The Blonde d’Aquitaine T3811>G3811 mutation in the myostatin gene: association with growth, carcass, and muscle phenotypes in veal calves

Abstract

The mutation T3811 → G3811 (TG3811) discovered in the myostatin gene of the Blonde d’Aquitaine breed is suspected of contributing to the outstanding muscularity of this breed. An experiment was designed to estimate the effect of this mutation in an F2 and back-cross Blonde d’Aquitaine × Holstein population. By genotyping all known mutations in the myostatin gene, it was ensured that the TG3811 mutation was indeed the only known mutation segregating in this population. Fifty-six calves (43 F2, 13 back-cross) were intensively fattened and slaughtered at 24.0 ± 1.4 wk of age. The effects of the mutation were estimated by comparing the calves with the [T/T] (n = 18), [T/G] (n = 30), and [G/G] (n = 8) genotypes. Highly significant substitution effects (P < 0.001), above + 1.2 phenotypic SD, were shown on carcass yield and muscularity scores. Birth weight (P < 0.001) was positively affected by the mutation (+0.8 SD) but not growth rate (P = 0.97), while carcass length (P = 0.03), and fatness (P ≤ 0.03) were negatively affected (–0.5 to –0.7 SD). The characteristics of the Triceps brachii muscle were affected by the mutation (P < 0.001), with lower ICDH activity (oxidative) and a higher proportion of myosin type 2X muscle fibers (fast twitch). The effects of the TG3811 mutation were similar to those of other known myostatin mutations, although the Blonde d’Aquitaine animals, which are predominantly [G/G] homozygous, do not exhibit extreme double muscling.

Effect of Myostatin Gene Mutation on Slaughtering Performance and Meat Quality in Marchigiana Bulls

“…Concerning the amount of fat on the outside of the carcass and in the thoracic cavity, heterozygous Marchigiana bulls showed a higher, although not significant, frequency in class 2, with a slight fat cover, than normal ones ( Table 5 b). These findings confirm what has already been observed in previous research in several cattle breeds with hypertrophic animals, all characterized by a moderate carcass fat cover (mainly class 2 or 3) [ 7 , 30 , 34 , 36 , 37 , 38 ].…”

“…Orthogonal contrasts showed a significantly higher frequency in the heterozygous group of class E than class U + R carcasses, whereas no significant difference between U and R classes was found ( Table 5 a). These findings confirm the better muscular conformation of hypertrophic bulls, due to a greater convexity of round, back, and shoulder muscular masses, as a consequence of the muscular hypertrophy observed and reported by several authors [ 7 , 18 , 30 , 34 , 36 , 37 , 38 ].…”

“…In addition, the ADG was not affected by genotype at the MSTN gene, resulting in quite a similarity in heterozygous and normal bulls. The daily gain weights observed herein were slightly lower than the daily gains observed by Casas et al [ 33 ] in Charolaise and Belgian Blue x British Breed crosses wild-type or heterozygous at MSTN gene, and the ones reported by Vinet et al [ 36 ] in a crossbred bulls’ population obtained by mating homozygotes mutated Blonde d’Aquitaine bulls to Holstein cows.…”

“…However, heterozygotes Marchigiana bulls reached 426.09 kg in carcass weight. Carcass traits of heterozygous bulls of French beef breeds [ 37 ], of Charolais and Belgian Blues crosses bulls [ 33 ], of British South Devon cattle breed [ 38 ], and of fifty-six Blond d’Aquitaine × Holstein crossbred calves [ 36 ] reached superior values compared to normal ones.…”

“…This trait contributes to quantifying the production efficiency and the economic benefits either for breeders or for the beef cattle industry. Therefore, Marchigiana heterozygotes showed better performance in dressing yield as compared to heterozygotes of Blond d’Aquitaine crosses, Charolaise, Piemontese, Asturiana de los Valles, and Limousine beef cattle breeds [ 33 , 36 , 39 , 40 ]. This may be ascribed to the increase in muscles mass, the fineness of the limb bones, and the reduction of the fifth quarter and of skin weight [ 7 , 32 ], reached in the Marchigiana breed through recent selection schemes applied by ANABIC [ 31 ].…”