Chenoweth P J, Brinks J S, Nett T M
Animal Reproduction Laboratory Colorado State University Fort Collins, CO 80523 USA.
Theriogenology. 1979 Oct;12(4):223-33. doi: 10.1016/0093-691x(79)90006-2.
Three methods of assessing sex-drive were compared in 113 yearling beef bulls. These were the serving capacity score (SC), the libido score (L) and reaction time to first service (R). Ovariectomized heifers restrained in service crates were the stimulus for all tests. Bulls were assessed twice by each method. For the first libido and serving capacity tests (L1 and SC1), the heifers were induced to show estrus. For the second tests (L2 and SC2), the heifers were not induced to show estrus. On a non test day, single blood samples were taken from all bulls and assayed for LH and testosterone. Reaction times to first service (R1 and R2) in the two serving capacity tests were not significantly correlated. Although the numbers of services (SC1 and SC2) in both serving capacity tests, were significantly correlated (r = .67), 57% of the bulls did not achieve a service in both the tests with heifers in heat and with heifers not in heat. Libido scores between the test with heifers in heat and heifers not in heat were significantly correlated (r = .67). The libido score method had the advantage that more bulls received a positive score and the test duration was shorter than in the serving capacity test. Of the three scoring procedures compared, libido score appeared to have most advantage in assessing sex-drive in yearling beef bulls. The total number of services achieved in the first serving capacity tests (using 'estrus' heifers) did not differ from that achieved in the second tests (using non-estrus heifers). The total services achieved in 10-min compartments of the 30-min serving capacity tests showed no difference either within or between tests. It is concluded that a 10-min test provides as much comparative information on the sex-drive of yearling beef bulls as longer tests. Further, the use of females in estrus appears unnecessary to satisfactorily assess bull sex-drive, provided proper restraint and presentation of stimulus females is employed. LH and testosterone values were not significantly correlated or were poorly correlated with sex-drive measurements.
对113头一岁肉牛公牛的三种性欲评估方法进行了比较。这三种方法分别是配种能力评分（SC）、性欲评分（L）和首次配种反应时间（R）。所有测试均以限制在配种栏中的去势母牛作为刺激对象。每种方法对公牛进行两次评估。在第一次性欲和配种能力测试（L1和SC1）中，诱导母牛发情。在第二次测试（L2和SC2）中，不诱导母牛发情。在非测试日，从所有公牛身上采集单份血样，检测促黄体生成素（LH）和睾酮。两次配种能力测试中的首次配种反应时间（R1和R2）无显著相关性。虽然两次配种能力测试中的配种次数（SC1和SC2）显著相关（r = 0.67），但57%的公牛在与发情母牛和未发情母牛的测试中都未能完成一次配种。发情母牛和未发情母牛测试之间的性欲评分显著相关（r = 0.67）。性欲评分法的优点是获得阳性评分的公牛更多，且测试持续时间比配种能力测试短。在比较的三种评分程序中，性欲评分在评估一岁肉牛公牛的性欲方面似乎最具优势。第一次配种能力测试（使用“发情”母牛）中完成的配种总数与第二次测试（使用未发情母牛）中完成的配种总数没有差异。30分钟配种能力测试中10分钟时间段内完成的总配种次数在测试内和测试间均无差异。得出的结论是，10分钟的测试与更长时间的测试一样，能提供关于一岁肉牛公牛性欲的同等比较信息。此外，只要对刺激母牛进行适当的约束和展示，似乎没有必要使用发情母牛来令人满意地评估公牛的性欲。LH和睾酮值与性欲测量值没有显著相关性或相关性很差。
