Author
Moyle, Jonathan | |
YOHO, DOUGLAS - University Of Arkansas | |
WHIPPLE, SARAH - University Of Arkansas | |
Donoghue, Ann - Annie | |
BRAMWELL, RICHARD - University Of Arkansas |
Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/5/2011 Publication Date: 3/1/2012 Citation: Moyle, J.R., Yoho, D.E., Whipple, S.M., Donoghue, A.M., Bramwell, R.K. 2012. Sperm production and testicular development of broiler breeder males reared on shortened growth cycles. Journal of Applied Poultry Research. 21:88-94. Interpretive Summary: Feed restriction is an important tool used in the rearing of broiler breeders to control growth and maintain body weight. Feed restriction during the growing phase typically provides 60-80% less than what birds would consume if provided feed ad libitum, resulting in a perceived animal welfare issue. Because males are typically more rigorously feed restricted than females, this is thought to be especially stressful to the growing cockerels. During this time, the reproductive systems of the males are going through formative stages and improper management can have lifelong effects on their reproductive performance. Therefore, the objective of this study was to raise males under feed management programs that would require less severe feed restriction while still rearing replacement breeder males to the recommended target body weight of 3.060kg at 24, 21, 18, 15 and 12 wks of age, respectively. Males were placed at three wk intervals so that all males were light stimulated on the same calendar date and at the same time and body weight but at different ages. A total of five treatment groups were used, based on age of the male at light simulation. All males were reared in the same light controlled house at the University of Arkansas Research Farm. Males were light stimulated and testes development, semen analysis, fertility and mating activity were recorded for each group of males. To measure semen production, males were housed in individual cages, with 24 males from each treatment group tested. Results found that males lit at 18 wks of age had the highest semen volume (0.46ml) followed by males lit at 24 (0.31ml), 15 (0.29ml), 21(0.27ml) and 12 wks (0.27ml), respectively. Sperm count per ejaculate was highest for the males lit at 18 wks of age followed by males lit at 21, 24, 15, and 12 wks, respectively. Males that were 21 wks or older at the time of lighting responded quicker to light stimulation than did younger males. Technical Abstract: Feed restriction is an important tool used in the rearing of broiler breeders to control growth and maintain body weight. Feed restriction during the growing phase typically provides 60-80% less than what birds would consume if provided feed ad libitum, resulting in a perceived animal welfare issue. Because males are typically more rigorously feed restricted than females, this is thought to be especially stressful to the growing cockerels. During this time, the reproductive systems of the males are going through formative stages and improper management can have lifelong effects on their reproductive performance. Therefore, the objective of this study was to raise males under feed management programs that would require less severe feed restriction while still rearing replacement breeder males to the recommended target body weight of 3.060kg at 24, 21, 18, 15 and 12 wks of age, respectively. Males were placed at three wk intervals so that all males were light stimulated on the same calendar date and at the same time and body weight but at different ages. A total of five treatment groups were used, based on age of the male at light simulation. All males were reared in the same light controlled house at the University of Arkansas Research Farm. Males were light stimulated and testes development, semen analysis, fertility and mating activity were recorded for each group of males. To measure semen production, males were housed in individual cages, with 24 males from each treatment group tested. Results found that males lit at 18 wks of age had the highest semen volume (0.46ml) followed by males lit at 24 (0.31ml), 15 (0.29ml), 21(0.27ml) and 12 wks (0.27ml), respectively. Sperm count per ejaculate was highest for the males lit at 18 wks of age followed by males lit at 21, 24, 15, and 12 wks, respectively. Males that were 21 wks or older at the time of lighting responded quicker to light stimulation than did younger males. |