Abstract

The association between selenium and milk production was investigated on 98 farms in the Rangitaiki Plains and Galatea Basin during the 1981-82 dairy season. Ten blood samples per herd from randomly selected cows were tested for selenium on 4 occasions through the season. Animal, farm management and trace element supplementation data were also collected. Mean herd selenium levels varied considerably and there was a statistically significant association between herds with low blood selenium and low milk production in terms of kilograms of milkfat per hectare. Selenium milk response trials were carried out in 7 dairy herds in the Rangitaiki Plains district in the 1982-83 dairy season. Half of each herd received injections of selenium each 2 months with the remaining animals acting as controls. In 1 herd additional copper and copper/selenium groups were included. Using Livestock Improvement Association production figures, positive milk volume and milkfat responses were shown to occur on 6 of the farms. On 2 farms volume responses were significant at the 5% level. It was considered that selenium deficiency has a small effect on milk and milkfat production on farms in this district, but that this effect is mediated by other factors.

BC, Farquharson

Proceedings of the New Zealand Society of Animal Production, Volume 44, , 147-150, 1984