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

Abstract

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.

Genetic analyses of sensory characteristics and relationships with fatty acid composition in the meat from Scottish Blackface lambs

“…The estimate of heritability for toughness (0.15) is similar to low values previously for temperate cattle breeds, which are generally close to 0.10 (e.g. Van Vleck et al, 1992;Barkhouse et al, 1996;Splan et al, 1998;Johnston et al, 2003), suggesting that selection for decreased toughness would result in little genetic progress. Only the studies of Wilson et al (1976) and Nephawe et al (2004) report higher heritabilities for toughness, being 0.23 and 0.26, respectively.…”

Quantitative and molecular genetic influences on properties of beef: a review

“…Cattle of high Bos indicus content had lower marbling scores at a given age and produced less tender and more variable steaks than Bos taurus breeds (Koch et al 1982;Crouse et al 1989;DeRouen et al 1992;Van Vleck et al 1992;Wheeler et al 1994;Barkhouse et al 1996.) Some early breed comparison studies have been criticised on the basis of failure to control processing factors that may lead to cold shortening, which results in tougher meat, particularly in leaner and lighter breeds.…”

“…Initial yield (kg), an index of the myofibrillar contribution to meat toughness Warner Bratzler peak force Peak force, also known as shear force (kg), which represents the total meat toughness Peak force -initial yield Difference between peak force and initial yield (kg), which is an index of the contribution of connective tissue to meat toughness Compression Compression (kg) , measured to determine differences in connective tissue content between muscles (Harris and Shorthose 1988) Cooking loss Cooking loss (%), determined from weights taken before and after cooking at 80°C for 1 h in a thermostatically controlled waterbath Tenderness index Index of meat tenderness that relates to consumer scoring of meat tenderness on a scale of 0 = extremely tender to 15 = extremely tough using the equation: Index = (1.4 × compression) + (0.6 × peak force) + (0.12 × cooking loss) -2.6 (Harris and Shorthose 1988) Myofibrillar fragmentation index A biochemical measure of beef tenderness predicted by absorbance (Barkhouse et al 1996), with low values indicating tough meat and high values indicating tender meat Calpastatin activity Amount of calpastatin activity measured in M. longissimus dorsi at 24 h post-slaughter, according to the method of Shackelford et al (1994a) Subjective sensory panel tests Tenderness/juiciness/flavour/overall acceptability Sensory taste panel tests use subjective scores of individual components of beef eating quality (tenderness, juiciness and flavour) and also an overall eating quality score, combining tenderness, juiciness and flavour. Panellists may be either trained or untrained, and the scoring scale varies considerably across experiments…”

“…Application of processing techniques such as electrical stimulation, tenderstretching and correct aging of meat can be used to overcome the effects of cold shortening (Harris and Shorthose 1988). It is therefore possible that beef tenderness measured either with or without correct application of processing techniques to overcome cold Barkhouse et al (1996); Crews and Franke (1998); Gregory et al (1994b); Gregory et al (1995); Hirooka et al (1996); Johnston et al (1992a); O'Connor et al (1997); Shackelford et al(1994a); Splan et al (1998);Van Vleck et al (1992); Wheeler et al (1996); Wulf et al (1996). B Individual estimates of heritability were weighted by the relative amount of information (inverse of their estimated sampling variance).…”

Relationships of sire breeding values and cutting parts of progeny in Czech Fleckvieh bulls

“…Prediction of breeding values for tenderness of market animals was studied by BARKHOUSE et al (1996). 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.…”