Breeding soundness evaluation of extensively managed bulls in Costa Rica
Saved in:
| Authors: | , , , , |
|---|---|
| Format: | artículo |
| Publication Date: | 1999 |
| Description: | This paper describes the results of single breeding soundness evaluations (BSE) in 898 Bos indicus, Bos taurus and B. indicus x B. taurus bulls, 1 to 12 yr. old, extensively reared in different climatic regions of Costa Rica and representing approximately 2% of the total breeding bull population. Thirty-three percent (n= 296) of the bulls were classified as unsound for breeding owing to clinical problems (9.1%, n= 82), low scrotal circumference (SC) being the most common finding, followed by unsatisfactory sperm morphology (23.9%, n= 214). The prevalence of bulls unsound for breeding was lowest in Bos indicus (29%, P<0.01), intermediate in B. taurus (41%), and highest in B. indicus x B. taurus (48%). The percentages of abnormal sperm heads, acrosomes and midpieces tended to be higher in the ejaculates of bulls with softer testicular consistency (P<0.001), a long scrotum (P<0.01) or a low SC (P<0.05), and such bulls were more often classified as being unsound for breeding (P<0.05). Frequencies of sperm abnormalities were higher in bulls < 2 yr of age than in older males (P<0.01) and were highest in B. indicus x B. taurus bulls (P<0.001). The results confirm differences between species in their adaptability to a tropical environment and support earlier evidence of an association between SC, testicular consistency and scrotal length clinical parameters, and testicular function in bulls. |
| Country: | Repositorio UNA |
| Institution: | Universidad Nacional de Costa Rica |
| Repositorio: | Repositorio UNA |
| Language: | Inglés |
| OAI Identifier: | oai:https://repositorio.una.ac.cr:11056/22944 |
| Online Access: | http://hdl.handle.net/11056/22944 |
| Access Level: | acceso abierto |
| Keyword: | TORO GANADO BOVINO BULLS CATTLE REPRODUCCIÓN ANIMAL ANIMAL REPRODUCTION ESPERMATOZOIDES SPERM |