NZ farming heading into headwinds

Sheep farmers will need to focus on genetics to help solve animal health and welfare problems, Jo Cuttance writes.

Zealand sheep farming is facing many headwinds and needs to think about how they are going to be addressed, an agricultural scientist says.

A review of the New Zealand’s sheep industry and opportunities for change to meet future challenges was the topic presented by AgResearch senior scientist Dr Tricia Johnson at this year’s NZ Grassland Association conference recently.

Johnson talked about NZ sheep breeds, how they delivered to the industry and where they needed to be heading in the future.

Genetic selection within the sheep industry’s production systems and breeding programmes has emphasised the number of lambs born and their growth rates, driven by what the industry wanted and paid for. In the past there was also an emphasis on wool weight, micron, and wool colour. Johnson said now the key driver for a lot of sheep farmers was carcaseweight, the leaner the better.

NZ had an issue with its heavy reliance on the use of on-farm chemicals to achieve some of those outcomes. For example, drenching lambs on a regular basis, using zinc oxide for facial eczema and the use of pesticides for treating or preventing flystrike.

Johnson said the sheep industry was facing some headwinds with economic challenges. For example, for strong-wool farmers it cost more to take the fleece off than they’d get from selling it. There were environmental challenges, cultural and social challenges. Also, consumers had increasingly different expectations around the quality and the types of products they were willing to pay for.

There were toolbox challenges for the sheep industry as well. The tools farmers used were increasingly under question: for example, the use of drenches as drench resistance became an increasing issue with triple-drench resistance on several farms across NZ.

Think hard about genetics

Johnson said genetics was an environmentally and ethically appropriate way to achieve some of the fundamental things we needed our sheep of the future to have.

Genetic selection was not an overnight miracle, but we needed to start breeding animals to be more resilient and able to cope with future production systems that we needed to have.

Johnson said as you start adding more traits into your selection programmes the less progress you make on any individual trait. However, we cannot ignore some of the traits needed if we are to have a successful industry in the future.

For traits that are a result of climate change, there were two approaches to think about: mitigation and adaptation.

There had been a lot of emphasis placed on climate change in terms of mitigation, but also adaptation needed to be considered, she said.

“The climate is changing and although we will do everything we can to contribute to mitigating it, we will still experience change.”

In terms of mitigation, NZ was leading the world in its breeding programme for low-methane sheep. Other traits for future mitigation options included, but were not limited to, improved growth rates so less maintenance feed was required, fewer ewes but the same number of lambs born, and less disease resulting in lower replacement rates.

Johnson said these were all parts of the way NZ could go towards having a mitigation aspect to our breeding programme.

She said adaption and resilience was confronting the sheep industry now, particularly in certain parts in theNorth Island but equally in the South Island.

She asked how changing weather patterns would affect sheep breeding, because NZ was far from exclusively a temperate climate – the top of the North now had a sub-tropical climate and the whole country was experiencing more and more hot years. She said heat stress had not been documented in NZ sheep until 18 months ago, and it was not just the temperature but the effects of humidity that needed research.

The issue for NZ was that most of our sheep breeds were temperate derived, Johnson said. They had not seen the hot, humid conditions we’re now experiencing so did not know how to perform in those conditions. They were not physiologically designed for it. Maybe there were some out there that could handle a Northland autumn, but the measurements had not been done. “We can tell you Romneys don’t,” she said.

We need to think about what other breeds we can start to use within our industry. Johnson said there had been a proliferation of minority breeds entering NZ over the past 20 years but it had been ad hoc and with limited numbers. Quite a few of those breeds, such as Damaras and Dorpers, came from hot countries, but they did not know what humidity felt like.

“They know what hot, hot conditions look like, but their feet and overall body do not know how to combat a humid Northland environment.”

Some of the tools that were used in the industry were changing and they would drive how productive and how successful we can be in the future, she said. The European Union had banned high doses of prophylactic zinc, yet outside of genetics, that was the number-one tool for preventing facial eczema in the North Island.

Johnson said NZ also had increasing resistance to some drenches and there were issues for some of these diseased traits, but genetics was the key to deal with those issues.

Other physical traits needed consideration, including tail length, bare bellies, and a bare breech; these offered huge opportunities to the industry.

Production and product quality would continue to be exceptionally important, she said.

To get to where we need to go, Johnson said we needed to go back to understanding the basics and thoroughly theme-type these animals to understand what attributes they could bring to the industry.

Then there needed to be integration of some of those traits into existing breeds. For example a Romney base that was already known to have a facial eczema tolerance.