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 quantitative 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 were first trained for semen collection (twice a week for 2 consecutive wk), and then divided into five groups (seven males each), each group being collected either once every 2 wk, once every week, twice every week, three times every week (each for 4 wk) or five to seven times per week (each for 2 wk). Volume, sperm concentration, and sperm number per ejaculate were determined for each ejaculate. No significant differences between groups were observed for sperm concentration (P > 0.05), but males collected once every 2 wk, 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 frequencies (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 differences between groups were observed for body weight (25.8 +/- 1.7 kg), testicular weight (51.5 +/- 2.2 g), or total number of elongated spermatids per male (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 ejaculates (volume, sperm concentration, and sperm per ejaculate), sperm viability between groups was also tested using the Sybr14/PI fluorescence test. Our results demonstrated: 1) a favorable effect of high semen collection frequencies on sperm viability and, 2) a marked decline in sperm viability during 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 reproductive capacity more efficiently when semen collection is undertaken at a high rather than a low frequency.