Effects of Semen Sexing Agent (Heiferplustm) on Sperm Characteristics and Fertility in Cows

The demand for predetermination of sex in livestock offspring is high. This is of critical importance to provide the most efficient production of the world’s food supply. In agriculture over the past generation, the application of sex pre-selection to production systems becomes increasingly necessary [1]. In beef cattle, the increased growth rate and efficient production of lean meat by males have financial advantages [2]. In contrast, dairy farmers generally seek female dairy breed calves to perpetuate their herd while male beef crossbred animals are desired for reasons above, that is, increased growth rate and efficient production of lean meat [3]. In natural reproduction, the sex ratio is approximately 50:50 [4]. In the dairy cattle industry, only female animals (and very few breeding males) are productive and most male calves are slaughtered with little financial return to the farmers. Because of high market prices for replacement heifers, high milk prices, reproductive inefficiency of dairy herds and the shortage of heifers for replacements, sexed semen has been used to get more heifers [5]. The only accurate and potentially cost effective approach for achieving sex pre-selection at the present time involves separating the X-chromosome from the Y-chromosome bearing sperm followed by its use for artificial insemination (AI), or for in vitro fertilization (IVF) with subsequent embryo transfer (EF) [6]. Abstract The present study was designed to study the effects of Heiferplus, a sperm sexing agent on sperm characteristics, conception rate, sex ratio, abortion rate and maternal mortality in Goudali and F1 Goudali-Simmental (Simgoud) cattle breeds. The first part of the study consisted of evaluating in vitro, the effects of Heiferplus on sperm characteristics. For the second part, 48 cows (300 350 kg) of each breed were divided into 2 groups (24 cows in parity 1 and 24 in parity 2). Each group was again subdivided into 12 cows each which were inseminated with semen containing Heiferplus and the other 12 without. Pregnancy diagnosis was done 28 days following artificial insemination and 60 days after, the sex of foetus was determined using trans-rectal ultra sonography. The motility of sperm with Heiferplus was 4.4 ± 0.55 and that of sperm without was 4.6 ± 0.55. The viability of sexed sperm was 84.92 ± 5.17and that of unsexed sperm was 75.46 ± 9.88. Sperm morphology showed 90.4 ± 1.67 normal sperm for semen with Heiferplus and 90.0 ± 1.58 for semen without Heiferplus. Conception rate in both breeds was improved by an average of 4.13% in Heiferplus cows as compared to the control group. Female calf percentage in Heiferplus cows was 72.09%, significantly higher than that of control. Breed, parity and body condition score had no significant effect on calf sex. Abortion rate (13.95% in Heiferplus cows and 14.63% in control) was not significantly affected by Heiferplus. Maternal mortality rate was 4.65% for Heiferplus cows and 4.88% for control, thus, no significant difference. It was concluded in this study that Heiferplus increases female sex ratio but has no significant effect on semen characteristics, conception rate, abortion rate and maternal mortality.