ewe lambs, photoperiod, reproduction
Previous work at SDSU and numerous other locations report poor success when mating ewe lambs to lamb for their first time in the fall. This is true regardless of whether they are born the previous fall (7 to 8 months of age at exposure) or the previous spring (12 to 13 months of age at exposure). It appears that the triggering factor is a shift in the daily period of time they are exposed to light versus dark.
Under natural conditions during the spring (April-May), day length is increasing which inhibits cyclic activity. It was hypothesized that, if the day length is extended artificially prior to the desired breeding season and allowed to return to a natural shorter day, cyclic activity might be improved. This study was initiated to evaluate the effect of an artificially extended photoperiod in mid winter on reproductive performance of April-born ewe lambs exposed at 12 to 13 months of age.
Number of Pages
South Dakota State University
Copyright © 1995 South Dakota State University
Slyter, A. L.; Anderson, G.; Hanson, D.; and Read, Bruce, "Effect of Extended Light on Growth and Reproductive Performance of Ewe Lambs: Progress Report" (1995). South Dakota Sheep Field Day Proceedings and Research Reports, 1995. 3.