Can Sexed Semen Accelerate Expansion in Irish Dairy Herds?
The opportunities offered by sexed semen to the dairy industry are extensive with a 90 per cent gender bias capability, writes the Irish Agriculture and Food Development Authority.The ability to increase the number of heifer calves born by selecting the sex of offspring at conception is of great benefit to dairy industries around the world.
The technology for sorting semen is capable of delivering a 90% bias in resulting offspring, although the fertility of the sexed semen product is reduced compared with conventional semen. Much of the deterioration in fertility can be avoided if the sexed semen is used fresh rather than frozen-thawed.
A bio-economic model has been developed to determine the effects of using sexed semen (on maiden heifers only) on replacement heifer numbers, rate of herd expansion, and overall farm profitability. Figure 1 illustrates the greater numbers of replacement heifer calves and faster rates of herd expansion (from 100 up to a maximum of 150 cows) facilitated by the use of either fresh or frozenthawed sexed semen compared with conventional frozen-thawed semen.
The use of sexed semen increased overall farm profitability. The rapid expansion facilitated by sexed semen use, however, increased financial pressure on the farm business, with negative cash flows in years of greatest expansion.

January 2013