24 research outputs found

    Correlations of visual scores, carcass traits, feed efficiency and retail product yield in Nellore cattle

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    The growing use of visual scores (VS) and ultrasound (US) for carcass evaluation in breeding programs, calls for a knowledge of the relationships between these traits and other relevant characteristics, such as feed efficiency and production of commercial cuts. The objective of this study was to evaluate correlations between body visual scores and carcass traits identified by ultrasound (US) and feed efficiency (FE), carcass weight (HCW), dressing percentage (DP) and retail product yield (RPY) in beef cattle. Nellore cattle (male), 42 non-castrated [NCAST] and 44 castrated [CAST]) were evaluated by both VS and US, at the postweaning (15-month old) and finishing phases (21-month old). Visual scores of conformation (C), precocity (P) and muscling (M) were assessed and the backfat thickness (UBFT), rump fat thickness (URFT) and ribeye area (UREA) were measured by ultrasound. Gain-to-feed (G:F) ratio and residual feed intake (RFI) were measured in feedlot. Hot carcass weight, DP and RPY were determined at harvest. Non-castrated cattle had greater HCW and RPY but lower UBFT and URFT than CAST. Postweaning VS and US were poorly correlated with FE in both sexual conditions. Finishing VS were negatively correlated with G:F in CAST and finishing URFT was negatively correlated with RPY in NCAST. The relationship of VS and US with feed efficiency and meat yield is affected by age at the date of evaluation and by castration. Feed efficiency is not related to the yield of meat cuts in Nellore cattl

    Comparison of growth rates in the tissues of primal cuts of Canadian composites

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    Beef composites (C) have combined favourable traits of pure breeds. The objective was to compare the growth rates (GR) of muscle (M) and fat (F) in the primal cuts of serially harvested Beefbooster® C types (SM = C of small breeds, AH = C of Angus and Hereford and GLC = C with Gelbvieh, Limousin or Charolais terminal sires) from 274 - 456 days (d) of age to determine harvest times that reflect an increase M and a decrease F. Analysis of covariance obtained the slopes (GR/d) for M and F within each cut and C type. In the SM and AH the GR of overall F in all primal cuts exceeded that of M by 24.8 g/d and 4.91g/d respectively, while in GLC the gain of M exceeded that of F by 6.77 g/d. We suggest that the SM and AH could be harvested at least 30 d earlier than GLC thereby increasing the proportion of carcass M and decreasing F
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