A study of the nutritive value of untopdressed hill country pastures

Abstract

Pastures provide the natural food supply of grazing animals and are the raw materials for the world's wool, meat and dairying industries. In an effort to increase livestock production, research workers have been developing techniques by which pasture production can be raised to the level that provides for the increased numbers and quality of stock being carried in the agricultural countries. The earliest investigations on pasture improvement were concerned with the quantity of fodder produced, expressed as yield of dry matter per acre. It was thus shown that fertilisation increased total pasture yields while plants of higher palatability and having varying growth seasons, were bred in an endeavour to provide a supply of nutritious forage throughout the grazing season. It is now realised, however, that the relative productiveness of pastures in different localities is a function, not only of the quantity of herbage produced, but also of its quality. Any analyses and digestibility determinations so far carried out have been concerned mainly with the improved dairying and fat lamb raising swards so that little is yet known of the level of nutrition provided by the natural hill and high country pastures, the pastures which are so important in the present economy of this country. As far back as 1929 Rigg and Askew (1929) pointed out that there are many New Zealand pastures which are not associated with symptoms of mineral deficiency but do not produce to their optimum levels. It is natural to expect that the lower quality pastures are to be found on the second and third class hillcountry, thus it would appear to be due time for a comprehensive study of the nutritive value of the forage grown on these areas. With these thoughts in mind the present work was inaugurated to serve as a preliminary survey of the level of nutrition provided by untopdressed pastures on the hill and high country areas of the South Island.