Reducing the impact of adverse summer-autumn pasture conditions on livestock performance: results from farmer experience
A group of 12 farmers managing a total of 8845 ha in the West Waikato Region of the North Island, conducted a project to understand and overcome poor livestock performance during the summer- autumn period. Pastures and livestock were monitored to measure the impact of the conditions. Metabolisable energy (ME) of pasture averaged 9.0, 9.8 and 9.3 mega joules per kg of dry matter over the 3 years of study and elevated levels of pasture toxins were consistently found from mid- January to the end of May. To counter these conditions, farmers adopted varying strategies including pasture management and alternative feeding (silage and forage crops). A computerbased tool that enabled the user to make livestock feeding decisions based on the pasture cover, the ME of the pasture, and the quantity and ME of a feed supplement was developed. Farmers were able to reduce the proportion of damaged livers in lambs from 60 to 40% of the flock, which was against the district trend. When the right strategies were implemented, lamb and cattle liveweight gains increased from 52 to 146 g/day and 0.34 to 0.5 kg/day respectively. On average, ewe reproductive performance also improved during the period from 2.4 to 2.8% of lambs scanned/kg ewe body weight. The project emphasised to farmers that their resident pastures did not meet the needs of a high performing livestock production system and that alternative feeding strategies were required if higher performance was to be achieved. Keywords: Androvax, livestock feeding, metabolisable energy, pasture toxins, zinc