West Central Research and Outreach Center, University of Minnesota, Morris, Minnesota, United States of America.
Department of Animal Science, University of Minnesota, St. Paul, Minnesota, United States of America.
PLoS One. 2017 Nov 3;12(11):e0187686. doi: 10.1371/journal.pone.0187686. eCollection 2017.
Meat from Holstein and crossbred organic dairy steers finished on winter rye and winter wheat pastures was evaluated and compared for meat quality, fatty acid and amino acid profiles, and consumer acceptability. Two adjacent 4-ha plots were established with winter rye or winter wheat cover crops in September 2015 at the University of Minnesota West Central Research and Outreach Center (Morris, MN). During spring of 2015, 30 steers were assigned to one of three replicate breed groups at birth. Breed groups were comprised of: Holstein (HOL; n = 10), crossbreds comprised of Montbéliarde, Viking Red, and HOL (MVH; n = 10), and crossbreds comprised of Normande, Jersey, and Viking Red (NJV; n = 10). Dairy steers were maintained in their respective replicate breed group from three days of age until harvest. After weaning, steers were fed an organic total mixed ration of organic corn silage, alfalfa silage, corn, soybean meal, and minerals until spring 2016. Breed groups were randomly assigned to winter rye or winter wheat and rotationally grazed from spring until early summer of 2016. For statistical analysis, independent variables were fixed effects of breed, forage, and the interaction of breed and forage, with replicated group as a random effect. Specific contrast statements were used to compare HOL versus crossbred steers. Fat from crossbreds had 13% greater omega-3 fatty acids than HOL steers. Furthermore, the omega-6/3 ratio was 14% lower in fat from crossbreds than HOL steers. For consumer acceptability, steaks from steers grazed on winter wheat had greater overall liking than steers grazed on winter rye. Steak from crossbreeds had greater overall liking than HOL steers. The results suggest improvement in fatty acids and sensory attributes of beef from crossbred dairy steers compared to HOL steers, as well as those finished on winter wheat compared to winter rye.
荷斯坦牛和杂交有机奶牛育肥在冬季黑麦和冬小麦牧场上的肉进行了评估和比较，比较了肉质、脂肪酸和氨基酸谱以及消费者接受度。2015 年 9 月，在明尼苏达大学中西研究与推广中心（莫里斯，MN）建立了两个相邻的 4 公顷的试验区，试验区种植了冬季黑麦或冬小麦覆盖作物。2015 年春季，30 头育肥牛在出生时被分配到三个重复的品种组中的一个。品种组由荷斯坦牛（HOL；n = 10）、由蒙贝利亚尔、维京红和 HOL 组成的杂交品种（MVH；n = 10）以及由诺曼底、泽西和维京红组成的杂交品种（NJV；n = 10）组成。从三天大开始，奶牛育肥牛就在各自的重复品种组中饲养，直到收获。断奶后，育肥牛以有机玉米青贮、苜蓿青贮、玉米、豆粕和矿物质的有机全混合日粮饲养，直到 2016 年春季。2016 年春季，品种组被随机分配到冬季黑麦或冬小麦，并进行轮牧，直到初夏。为了进行统计分析，独立变量是品种、饲料的固定效应，以及品种和饲料的相互作用，以重复组作为随机效应。使用特定的对比语句来比较 HOL 与杂交育肥牛。杂交牛的 omega-3 脂肪酸比 HOL 育肥牛多 13%。此外，杂交牛的 omega-6/3 比值比 HOL 育肥牛低 14%。就消费者接受度而言，在冬小麦上放牧的育肥牛的牛排比在冬黑麦上放牧的育肥牛的牛排更受整体欢迎。杂交育肥牛的牛排比 HOL 育肥牛更受欢迎。结果表明，与 HOL 育肥牛相比，杂交奶牛育肥牛的脂肪酸和感官特性得到了改善，与冬季黑麦相比，冬季小麦育肥牛的脂肪酸和感官特性也得到了改善。
