Overcoming Poor Summer-Autumn Pastures

Twelve farmers in West Waikato have worked together over three years to understand and overcome poor live-stock performance during summer-autumn. Supported by Rex Webby of AgResearch, the group manages nearly 9,000 ha, carrying over 100,000 stock units on warm North Island hill country west of Hamilton.

The resident ryegrass dominant pastures in the region are at their worst from January to April. Climatic conditions cause pasture quality to deteriorate quickly and the pasture becomes a haven for fungi that are toxic to livestock. The farmer group aimed to understand the relationships between their livestock feeding needs and the forage quantity, energy levels and fungal toxin contamination present in the pasture at the time.

By doing so, they hoped to improve livestock performance and supply animals into higher value markets. They monitored pastures and live-stock and adopted varying strategies, including pasture management and feeding silage and forage crops.

By making the right decisions they were able to reduce damaged livers in lambs, caused by a toxin from the fungus Pithomyces chartarum, from 60% to 40% of the flock. This was against the district trend when there were three successive years of high pasture fungal contamination. In years exacerbated by drought, using the right strategies increased their lamb liveweight gains from 52 to 146 g/day, and cattle liveweight gains from 0.34 to 0.5 kg/day. Ewe reproductive performance was
also improved.

Understanding the limitations of their pastures as a feed source in summer-autumn has been an important realisation for these farmers. They are now better positioned to continue to improve and produce a product to meet customer needs.

16th April 2003
Source: Deric Charlton