Comparative efficiency of the application of sexed semen in dairy cows and heifers

ABSTRACT COMPARATIVE EFFICIENCY OF THE APPLICATION OF SEXED SEMEN IN DAIRY COWS AND HEIFERS Kiremitçi S. Aydın Adnan Menderes University, Health Sciences Enstitute, Reproduction and Artificial Insemination Program, Master Thesis, Aydın, 2024. Objective: This study was designed to investigate the comparative efficacy of the use of sexed semen in dairy cows and heifers. Material and Methods: The present study was performed in a commercial dairy farm. Dairy cows (n=25) and heifers (n=25) were used in this study. All the animals were synchronized with progesterone combined ovsynch protocol (GnRH–Progesterone–7d–PGF2α–2d–GnRH– 16h–AI). Synchronized animals were inseminated with sexed semen. Conception rates and embryonic losses were determined with trans-rectal ultrasound respectively 35 and 65 days after artificial inseminations. Moreover, fetal losses were recorded before and during parturition in heifers and cows. All the data was analyzed SPSS statistical software. The parameters belong to dairy cows and heifers were compared with Chi-square test. Results: Pregnancy rates were determined similar in dairy cows (52%) and (72%) heifers (p>0.05). Similarly, embryonic loss rates were not found statistically different between dairy cows (7.7%) and heifers (5.6%). Fetal loss rates were detected before parturition and during parturition in heifers (5.9%; 12.5%) and cows (8.3%; 9.1%) respectively (p>0.05). The reliability of sexed semen was defined as 82.8%. Conclusion: The use of sexed semen in dairy cows and heifers were provided similar results under the present conditions. Keywords: Cow, Heifer, Sexed Semen, Ovsynch, Progesterone. ix