Birth of First In vitro Produced Calves in Bangladesh and Their Reproductive Fitness

Abstract

The goal of the current study is to produce calves by implanting recipient cows with in vitro generated embryos. For in vitro maturation, slaughterhouse-driven cumulus-oocyte-complexes (COCs) with an even cytoplasm and at least three layers of compact cumulus cells were chosen (IVM). For the purpose of in vitro fertilization, capacitated fresh spermatozoa and presumed matured COCs were co-cultured for 18 to 20 hours (IVF). Cumulus cells were removed by carefully pipetting them into TL-HEPES. The zygotes spent three days in an in vitro culture (IVC) droplet. After this initial phase of culture, the 8–32 cell embryos were moved to IVC-II media, where they remained until Day 8 of development. On day 8, these embryos were transferred into recipient cows, with two embryos transferred to each of the five recipient cows. On day 60 of embryo transfer (ET), rectal palpation was used to assess pregnancy followed by ultrasonography on day 90. Out of five recipients, one cow delivered twine calves with a pregnancy rate of 20%. The calves were named Falguni and Chaitali. The duration of gestation was 277 days. Falguni weighed 12.87 kg at birth, whereas Chaitali weighed 18.59 kg. Falguni and Chaitali both showed typical growth patterns, with an average 254.77 g and 463.15 g/day. At a regular age, both heifer calves reach puberty and give birth. This research emphasizes the possibility that ovocytes from slaughterhouse ovaries can be used to produce healthy IVP calves, which would be a major step forward in Bangladesh’s fast expansion of high-yield dairy cattle.