Reproductive Outcomes and Endocrine Profile in Artificially Inseminated versus Embryo Transferred Cows

Abstract

The increasing use of in vitro embryo production (IVP) followed by embryo transfer (ET), alongside with cryopreservation of embryos, has risen concerns regarding the possible altered pregnancy rates, calving or even neonatal mortality. One of the hypotheses for these alterations is the current culture conditions of the IVP. In an attempt to better mimic the physiological milieu, embryos were produced with female reproductive fluids (RF) as supplements to culture medium, and another group of embryos were supplemented with bovine serum albumin (BSA) as in vitro control. Embryos were cryopreserved and transferred while, in parallel, an in vivo control (artificial insemination, AI) with the same bull used for IVP was included. An overview on pregnancy rates, recipients’ hormonal levels, parturition, and resulting calves were recorded. Results show much similarity between groups in terms of pregnancy rates, gestation length and calves’ weight. Nonetheless, several differences on hormonal levels were noted between recipients carrying AI embryos especially when compared to BSA. Some calving issues and neonatal mortality were observed in both IVP groups. In conclusion, most of the parameters studied were similar between both types of IVP derived embryos and the in vivo-derived embryos, suggesting that the IVP technology used was efficient enough for the safe production of calves.

The Metabolic Signature of In Vitro Produced Bovine Embryos Helps Predict Pregnancy and Birth after Embryo Transfer

“…Accurate selection of competent in vitro produced (IVP) embryos for transfer to recipients is essential to maximize pregnancy and birth rates. Currently, the selection of viable IVP embryos is based on morphology and development stage, subjective criteria that rarely allow birth rates over 45% with either fresh or cryopreserved embryos [ 1 , 2 , 3 , 4 , 5 ]. The interest in identifying reliable markers of embryonic viability is higher in IVP, and mainly with respect to cryopreserved embryos, because of their intrinsic reduced viability to term.…”

Effects of Season on Donor and Recipient Cows and Calf Performance from Birth to Weaning in Embryo Transfer Programs in the Tropics

“…Likewise, Pimenta-Oliveira et al [ 29 ], found differences in birth weight of the offspring between the IVP embryos and AI. Nonetheless, Lopes et al [ 30 ], compared the growth of calves born by ET with those from AI, and their results showed much similarity between groups in terms of pregnancy rates, gestation length and calves’ birth weight. In our study, male calves recorded higher birth weights than females.…”

Game-Changing Approaches in Sperm Sex-Sorting: Microfluidics and Nanotechnology

“…Using sex-sorted semen for artificial insemination of in vitro fertilization enables livestock producers to preserve or increase their herds without having to purchase additional females or exposing the herd to potential pathogens and diseases [ 71 , 72 , 73 ]. Additionally, the use of sex-sorted semen in conjunction with other reproductive biotechnologies has the potential of improving the global livestock management by allowing for the predetermination of an animal’s sex, thus maximizing the profitability of farms [ 74 , 75 , 76 , 77 , 78 ].…”