MOET Efficiency in a Spanish Herd of Japanese Black Heifers and Analysis of Environmental and Metabolic Determinants

Abstract

Multiple ovulation and embryo transfer (MOET) systems have been intensively implemented in Japanese Black cattle in Japan and to create Japanese Black herds out of these areas. Environmental conditions influence MOET efficiency. Thus, we describe results of 137 in vivo, non-surgical embryo flushings performed between 2016–2020, in a full-blood Japanese Black herd kept in Spain and the possible effects of heat, year, bull, donor genetic value, and metabolic condition. Additionally, 687 embryo transfers were studied for conception rate (CR) and recipient related factors. A total of 71.3% of viable embryos (724/1015) were obtained (5.3 ± 4.34/flushing). Donor metabolites did not affect embryo production (p > 0.1), although metabolite differences were observed over the years, and by flushing order, probably related to the donor age. CR was not affected by embryo type (fresh vs. frozen), recipient breed, and whether suckling or not suckling (p > 0.1). CR decreased significantly with heat (44.3 vs. 49.2%; (p = 0.042)) and numerically increased with recipient parity and ET-number. Pregnant recipients showed significantly higher levels of cholesterol-related metabolites, glucose, and urea (p < 0.05). Therefore, adequate MOET efficiency can be achieved under these conditions, and heat stress should be strongly avoided during Japanese Black embryo transfers. Moreover, recipients’ metabolites are important to achieve pregnancy, being probably related to better nutrient availability during pregnancy.

Effect of Milk-Feeding Frequency and Calcium Gluconate Supplementation on Growth, Health, and Reproductive and Metabolic Features of Holstein Heifers at a Rearing Farm

“…Neither feeding frequency nor gluconate supplementation significantly or clearly affected any of the reproductive indices that we examined, and the values in our study were similar to those reported for heifers on commercial farms in other European countries and USA [20,61,62] which have been associated with efficient rearing [20,63,64]. Consistently with this, we found that levels of total cholesterol as well as low-and high-density lipoprotein were within physiological ranges for prepubertal calves and pubertal heifers [65][66][67], suggesting healthy follicle growth and good reproductive performance in the future [68].…”

Efficiency of Multiple Ovulation and Embryo Transfer (MOET) in a Cattle Farm over a Period of Ten Years in Gujarat

“…The average of total embryos obtained in our study was 7.8, which is in close agreement with Vázquez-Mosquera et al (2022). However they found average viable embryos to be 7.1, whereas in our study it was only 4.8.…”