Abstract #201

Section: Superovulation
Session: Superovulation
Format: Poster
Location: Rio Exhibit Hall B
# 201
M. Sugawara*1, Y. Kaneda1, A. Miyoshi1, H. Sekizawa2, O. Dochi3, 1North Bull Inc, Sendai, Miyagi, Japan;, 2Sekizawa Animal Clinic, Nasushiobara, Tochigi, Japan;, 3Department of of Sustainable Agriculture, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.

Superovulation treatment using FSH requires injection twice a day, for 3 to 4 days. This conventional method requires frequent handling of donors and higher labour costs. Therefore, simplification of the superovulation treatment protocol is needed to reduce animal handling and labour costs. The objective of this study was to investigate the effect of a single subcutaneous FSH injection and the timing of prostaglandin F (PGF; cloprostenol) administration on the superovulatory response in Japanese Black cows (Hiraizumi et al. 2015 Theriogenology 83, 466–473) and to determine whether the superovulation treatment protocol can be used in on-farm conditions. A total of 270 Japanese Black cows were used in this study. Twenty Armour units of pFSH dissolved in 30 mL of saline was injected subcutaneously in the neck region. In Experiment 1, 32 cows received an intravaginal progesterone device (CIDR) at random stages of the oestrous cycle (Day 0), and 2 mg of oestradiol benzoate on Day 1 (24 h after CIDR insertion). On Day 6, FSH was injected subcutaneously, and 16 cows were simultaneously injected with 0.5 mg of PGF (0-h PGF, Group A); the other 16 cows were injected with 0.5 mg of PGF at 48 h (on Day 8) after FSH injection (48-h PGF, Group B). The CIDR was removed at 60 h after FSH injection and AI was done 42 to 48 h after CIDR removal. Embryo collections were performed 7 days after AI. In Experiment 2, 238 cows were used in farm conditions. The cows were superstimulated using the same protocol as that used for Group A. Data were analysed by ANOVA for the mean numbers of collected ova/embryos and transferrable embryos and chi-square test for the proportion of transferrable embryos. In Experiment 1, there were no differences in the mean numbers of ova/embryos collected (16.9 ± 12.3 v. 16.1 ± 17.1) or transferrable embryos (11.1 ± 9.5 v. 7.2 ± 6.2). However, the proportion of transferrable embryos for Group A was significantly higher than that of Group B (65.9 v. 44.7%; P < 0.01). In Experiment 2, the mean numbers of ova/embryos collected and transferrable embryos were 15.7 ± 13.3 and 6.8 ± 7.8, respectively. These results showed that a superovulation treatment protocol involving a single subcutaneous injection of FSH with simultaneous PGF injection can be effectively used for Japanese Black cows under on-farm conditions.