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Daily Activity Measures And Milk Yield Immediately Before And After A Fertile Estrus, J. S. Stevenson
Daily Activity Measures And Milk Yield Immediately Before And After A Fertile Estrus, J. S. Stevenson
Kansas Agricultural Experiment Station Research Reports
The objective was to characterize changes in milk yield and other physical measures during a 7-day periestrual period encompassing estrus (day 0) and insemination. Lactating dairy cows milked thrice daily were fitted with CowManager SensOor ear tags capable of assessing real time eating, rumination, resting, high activity (estrus), ear-surface temperature, and providing heat alerts. Daily milk was unchanged during the periestrual period. Daily ear-surface temperature was greater during days 1 to 3 compared with day 0. Daily rumination and resting times reached nadirs on day 0, with decreases occurring 48 hours before estrus. Both rumination and resting times increased by …
Resynchronizing Returns To Estrus After A Prior Insemination, J. S. Stevenson, J. A. Sauls-Hiesterman
Resynchronizing Returns To Estrus After A Prior Insemination, J. S. Stevenson, J. A. Sauls-Hiesterman
Kansas Agricultural Experiment Station Research Reports
In two experiments, GnRH and a progesterone insert (CIDR) were applied to cows after insemination (day 0) to reprogram or synchronize the returning estrus of cows that failed to conceive to that previous insemination. The combination of GnRH (day 14) and a CIDR insert (days 17 to 24) in experiment 1 (n = 347 cows) increased the proportion of nonpregnant cows returning to estrus before pregnancy diagnosis on day 32 by 7.4 percentage points, increased the synchrony of their return by 24.4 percentage points, but delayed that return by 2.3 days compared with controls. In experiment 2 (n = 863 …