Effects of genetic merit for carcass weight, breed type and slaughter weight on performance and carcass traits of beef × dairy steers

Abstract

Crossbreeding of Holstein-Friesian dairy cows with both early maturing (e.g. Aberdeen Angus (AA)) and late maturing (e.g. Belgian Blue (BB)) beef breeds is commonly practised. In Ireland, genetic merit for growth rate of beef sires is expressed as expected progeny difference for carcass weight (EPD CWT ). The objective of this study was to compare the progeny of Holstein-Friesian cows, sired by AA and BB bulls of low (L) and high (H) EPD CWT for performance and carcass traits. A total of 118 spring-born male progeny from 20 (9 AA and 11 BB) sires (8 L and 12 H) were managed together from shortly after birth to about 19 months of age. They were then assigned to one of two mean slaughter weights (560 kg (light) or 620 kg (heavy)). Following slaughter, carcasses were graded for conformation class and fat class, the 6th to 10th ribs joint was dissected as an indicator of carcass composition, and samples of subcutaneous fat and musculus longissimus were subjected to Hunterlab colour measurements. A sample of m. longissimus was also chemically analysed. Slaughter and carcass weights per day of age for AAL, AAH, BBL and BBH were 747, 789, 790 and 805 (s.e. 10.5) g, and 385, 411, 427 and 443 (s.e. 4.4) g, respectively. Corresponding carcass weight, kill-out proportion, carcass conformation class (scale 1 to 5) and carcass fat class (scale 1 to 5) values were 289, 312, 320 and 333 (s.e. 4.0) kg, 516, 522, 542 and 553 (s.e. 3.5) g/kg, 2.5, 2.4, 3.0 and 3.1 (s.e. 0.10), and 3.4, 3.5, 2.9 and 2.8 (s.e. 0.11). There were few breed type 3 genetic merit interactions. Delaying slaughter date increased slaughter weight, carcass weight and all measures of fatness. It also reduced the proportion of carcass weight in the hind quarter and the proportions of bone and muscle in the ribs joint. None of these effects accompanied the increase in carcass weight due to higher EPD CWT . It is concluded that BB have superior production traits to AA. Selection of sires for higher EPD CWT increases growth rate, kill-out proportion and carcass weight of progeny with little effect on carcass or muscle traits. The extra carcass weight due to higher EPD CWT is more valuable commercially than a comparable carcass weight increment from a delay in slaughter date because it comprises a higher proportion of muscle.

Compensatory growth in crossbred Aberdeen Angus and Belgian Blue steers: Effects on the colour, shear force and sensory characteristics of longissimus muscle

“…The lack of difference in intramuscular fat concentration between feeding treatments supports the findings of Moloney et al (2008) and likely reflects the duration of the re-alimentation period. The higher intramuscular fat concentration in muscle from AN in the present study supports the findings of other studies for the same genotypes (Keane et al, 2011) and reflects the maturity of the AN breed compared to the BB breed.…”

“…The difference in redness between genotypes supports the findings of Keane et al (2011) and Cuvelier et al (2006a, b). However, Campion et al (2009) found no difference in redness between AN and BB genotypes Carotenoid consumption by cattle results in accumulation in adipose tissue and more yellow colour (for review, see Dunne et al, 2009).…”

Proteomic profiling of bovine M. longissimus lumborum from Crossbred Aberdeen Angus and Belgian Blue sired steers varying in genetic merit for carcass weight1

“…A number of studies to date have investigated the physical and physiological differences in animals varying in EPD cwt (Crews et al, 2004;Keane et al, 2011). In addition, Bernard et al (2009) examined the effects of genetic selection in favor of high muscle growth on global gene expression in muscle tissue of young Charolais bulls.…”

Advances of Molecular Markers and Their Application for Body Variables and Carcass Traits in Qinchuan Cattle

“…Numerous studies have demonstrated that intramuscular fat content of cattle and beef quality are influenced by factors of the production or processing system including the breed, sex, age, housing system, feeding, and pre-slaughter handling, but also the individual genetic background of an animal [18,19] (Figure 1). The impact of breed on suitability for meat production was reported by many authors, but it is difficult to pinpoint the best breed for beef production and it is unlikely that one breed will have all the desirable traits for survival, growth, and quality meat production [20,21,22]. Breeds differ in many aspects including degree of muscling, intramuscular fat content, meat aroma, juiciness, and tenderness.…”