North Florida Research and Education Center, University of Florida, 3925 Highway 71, Marianna, FL 32446, USA.
Vet Clin North Am Food Anim Pract. 2013 Nov;29(3):567-78. doi: 10.1016/j.cvfa.2013.07.003. Epub 2013 Aug 12.
At weaning, heifers should be considered for replacements based on their dam's previous performance; heifer calving date, age, and weight; and previous exposure to implants. Before breeding, heifers should be selected as replacements based on whether they have attained puberty (determined by a prebreeding examination), do not have abnormal pelvic areas, or fail to meet temperament standards. After breeding, heifers should be selected as replacements if they conceive early in the breeding season, are capable of achieving 85% of their mature weight by calving, and calve at a body condition of 5.5 to 6.0.
在断奶时,应根据其母本的先前表现、小母牛的配种日期、年龄和体重以及先前接触过的植入物来考虑是否更换小母牛。在配种前,应根据小母牛是否达到性成熟(通过配种前检查确定)、是否有异常的骨盆区域或不符合气质标准来选择是否更换小母牛。配种后,如果小母牛能在配种季节早期怀孕、能在分娩时达到其成熟体重的 85%且体况评分为 5.5 至 6.0,则应选择其作为后备牛。