q000378:metabolism
D013739:Testosterone; D000520:alpha-Glucosidases; D002331:Carnitine