Reproductive longevity, or how long a cow remains reproductively capable, is one of the most important influences on herd profitability. Here, a herd of B. indicus-B. taurus crossbred cows were used to characterize the effect of the first calving season period on measures of future cow productivity, and the influence of the cow’s own birth period on her potential for future productivity. There was a clear advantage to heifers calving within the first 21 days of the first calving season. These females were more likely to meet reproductive longevity benchmarks, had significantly greater average lifetime calf crop weaned, and their first calves were significantly heavier at weaning. Earlier-born cows had greater heifer pregnancy rates than later-born cows.
