NZAEL releases revised economic values

NZAEL releases revised economic values

Revised economic values from the National Breeding Objective (NBO) review of dairy cattle were released by DairyNZ subsidiary NZ Animal Evaluation Limited (NZAEL) today.

NZAEL Chairman, Warren Larsen says the changes will allow dairy farmers to make better sire and cow selection decisions to maximise farm profit.

“The NBO (currently delivered via breeding worth) sets the direction of genetic change in the national dairy herd and affects the appearance, performance and profitability of cows on nearly every dairy farm in New Zealand,” says Warren.

The main changes were to the economic values for residual survival, which is three times higher and to fertility, which is two and a half times higher. Residual survival includes genetic factors such as temperament, milking speed, udder quality and lameness.

Other traits such as milkfat, protein, milk volume and liveweight, had not materially changed in economic value, while the emphasis on somatic cell scores has increased slightly.

The NBO and its expression as breeding worth (BW) are reviewed regularly to ensure that it remains practically relevant and accurate and involves consulting with dairy farmers, milk processors and breeding companies throughout New Zealand.

During the current review, a software tool, 1000Minds, was used by NZAEL in conjunction with Dunedin based AbacusBio scientists, Dr Peter Amer and Dr Tim Byrne.

The tool was used to gain feedback from farmers on the traits they valued in their cows, says Dr Amer.

“The survey results and submissions showed us farmers want better balanced cows and value production combined with improved fertility and longevity.

DairyNZ NZAEL manager Dr Jeremy Bryant says the consultation process also highlighted the need to update the economic models used to calculate economic values for use in BW.

“Economic values place a monetary value on each additional unit improvement for a particular trait,” says Jeremy.

“For instance, the economic value of each additional percentage increase in cows calving within 42 days of the start of calving,” he says.

AbacusBio in conjunction with NZAEL, a subsidiary of DairyNZ, has developed these economic models to re-estimate economic values.

While no new traits are included in BW this time round, several new traits, including late lactation body condition score, were potential candidates for inclusion in February 2014.

Dr Bryant said the changes continue a natural evolution of New Zealand breeding goals towards an increasing focus on robustness and longevity that support on-going feed conversion efficiency and production improvements.”

“The changes driven by feedback and science will accelerate genetic gains in fertility and survival,” he says.

“Most farms will not notice a marked decrease or increase in herd average BW due to these changes, except if the herds have genetically poor or very good levels of fertility, residual survival or somatic cell scores.

Jersey dairy cattle generally have the greatest increase in BW as they have, on average, higher genetic levels of fertility than Friesian or Ayrshires.

For more information on the changes, visit www.nzael.co.nz

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