Steven A. Simpkins, Wendell H. McElhenney, W.B. Mikel, Hardin Rahe, Dwight F. Wolfe, Don R. Mulvaney, and Sarah P. Lino
Piedmontese beef cattle, a heavily muscled breed that recently was introduced into the United States, may provide Alabama beef producers with new breeding options and also may help AAES researchers unlock new information on the genetic links to quality attributes of beef.
Muscularity and tenderness are carcass traits that are receiving increased emphasis in beef cattle breeding programs; however, it is difficult to improve muscling and meat texture without compromising other important carcass traits, such as flavor. One possible approach to enhance muscling may be to use "double-muscled" sires in cross breeding schemes. Double-muscled does not mean that cattle have twice the muscles, but refers to cattle that have an increase in muscle fibers due to a genetic mutation of the myostatin gene.
A double-muscled breed, Piedmontese, exhibits superior muscularity and leanness because of mutations of the myostatin gene. This gene is involved in control of the number of muscle cells. Information about performance of Piedmontese-sired calves relative to more established breeds is limited, especially with regard to how double-muscled breeds fit into Alabama production schemes. An AAES study was initiated at the E.V. Smith Research Center in Shorter to evaluate growth and tenderness characteristics in calves sired by Piedmontese bulls compared to more traditional crosses with Hereford sires. The study also evaluated the effectiveness of using sires' standardized ribeye area (SREA) per unit weight to increase muscling in progeny in a nondouble-muscled beef breed.
Sixty-five steer and heifer calves from matings of Gelbvieh or Angus crossbred cows with high-muscled Polled Hereford (HH), moderate-muscled Polled Hereford (MH), or Piedmontese (PI) bulls were evaluated for growth from birth to slaughter. Assignment of the bulls to the HH group was based on SREA after weaning. Calves were placed on a high-energy ration until they reached a 0.45-inch backfat thickness (based on ultrasound scans).
No differences in initial feedlot weight among groups, sires within muscle groups, season, or sex at the initiation of feeding were observed. Calves from Gelbvieh crossbred cows were 72 pounds heavier than calves from Angus crossbred cows. Average daily gain did not differ significantly between HH and MH nor between either Hereford group compared indivdiually to PI. When data from the Hereford groups were combined, PI-sired calves gained 0.35 pound per day less than Hereford-sired calves. Days on feed did not differ between HH and MH or Hereford and PI; however, days on feed were greater for PI sired calves compared to MH calves (164 versus 132 days). Calves from Gelbvieh crossbred cows gained 0.57 pound per day faster than calves from Angus crossbred cows. Steer calves gained 0.46 pound per day faster than heifer calves. Also, calves from a spring breeding season gained 0.46 pound per day faster than calves from the fall calving season. Total feedlot gain of HH was 66 pounds greater than that of MH, but no differences between Hereford and Piedmontese were observed. Differences in gain between HH and MH could be due to the genetic propensity of MH to exhibit an early maturity pattern of development and begin to deposit fat (adipose) tissue at a lighter weight than HH calves. Differences between crossbred cow groups should not be interpreted as "breed" differences because of the limited number of sires represented.
No significant differences were observed between the Hereford groups for carcass measurements. Piedmontese-sired calves exhibited 0.4 units lower numerical yield grade and a 13.5% larger ribeye. No differences among the muscling groups were detected for marbling scores.
Strip loin steaks, approximately one inch thick were taken from the carcasses and cooked in a oven to an internal temperature of 132oF. The steaks were evaluated for tenderness, juiciness, flavor (off-flavor problems and flavor intensity), and weight loss during cooking.
No differences were detected in juiciness of the steaks, but steaks from PI-sired calves were more tender than steaks from Hereford-sired calves. There was less detectable off-flavor in steaks from PI-sired calves than that of Hereford; however, intensity of flavor as detected by sensory analysis was less in steaks from PI-sired calves. Panelists also determined that steaks from PI-sired calves had a higher degree of overall acceptability compared to Hereford-sired calves. Cooking loss was 20% less in PI-sired calves than in HH or MH calves.
Use of standardized ribeye area in Hereford cattle did not substantially improve muscularity in offspring; however, calves sired by the HH sires gained faster in the feedlot. Other objective predictors of muscling need to be explored and other strategies for using ultrasound ribeye measurements need to be considered. Use of double-muscled sires offers a model for studying ways to improve muscling and beef tenderness. Understanding the mechanisms by which the Piedmontese exhibit increased muscling, decreased marbling, and increased tenderness may greatly contribute to solving an industry problem of variability in tenderness and excessive carcass fat.
Wolfe is Professor of Large Animal Surgery and Medicine and Simpkins is a Student in Veterinary Medicine; McElhenney is a Research Fellow, Rahe is former Associate Professor, Mulvaney is Associate Professor, Lino is Lab Technician, and Mikel is former Associate Professor of Animal and Dairy Sciences.
Piedmontese beef cattle, a heavily muscled breed that recently was introduced into the United States, may provide Alabama beef producers with new breeding options and also may help AAES researchers unlock new information on the genetic links to quality attributes of beef.
Muscularity and tenderness are carcass traits that are receiving increased emphasis in beef cattle breeding programs; however, it is difficult to improve muscling and meat texture without compromising other important carcass traits, such as flavor. One possible approach to enhance muscling may be to use "double-muscled" sires in cross breeding schemes. Double-muscled does not mean that cattle have twice the muscles, but refers to cattle that have an increase in muscle fibers due to a genetic mutation of the myostatin gene.
A double-muscled breed, Piedmontese, exhibits superior muscularity and leanness because of mutations of the myostatin gene. This gene is involved in control of the number of muscle cells. Information about performance of Piedmontese-sired calves relative to more established breeds is limited, especially with regard to how double-muscled breeds fit into Alabama production schemes. An AAES study was initiated at the E.V. Smith Research Center in Shorter to evaluate growth and tenderness characteristics in calves sired by Piedmontese bulls compared to more traditional crosses with Hereford sires. The study also evaluated the effectiveness of using sires' standardized ribeye area (SREA) per unit weight to increase muscling in progeny in a nondouble-muscled beef breed.
Sixty-five steer and heifer calves from matings of Gelbvieh or Angus crossbred cows with high-muscled Polled Hereford (HH), moderate-muscled Polled Hereford (MH), or Piedmontese (PI) bulls were evaluated for growth from birth to slaughter. Assignment of the bulls to the HH group was based on SREA after weaning. Calves were placed on a high-energy ration until they reached a 0.45-inch backfat thickness (based on ultrasound scans).
No differences in initial feedlot weight among groups, sires within muscle groups, season, or sex at the initiation of feeding were observed. Calves from Gelbvieh crossbred cows were 72 pounds heavier than calves from Angus crossbred cows. Average daily gain did not differ significantly between HH and MH nor between either Hereford group compared indivdiually to PI. When data from the Hereford groups were combined, PI-sired calves gained 0.35 pound per day less than Hereford-sired calves. Days on feed did not differ between HH and MH or Hereford and PI; however, days on feed were greater for PI sired calves compared to MH calves (164 versus 132 days). Calves from Gelbvieh crossbred cows gained 0.57 pound per day faster than calves from Angus crossbred cows. Steer calves gained 0.46 pound per day faster than heifer calves. Also, calves from a spring breeding season gained 0.46 pound per day faster than calves from the fall calving season. Total feedlot gain of HH was 66 pounds greater than that of MH, but no differences between Hereford and Piedmontese were observed. Differences in gain between HH and MH could be due to the genetic propensity of MH to exhibit an early maturity pattern of development and begin to deposit fat (adipose) tissue at a lighter weight than HH calves. Differences between crossbred cow groups should not be interpreted as "breed" differences because of the limited number of sires represented.
No significant differences were observed between the Hereford groups for carcass measurements. Piedmontese-sired calves exhibited 0.4 units lower numerical yield grade and a 13.5% larger ribeye. No differences among the muscling groups were detected for marbling scores.
Strip loin steaks, approximately one inch thick were taken from the carcasses and cooked in a oven to an internal temperature of 132oF. The steaks were evaluated for tenderness, juiciness, flavor (off-flavor problems and flavor intensity), and weight loss during cooking.
No differences were detected in juiciness of the steaks, but steaks from PI-sired calves were more tender than steaks from Hereford-sired calves. There was less detectable off-flavor in steaks from PI-sired calves than that of Hereford; however, intensity of flavor as detected by sensory analysis was less in steaks from PI-sired calves. Panelists also determined that steaks from PI-sired calves had a higher degree of overall acceptability compared to Hereford-sired calves. Cooking loss was 20% less in PI-sired calves than in HH or MH calves.
Use of standardized ribeye area in Hereford cattle did not substantially improve muscularity in offspring; however, calves sired by the HH sires gained faster in the feedlot. Other objective predictors of muscling need to be explored and other strategies for using ultrasound ribeye measurements need to be considered. Use of double-muscled sires offers a model for studying ways to improve muscling and beef tenderness. Understanding the mechanisms by which the Piedmontese exhibit increased muscling, decreased marbling, and increased tenderness may greatly contribute to solving an industry problem of variability in tenderness and excessive carcass fat.
Wolfe is Professor of Large Animal Surgery and Medicine and Simpkins is a Student in Veterinary Medicine; McElhenney is a Research Fellow, Rahe is former Associate Professor, Mulvaney is Associate Professor, Lino is Lab Technician, and Mikel is former Associate Professor of Animal and Dairy Sciences.
:lol:
