Bjorklund E A, Heins B J, Dicostanzo A, Chester-Jones H
Department of Animal Science, University of Minnesota, St. Paul 55108.
Department of Animal Science, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2014 Mar;97(3):1817-27. doi: 10.3168/jds.2013-6983. Epub 2014 Jan 25.
Bull calves (n=49), born at the University of Minnesota West Central Research and Outreach Center (Morris) between March and May 2011, were used to compare growth measurements and profitability of conventional and organic dairy steers. Calves were assigned to 1 of 3 replicated groups at birth: conventional (CONV; n=16), organic (pasture and concentrate; ORG; n=16), or organic grass only (GRS; n=17), and analysis of variables was on a pen basis. Breed groups of calves were Holstein (HO; n=9); Holsteins (n=11) maintained at 1964 breed average level; crossbreds (n=19) including combinations of HO, Montbéliarde, and Swedish Red; and crossbreds (n=10) including combinations of HO, Jersey, Swedish Red, and Normande. The CONV steers were fed a diet of 80% concentrate and 20% forage. The ORG steers were fed a diet of organic corn, organic corn silage, and at least 30% of their diet consisted of organic pasture during the grazing season. The GRS steers grazed pasture during the grazing season and were fed high-quality hay or hay silage during the nongrazing season. Intakes of a total mixed ration were recorded daily with herd management software. A profit function was defined to include revenues and expenses for beef value, feed intake, pasture intake, health cost, and yardage. The GRS (358.6 kg) steers had lesser total gains from birth to slaughter than ORG (429.6 kg) and CONV (534.5 kg) steers. Furthermore, the GRS (0.61 kg/d) steers had lesser average daily gain from birth compared with ORG (0.81 kg/d) and CONV (1.1 kg/d) steers. The GRS and ORG steers had smaller rib eye area (49.5 and 65.8 cm(2), respectively) compared with CONV (75.4 cm(2)) steers. For profitability, GRS steers had 43% greater profit than CONV steers due to organic beef price premiums and lower feed costs. On the other hand, ORG steers had substantially less profit than CONV steers. The higher cost of production for the ORG steers is due to the extreme high value of organic corn. The results of the current study illustrate the economic potential of alternative strategies for growing and marketing male offspring of organic dairy cattle in the Midwest.
2011年3月至5月间出生于明尼苏达大学西部中心研究与推广中心（莫里斯）的公牛犊（n = 49），被用于比较传统和有机奶牛育肥牛的生长指标及盈利能力。犊牛出生时被分配到3个重复组中的1组：传统组（CONV；n = 16）、有机组（牧场和精饲料；ORG；n = 16）或仅有机草饲组（GRS；n = 17），变量分析以栏为基础。犊牛的品种组包括荷斯坦牛（HO；n = 9）；维持在1964年品种平均水平的荷斯坦牛（n = 11）；杂交牛（n = 19），包括荷斯坦牛、蒙贝利亚牛和瑞典红牛的组合；以及杂交牛（n = 10），包括荷斯坦牛、泽西牛、瑞典红牛和诺曼底牛的组合。CONV育肥牛的日粮为80%精饲料和20%粗饲料。ORG育肥牛的日粮为有机玉米、有机玉米青贮料，且在放牧季节其日粮至少30%由有机牧场饲料组成。GRS育肥牛在放牧季节放牧牧场，在非放牧季节饲喂优质干草或青贮干草。每天使用牛群管理软件记录全混合日粮的摄入量。定义了一个利润函数，包括牛肉价值、饲料摄入量、牧场摄入量、健康成本和场地费用的收入和支出。GRS（358.6千克）育肥牛从出生到屠宰的总增重低于ORG（429.6千克）和CONV（534.5千克）育肥牛。此外，GRS（0.61千克/天）育肥牛从出生起的平均日增重低于ORG（0.81千克/天）和CONV（1.1千克/天）育肥牛。与CONV（75.4平方厘米）育肥牛相比，GRS和ORG育肥牛的眼肌面积较小（分别为49.5和65.8平方厘米）。在盈利能力方面，由于有机牛肉价格溢价和较低的饲料成本，GRS育肥牛的利润比CONV育肥牛高43%。另一方面，ORG育肥牛的利润远低于CONV育肥牛。ORG育肥牛较高的生产成本是由于有机玉米的极高价格。本研究结果说明了美国中西部地区有机奶牛雄性后代养殖和销售替代策略 的经济潜力。
