Semen traits in Cornish roosters during the process of physiological ageing

In this paper, we determined the evolution of ejaculate volume, sperm concentration, motility and viability along with the evolution of the activity of some enzymes (TGO, alkaline phosphatase, ATPase and lactic dehydrogenase) in seminal plasma of Cornish roosters at 30, 42, 57 and 63 weeks of age. The monitored parameters showed a specific evolution that characterizes the physiological ageing process in Cornish roosters. Thus, the volume of ejaculate showed a significant decrease (P = 0.011) from 0.39 to 0.32 microliters. The number of sperm per ejaculate decreased from 0.86 to 0.29x109 (P = 0.002). Motility decreased from 69% to 41% (P = 0.001) and sperm viability decreased from 89 to 74% (P = 0.00). The percentage of abnormal spermatozoa decreased not significantly, from 96 to 94%, some types of abnormalities increasing and others decreasing in frequency during the monitoring period. The activity of the monitored enzymes characterized the decrease of the anaerobic metabolism of spermatozoa and the increase of the membrane permeability of the spermatozoa in the physiological ageing process