Location: Nutrition, Growth and PhysiologyTitle: Production performance of cows raised with different postweaning growth patterns
Submitted to: Translational Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2021
Publication Date: 7/1/2021
Citation: Freetly, H.C., Cushman, R.A., Bennett, G.L. 2021. Production performance of cows raised with different postweaning growth patterns. Translational Animal Science. 5(3):1-7. https://doi.org/10.1093/tas/txab031.
Interpretive Summary: Reducing the number of cows replaced annually decrease the cost of beef production. This study demonstrates that using nutrition to alter the growth pattern of heifers near puberty can increase the total weight of calf weaned over six years, and that these findings are consistent over a wide range of cattle of different genetic types. There is also an indication that altered growth patterns can change the age that a cow is removed from the herd. This study demonstrated the importance of proper nutritional management at young ages on subsequent lifetime cow performance.
Technical Abstract: The period of heifer development is a relatively small fraction of a cow’s life; however, her pattern of growth may have permanent effects on her productivity as a cow. We hypothesized that altering the growth pattern during the peri-pubertal period would increase life-time productivity across genetic types of Bos taurus cows. The objective was to determine the stayability, calf production, and weight of calf weaned across six calf crops. Heifers (n = 685) were placed on one of two developmental programs at 256 ± 1 d of age. Control heifers received a diet that provided 228 kcal ME·(BW, kg)-0.75 daily, and Stair-Step heifers were allocated 157 kcal ME·(BW, kg)-0.75 daily for 84 or 85 d, and then the daily allocation was increased to 277 kcal ME·(BW, kg)-0.75. Stair-Step heifers (0.33 ± 0.02 kg/d) had a lower ADG than Control heifers (0.78 ± 0.02 kg/d; P < 0.001) during Period 1, and Stair-Step heifers (0.93 ± 0.03 kg/d) had a greater ADG than Controls (0.70 ± 0.03 kg/d; P < 0.001) during Period 2. There were no treatment (P = 0.28) or breed type differences (P = 0.42) for the proportion of cows weaning a calf; however, the proportion of cows weaning a calf decreased with cow age (P < 0.001). Calves from Stair-Step dams had heavier weaning weights (193 ± 1 kg) compared to Control calves (191 ± 1 kg; P = 0.007). There was not a treatment (P = 0.25) or breed type differences in cumulative BW weaned (P = 0.59). A diverse genetic population of cattle within Bos taurus was tested and responses in calf production did not differ between stair-step growth pattern and a more constant nonobese growth pattern.