239 Effect of dietary flaxseed supplementation on folliculo-endocrine, superovulatory response, embryo quality, and pregnancy rate in Sahiwal cows

Increasing the dietary energy through saturated or unsaturated fat improves the reproductive indices in the high yielding dairy cows. Sahiwal is an excellent indigenous milch breed of India. To conserve the Sahiwal breed and exploit the genetically superior females, multiple ovulation embryo transfer (MOET) is an established technique. We hypothesised that flaxseed supplementation during the window of superovulatory protocol would improve the ovarian response to superstimulation, embryo quality, and pregnancy rate in the Sahiwal cows. The present study was conducted at Cattle and Buffalo farm, ICAR-IVRI, Izatnagar, India. The experimental Sahiwal cows (n = 20) were selected and divided into two groups, control (n = 10) and treatment (n = 10). The treatment group was supplemented with crushed flaxseed at 300 g/100 kg bodyweight once daily for 40–42 days from the day of oestrus (Day 0), while the non-supplemented group served as control. The superovulation protocol was started in donor Sahiwal cows on the ninth day of the oestrous cycle. FSH was given in eight divided doses in morning and evening in a tapering manner for four days (total 220 µg). Superovulatory oestrus was monitored twice in a day, i.e. morning and evening, using teaser bull after 500 µg cloprostenol injection, given along with fifth dose of pFSH. Artificial insemination with high-quality frozen semen of the same bull was performed three times at an interval of 12 h. Flushing was done on Day 7, post-superovulatory-oestrus and embryos were identified under the Stereozoom microscope. Quality of the embryo was assessed according to the criteria of IETS. Only Grade 1 embryos (n = 40) were transferred in HF cross-bred recipients. Follicular and luteal dynamics, superovulatory response was analysed by independent t-test, embryo quality by chi-squared test, and pregnancy rate by Fisher’s exact test. Serum cholesterol, BHBA, NEFA, TNF-α, and IGF-1 were analysed using ELISA and progesterone using RIA and were statistically analysed by two-way repeat measures ANOVA. Significant differences were reported if P ≤ 0.05. Preovulatory follicle diameter (mm) was significantly larger at post-supplementation oestrus in the treatment group (13.53 ± 0.45) compared with control (12.11 ± 0.31). The maximum diameter of corpus luteum (mm) was significantly greater in the treatment group (19.9 ± 0.4) than control (18.5 ± 0.5). No significant effect on the number of embryos per cow in treatment group (5.3 ± 0.5) compared with control (6.1 ± 1.5) but feeding flaxseed increased pregnancy rate in (45 vs 35%), Grade 1 embryos (66.7 vs 44.9%) and decreased the dead or degenerated embryos (2.3 vs 18.6%) compared with control group. Flaxseed supplementation reduced the serum NEFA, BHBA, and TNF-α concentration and increased the cholesterol, IGF-1, and progesterone concentration. Supplementing crushed flaxseed for six weeks around the superovulatory window increased the size of preovulatory follicle diameter, corpus luteum, and progesterone concentration, reduced the number of anovulatory follicles, and improved the embryo quality and pregnancy rate in Sahiwal cows.