Keen J E, Rupp G P, Wittenberg P A, Walker R E
USDA, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, USA.
J Am Vet Med Assoc. 1999 Apr 15;214(8):1212-7.
To evaluate the breeding soundness examination procedure in plains bison bulls.
Multiyear (1993 through 1997) cross-sectional clinical procedure evaluation.
Two hundred thirty-four 28- to 30-month-old bison bulls at Custer State Park.
Breeding soundness examinations were performed on all bison bulls using 1992 Society for Theriogenology guidelines for beef cattle semen evaluation and reproductive tract examination. Linear and logistic regression analyses were used to detect correlations and associations among breeding soundness examination variables.
Scrotal circumference (SC) was significantly correlated with body weight, percentage of normal spermatozoa, percentage of primary spermatozoal defects, and percentage of motile spermatozoa. Scrotal circumference was positively associated with increased odds of semen collection, satisfactory motility (> or = 30% motility), satisfactory morphology (> or = 70% normal spermatozoa), and simultaneous satisfactory motility and morphology. Receiver-operator characteristic curve analysis selected 29 cm as the optimal SC cutoff most predictive of simultaneous satisfactory spermatozoal motility and morphology. Only 36.2% (83/229) of the bison bulls had a SC of 29 cm or greater and satisfactory spermatozoal motility and morphology.
SC is a good indicator of adequate spermatozoal motility and structure in bison. We recommend use of 30% spermatozoal motility, 70% normal spermatozoal morphology, and 29-cm SC as minimal satisfactory measurements for breeding soundness examinations of 28- to 30-month-old bison bulls that have been raised on forage-based nutrition.
评估平原野牛公牛的繁殖健全性检查程序。
多年（1993年至1997年）横断面临床程序评估。
卡斯特州立公园的234头28至30月龄的野牛公牛。
根据1992年兽医学协会关于肉牛精液评估和生殖道检查的指南，对所有野牛公牛进行繁殖健全性检查。采用线性和逻辑回归分析来检测繁殖健全性检查变量之间的相关性和关联性。
阴囊周长（SC）与体重、正常精子百分比、初级精子缺陷百分比和活动精子百分比显著相关。阴囊周长与精液采集几率增加、活动力满意（活动力≥30%）、形态满意（正常精子≥70%）以及活动力和形态同时满意呈正相关。受试者工作特征曲线分析选择29厘米作为最能预测精子活动力和形态同时满意的最佳SC临界值。只有36.2%（83/229）的野牛公牛阴囊周长为29厘米或更大，且精子活动力和形态满意。
阴囊周长是野牛精子活动力和结构是否充足的良好指标。我们建议将30%的精子活动力、70%的正常精子形态和29厘米的阴囊周长作为对以草料为基础营养饲养的28至30月龄野牛公牛进行繁殖健全性检查的最低满意测量值。
