Efficiency of artificial insemination with sexed semen in cattle: reproductive viability

Abstract

The insemination with sorted sperm by flow-cytometry technique has been used successfully to produce male or female calves, according to the choice of the producer. The aim of this experiment was to evaluate the rate of birth of a commercial sorted sperm and compare its efficiency with non sexed semen and analyse the economic viability of the sexed semen. The experiment was conducted in October and November 2006, at Guaraniaçu-PR, where 342 Nellore heifers were used. All animals belonged to the same category and age (24 months). The animals were managed in a system of rotation of pasture (Brachiaria decumbens), with mineral supplementation. They were separated in two groups: Group I (control) formed by 155 heifers and Group II (sexed sperm) formed by 187 heifers. The animals body condition scores were between 2.5 and 3.0 (range from 1 to 5). Artificial insemination was carried out in both groups followed by the observation of estrus system (morning and afternoon), the insemination being occurred 12 hours after the estrus. In group I was used a commercial not sexed semen of a Nellore bull, from a company of collection and freezing semen. In group II was used sexed female semen, from the same company of IA. The results showed a significant difference in the rates of birth (P<0.05), 23% in the sexed semen and 46.45% for conventional, generating an increase in the cost of calf produced with sexed semen. The accuracy of sexed semen was 93,02%.