Читать книгу Bovine Reproduction - Группа авторов - Страница 99

1 1 Johnson, W., Thompson, J., Kumi‐Diaka, J. et al. (1995). The determination and correlation of reproductive parameters of performance‐tested Hereford and Simmental bulls. Theriogenology 44: 973–982.

2 2 Bell, D., Spitzer, J., Bridges, W. Jr., and Olson, L. (1996). Methodology for adjusting scrotal circumference to 365 or 452 days of age and correlations of scrotal circumference with growth traits in beef bulls. Theriogenology 46: 659–669.

3 3 Coulter, G. and Keller, D. (1982). Scrotal circumference of young beef bulls: 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, L., Barth, A., Wilde, R., and Kastelic, J. (2012). Testicular ultrasonogram pixel intensity during sexual development and its relationship with semen quality, sperm production, and quantitative testicular histology in beef bulls. Theriogenology 78: 69–76.

46 46 Brito, L., Silva, A., Rodrigues, L. et al. (2002). Effect of age and genetic group on characteristics of the scrotum, testes and testicular vascular cones, and on sperm production and semen quality in AI bulls in Brazil. Theriogenology 58: 1175–1186.

47 47 Wolf, F., Almquist, J., and Hale, E. (1965). Prepuberal behavior and puberal characteristics of beef bulls on high nutrient allowance. J. Anim. Sci. 24: 761–765.

48 48 Lunstra, D., Ford, J., and Echternkamp, S. (1978). Puberty in beef bulls: hormone concentrations, growth, testicular development, sperm production and sexual aggressiveness in bulls of different breeds. J. Anim. Sci. 46: 1054–1062.

49 49 Jimenez‐Severiano, H. (2002). Sexual development of dairy bulls in the Mexican tropics. Theriogenology 58: 921–932.

50 50 Aravindakshan, J., Honaramooz, A., Bartlewski, P. et al. (2000). Pattern of gonadotropin secretion and ultrasonographic evaluation of developmental changes in the testis of early and late maturing bull calves. Theriogenology 54: 339–354.

51 51 Killian, G. and Amann, R. (1972). Reproductive capacity of dairy bulls. IX. Changes in reproductive organ weights and semen characteristics of Holstein bulls during the first thirty weeks after puberty. J. Dairy Sci. 55: 1631–1635.

52 52 Wildeus, S. and Entwistle, K. (1982). Postpubertal changes in gonadal and extragonadal sperm reserves in Bos indicus strain bulls. Theriogenology 17: 655–667.

53 53 Weisgold, A. and Almquist, J. (1979). Reproductive capacity of beef bulls. VI. Daily spermatozoal production, spermatozoal reserves and dimensions and weight of reproductive organs. J. Anim. Sci. 48: 351–358.

54 54 Amann, R., Kavanaugh, J., Griel, L. Jr., and Voglmayr, J. (1974). Sperm production of Holstein bulls determined from testicular spermatid reserves, after cannulation of rete testis or vas deferens, and by daily ejaculation. J. Dairy Sci. 57: 93–99.

55 55 Almquist, J. (1982). Effect of long term ejaculation at high frequency on output of sperm, sexual behavior, and fertility of Holstein bulls; relation of reproductive capacity to high nutrient allowance. J. Dairy Sci. 65: 814–823.

56 56 Godinho, H. and Cardoso, F. (1984). Gonadal and extragonadal sperm reserves of the Brazilian Nelore zebu (Bos indicus). Andrologia 16: 131–134.

57 57 Brito, L., Silva, A., Barbosa, R., and Kastelic, J. (2004). Testicular thermoregulation in Bos indicus, crossbred and Bos taurus bulls: relationship with scrotal, testicular vascular cone and testicular morphology, and effects on semen quality and sperm production. Theriogenology 61: 511–528.

58 58 Amann R, Almquist J. (1976), Bull management to maximize sperm output. Proceedings of the 6th Technical Conference on Artificial Insemination and Reproduction. Columbia, MO: National Association of Animal Breeders, pp. 1–10.

59 59 Amann R. (1990), Management of bulls to maximize sperm output. Proceedings of the 13th Technical Conference on Artificial Insemination and Reproduction. Columbia, MO: National Association of Animal Breeders, pp. 84–91.

60 60 Lunstra, D. and Echternkamp, S. (1982). Puberty in beef bulls: acrosome morphology and semen quality in bulls of different breeds. J. Anim. Sci. 55: 638–648.

61 61 Brito, L., Barth, A., Wilde, R., and Kastelic, J. (2012). Effect of growth rate from 6 to 16 months of age on sexual development and reproductive function in beef bulls. Theriogenology 77: 1398–1405.

62 62 Arteaga, A., Baracaldo, M., and Barth, A. (2001). The proportion of beef bulls in western Canada with mature spermiograms at 11 to 15 months of age. Can. Vet. J. 42: 783–787.

63 63 Persson, Y. and Soderquist, L. (2005). The proportion of beef bulls in Sweden with mature spermiograms at 11–13 months of age. Reprod. Domest. Anim. 40: 131–135.

64 64 Felton‐Taylor, J., Prosser, K., Hernandez‐Medrano, J. et al. (2020). Effect of breed, age, season and region on sperm morphology in 11,387 bulls submitted to breeding soundness evaluation in Australia. Theriogenology 142 (1–7).

65 65 Brito, L., Barth, A., Wilde, R., and Kastelic, J. (2012). Testicular vascular cone development and its association with scrotal temperature, semen quality, and sperm production in beef bulls. Anim. Reprod. Sci. 134: 135–140.

66 66 Cook, R., Coulter, G., and Kastelic, J. (1994). The testicular vascular cone, scrotal thermoregulation, and their relationship to sperm production and seminal quality in beef bulls. Theriogenology 41: 653–671.

67 67 Kirby, A. (1953). Observations on the blood supply of the bull testis. Br. Vet. J. 109: 464–472.

68 68 Kirby, A. and Harrison, R. (1954). A comparison of the vascularization of the testis in Afrikaner and English breeds of bull. Proc. Soc. Study Fertil. 6: 129–139.

69 69 Hofmann, R. (1960). Die Gefabarchitektur des bullenhodens, Zugleich eim Versuch ihrer funktionellen Deutung. Zentralbl. Vetrinarmed. 7: 59–93.

70 70 Almquist, J. and Amann, R. (1961). Reproductive capacity of dairy bulls. II. Gonadal and extra‐gonadal sperm reserves as determined by direct counts and depletion trials: dimensions and weight of genitalia. J. Dairy Sci. 44: 1668–1678.

71 71 Abdel‐Razek, A. and Ali, A. (2005). Developmental changes of bull (Bos taurus) genitalia as evaluated by caliper and ultrasonography. Reprod. Domest. Anim. 40: 23–27.

72 72 Coulter, G. (1986). Puberty and postpubertal development of beef bulls. In: Current Therapy in Theriogenology, 2e (ed. A.D. Morrow), 142–148. Philadelphia: Saunders.

73 73 Ashdown, R., David, J., and Gibbs, C. (1979). Impotence in the bull: 1. Abnormal venous drainage of the corpus cavernosum penis. Vet. Rec. 104: 423.

74 74 Barber, K. and Almquist, J. (1975). Growth and feed efficiency and their relationship to puberal traits of Charolais bulls. J. Anim. Sci. 40: 288–301.

75 75 Price, E. and Wallach, S. (1991). Development of sexual and aggressive behaviors in Hereford bulls. J. Anim. Sci. 69: 1019–1027.

76 76 Lane, S., Kiracofe, G., Craig, J., and Schalles, R. (1983). The effect of rearing environment on sexual behavior of young beef bulls. J. Anim. Sci. 57: 1084–1089.

77 77 Price, E. and Wallach, S. (1990). Short‐term individual housing temporarily reduces the libido of bulls. J. Anim. Sci. 68: 3572–3577.

78 78 Boyd, G. and Corah, L. (1988). Effect of sire and sexual experience on serving capacity of yearling beef bulls. Theriogenology 29: 779–790.

79 79 Price, E. and Wallach, S. (1991). Inability to predict the adult sexual performance of bulls by prepuberal sexual behaviors. J. Anim. Sci. 69: 1041–1046.

80 80 Chenoweth, P., Brinks, J., and Nett, T. (1979). A comparison of three methods of assessing sex‐drive in yearling beef bulls and relationships with testosterone and LH levels. Theriogenology 12: 223–233.

81 81 Landaeta‐Hernandez, A., Chenoweth, P., and Berndtson, W. (2001). Assessing sex‐drive in young Bos taurus bulls. Anim. Reprod. Sci. 66: 151–160.

82 82 de Araujo, J., Borgwardt, R., Sween, M. et al. (2003). Incidence of repeat‐breeding among Angus bulls (Bos taurus) differing in sexual performance. Appl. Anim. Behav. Sci. 81: 89–98.

83 83 Chenoweth, P., Farin, P., Mateos, E. et al. (1984). Breeding soundness and sex drive by breed and age in beef bulls used for natural mating. Theriogenology 22: 341–349.

84 84 Bratton, R., Musgrave, S., Dunn, H., and Foote, R. (1959). Causes and prevention of reproductive failure in dairy cattle: II. Influence of underfeeding and overfeeding from birth to 80 weeks of age on growth, sexual development, and semen production in Holstein bulls. Cornell Uni. Agric. Experiment. Station Bull. 940: 1–45.

85 85 Flipse, R. and Almquist, J. (1961). Effect of total digestible nutrient intake from birth to four years of age on growth and reproductive development and performance of dairy bulls. J. Dairy Sci. 44: 905–914.

86 86 Brito, L., Barth, A., Rawlings, N. et al. (2007). Effect of feed restriction during calfhood on serum concentrations of metabolic hormones, gonadotropins, testosterone, and on sexual development in bulls. Reproduction 134: 171–181.

87 87 Brito, L., Barth, A., Rawlings, N. et al. (2007). Effect of improved nutrition during calfhood on serum metabolic hormones, gonadotropins, and testosterone concentrations, and on testicular development in bulls. Domest. Anim. Endocrinol. 33: 460–469.

88 88 Brito, L., Barth, A., Rawlings, N. et al. (2007). Effect of nutrition during calfhood and peripubertal period on serum metabolic hormones, gonadotropins and testosterone concentrations, and on sexual development in bulls. Domest. Anim. Endocrinol. 33: 1–18.

89 89 Harstine, B., Maquivar, M., Helser, L. et al. (2015). Effects of dietary energy on sexual maturation and sperm production in Holstein bulls. J. Anim. Sci. 93: 2759–2766.

90 90 Dance, A., Thundathil, J., Wilde, R. et al. (2015). Enhanced early‐life nutrition promotes hormone production and reproductive development in Holstein bulls. J. Dairy Sci. 98: 987–988.

91 91 Byrne, C., Fair, S., English, A. et al. (2018). Plane of nutrition before and after 6 months of age in Holstein‐Friesian bulls: I. Effects on performance, body composition, age at puberty, and postpubertal semen production. J. Dairy Sci. 101: 3447–3459.

92 92 Lunstra, D., Gregory, K., and Cundiff, L. (1988). Heritability estimates and adjustment factors for the effects of bull age and age of dam on yearling testicular size in breeds of bulls. Theriogenology 30: 127–136.

93 93 Bagu, E., Davies, K., Epp, T. et al. (2010). The effect of parity of the dam on sexual maturation, serum concentrations of metabolic hormones and the response to luteinizing hormone releasing hormone in bull calves. Reprod. Domest. Anim. 45: 803–810.

94 94 Mann, T., Rowson, L., Short, R., and Skinner, J. (1967). The relationship between nutrition and androgenic activity in pubescent twin calves, and the effect of orchitis. J. Endocrinol. 38: 455–468.

95 95 Meacham, T., Cunha, T., Warnick, A. et al. (1963). Influence of low protein rations on growth and semen characteristics of young beef bulls. J. Anim. Sci. 22: 115–120.

96 96 Meacham, T., Warnick, A., Cunha, T. et al. (1964). Hematological and histological changes in young beef bulls fed low protein rations. J. Anim. Sci. 23: 380–384.

97 97 Pruitt, R. and Corah, L. (1985). Effect of energy intake after weaning on the sexual development of beef bulls. I. Semen characteristics and serving capacity. J. Anim. Sci. 61: 1186–1193.

98 98 Pruitt, R., Corah, L., Stevenson, J., and Kiracofe, G. (1986). Effect of energy intake after weaning on the sexual development of beef bulls. II. Age at first mating, age at puberty, testosterone and scrotal circumference. J. Anim. Sci. 63: 579–585.

99 99 Skinner, J. (1981). Nutrition and fertility in pedigree bulls. In: Environmental Factors in Mammal Reproduction (eds. D. Gilmore and B. Cook), 160–168. London: MacMillan.

100 100 Coulter, G. and Kozub, G. (1984). Testicular development, epididymal sperm reserves and seminal quality in two‐year‐old Hereford and Angus bulls: effects of two levels of dietary energy. J. Anim. Sci. 59: 432–440.

101 101 Coulter, G., Carruthers, T., Amann, R., and Kozub, G. (1987). Testicular development, daily sperm production and epididymal sperm reserves in 15‐mo‐old Angus and Hereford bulls: effects of bull strain plus dietary energy. J. Anim. Sci. 64: 254–260.

102 102 Coulter, G. and Bailey, D. (1988). Epididymal sperm reserves in 12‐month‐old Angus and Hereford bulls: effects of bull strain plus dietary energy. Anim. Reprod. Sci. 16: 169–175.

103 103 Coulter, G., Cook, R., and Kastelic, J. (1997). Effects of dietary energy on scrotal surface temperature, seminal quality, and sperm production in young beef bulls. J. Anim. Sci. 75: 1048–1052.

104 104 Seidel G Jr, Pickett B, Wilsey C, Seidel S., (1980) Effect of high level of nutrition on reproductive characteristics of Angus bulls. Proceedings of the 9th International Congress on Animal Reproduction and Artificial Insemination. Madrid: Editorial Garsi, p. 359.

105 105 Hopkins, F. and Spitzer, J. (1997). The new Society for Theriogenology breeding soundness evaluation system. Vet. Clin. North Am. Food Anim. Pract. 13: 283–293.

106 106 Kennedy, S., Spitzer, J., Hopkins, F. et al. (2002). Breeding soundness evaluations of 3,648 yearling beef bulls using the 1993 Society for Theriogenology guidelines. Theriogenology 58: 947–961.

107 107 Higdon, H., Spitzer, J., Hopkins, F., and Bridges, W. Jr. (2000). Outcomes of breeding soundness evaluation of 2,898 yearling bulls subjected to different classification systems. Theriogenology 53: 1321–1332.

108 108 Chenoweth, P., Chase, C. Jr., Thatcher, M. et al. (1996). Breed and other effects on reproductive traits and breeding soundness categorization in young beef bulls in Florida. Theriogenology 46: 1159–1170.

109 109 Godfrey, R. and Dodson, R. (2005). Breeding soundness evaluations of Senepol bulls in the US Virgin Islands. Theriogenology 63: 831–840.

110 110 Carson, R. and Wenzel, J. (1997). Observations using the new bull‐breeding soundness evaluation forms in adult and young bulls. Vet. Clin. North Am. Food Anim. Pract. 13: 305–311.

111 111 Barth, A. and Waldner, C. (2002). Factors affecting breeding soundness classification of beef bulls examined at the Western College of Veterinary Medicine. Can. Vet. J. 43: 274–284.

112 112 Fonseca, V., Santos, N., and Malinski, P. (1997). Andrological classification of zebu bulls based on scrotal perimeter and morpho‐physic of the semen characteristics. Rev. Bras. Reprod. Anim. 21: 36–39.

113 113 Vale Filho, V., Bergmann, J., Andrade, V. et al. (1997). Andrologic characterization of Nelore bulls selected for the first breed season. Rev. Bras. Reprod. Anim. 21: 42–44.

114 114 Hahn, J., Foote, R., and Seidel, G. Jr. (1969). Testicular growth and related sperm output in dairy bulls. J. Anim. Sci. 29: 41–47.

115 115 Coulter, G. and Foote, R. (1976). Relationship of testicular weight to age and scrotal circumference of Holstein bulls. J. Dairy Sci. 59: 730–732.

116 116 Quirino, C., Bergmann, J., Vale Filho, V. et al. (1999). Evaluation of four mathematical functions to describe scrotal circumference maturation in Nellore bulls. Theriogenology 52: 25–34.

117 117 Loaiza‐Echeverri, A., Bergmann, J., Toral, F. et al. (2013). Use of nonlinear models for describing scrotal circumference growth in Guzerat bulls raised under grazing conditions. Theriogenology 79: 751–759.

118 118 Sylla, L., Stradaioli, G., Borgami, S., and Monaci, M. (2007). Breeding soundness examination of Chianina, Marchigiana, and Romagnola yearling bulls in performance tests over a 10‐year period. Theriogenology 67: 1351–1358.

119 119 Troconiz, J., Beltran, J., Bastidas, H. et al. (1991). Testicular development, body weight changes, puberty and semen traits of growing Guzerat and Nellore bulls. Theriogenology 35: 815–826.

120 120 Silveira, T., Siqueira, J., Guimaraes, S. et al. (2010). Maturação sexual e parâmetros reprodutivos em touros da raça Nelore criados em sistema extensivo. Rev. Bras. Zootec. 39: 503–511.

121 121 Menegassi, S., Barcellos, J., Peripolli, V. et al. (2011). Measurement of scrotal circumference in beef bulls in Rio Grande do Sul. Arq. Bras. Med. Vet. Zootec. 63: 87–93.

122 122 Smith, B., Brinks, J., and Richardson, G. (1989). Estimation of genetic parameters among breeding soundness examination components and growth traits in yearling bulls. J. Anim. Sci. 67: 2892–2896.

123 123 Beef Improvement Federation. (2010), Guidelines for Uniform Beef Improvement Programs, 9th edn. Available at http://www.beefimprovement.org.

124 124 Casas, E., Lunstra, D., Cundiff, L., and Ford, J. (2007). Growth and pubertal development of F1 bulls from Hereford, Angus, Norwegian Red, Swedish Red and White, Friesian, and Wagyu sires. J. Anim. Sci. 85: 2904–2909.

125 125 Chase, C. Jr., Chenoweth, P., Larsen, R. et al. (1997). Growth and reproductive development from weaning through 20 months of age among breeds of bulls in subtropical Florida. Theriogenology 47: 723–745.

126 126 Fields, M., Hentges, J. Jr., and Cornelisse, K. (1982). Aspects of the sexual development of Brahman versus Angus bulls in Florida. Theriogenology 18: 17–31.

127 127 Rocha, A., Carpena, M., Triplett, B. et al. (1995). Effect of ruminally undegradable protein from fish meal on growth and reproduction of peripuberal Brahman bulls. J. Anim. Sci. 73: 947–953.

128 128 Silva‐Mena, C. (1997). Peripubertal traits of Brahman bulls in Yucatan. Theriogenology 48: 675–685.

129 129 Freneau, G., Vale Filho, V., Marques, A. Jr., and Maria, W. (2006). Puberdade em touros Nelore criados em pasto no Brasil: características corporais, testiculares e seminais e de índice de capacidade andrológica por pontos. Arq. Bras. Med. Vet. Zootec. 58: 1107–1115.