Conception rate of Holstein and Japanese Black cattle following embryo transfer in southwestern Japan

Abstract

This study aimed to quantify and compare conception rates to embryo transfer (ET) of Holstein and Japanese Black cattle in southwestern Japan. A 10-year retrospective epidemiological survey was conducted. The recipient numbers for Holstein and Japanese Black cattle was 621 and 527, respectively. Conception rates of Holstein and Japanese Black cattle during the study period were 45.4% and 42.3%, respectively. There was no significant difference between both breeds. However, a different trend of conception rate to ET in Holstein and Japanese Black cattle was observed. In Holstein cattle, conception rate in August to October was lower than in the other months and was significantly lower (p < .05) than in April. Particularly, conception rate in October of Holstein cattle was the lowest (31.0%). In Japanese Black cattle, conception rates in December (24.2%) and January (31.3%) were lower than in the other months. Conception rate of Japanese Black cattle declined as the temperature-humidity index (THI) decreased, exhibiting significantly lower levels in the ≤45 THI class than in any other THI class (p < .05). By contrast, in Holstein cattle, no relationship was observed between conception rate and THI on the day of ET. These observations suggest the importance of appropriate management that considers seasonal reactivity in each breed.

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

“…CRs after embryo transfer in our study were 50.0% for fresh embryos and 47.5% for frozen–thawed embryos, very close to the corresponding values of 51.1% and 44.0% published for another herd of Japanese Black cattle [ 70 ]. CRs in the current study did not differ significantly across various breeds, including Simmental, Charolais, Brown Swiss, Holstein, or crossbreeds, which is consistent with a report of similar CRs between beef and dairy breeds [ 79 ]. The similarity in CR between fresh or frozen–thawed embryos in the Japanese Black cattle in the present study echoes previous results for Aberdeen Angus [ 80 ].…”

Effects of heat stress on the endometrial epidermal growth factor profile and fertility in dairy cows

“…The pregnancy rate after ET between June and September (the summer period) in the present study (40.3%) was similar to that in a previous study, which was performed during the same season in the same region (43.7%, n = 197) [71]. The pregnancy rate in the present study was within the range of previously reported pregnancy rates after ET during the hot season (14.3-55.4%) [20,21,[23][24][25][26][72][73][74][75], and higher than that of AI during the summer period in the commercial farms used in the present study (24.5%, n = 3863, data were obtained between 2016 and 2017) (unpublished data).…”

Effectiveness of embryo transfer in cows - risk factors including in vivo derived and in vitro produced embryos

“…High temperature and humidity index (THI) (≥ 80) had a negative effect on the results of embryo transfer in the 8th, 7th and 6th day after heat [6]. Nabenishi et al [84] noted differences between CR in Japanese black and HF cattle in different seasons of the year. In Holstein-Friesian cattle the conception rates in August-October were lower than in other months.…”