Influence of Factors during Superovulation on Embryo Production in Korean Holstein Cattle

Abstract

ABSTRACT. The aim of this study was to investigate the influence of key parameters (donor parity, milk production, post-parturient day, season and milk recording data) associated with efficiency of embryo recovery (ER) in Holstein cattle. Elite Holstein cows and heifers were selected for ER, while Holstein heifers were used as recipients. The numbers of transferable embryos (TEs) produced were not significantly different when analyzed in terms of donor parity, milk production, postparturient day and season. However, the numbers of TEs were significantly increased when the milk protein (%; P)/fat (%; F) ratio was over 0.95 and/or the milk urea nitrogen (MUN) was between 12 and 18 dl/ml. The results from ET showed no differences in pregnancy rates among Holstein heifers receiving other types, developmental stage codes and quality grades of embryos. The mean interval from ER to artificial insemination was 60.6 days. Moreover, 19 offspring that had milk recording data showed a similar milk yield performance to that of the donor cows. In conclusion, this study showed that in Holstein cows, embryos were recovered and transferred and resulted in production of viable calves. Furthermore, P/F ratio and MUN could be candidate indicators for selection of high-efficiency donor cows.KEY WORDS: embryo recovery, embryo transfer, Holstein cattle, milk protein/fat ratio, superovulation.

Polymorphisms of the bovine growth differentiation factor 9 gene associated with superovulation performance in Chinese Holstein cows

“…Maximal TNO and NTE occurred during the spring season, which is inconsistent with a previous finding (Lee et al, 2012) that NTE is highest during the fall. However, Lerner et al (1986) have reported that season has no significant effects on NTE.…”

Hexavalent chromium is cytotoxic and genotoxic to hawksbill sea turtle cells

“…Several studies have recognized metals as a threat to sea turtles; however, Cr levels in sea turtles have only been reported in two studies. One study found low levels of Cr in blood plasma of hawksbill sea turtles (Suzuki et al, 2012). This outcome is not surprising as in humans and other terrestrial animals blood plasma levels are low (ATSDR 2012).…”

“…Only two of these studies measured Cr. One study reported low Cr levels (0.039 μg/ml) in the plasma of captive hawksbills (Suzuki et al, 2012). The other reported average Cr levels from 12 stranded loggerhead turtles in the Mediterranean of 1.05, 1.57, and 1.43 mg/kg dry weight in liver, kidney and muscle, respectively, with the highest levels found in lung tissue (2.29 mg/kg) (Storelli et al, 1998).…”

Effects of choice of month of treatment and parity order on bovine superovulation traits

“…Previous studies reported that the increasing parity did not affect the embryo recovery (ER) or transferable embryo (TE) content (Donaldson, 1984;Lerner et al, 1986;Hasler, 1992), although a large-scale parity order analysis could not be undertaken in Korea (Lee et al, 2012). However, Gebeyehu (2007) found that the parity order was significantly higher (P < 0.01) for days open and the calving interval.…”