Genetic and phenotypic characterisation of animal, carcass, and meat quality traits from temperate and tropically adapted beef breeds. 4. Correlations among animal, carcass, and meat quality traits

Abstract

Abstract. Beef cattle data from temperate (TEMP, n = 3947) and tropically adapted (TROP, n = 4137) breeds were analysed to compute estimates of genetic and phenotypic correlations between animal, abattoir carcass, and meat quality measures. Live animal traits included: liveweight (S2LWT), scanned subcutaneous rump fat depth (S2P8), scanned eye muscle area (S2EMA), flight time (S1FT), and finishing average daily gain (FADG). Carcass traits included: hot carcass weight (CWT), retail beef yield percentage (RBY), intramuscular fat percentage (IMF), subcutaneous rump fat depth (P8), eye muscle length by width (ELW), and meat colour score (MEATC). Meat quality measures taken on 2 muscles [M. longissimus thoracis et lumborum (LTL) and M. semitendinosus (ST)] included: shear force of LTL (LTL_SF) and ST (ST_SF); compression of the ST (ST_C); cooking loss % of the LTL (LTL_CL%) and ST (ST_CL%); Minolta LTL L* (LTL_L*), a* (LTL_a*), ST a* (ST_a*); and consumer-assessed LTL tenderness score (LTL_TEND). Genetic and phenotypic correlations between animal measures and related carcass traits were moderate to very high for TEMP and TROP. Genetic correlations between S2LWT and CWT were 0. 89 and 0.82, between S2P8 and P8 0.80 and 0.88, and between S2EMA and ELW 0.62 and 0.68, for TEMP and TROP, respectively. Genetic correlations between animal measures and other carcass traits varied; moderate genetic correlations were estimated between S2P8 and RBY (-0.57, -0.19 for TEMP, TROP) and S2P8 and IMF (0.39, 0.23 for TEMP, TROP). Genetic correlations between animal and meat quality measures were moderate to low. For TEMP, moderate genetic correlations were estimated between S2P8 and LTL_TEND (0.38), FADG and ST_a* (-0.49), and FADG and LTL_TEND (0.45); and for TROP, S1FT and LTL_SF (-0.54), and S2EMA and LTL_L* (-0.46). Phenotypic correlations between animal and meat quality were generally low and close to zero. Several moderate to high genetic correlations existed between carcass and meat quality traits. In general, fatness measures were genetically correlated with tenderness (e.g. IMF and LTL_TEND 0.61, 0.31 for TEMP, TROP). CWT was genetically correlated with meat colour (CWT and LTL_L* 0.66, 0.60 for TEMP, TROP) and objective tenderness measures (CWT and ST_C -0.52, -0.22 for TEMP, TROP). Once again phenotypic correlations between carcass and meat quality were low, indicating that few phenotypic predictors of meat quality traits were identified. Several of the genetic correlations show that both animal and abattoir carcass traits may be of use as indirect measures for carcass and meat quality traits in multiple trait genetic evaluation systems.A R 0 2 0 8 8 A n i ma l , c a r c a s s , a n d m e a t q u a l i t y t r a i t s i n b e e f A . R e v e r t e r e t a l .

Genetics of meat quality and carcass traits and the impact of tenderstretching in two tropical beef genotypes

“…Measurements of IMF were moderately heritable in BRAH (h 2 = 0.26), but for TCOMP, the trait was more highly heritable (h 2 = 0.64). Interestingly, the study of Reverter et al (2003b), where estimates were calculated from data pooled across tropically adapted genotypes, reported a heritability of 0.39, which represents an approximate midpoint for the range described by the genotype specific results presented for this experiment. Table 6 presents the genetic and phenotypic correlations between carcass and meat quality traits calculated for the pooled dataset.…”

“…Several studies (O'Connor et al 1997;Elzo et al 1998;Newman et al 2002;Johnston et al 2003b;Reverter et al 2003a;Riley et al 2003;Domingue 2005;Smith et al 2007) have examined the genetic parameters of meat quality and carcass traits in tropically adapted beef cattle. Generally, levels of phenotypic variation and heritabilities in this study were consistent with those presented by Johnston et al (2003b) and Reverter et al (2003b) from previous studies conducted by the Beef CRC in Australia. Some traits were lowly heritable (h 2 < 0.10): pH_U, LOSS_A, LOSS_T, a* and b* in BRAH, and pH_U, a* and b* in TCOMP, and these were not included in further analyses.…”

“…Studies by Reverter et al (2003b) and Johnston et al (2003b) examined the genetic parameters of carcass and meat quality traits in tropically adapted cattle in Australia, and reported that moderate heritabilities meant that selection to improve these traits was possible (h 2 = 0.18-0.50). Reverter et al (2003a) estimated the genetic relationships between liveweight, liveweight gain, flight time and real time ultrasound scanned 1 Animal Genetics and Breeding Unit is a joint venture of the New South Wales Department of Primary Industries and the University of New England.…”

“…Reverter et al (2003a) estimated the genetic relationships between liveweight, liveweight gain, flight time and real time ultrasound scanned 1 Animal Genetics and Breeding Unit is a joint venture of the New South Wales Department of Primary Industries and the University of New England. measurements of fat depth and eye muscle area measurements from live steers, and their carcass and meat quality traits assessed after slaughter.…”

Regrouping unfamiliar animals in the weeks prior to slaughter has few effects on physiology and meat quality in Bos taurus feedlot steers

“…The term breed in this analysis encapsulates not only genetics of the two lines but also the effects associated with property of origin, and pre-feedlot entry management. Flight time is a measure of temperament of cattle that has been found to be genetically correlated with growth rate (Burrow et al 2001;Petherick et al 2002) and genetically (Reverter et al 2003) and phenotypically (Voisinet et al 1997;Petherick et al 2002) correlated with meat quality in Bos indicus derived breeds. In addition, B. indicus and B. indicus cross cattle with short flight times tended to lose more weight during long distance road transport and recover weight more slowly in the month following transport than animals with slow flight times (H. M. Burrow and I. G. Colditz, unpubl.…”