The NDSU Dairy Research Center recently installed metal hallide lights to an intensity of approximately 30 foot candles. We also added an automated timer for 18 and six hours of light and darkness, respectively. We're in the process of collecting milk yield and intake data to document the impact of this investment. Sometimes a cow goes undetected in heat after she has been injected with prostaglandin to induce heat. Dr. Steve Milliken, a Lancaster County veterinarian, recently offered 10 possible reasons as posted on the Dairy-L list service.
Shot is given at the wrong stage of the cycle.
The corpus luteum is responsive to prostaglandin from about day seven to 17 after the previous heat. Poor footing in exercise area. Cows on smooth concrete surfaces show poor heats. Poor cow comfort, foot rot, hairy heal warts, laminitis or hooves in need of trimming all can keep a cow from displaying heat. Sex and the single cow.