Data/hora: 06/06/2024 02:27:53

Provedor de dados: 	19	
País: 	Japan	
Título: 	Factors Affecting the Fertility of Ewes after Intrauterine Insemination with Frozen-Thawed Semen During the Non-Breeding Season	
Autores: 	FUKUI, Yutaka; KOHNO, Hirohide; OKABE, Kentaro; KATSUKI, Sara; YOSHIZAWA, Masahiro; TOGARI, Tetsuro; WATANABE, Hiroyuki; 福井, 豊.	
Data: 	2010	
Ano: 	2010	
Palavras-chave: 	Artificial insemination; Fertility; Frozen semen; Sheep.	
Resumo: 	In this study, two successive field trials were conducted during the non-breeding season to investigate various factors affecting on fertility of Suffolk ewes after intrauterine insemination with frozen-thawed semen. In the first year (Experiment 1), three sperm numbers per insemination dose (0.25, 0.5 and 1 million sperm) and five sheep farms were used, and in the second year (Experiment 2), parity, age, body weight, body condition score (BCS) and postpartum days were investigated to compare pregnancy and lambing rates. High pregnancy and lambing rates (70.6 and 70.6%, respectively) were obtained with 0.25 million sperm per dose. There were no significant differences in the pregnancy and lambing rates among the five farms, but there was a tendency for one farm to have higher pregnancy (75.8%, P=0.065) and lambing (72.7%, P=0.077) rates than those (46.7-53.3% and 45.2-53.3% for the pregnancy and lambing rates, respectively) of the other farms. In Experiment 2, ewe age significantly affected both the pregnancy and lambing rates. Nulliparous ewes had a higher lambing rate (72.0%) than that (44.2%) of multiparous ewes, but a significant difference was not revealed. Regardless of body weight, BCS tended to be an important factor influencing on fertility of ewes. Body weight and the postpartum days did not affect the fertility of ewes. It was concluded from these results that the fertility of Suffolk ewes after intrauterine insemination with frozen semen was significantly influenced by sperm number per dose and ewe age. Nulliparous ewes at less than three years of age and with a BCS of more than 3.0 are expected to have higher fertility than other ewes.	
Idioma: 	Inglês	
Identificador: 	http://ir.obihiro.ac.jp/dspace/handle/10322/2817	
Formato: 	application/pdf	
Fonte: 	日本繁殖生物学会