Premium
Effects of Ram Introduction After the Second Prostaglandin F 2 α Injection on Day 11 on the LH Surge Characteristics in Fat‐Tailed Ewes
Author(s) -
Yildiz S,
Saatci M,
Uzun M,
Güven B
Publication year - 2003
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1046/j.1439-0531.2003.00396.x
Subject(s) - prostaglandin f2alpha , zoology , medicine , prostaglandin , endocrinology , chemistry , biology
Contents The aim of this study was to evaluate the effects of ram introduction after the second prostaglandin F 2 α (PG F 2 α ) injection on day 11 on the secretion characteristics of pre‐ovulatory LH surge of fat‐tailed ewes. Multiparous Morkaraman ewes (n=12) were divided into three groups by balancing the groups for liveweight (BW) and body condition score (BCS). On the day of second PGF 2 α injection (0 h), performance tested rams (n=2) were either introduced to the ewes at 0 h (ram 0 group, n=4) or at 18 h (ram 18 group, n=4) or were not introduced (control group, n=4). Blood samples were collected at 6, 18, 42, 48, 56, 62, 66, 70, 74, 78 and 90 h for the determination of pre‐ovulatory LH surge. BCS and BW during the experimental period were 2.2 ± 0.2 units and 50.9 ± 2.3 kg, 2.4 ± 0.4 units and 49.2 ± 6.2 kg, 2.1 ± 0.3 units and 45.9 ± 4.4 kg, respectively for the ram 0, ram 18 and control groups (p > 0.05). No significant difference was observed in LH surge characteristics for the experimental groups. Peak LH concentrations were also not different between groups (p > 0.05) and they were 12.2 ± 8.3, 29.1 ± 9.9 and 15.8 ± 9.5 μg/l for the ram 0, ram 18 and control groups, respectively. There was, however, a significant correlation between peak LH concentrations and BCS (p < 0.05, R 2 =0.373). In conclusion, it appears that, compared with ram introduction, variability in body condition of the ewe has much pronounced effect on the amount of LH secreted after the usage of two PGF 2 α injections (11 days apart) as a tool for oestrus synchronization.