Reproductive performance of sexed versus conventional semen in Holstein heifers in various semiarid regions of Iran

Abstract

For comparing reproductive performance of sexed versus conventional semen a total of 3573 heifer insemination records collected from five herds in four provinces of Iran were investigated. The studied provinces were classified into three regions: hot semiarid (Tehran and Alborz provinces), temperate semiarid (Khorasan Razavi province) and cold semiarid (Zanjan province). Various parameters including the conception rate, number of services per conception, calf sex ratio, calf birth weight, gestation length, calving ease score, abortion and stillbirth as well as twining rate were investigated. The logistic regression method was deployed for the analysis of categorical variables while the GLM procedure was applied for the analysis of continuous variables. The average conception rate of sex sorted and conventional semen was 48.3 and 63.8%, respectively. The utilisation of sex sorted semen resulted in 91.1% female calves. The conception rate, number of services per conception, gestation length, calf birth weight and the calf sex ratio were among the reproductive variables that were significantly influenced by the semen sexing. A greater number of services per conception and calving ease score were observed in hot and temperate semiarid areas. These climatic regions also provided a lower incidence of female calf births compared to the cold semiarid regions. Our results highly reaffirm the previous findings on the reproductive performance of sex sorted semen. Yet, climatic and management practices of a herd within a special climate have to be considered when deciding for utilisation of sex sorted semen in a dairy farm. ARTICLE HISTORY

Game-Changing Approaches in Sperm Sex-Sorting: Microfluidics and Nanotechnology

“…Another study, performed by Seidel and Schenk (2008) [ 83 ], showed lower pregnancy rates from using sex-sorted semen as compared to non-sorted. The abovementioned findings are corroborated with more recent research carried out by Mikkopla et al (2015), [ 84 ], Joezy-Shekalgorabi et al (2017) [ 85 ], Dawod and Elbaz (2020) [ 81 ], and Drake et al (2020) [ 86 ] regarding the reproductive efficiency of sex-sorted sperm in cows and heifers. However, when determining whether or not to use sex-sorted semen in a dairy farm, the climatic and management practices of a herd in a particular environment must be taken into account.…”

Economic mechanism of the region breeding service activity

“…From an economic point of view, embryo transplantation is especially interesting for commercial farms that do not have breeding animals, but intend to create a breeding nucleus of cattle. For such agricultural enterprises, it is enough to have a broodstock -recipients (outbreds), to whom embryos can be transplanted [30][31][32][33][34][35].…”

An Exploration of Current and Perspective Semen Analysis and Sperm Selection for Livestock Artificial Insemination

“…Currently, cattle-sexed semen has a fertility rate of 71.5% to 78.5% that of whole semen [ 60 ]. Though these reduced rates are acceptable for dairy producers and some beef producers to use sexed semen, fertility rates are still the foremost issue facing sexed semen.…”