Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/27/2004
Publication Date: 2/5/2005
Citation: Jenkins, T.G., Ferrell, C.L. 2005. Cow efficiency during the preweaning period of tropically adapted cattle [abstract]. Journal of Animal Science 83(Suppl. 2)29. Paper No. 112.
Technical Abstract: Measures of productivity of mature tropically adapted F1 cows produced by mating Angus and Hereford, Brahman (Cycle III and VI) and Sahiwal (Cycle III), Nellore (Cycle IV), and Boran and Tuli (Cycle V) sires by AI or natural service to Angus and Hereford cows (AH). Comparisons were relative to Angus/Hereford F1s. Cycle III cow's daily rations were adjusted biweekly to achieve weight stasis for a 126 d test period. For other Cycles, individual cows were randomly assigned to a diet at one of three feeding rates, 140, 180 or 240-kcal ME/weight**0.75 (Cycle IV) or 132, 189- kcal ME/weight**0.75 or ad libitum (Cycle V). Daily milk yields were recorded via weigh-suckle-weigh. Brahman and Sahiwal cows produced significantly more total lactation yield (TY), weight of calf weaned (WCW) and were more efficient (Eff, weight calf weaned/feed consumed by cow). These breed crosses exhibited 15.2% and 11.8% more TY, 18.8% and 13.1% more WCW and were 3.8% and 7.2% more Eff relative to AH cows (802 kg, 200 kg, 38.5 Eff). In Cycle IV, Nellore TY and WCW was greater (P < 0.05). Nellore crosses produced 4.8% more TY, 20% more WCW and were 14.2% more Eff at DMI for maximum weaning weight than AH (789 kg, 121 kg, 28 Eff). Cycle V mean TY for Brahman was greater (P < 0.05) than Tuli but neither differed (P > 0.10) from AH or Boran cross cows. Relative to AH (1686 kg), Brahman, Boran and Tuli produced 6.9% and 1.9% more and 9.1% less TY; respectively. WCW of Brahman and Boran was greater (P < 0.05) than Tuli or AH which did not differ (P > 0.10). Brahman, Boran and Tuli produced 25.0%, 19.2%, and 4.2% more WCW than AH (169.4 kg). Brahman and Boran Eff exceeded (P < 0.05) Tuli which was greater (P < 0.05) than AH. Relative to Angus/Hereford (72.6), Brahman, Boran and Tuli F1s were 45%, 35%, and 15%; respectively, more Eff. Tropically adapted F1 cows mated to B. taurus sires were more effective in converting food resources to weight of calf at weaning during the preweaning period during spring and summer months of a temperate climate.