Med. Weter. 81
full text
| ANDRZEJ RAŚ, MAŁGORZATA NORYŃSKA-RAŚ, JULIA KLAJNA |
| Association of several factors with embryonic death in mares in north-east Poland. |
| The aim of this study was to investigate the impact of several factors on the occurrence of embryonic death in mares in north-east Poland. In the years 2018-2021 the pregnancy was diagnosed 12-19 days after mating in 3230 out of 4090 cold blooded mares (78.9%). During a re-examination carried out 45-60 days after mating, 288 mares (8.9%) were found not pregnant. The embryonic death rate was significantly higher in mares aged 14-23 years compared to younger ones (18.3% vs. 7.8%; p < 0.05). Mares treated previously for endometritis lost significantly more embryos than healthy mares (16.7% vs. 7.9%; p < 0.05). The embryonic loss rate was significant higher in mares with endometrial cysts than mares without endometrial cysts (16.9% vs. 8.5%; p < 0.05). Mares mated during foal heat showed a significantly higher embryonic death rate than mares mated in later heats (22.8% vs. 7.8%; p < 0.05). Mares with induction of ovulation lost significantly fewer pregnancies between both examinations than mares without induction of ovulation (5.7 vs. 9.4%; p < 0.05). In conclusion, age, history of endometritis, endometrial cysts, and mating during foal heat were associated with increased embryonic mortality in mares in north-east Poland. The age of mares and mating in the foal heat exerted the greatest influence on the embryonic death rate. The ovulation induction with hCG had beneficial effect on the embryonic death rate compared to that associated with spontaneous ovulation. |
| Key words: embryonic death, mares, age, history of endometritis, endometrial cysts, foal heat, induced ovulation |