Frequency of insemination and type of semen effect on quantity and quality of in vivo produced embryos from Boran heifers

Abstract

In vivo embryo production is a production of progenies from genetically superior cattles using multiple ovulation and embryo transfer technology (MOET). Embryo quality affects MOET and factors that determines embryo quality are Artificial Insemination (AI) frequencies and semen type. This study was conducted from March to November 2023 to evaluate effects of AI frequency and semen type on quantity and quality of in vivo produced embryos in Boran heifers. For this purpose Randomized Experimental Design was used in which 12 donor Boran heifers were super ovulated and embryos were collected. Donors were randomly allocated to two experimental groups: Group-one-6 donors were inseminated two times (3 donors each with conventional and sexed semen) at 12 and 18 hrs interval whereas in group two-6 donors were inseminated three times (3 donors each with conventional and sexed semen) at 12, 17 and 22 hrs interval. The results of this study showed that mean number of 7.2 ± 1.9 and 9.0 ± 2.5 for corpus luteum (CL) and 2.2 ± 0.7 and 5.7 ± 1.5 for un ovulated follicle (UOF) were counted from donors grouped under two and three times AI frequency. Mean number of CL and UOF counted from donors grouped under conventional and sexed semen treatment were 9.0 ± 2.8 and 7.2 ± 1.45; 4.8 ± 1.8 and 3.0 ± 0.8, respectively. The number of CL and UOF counted from donors under two and three times AI and conventional and sexed semen treatment were not significantly (p > 0.05) different. Mean number of total flush output counted from donors grouped under two and three times AI frequency were 3.5 ± 0.43 and 7.3 ± 2.2, respectively. For conventional and sexed semen treatment, mean number of total flush output counted from donors were 7.00 ± 1.93 and 3.8 ± 1.35, respectively. Mean number of transferable and non-transferable embryos counted from donors grouped under two and three times AI frequency were 0.5 ± 0.34 and 2.3 ± 1.0; 0.7 ± 0.3 and 2.3 ± 1.0, respectively. Mean number of transferable and non transferable embryos counted from donors under conventional and sexed semen treatment were 1.7 ± 1.0 and 1.7 ± 0.65; 1.8 ± 0.98 and 1.2 ± 0.6, respectively. Mean number of unfertilized oocytes (UFO) counted from donors under two and three times AI were 2.3 ± 1.4; 2.7 ± 1.3 and Mean number of UFO counted from donors under conventional and sexed semen treatment were 3.5 ± 1.15; 1.5 ± 0.6, respectively. No significant difference was observed between insemination frequencies and semen types in terms of total flush output, number of transferable and non-transferable embryos as well as UFOs recovered from Boran heifer donors (P>0.05).This findings demonstrated that inseminating Boran heifers two and three times both with sexed and conventional semen did not affect embryo quality and quantity produced in vivo from donors and it was recommended that it is enough to inseminate Boran heifers two times with conventional or sexed semen for in vivo embryo production.