NICOLA DENNIS3

Partnering with European experts key to improving dairy cow fertility

AbacusBio is working with DairyNZ to improve cow fertility through better genetic selection. AbacusBio consultant Nicola Dennis travelled to Ireland, France and Switzerland to work on this with fertility and modelling experts.

The AbacusBio team and their collaborators will be building a computer model, simulating the genetic, farm management and environmental factors that influence cow fertility, in order to tease out better ways to evaluate, and ultimately speed up the rate of genetic improvement in cow fertility.

In New Zealand’s seasonal and pasture-based farming systems, most dairy cows need to calve in early spring. Cows are required to get in-calf during a finite mating season to meet their calving deadline for the following spring. The earlier a cow gets back in-calf, the more productive she is to the farmer.

Cow fertility is already an important part of the breeding worth evaluations (the genetic ranking system used for dairy cattle) and is currently measured as the proportion of cows that calve within the first 42 days of the calving system. “This is a good start,” Nicola explains, “but is a bit of a blunt instrument because the calving rate is influenced by many management decisions and environmental conditions”.