IDENTIFICATION AND UTILIZATION OF MECHANISMS RESPONSIBLE FOR THE ADAPTATION OF CATTLE TO STRESSORS OF THE SUBTROPICS
Title: Effect of breed composition, temperament, and ELISA scores for paratuberculosis on phenotypic residual feed intake and growth in an Angus-Brahman multibreed herd.
| Elzo, M - UNIVERSITY OF FLORIDA |
| Riley, David |
| Hansen, G - NORTH CAROLINA ST. UNIV. |
| Johnson, D - UNIVERSITY OF FLORIDA |
| Myer, R - N. FL. RES.& EDU.CTR. |
| Rae, D - UNIVERSITY OF FLORIDA |
| Wasdin, J - UNIVERSITY OF FLORIDA |
| Driver, J - UNIVERSITY OF FLORIDA |
Submitted to: American Society of Animal Science Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 7, 2008
Publication Date: July 11, 2008
Citation: Elzo, M.A., Riley, D.G., Hansen, G.R., Johnson, D.D., Myer, R.O., Rae, D.O., Wasdin, J.R., Driver, J.D. 2008. Effect of breed composition, temperament, and ELISA scores for paratuberculosis on phenotypic residual feed intake and growth in an Angus-Brahman multibreed herd [absrtact]. American Society of Animal Science Proceedings.J. 86(1):204.
Breed composition, temperament, and subclinical paratuberculosis in dams are factors that may have an effect on growth and feed efficiency in beef cattle. The objective of this research was to assess the effect of breed group (Angus (A), Brahman (B), Brangus, 3/4 A 1/4 B, 1/2 A ½ B, and 1/4 A 3/4 B), chute score (CS), exit velocity (EV), and ELISA scores for paratuberculosis in dams of calves (ES) on 5 feed intake and growth traits in bulls, heifers, and steers (n = 461) ranging from 100% Angus to 100% Brahman. Traits were post-weaning phenotypic residual feed intake (RFI), daily feed intake (DFI), feed conversion ratio (FCR), average daily gain (ADG), and weight gain (WG). Calves were assigned to pens in a GrowSafe automated feeding facility by sire group and sex, and fed a concentrate diet (cottonseed hulls, corn, molasses, and a protein, vitamin, and mineral supplement). The pre-trial adjustment period lasted 21 d. Individual daily feed intake was collected during the 70 d feeding trial. Weights and temperament traits were recorded every 2 weeks. Phenotypic RFI was computed as the difference between actual and expected feed intakes. Traits were analyzed using mixed models. Fixed effects were contemporary group (year-pen), RFI group (except when trait was RFI), age of dam, sex of calf, age of calf, B fraction of calf, heterozygosity of calf, mean CS, mean EV, ES, and residual. The RFI groups were high (RFI > mean + 0.5 SD), medium (RFI between mean ± 0.5 SD), and low (RFI < mean - 0.5 SD; SD = 5.4 kg). Random effects were sire and residual. Brahman had lower (P < 0.01) RFI, DFI, and WG than Angus. Calves with higher mean EV had lower (P < 0.04) DFI and ADG than calves with lower mean EV. Neither mean CS nor ES were important for RFI, DFI, FC, ADG, and WG.