Production and processing studies on calpain-system gene markers for beef tenderness: Consumer assessments of eating quality1

Abstract

ABSTRACT:We investigated the effects of calpainsystem genetic markers on consumer beef quality ratings, including interactions of marker effects with hormonal growth promotant (HGP) use and tenderstretch hanging. Brahman cattle in New South Wales (NSW; n = 164) and Western Australia (WA; n = 141) were selected at weaning from commercial and research herds to achieve balance and divergence in calpastatin (CAST) and calpain 3 (CAPN3) gene marker status. Genotypes for μ-calpain (CAPN1-4751 and CAPN1-316) were also determined. Angus cattle (49 in NSW, 17 in WA) with favorable CAST and CAPN3 alleles, balanced for CAPN1-316 status, were also studied. Half the cattle at each site had HGP (Revalor-H, containing 200 mg trenbolone acetate and 20 mg 17β-estradiol) implants during grain fi nishing. One side of each carcass was suspended from the Achilles tendon (AT) and the other from the pelvis [tenderstretch (TS)]. Meat Standards Australia consumer panels scored 7-d aged striploin steaks from both AT and TS sides, and 7-d aged rump and oyster blade steaks from the AT side of each carcass. Two favorable CAST alleles increased tenderness ratings of AT-striploin, TS-striploin, rump, and oyster blade steaks by, respectively, 6.1, 4.2, 4.2, and 3.1 units, and overall liking by 4.7, 2.8, 2.9, 3.7 (all P < 0.04). Two favorable CAPN1-4751 alleles increased tenderness of AT-striploin, TS-striploin, and rump steaks by 6.5, 4.3, and 3.9 units, and overall liking by 5.6, 3.1, and 4.1 units. Two favorable CAPN3 alleles improved rump steaks by 3.7, 3.3, 3.7, and 3.5 units, for tenderness, juiciness, liking the fl avor, and overall liking. There were no signifi cant CAPN1-316 effects. The effect of HGP was greatest for the AT-striploin (reducing tenderness and overall liking by 8.2 units, P < 0.001), then TS-striploin (-5.6 for tenderness, -5.0 for overall liking, P < 0.001), and then rump (-4.4 for tenderness, -3.3 for overall liking, P < 0.007). Processing conditions differed considerably between NSW and WA. Rump steaks from NSW scored about 10 units greater than those from WA, but Angus and Brahman steaks from the same location with the same marker alleles had similar scores. In contrast, NSW Angus striploin steaks scored about 15 units greater for tenderness and overall liking (P < 0.001) than cattle with the same marker alleles at the other 3 location × breed combinations, which had generally similar scores. Therefore, calpain-system gene markers have benefi cial effects on eating quality, consistent with our previous fi ndings for objective meat quality.

Molecular value predictions: Associations with beef quality, carcass, production, behavior, and efficiency phenotypes in Brahman cattle1

“…For example, other studies have assessed the palatability of 1-and 14-d-aged (NBCEC, 2011) or 2-d-aged (Johnston and Graser, 2009) LM from Achilles-hung carcasses but did not report any other objective or consumer assessments of beef palatability or results for other abattoir processing methods. This is in stark contrast to the present study, which measured phenotypes for a broad range of commercially important palatability characteristics under various processing conditions, both within and between experiments and between cuts of beef (Cafe et al, 2010b;Robinson et al, 2012). These issues are particularly important in identifying ways to improve eating quality in beef from Bos indicus cattle, which can have substantially inferior eating quality than beef from Bos taurus cattle (Robinson et al, 2012).…”

“…These experiments were originally designed to assess the effects of calpain-system gene markers (calpastatin, CAST; calpain 3, CAPN3; μ-calpain, CAPN1-4751, and CAPN1-316) on production and beef quality characteristics of Bos indicus (Brahman) cattle, as well as to identify interactions of the gene markers with production [sex and hormonal growth promotant (HGP) implantation] and processing (carcass suspension, muscle, and duration of the postmortem aging period) effects (Cafe et al, 2010a(Cafe et al, , 2010bRobinson et al, 2012).…”

“…Consumer recruitment, steak preparation, and sample service are provided in greater detail by Robinson et al (2012). Consumers scored each sample for tenderness, juiciness, and liking the flavor on a 100-mm line, anchored at 0 (least favorable) and 100 (most favorable), and overall liking on a 100-mm line, anchored at 0 (least favorable) and 5 (most favorable).…”

“…There is also a need for evaluation of MVP against a broader range of production, carcass, and beef quality traits to quantify favorable or antagonistic relationships with other traits of interest. Improved tenderness is phenotypically associated with increased protein turnover (Koohmaraie et al, 2002), as well as with gene markers associated with protein turnover (Cafe et al, 2010b;Robinson et al, 2012), suggesting possible adverse associations of tenderness MVP with feed efficiency and marbling.…”

“…This hypothesis was tested using data from 2 previously published experiments (Cafe et al, 2010a(Cafe et al, , 2010bRobinson et al, 2012) designed to examine tenderness gene markers and their interactions with production and processing factors in Bos indicus (Brahman) cattle.…”