DairyNZ says it's found a way to boost the declining fertility rate of dairy cows.
Scientist Caroline Walker has compared North American and New Zealand Holstein genes in a bid to find out why calving rates are traditionally lower than pregnancy rates among the country's dairy herds.
And she's narrowed the search from 20,000 to 1500 genes which are preferable for establishing and maintaining pregnancy in milking cows.
She says US genetics have significantly contributed to a decline in fertility rates of dairy cows over the past 30 years, because they're 20% less likely to get in calf than their New Zealand counterparts.
Ms Walker says most genetic research on these breeds is focused on milk production traits and resistance to mastitis, and very little has been done on fertility.
She says the research will allow a farmer to choose genes for high-fertility.
The research took four years. More trials will be done over the next few years.