Genetic Parameters among Production, Carcass Composition and Carcass Quality Traits of Beef Cattle

Rios-Utrera, A.; Cundiff, L. V.; Gregory, K. E.; Koch, R. M.; Dikeman, M. E.; Koohmaraie, M.; and Van Vleck, L. Dale, "Genetic analysis of carcass traits of steers adjusted to age, weight, or fat thickness slaughter endpoints" (2005 2 ), KPH (%), marbling score (MS), yield grade (YG), predicted percentage of retail product (PRP), retail product weight (RPW, kg), fat weight (FW, kg), bone weight (BNW, kg), actual percentage retail product (RPP), fat percent (FP), and bone percent. Fixed effects in the model included breed group, feed energy level, dam age, birth year, significant (P < 0.05) interactions, covariate for days on feed, and the appropriate covariate for endpoint nested (except age) within breed group. Random effects in the model were additive genetic effect of animal and total maternal effect of dam. Parameters were estimated by REML. For some traits, estimates of h 2 and phenotypic variance changed with different endpoints. Estimates of h 2 for HCW, DP, RPW, and BNW at constant age, weight, or fat thickness were 0. 27, -, and 0.41; 0.19, 0.26, and 0.18; 0.42, 0.32, and

Section: Effect Of Endpoint On Heritability Estimatesmentioning

confidence: 53%

Section: Effect Of Endpoint On Heritability Estimatesmentioning

confidence: 70%

Genetic analysis of carcass traits of steers adjusted to age, weight, or fat thickness slaughter endpoints1

Utrera

Cundiff

Gregory

et al. 2005

“…These results do not agree with Reagan et al (1971), who found greater variation in shear force and taste panel tenderness scores for bulls than for steers. Previous heritability estimates for SF have ranged from 0.00 to 1.29 and averaged .27 (Alsmeyer et al, 1958;Busch and Dinkel, 1967;Dinkel and Busch, 1973;Wilson et al, 1976;Koch et al, 1982a;Shackelford et al, 1991;Van Vleck et al, 1992;Gregory et al, 1994. The estimate for SF in Group I of .02 was less than the average heritability estimate in the literature (.27), which may be due to sampling variance.…”

Section: Covariances Among Group I and Group Ii Tenderness Traitsmentioning

confidence: 88%

Prediction of breeding values for tenderness of market animals from measurements on bulls.

Barkhouse

Vleck

Cundiff

et al. 1996

ABSTRACT:Data were tenderness measures on steaks from 237 bulls (Group II) slaughtered after producing freezable semen and on 1,431 related steers and heifers (market animals, Group I ) from Angus, Hereford, Pinzgauer, Brahman, and Sahiwal crosses from the Germ Plasm Evaluation project at the U.S. Meat Animal Research Center. Tenderness was assessed through Warner-Bratzler Shear Force (SF), taste panel tenderness (TPT), marbling score (MS), and myofibrillar fragmentation index (MFI). For all traits, as fraction Bos indicus inheritance increased, implied tenderness decreased. Heritability estimates were generally not significantly different from zero. Genetic correlations generally indicated favorable associations among the traits. The range in predicted breeding values of bulls for market animal tenderness was small and from −.34 to .32 kg for market animal shear force. Because of low estimates of heritability for SF or TPT, results from this experiment indicate that selection based on tenderness of steaks sampled from intact or late castrate males slaughtered following collection of freezable quality semen would not be very effective in improving average tenderness of steaks from steers or heifer progeny. If a mean of heritability estimates reported in the literature of .27 for shear value was assumed for market steer and heifer progeny instead of .02 as found in the present study, then selection based on estimates of shear force in young bulls would be relatively more effective in improving shear force of market progeny.

“…These estimates did not agree with those of Koots et al (1994b), who reported average estimates of genetic correlations at a constant age between marbling score and longissimus muscle area to be −.21. Dinkel and Busch (1973) reported an estimate of direct genetic correlation between marbling score and longissimus muscle area to be −.17.…”

Section: Genetic Correlationsmentioning

confidence: 99%

Parameter estimates for genetic effects on carcass traits of Korean native cattle.

Lee

Choi²,

Kim³

et al. 2000

Data (n = 1,746) collected from 1985 through 1995 on Korean Native Cattle by the National Livestock Research Institute of Korea were used to estimate genetic parameters for marbling score, dressing percentage, and longissimus muscle area, with backfat thickness, slaughter age, or slaughter weight as covariates. Estimates were obtained with REML. Model 1 included animal genetic and residual random effects. Model 2 was extended to include an uncorrelated random effect of the dam. Model 3 was based on Model 1 but also included sire × region × year-season interaction effects. Model 4 combined Models 2 and 3. All models included fixed effects for region × year-season and age of dam × sex combinations. From single-trait analyses, estimates of heritability with covariates to adjust for backfat thickness, slaughter age, and slaughter weight from Model 4 were, respectively, .10, .08, and .01 for marbling score; .09, .12, and .16 for dressing percentage; and .18, .17, and .24 for longissimus muscle area. From three-trait analyses, estimates of genetic correlations between marbling score and dressing percentage, marbling score and longissimus muscle area, and dressing percentage and longissimus muscle area were, respec-