Vogt D W, Massey J W, Ellersieck M R, Bierschwal C
J Am Vet Med Assoc. 1984 May 1;184(9):1125-6.
Scrotal circumference measurements on 870 Angus, 759 Polled Hereford, and 309 Simmental bulls ranging in age from 484 to 704 days were analyzed to develop an appropriate method of adjustment of scrotal circumference for differences associated with age of the bull. Data were separated by breed, year, and season and then each subset of data was subjected to statistical analysis. Adjustment factors to remove differences due to age were developed for bulls of the three breeds studied.
对870头安格斯公牛、759头无角海福特公牛和309头西门塔尔公牛的阴囊周长进行了测量，这些公牛年龄在484至704天之间，旨在开发一种合适的方法，针对与公牛年龄相关的差异来调整阴囊周长。数据按品种、年份和季节进行了分类，然后对每个数据子集进行了统计分析。针对所研究的三个品种的公牛，制定了消除年龄差异的调整因子。
