177 Application of sexed semen during timed artificial insemination following oestrous synchronisation in dairy and beef cows for emerging farmers in South Africa
T. L. Magopa A C , M. L. Mphaphathi A , T. Mulaudzi C , M. R. Ledwaba A B , M. A. Thema A B , S. M. Sithole A B , M. D. Sebopela A B and T. L. Nedambale A BA Agricultural Research Council, Animal Production, Germplasm Conservation & Reproduction Biotechnologies, Irene, RSA
B Tshwane University of Technology, Faculty of Science, Department of Animal Sciences, Pretoria, RSA
C University of South Africa, Department of Agriculture and Animal Health, Johannesburg, RSA
Reproduction, Fertility and Development 35(2) 216-216 https://doi.org/10.1071/RDv35n2Ab177
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
The objectives of the present study were to compare oestrus expression and pregnancy rate following timed artificial insemination (TAI) with frozen-thawed X-sexed or non-sexed semen in dairy and beef cows. A total of 227 cows (dairy n = 130 and beef n = 97) from emerging cattle farmers of Gauteng province, South Africa, at least 90 days postpartum, and with a body condition score of 2.5 and higher (1–5 scale) were used. All cows were assigned to nine-day OvSynch + controlled intravaginal drug release [CIDR] + TAI protocol, wherein on Day 0, they received 2 mL intramuscular (IM) of Oestradiol benzoate® ([EB] VTech) and a controlled intravaginal drug release (CIDR®, Pfizer Laboratories) insertion. On Day 5, all cows received 2.5 mL (IM) of pregnant mare serum gonadotrophin (Chronogest®, Intervet International B.V.). On Day 8, CIDR® was removed and cows received an adhesive tail-head heat mount detector (Kamar®) and 2 mL (IM) of prostaglandin F2α (PGF) (Estrumate®, Intervet). On Day 9, cows received 1 mL (IM) of EB. 55 h after CIDR® removal, TAI was performed with X-sexed or non-sexed semen from eight sires (four Holstein Friesian and four Angus), two X-sorted and two non-sexed sperm from each cattle type (dairy and beef), purchased from ABS Genetics. Pregnancy was verified 35 days following TAI using transrectal ultrasonography (Ibex pro™, linear transducer 5–8 MHz). Analyses of variance signified that type of bull and type of semen influenced sperm quality. Chi-square test was used to compare the proportion of oestrus response and pregnancy rate. The post-thaw average total sperm motility for dairy (66.8% and 70.7%) and beef (58.8% and 83.8%) sexed sperm and non-sexed sperm were recorded, respectively. The proportion of oestrus expression was greater in dairy (86.9%) than in beef (65.0%) cows (P < 0.05). The average pregnancy rates of dairy (34.0% and 41.2%) and beef (36.0% and 40.4%) sexed and non-sexed semen were recorded, respectively. In conclusion, oestrous expression and pregnancy rate of dairy and beef cows were satisfactory. Sexed semen can be successfully utilised through assisted reproductive biotechnologies in organised emerging cattle farming systems.
The authors would like to thank the Agricultural Research Council (ARC) and the Gauteng Department of Agriculture Rural Development (GDARD) for funding.
