Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract only
Publication Acceptance Date: 5/15/2006
Publication Date: 6/15/2006
Citation: Waterman, R.C., Geary, T.W., Paterson, J.A., Ansotegui, R.P., Lipsey, R.J. 2006. Performance of early weaned (~ 80 d) vs normal weaned (~ 215 day) calves in the Northern Great Plains. Journal of Animal Science Supplement 84(Suppl. 2):56. Interpretive Summary:
Technical Abstract: Early weaning, in spring calving production systems, has intrigued many producers to consider this alternative management practice especially during extended droughts and for young developing cows. The objective of the present study was to evaluate performance of early-weaned calves (approximately 80 d of age) and cost of production for two rations that were isonitrogenous and isocaloric but differing in ruminal degradable and undegradable protein (RDP and RUP respectively) compared to normal weaned calves (approximately 215 d of age). Three hundred seventy-three Simmental × Angus calves (108.2 ± 1.07 kg) were randomly allocated to one of three treatments: 1) Weaned and fed a 33:67 forage:concentrate diet containing 15.4 % CP (37 % RUP) and 1.57 Mcal of NEm/ kg (EW1); 2) Weaned and fed a 33:67 forage:concentrate diet containing 15.4 % CP (43 % RUP) and 1.62 Mcal of NEm/kg (EW2); or 3) suckled and grazed range forage until normal weaning (NW). Calf weight and age were similar at time of early weaning for all treatments (P > 0.10). At the time of normal weaning body weight was heavier (P > 0.01) for EW vs. NW steers and a tendency for EW2 steers to be heavier (P = 0.15) than EW1 steers. Similarly, EW heifers were heavier (P < 0.01) when compared to NW heifers; however, body weights at normal weaning did not differ between EW treatments (P = 0.62). Total cost'calf-1' d -1 was greater (P < 0.01) for EW treatments than NW; furthermore, calves receiving EW2 had a higher cost'calf-1' d -1 than calves receiving EW1. Value of calves at time of normal weaning were greater (P < 0.01) for all EW treatments when compared to NW calves ($816.55, $824.82, and $779.71, for EW1, EW2, and NW steers, respectively and $714.51, $718.75 and $686.55, for EW1, EW2, and NW heifers, respectively). Calf value did not differ between EW treatments (P > 0.10). This study demonstrates that early weaning may be an effective management option when forage is limited or removal of production pressures for young cows is desired; however, the additional calf value by itself was not enough to overcome cost of EW diets.