High Ejaculation Frequency Enhances Semen Production in Taiwan Country Chickens

Abstract

The objective of this study were to investigate the effect of ejaculation frequency on semen characteristics and to establish a method for quick assessment of sperm concentration in TCC using packed cell volume (PCV) as the parameter (Trial 1). Eighty senior roosters, averaging 61 wk-old, were used and the sperm concentrations were determined using a hemacytometer. The PCV value was measured in a capillary (0.75 mm in inner diameter) by centrifugation. A simple linear regression analysis suggested that the sperm concentrations were significantly correlated with PCV values (r=0.62, p<0.001). Trial 2 was conducted to determine the optimal ejaculation frequency of TCC roosters in a weekly semen collection program. The male birds were subjected to 1, 2, 3 or 6 ejaculations per week for four consecutive weeks and semen characteristics including ejaculation volume (EV, mL), sperm motility (%), PCV (%), sperm concentration (ESC, ×10 9 /mL), weekly sperm production (WSP, ×10 9 /wk) and average motile sperm numbers (AMSN, ×10 9 /ejac) were determined. Average EV was greater in the group with 3 ejac/wk than with only 1 ejac/wk in weeks 1 and 3 of the collection period. WSP increased with ejaculation frequency during the first 3 weeks of collection (p<0.05). Sperm motility was better in the birds with 6 ejac/wk than in single ejaculation group for the first 2 wk and no significant differences were found for the last 2 wk of study. In contrast, the PCV value showed a trend of reduction for the first 2 wks in the 6 ejac/wk group. Surprisingly, no significant differences were detected in the AMSN among treatment groups. The weekly motile sperm production (WMSP) increased with ejaculation frequency. Based on our observation, PCV values could be used for a quick estimation of sperm concentration and an intensive semen collection program enhanced weekly sperm production in TCC roosters.

Sexually extravagant males age more rapidly

“…Ejaculate quality may also be influenced by collection frequency, which can result in a depletion or ageing of sperm reserves (e.g. Fan et al. 2004).…”

“…Ejaculate quality may also be influenced by collection frequency, which can result in a depletion or ageing of sperm reserves (e.g. Fan et al 2004). Thus, the Ônumber of ejaculates collected to dateÕ in a given year and the Ôdays since last ejaculationÕ, were also considered in models to statistically control for depletion or ageing effects if present.…”

Influence of Semen Collection Frequency and Seasonal Variations on Fresh and Frozen Semen Quality in Thai Native Roosters

“…Twice-aweek collection theoretically results in maximal output for broiler breeders but not for all roosters [9]. Six collections per week in Taiwanese chickens enhanced the total sperm and motile sperm production in a week [10]. In contrast, more than three rounds of collections per week in turkeys decreased the semen volume [11].…”