Photoperiodic disruption of photorefractoriness in the ewe.

  title={Photoperiodic disruption of photorefractoriness in the ewe.},
  author={Gary L Jackson and Mark Gibson and David E. Kuehl},
  journal={Biology of reproduction},
  volume={38 1},
The primary objective of this study was to determine the duration of exposure to a long-day or short-day photoperiod required to disrupt photorefractoriness to short-day and long-day photoperiods, respectively. In Experiment 1, 4 groups of Suffolk breed ewes--designated B1, B2, B3, and B4--were placed in photochambers one day before the winter solstice, exposed to a 16L:8D photoperiod for 0, 30, 60, or 90 days, and then exposed to a 10L:14D photoperiod until the time of the summer solstice… CONTINUE READING