Relationship between carcass traits and phenotypic residual feed intake, breed composition, temperament, and ELISA scores for paratuberculosis in an Angus-Brahman multibreed herd.

Authors: ELZO, M - UNIVERSITY OF FLORIDA; JOHNSON, D - UNIVERSITY OF FLORIDA; Riley, David; HANSEN, G - N. CAROLINA ST. UNIV.; MYER, R - N. FL. RES. & EDU. CTR.; RAE, D - UNIVERSITY OF FLORIDA; WASDIN, J - UNIVERSITY OF FLORIDA; DRIVER, J - UNIVERSITY OF FLORIDA

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 2/7/2008
Publication Date: 7/11/2008
Citation: Elzo, M.A., Riley, D.G., Hansen, G.R., Johnson, D.D., Myer, R.O., Rae, D.O., Wasdin, J.G., Driver, J.D. 2008. Relationship between carcass traits and phenotypic residual feed intake, breed composition, temperament, and ELISA scores for paratuberculosis in an Angus-Brahman multibreed herd [abstract]. Journal of Animal Science Supplement. 86(1):205.

Interpretive Summary:

Technical Abstract: Identification of factors that permit animals to grow quickly and efficiently, and have desirable carcass characteristics remains a primary goal in beef production. The objective was to evaluate the relationship between 7 carcass traits and breed group (Angus (A), Brahman (B), Brangus, 3/4 A 1/4 B, 1/2 A 1/2 B, and 1/4 A 3/4 B), residual feed intake (RFI) group (high: RFI > mean + 0.5 SD; medium: RFI between mean ± 0.5 SD; low: RFI < mean - 0.5 SD), chute temperament score (CS), exit velocity (EV), and dam ELISA score for paratuberculosis (ES) in 84 steers ranging from 100% A to 100% B. Carcass traits were hot carcass weight (HCW), longissimus muscle area (LMA), fat thickness (FT), kidney, pelvic, and heart fat (KPH), marbling score (MS), Warner-Bratzler shear force (SF), and tenderness score (TS). Records of ES were taken preweaning, and CS, EV, and RFI (actual minus expected feed intake) were obtained post-weaning during a 70-d feeding trial at a GrowSafe automated feeding facility. Subsequently, animals were sent to a South Texas feedlot, and commercially slaughtered at approximately 14 mm of FT. Carcass traits were collected at the slaughter facility, and SF and TS were obtained at the Florida Meat Processing Lab. Traits were analyzed using mixed models. Fixed effects were pen, RFI group, age of dam, age of calf, B fraction of calf, calf heterozygosity, mean CS, mean EV, and ES. Random effects were sire and residual. Brahman had lighter HCW (P < 0.05), smaller LMA (P < 0.001), lower MS (P < 0.02), higher SF (P < 0.03), and lower TS (P < 0.001) than Angus. High KPH was associated with high mean EV (P < 0.03). Mean CS, RFI group, and ES were non-significant for all carcass traits.