Journal ArticleDOI
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
Leonardo F.C. Brito,Antonio Emidio Dias Feliciano Silva,L. H. Rodrigues,Flaviana Vieira,L.A.G. Deragon,John P. Kastelic +5 more
TLDR
Age and genetic group affected the characteristics of the scrotum, testes, and TVC, sperm production and semen quality in bulls and could be assessed for breeding soundness evaluation.About:
This article is published in Theriogenology.The article was published on 2002-10-01. It has received 122 citations till now. The article focuses on the topics: Semen quality & Sperm.read more
Citations
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Journal ArticleDOI
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
Leonardo F.C. Brito,Antonio Emidio Dias Feliciano Silva,Antonio Emidio Dias Feliciano Silva,Rogério Taveira Barbosa,John P. Kastelic +4 more
TL;DR: Morphology of the TVC may contribute to the greater resistance of B. indicus bulls to high ambient temperatures by conferring a better testicular blood supply and by facilitating heat transfer between the testicular artery and veins.
Journal ArticleDOI
Effects of age and environmental factors on semen production and semen quality of Austrian Simmental bulls.
TL;DR: Temperature, either on day of semen collection or during epididymal maturation or spermatogenesis, had important but inconsistent effects on semen production and sperm quality, however, ambient temperatures in the range of 5-15 degrees C were found to be optimal for semen production.
Journal ArticleDOI
Sexual development in early- and late-maturing Bos indicus and Bos indicus × Bos taurus crossbred bulls in Brazil
Leonardo F.C. Brito,Antonio Emidio Dias Feliciano Silva,Maria Marina Unanian,Margot Alves Nunes Dode,Rogério Taveira Barbosa,John P. Kastelic +5 more
TL;DR: Early-maturing bulls were more developed in the pre-pubertal period and attained puberty at earlier stages of body and testicular development than late-matured bulls.
Journal ArticleDOI
Reproductive Traits and Their Heritabilities in Beef Cattle
TL;DR: This review evaluates historic and current measures of assessing fertility and the heritabilities of these traits in beef cattle, and assesses whole-herd reporting and improved analysis techniques.
The effects of heat on the testes of mammals
TL;DR: Evidence of long-term effects, following either locally applied heat or temporary induced cryptorchidism, appears to be different from those seen following irradiation, and may indicate a failure of Sertoli cell function.
References
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Environmental, Management, and Genetic Factors Affecting Semen Production in Holstein Bulls
TL;DR: Genetics, management, and environmental factors clearly contribute to semen production in Holstein bulls and generally improved significantly with age of young bulls.
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Bovine testicular measurements as indicators of reproductive performance and their relationship to productive traits in cattle: A review
G.H. Coulter,Robert H. Foote +1 more
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Age, season and breed effects on testicular volume and semen traits in young beef bulls.
TL;DR: Angus bulls exhibited stable to slight increases in testes size, semen volume and semen quality, suggesting that this breed had reached its most rapid stage of development by 16 months of age, while Hereford bulls showed a decline in testicular size and semenquality suggesting that Hereford Bulls suffered from the environmental stresses of the semitropical summer in Florida.
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Caliper and ultrasonographic measurements of bovine testicles and a mathematical formula for determining testicular volume and weight in vivo.
TL;DR: Caliper measurements are reliable, inexpensive and much simpler to obtain than ultrasound determinations for in vivo testicle length, width, volume and weight.
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Changes in circulating hormone concentrations, testes histology and testes ultrasonography during sexual maturation in beef bulls.
TL;DR: It is concluded that testis echogenicity increased during the most active phase of growth of the seminiferous tubules as more mature germ cells were produced and testosterone secretion rose markedly with the production of mature spermatozoa.