Reproductive Management of Rams and Ram Lambs during the Pre-Breeding Season in US Sheep Farms

Abstract

In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram on reproductive results, because one male has the potential to affect a large group of females and therefore greatly affects the entire flock. Unfortunately, the selection of males for breeding in the US sheep industry has been traditionally conducted based on phenotypical traits, without a genetic/reproductive evaluation, and/or health assessment or records. Therefore, it is important to establish integrative management practices to select the rams and ram lambs to be used in the breeding season. Among these practices are genomic testing, a comprehensive breeding soundness evaluation and assessment of health status and records of the males before the breeding season, to detect and correct potential issues.

Comportamiento reproductivo del carnero en un rebaño de ovejas "Obispo" de la montaña del estado de Guerrero, México

“…La correlación de Spearman más alta fue entre la CE y el PC (rs [60]=0,83; P<0,001), y la CE mostró correlaciones positivas mayores de 0,5 con las demás variables (P<0,001). La CE es una característica muy importante al estar relacionada positivamente con la producción espermática [17].…”

“…La CE del borrego "Obispo" fue similar a lo reportado en borrego Pelibuey [7]; pero el PC y CE reportados en machos criollos de Chiapas [24] resultaron ser ligeramente inferiores a la encontrada en machos Obispo. Proporcionalmente, el macho ovino criollo tiene mayor relación de CE y razas como la Suffolk, que son de mayor talla [17].…”

“…Estudios realizados bajo condiciones tropicales [2,8] y en condiciones templadas [17], evaluaron la capacidad de monta durante 10 y 20 min, respectivamente. Los resultados de estos estudios mostraron un amplio rango para el número de servicios, y los promedios son menores comparados con los observados en este estudio para carneros "Obispo", que fueron sometidos a una prueba individual de libido más corta (5 min).…”

An Update on South African Indigenous Sheep Breeds’ Extinction Status and Difficulties during Conservation Attempts: A Review

“…This alone hinders the success of the conservation program because the history of that donor is not known [76]. Moreover, nutrition, management, environment, and the climate have been proven to affect reproduction adversely [77]. Therefore, when ovaries are collected in the abattoir, it is very unlikely to be provided with such information.…”

Bacterial Diseases Affecting Sheep and Goats

“…Both bucks and rams develop orchitis as a consequence of infection. Systemic signs are negligible amongst either species during initial phases, yet certain researchers have associated a sudden decrease in milk yield and compromised sperm count with the clinical onset of the disease (Maquivar et al 2021). Some animals may also develop arthritis in chronic cases of infection.…”