Comparative study of reproductive and estrus characteristics of sexed and conventional semen in crossbred cows under field conditions

TL;DR

This study compares the effectiveness of sexed and conventional semen in crossbred cows, finding similar conception rates under field conditions.

Contribution

The study provides field-based evidence that sexed semen does not significantly differ from conventional semen in conception rates in crossbred cows.

Findings

Conception rates for sexed and conventional semen were not significantly different at first insemination.

Estrus duration was identified as a key factor affecting conception rates in field conditions.

Factors like age, parity, and cervical mucus properties did not show significant differences between the two semen types.

Abstract

Sexed semen (SS), a reproductive biotechnology tool, can alter the sex ratio of offspring in bovines. This study elucidates a comparative analysis of estrus-related parameters influencing conception rate and pregnancy losses under field conditions between conventional and SS.

In the present study, artificial insemination with (SS; n = 143) and conventional semen (CS; n = 143) was performed at spontaneous estrus, i.e., 16–18 h after the onset of estrus signs, to analyze their comparative evaluation in terms of conception rates in crossbred cows under field conditions. Different parameters such as age, parity, body condition score (BCS), estrus duration, inter-estrus interval (IEI), diameter of pre-ovulatory follicle (DPOF) at estrus, and cervical mucus properties (pH and spinnbarkeit [SBK]) were recorded for each cow.

The first insemination conception rates for sexed and conventional semen were 55.24% and 63.63% whereas the overall conception rates were 49.14% and 57.37% on days 35 and 75 post-insemination, respectively, with no significant difference (p > 0.05). Conception rates between sexed and CS inseminations were statistically significant (p < 0.01), whereas factors such as age, parity, BCS, DPOF, IEI), and SBK value exhibited no substantial variance (p > 0.05) for both types of semen straw.

SS straws yielded a conception rate equivalent to CS straws, with estrus duration being the key factor affecting conception under field conditions.