Economic and Genetic Aspects of Using Sexed Semen in Traditional and Genomic Evaluation of Iranian Holstein Dairy Cattle: A Simulation Study

Abstract

In recent years, sexed semen has been commercially available. Due to its lower fertility and higher price compared to conventional semen, economic evaluation should be undertaken before recommending the technology to dairy producers in each country. The objectives of the present study were to evaluate the advantages and disadvantages of the sexed semen usage at farm level in economic conditions of Iran based on total net present value (TNPV) and to estimate the impact of sexed semen on the rate of genetic improvement in dairy cattle population with and without using genomic information. Three relative conception rates (RCR) of sexed semen compared to the conventional semen were assumed i.e. 0.80, 0.75, and 0.70. Visual basic 6 and Excel software were used for calculations. The results showed that greater numbers of sexed semen services in heifers resulted in higher TNPV for all assumed RCRs, but for cows in parities 1 and 2, use of two sexed semen services for RCR, 0.80 and 0.75 resulted in the highest TNPV; while, for RCR= 0.70, the results indicated that using sexed semen was not economical. By using traditional evaluation, genomic evaluation with 3k chip, and genomic evaluation with 50k chip, the additional genetic gains in 305-day milk yield were, respectively, approximately 25, 34, and 38% higher than the current annual genetic progress for this trait in Iran (that is, about 53 kg per year). Keywords: Economic evaluation, Genetic gain, Milk yield, Net present value