13 EFFECT OF 6 TIMES REUSING OF CONTROLLED INTERNAL DRUG RELEASE (CIDR) FOR SHORT TERM (6 DAYS) ON PROGESTERONE LEVEL AND REPRODUCTIVE PERFORMANCE OF AWASSI EWES
A. Swelum A B , A. Mouamen A and A. Alowaimer AA Department of Animal Production, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia;
B Department of Theriogenology, Faculty of Veterinary Medicine, Zagazig University, Sharkia, Egypt
Reproduction, Fertility and Development 28(2) 136-136 https://doi.org/10.1071/RDv28n2Ab13
Published: 3 December 2015
Abstract
This study was carried out using 120 multiparous Awassi ewes during breeding season to compare the effect of 6 times reusing of CIDR short term (6 days) on hormonal and reproductive performance. Ewes were equally and randomly allotted into 6 consecutive oestrus synchronization treatments. For group CIDR6×1, the ewes (n = 20) received new CIDR for 6 days with 300 IU of eCG at withdrawal time. For the other 5 groups, the same protocol was used, differing only by the use of the same CIDR for a second time in CIDR6×2, for a third time in CIDR6×3, for a fourth time in CIDR6×4, for a fifth time in CIDR6×5, and for a sixth time in CIDR6×6. Oestrus was detected using a vasectomized ram starting 12 h after progestagen withdrawal and repeated every 12 h up to 84 h. Blood samples were collected at withdrawal time (Day 6). Progesterone serum concentrations were measured using commercial ELISA kits and micro-titrimetric plates. Timed insemination was performed 48 h after CIDR withdrawal. Pregnancy and number of fetuses were diagnosed by ultrasonography at Day 23 after insemination and confirmed at Day 35 and 60. Comparisons among groups was evaluated using chi-square (χ2) test in all parameters except hormones levels, which was analysed by repeated-measures ANOVA, using SAS (SAS Institute Inc., Cary, NC, USA, 2000). The results revealed that there is no significant difference between the percentages of ewes detected in heat in groups CIDR6×1, CIDR6×2, and CIDR6×3 (55, 70, and 55%, respectively). While, the percentages of ewes detected in heat in group CIDR6×2 was significantly (P ≤ 0.05) higher than in groups CIDR6×4, CIDR6×5, and CIDR6×6 (35, 35, 31.58%, respectively). On the other hand, pregnancy rate was significantly (P ≤ 0.05) higher in CIDR6×2 (65%; 13/20) than CIDR6×3, CIDR6×4, CIDR6×5, and CIDR6×6 (30, 30, 30, and 15.79, respectively). No significant difference was detected in pregnancy rate between CIDR6×1 and CIDR6×2. No significant differences were detected in progesterone between CIDR6×1 and CIDR6×2, CIDR6×3, CIDR6×4, CIDR6×5, and CIDR6×6 (1.73, 1.67, 1.87, 1.57, 1.60, and 1.36 ng mL–1, respectively). These results indicated that reusing of CIDR devices for short term are efficient in synchronizing oestrus in ewes.
