relationship to paired testes weight, effect of breed, and predictability. Can. J. Anim. Sci. 62: 133–139.
4 4 Coulter, G., Mapletoft, R., Kozub, G., and Cates, W. (1987). Scrotal circumference of two‐year‐old bulls of several beef breeds. Theriogenology 27: 485–491.
5 5 Gregory, K., Lunstra, D., Cundiff, L., and Koch, R. (1991). Breed effects and heterosis in advanced generations of composite populations for puberty and scrotal traits of beef cattle. J. Anim. Sci. 69: 2795–2807.
6 6 Lunstra, D. and Cundiff, L. (2003). Growth and pubertal development in Brahman‐, Boran‐, Tuli‐, Belgian Blue‐, Hereford‐ and Angus‐sired F1 bulls. J. Anim. Sci. 81: 1414–1426.
7 7 Pratt, S., Spitzer, J., Webster, H. et al. (1991). Comparison of methods for predicting yearling scrotal circumference and correlations of scrotal circumference to growth traits in beef bulls. J. Anim. Sci. 69: 2711–2720.
8 8 Fordyce, G., McGowan, M., Lisle, A. et al. (2014). Scrotal circumference of Australian beef bulls. Theriogenology 81: 805–812.
9 9 Evans, A., Davies, F., Nasser, L. et al. (1995). Differences in early patterns of gonadotrophin secretion between early and late maturing bulls, and changes in semen characteristics at puberty. Theriogenology 43: 569–578.
10 10 Brito, L., Silva, A., Unanian, M. et al. (2004). Sexual development in early‐ and late‐maturing Bos indicus and Bos indicus × Bos taurus crossbred bulls in Brazil. Theriogenology 62: 1198–1217.
11 11 Martins, J., Souza, F., Ferreira, M. et al. (2011). Desenvolvimento reprodutivo de tourinhos Gir selecionados para producao de leite. Arq. Bras. Med. Vet. Zootec. 63: 1277–1286.
12 12 Latimer, F., Wilson, L., Cain, M., and Stricklin, W. (1982). Scrotal measurements in beef bulls: heritability estimates, breed and test station effects. J. Anim. Sci. 54: 473–479.
13 13 Knights, S., Baker, R., Gianola, D., and Gibb, J. (1984). Estimates of heritabilities and of genetic and phenotypic correlations among growth and reproductive traits in yearling Angus bulls. J. Anim. Sci. 58: 887–893.
14 14 Gipson, T., Vogt, D., Ellersieck, M., and Massey, J. (1987). Genetic and phenotypic parameter estimates for scrotal circumference and semen traits in young beef bulls. Theriogenology 28: 547–555.
15 15 Meyer, K., Hammond, K., Mackinnon, M., and Parnell, P. (1991). Estimates of covariances between reproduction and growth in Australian beef cattle. J. Anim. Sci. 69: 3533–3543.
16 16 Garmyn, A., Moser, D., Christmas, R., and Minick Bormann, J. (2011). Estimation of genetic parameters and effects of cytoplasmic line on scrotal circumference and semen quality traits in Angus bulls. J. Anim. Sci. 89: 693–698.
17 17 Vargas, C., Elzo, M., Chase, C. Jr. et al. (1998). Estimation of genetic parameters for scrotal circumference, age at puberty in heifers, and hip height in Brahman cattle. J. Anim. Sci. 76: 2536–2541.
18 18 Neely, J., Johnson, B., Dillard, E., and Robison, O. (1982). Genetic parameters for testes size and sperm number in Hereford bulls. J. Anim. Sci. 55: 1033–1040.
19 19 Nelsen, T., Short, R., Urick, J., and Reynolds, W. (1986). Heritabilities and genetic correlations of growth and reproductive measurements in Hereford bulls. J. Anim. Sci. 63: 409–417.
20 20 Bourdon, R. and Brinks, J. (1986). Scrotal circumference in yearling Hereford bulls: adjustment factors, heritabilities and genetic, environmental and phenotypic relationships with growth traits. J. Anim. Sci. 62: 958–967.
21 21 Crews, D. Jr. and Porteous, D. (2003). Age of dam and age at measurement adjustments and genetic parameters for scrotal circumference of Canadian Hereford bulls. Can. J. Anim. Sci. 83: 183–188.
22 22 Kriese, L., Bertrand, J., and Benyshek, L. (1991). Age adjustment factors, heritabilities and genetic correlations for scrotal circumference and related growth traits in Hereford and Brangus bulls. J. Anim. Sci. 69: 478–489.
23 23 Evans, J., Golden, B., Bourdon, R., and Long, K. (1999). Additive genetic relationships between heifer pregnancy and scrotal circumference in Hereford cattle. J. Anim. Sci. 77: 2621–2628.
24 24 Kealey, C., MacNeil, M., Tess, M. et al. (2006). Genetic parameter estimates for scrotal circumference and semen characteristics of line 1 Hereford bulls. J. Anim. Sci. 84: 283–290.
25 25 Coulter, G., Rounsaville, T., and Foote, R. (1976). Heritability of testicular size and consistency in Holstein bulls. J. Anim. Sci. 43: 9–12.
26 26 Keeton, L., Green, R., Golden, B., and Anderson, K. (1996). Estimation of variance components and prediction of breeding values for scrotal circumference and weaning weight in Limousin cattle. J. Anim. Sci. 74: 31–36.
27 27 Yokoo, M., Lobo, R., Araujo, F. et al. (2010). Genetic associations between carcass traits measured by real‐time ultrasound and scrotal circumference and growth traits in Nelore cattle. J. Anim. Sci. 88: 52–58.
28 28 Boligon, A., Silva, J., Sesana, R. et al. (2010). Estimation of genetic parameters for body weights, scrotal circumference, and testicular volume measured at different ages in Nellore cattle. J. Anim. Sci. 88: 1215–1219.
29 29 Eler, J., Silva, J., Evans, J. et al. (2004). Additive genetic relationships between heifer pregnancy and scrotal circumference in Nellore cattle. J. Anim. Sci. 82: 2519–2527.
30 30 Quirino, C. and Bergmann, J. (1998). Heritability of scrotal circumference adjusted and unadjusted for body weight in Nellore bulls, using univariate and bivariate animal models. Theriogenology 49: 1389–1396.
31 31 McAllister, C., Speidel, S., Crews, D. Jr., and Enns, R. (2011). Genetic parameters for intramuscular fat percentage, marbling score, scrotal circumference, and heifer pregnancy in Red Angus cattle. J. Anim. Sci. 89: 2068–2072.
32 32 Godfrey, R., Randel, R., and Parish, N. (1988). The effect of using the Breeding Soundness Evaluation as a selection criterion for Santa Gertrudis bulls on bulls in subsequent generations. Theriogenology 30: 1059–1068.
33 33 Moser, D., Bertrand, J., Benyshek, L. et al. (1996). Effects of selection for scrotal circumference in Limousin bulls on reproductive and growth traits of progeny. J. Anim. Sci. 74: 2052–2057.
34 34 Eriksson, P., Lundeheim, N., and Söderquist, L. (2012). Changes in mean scrotal circumference in performance tested Swedish beef bulls over time. Acta Vet. Scand. 54: 74.
35 35 Garcia Guerra, A., Hendrick, S., and Barth, A. (2013). Increase in average testis size of Canadian beef bulls. Can. Vet. J. 54: 485–490.
36 36 Mwansa, P., Kemp, R., Crews, D. Jr. et al. (2000). Comparison of models for genetic evaluation of scrotal circumference in crossbred bulls. J. Anim. Sci. 78: 275–282.
37 37 Coe, P. and Gibson, C. (1993). Adjusted 200‐day scrotal size as a predictor of 365‐day scrotal circumference. Theriogenology 40: 1065–1072.
38 38 Barth, A. and Ominski, K. (2000). The relationship between scrotal circumference at weaning and at one year of age in beef bulls. Can. Vet. J. 41: 541–546.
39 39 Toelle, V. and Robison, O. (1985). Estimates of genetic correlations between testicular measurements and female reproductive traits in cattle. J. Anim. Sci. 60: 89–100.
40 40 Smith, B., Brinks, J., and Richardson, G. (1989). Relationships of sire scrotal circumference to offspring reproduction and growth. J. Anim. Sci. 67: 2881–2885.
41 41 Martinez‐Velazquez, G., Gregory, K., Bennett, G., and Van Vleck, L. (2003). Genetic relationships between scrotal circumference and female reproductive traits. J. Anim. Sci. 81: 395–401.
42 42 Macmillan, K. and Hafs, H. (1968). Gonadal and extra gonadal sperm numbers during reproductive development of Holstein bulls. J. Anim. Sci. 27: 697–700.
43 43 Curtis, S. and Amann, R. (1981). Testicular development and establishment of spermatogenesis in Holstein bulls. J. Anim. Sci. 53: 1645–1657.
44 44 Aponte, P., de Rooij, D., and Bastidas, P. (2005). Testicular development in Brahman bulls. Theriogenology 64: 1440–1455.
45 45 Brito,