Successful induction of oestrus, ovulation and pregnancy in adult ewes and ewe lambs out of the breeding season using a GnRH+progesterone oestrus synchronisation protocol

Autor: M. F. Martínez, B. Smaill, G. Tattersfield, Laurel D. Quirke, B. McLeod, J. L. Juengel
Rok vydání: 2015
Předmět:
Zdroj: Animal Reproduction Science. 155:28-35
ISSN: 0378-4320
Popis: A series of experiments was designed to assess the effect of a treatment protocol (U-synch) for inducing oestrus and ovulation out of the breeding season in adult ewes and ewe lambs. The protocol consisted of a 7-day treatment with an intravaginal progesterone-releasing device (IPRD), administration of GnRH at IPRD insertion on Day 0, and equine chorionic gonadotropin (eCG) and prostaglandin F2α at IPRD removal on Day 7. In Experiment 1, 50 or 100 μg GnRH were sufficient to induce ovulation at the beginning of the protocol in 3/9 and 4/9 ewes, respectively; while the resulting proportion of sheep ovulating after the treatment protocol was 88.9% and 77.8% in ewes initially treated with 50 or 100 μg GnRH, respectively. In Experiment 2, the proportion of Romney-cross ewe lambs ovulating was greater (P
Databáze: OpenAIRE