Canadian, American, and Japanese carcass grades of heifers fed to heavy weights to enhance marbling

Abstract

Japanese carcass grades of heifers fattened to heavy weights to enhance marbling. Can. J. Anim. Sci. 77: [393][394][395][396][397][398][399][400][401][402]. Yield and quality grades were measured in two studies evaluating common breeds (Angus, Hereford, Hereford × Angus and Holstein) and nutrition programs for production of highly marbled beef for the Japanese market. Weaned heifer calves (n = 221, initial weight 265 kg) were slaughtered at 500, 590, and 680 kg in exp. 1. In exp. 2, yearling heifers (n = 216, initial weight 395 kg) were slaughtered at 590 and 680 kg. Cattle were assigned to either a high plane of nutrition (HP) until slaughter or to a moderate plane of nutrition until 500 kg (exp. 1) or 550 kg (exp. 2), followed by HP to slaughter (MHP). Carcasses were graded at the Japanese (6/7th rib) and Canadian/US (12/13th rib) grading sites. Extended feeding of heifers from the three beef breeds for 199 to 474 d and to slaughter weights up to 680 kg enhanced marbling at the cost of very poor USDA and Canada yield grades (extremely fat carcasses). Most carcasses had sufficient marbling to qualify for Canada AAA or USDA Choice quality grades, but only achieved average Japanese quality grades. Carcasses were frequently downgraded by the Japanese grading system because of coarse marbling texture, poor fat texture, and soft or coarse muscle texture, especially at the higher slaughter weights. Compared with the beef breeds, Holsteins produced leaner carcasses with at least as much marbling, and had superior Japanese quality grades, similar Japanese yield grades, and superior Canadian and US yield grades. However, carcasses with dairy conformation may be subjectively downgraded by grading systems in most countries, including Japan. Feeding early-maturing cattle high grain diets to excessive slaughter weights was not effective in producing beef with sufficient marbling to achieve the highest Japanese (5) or US (Prime) quality grades, but produced carcasses that were too fat for North American markets.

Meat quality of heifers fattened to heavy weights to enhance marbling

“…The intramuscular fat concentration was more sensitive to treatment effects than the subjective marbling scores discussed previously (Dubeski et al 1997b), probably because large marbling deposits are scored only slightly higher than small flecks of marbling. In the current experiments, the increase in intramuscular fat concentration achieved by the prolonged feeding using either the HP or MHP nutrition programs was small relative to the added time on feed or production cost (Dubeski et al 1997a) and the loss in yield grades due to extremely fat carcasses (Dubeski et al 1997b). …”

“…1, compared with 18.4 and 25.9 mm at 590 and 680 kg, respectively, in exp. 2 (Dubeski et al 1997b). Heavy carcasses cool relatively slowly and are less vulnerable to cold shortening, especially under the conventional chilling conditions of this study, than light carcasses with minimal subcutaneous fat (Aalhus et al 1991).…”

“…In exp. 1, Angus had superior marbling compared to HA and Hereford (P < 0.002) based on both intramuscular fat concentration (Table 2) and subjective marbling score (Dubeski et al 1997b). In exp.…”

Meat Science Lexicon

“…However, when evaluated by trained sensory panelists, there were no differences reported for flavor, tenderness, juiciness, or overall satisfaction (Moody et al, 1970). Other researchers have evaluated marbling texture; however, comparisons were not made among the marbling texture groups in most of these studies (Goll et al, 1965;Cross et al, 1975;Cross, 1977;Dubeski et al, 1997;de Mello et al, 2012ade Mello et al, , 2012bDurunna et al, 2014). Therefore, the objective of the current study was to evaluate the effects of marbling texture on consumer and trained sensory panel ratings of beef strip loins varying in marbling texture (fine, medium, and coarse) from 3 USDA quality groups.…”

“…www.meatandmusclebiology.com both levels (Smith et al, 2001). Marbling texture is impacted by a variety of factors including breed Yang et al, 2006;Albrecht et al, 2011) and animal diet (Dubeski et al, 1997;de Mello et al, 2012a, b;Durunna et al, 2014). But marbling texture's impact on beef palatability is unclear as it has not been the primary focus of much previous work.…”