Effects of frequency of semen collection on quantitative and qualitative characteristics of semen in turkey breeder males

The effects of various frequencies of semen collection on several quantitat ive and qualitative semen characteristics were investigated in adult turkey breeder males (30 to 40 wk of age). In Experiment 1, a total of 35 males w ere first trained for semen collection (twice a week for 2 consecutive wk), and then divided into five groups (seven males each), each group being col lected either once every 2 wk, once every week, twice every week, three tim es every week teach for 4 wk) or five to seven times per week teach for 2 w k). Volume, sperm concentration and sperm number per ejaculate were determi ned for each ejaculate. No significant differences between groups were obse rved for sperm concentration (P > 0.05), but males collected once every 2 w k, once per week, or twice per week had larger volumes than males collected at higher frequencies (P < 0.05). Thus there were significant differences for sperm number per ejaculate between groups (P < 0.05). Also, daily semen output (DSO) was markedly increased in males collected at the highest freq uencies (e.g., DSO = 0.62 x 10(9) and 1.93 x 10(9) in males collected once and five times per week). Finally, in euthanatized birds (36 wk) no differe nces between groups were observed for body weight (25.8 +/- 1.7 kg), testic ular weight (51.5 +/- 2.2 g), or total number of elongated spermatids per m ale (14.0 +/- 0.8 x 10(9)). In Experiment 2, 35 males were distributed into groups and collected under the same conditions as in Experiment 1. Besides quantitative analyses of ej aculates (volume, sperm concentration, and sperm per ejaculate), sperm viab ility between groups was also tested using the Sybr14/PI fluorescence test. Our results demonstrated: 1) a favorable effect of high semen collection f requencies on sperm viability and, 2) a marked decline in sperm viability d uring the first 2 d following a 2-d resting period in males collected five times a week. We concluded that turkey males express their optimal reproduc tive capacity more efficiently when semen collection is undertaken at a hig h rather than a low frequency.