Effects of Body Condition on Reproductive Performance of Range Beef Cows

Simnental-Angus crossbred cows were fed differing Levels of nutrition from December to May in each of 3 years to create a wide range in cow body condition or fleshiness at the beginning of the calving season (beginning mid-March) and when turned to summer pasture (early May) 1 month prior to the beginning of the breeding season (early June). Cows that were fleshier in March, May or June cycled earlier. Cows that were fleshier at the beginning of the breeding season calved earlier the following years. For cows that calved Late in the calving season, body condition prior to calving, in early May and at the beginning of the breeding season were all closely related to when they calved the following year. Cows that calved early in the calving season were able to withstand more nutritional stress, as body condition prior to calving and in May had less of an effect on calving interval than did body condition at the beginning of the breeding season