The utilization of lactose by the growing pig : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science

Abstract

The results of a recent Nationwide survey (Davenport 1966) showed that 93% of all pig units were still dependent on supplies of liquid dairy by-products - whey and skim milk - for their major source of pig food. Calculations made from figures for cheese and casein production (N.Z. Govt. Statistics, 1967) show that in 1966, approximately 500 million gallons of whey alone, were produced. Of this, a comparatively small amount is utilized by the dairy industry to produce alternative by-products. Condensed or dried whey production involves the costly removal of large volumes of water. This necessarily results in a high price to the consumer, and consequently a low consumer demand. The quantities of lactose produced are unlikely to increase appreciably as there is only a limited demand for this sugar, and it is still too early to tell whether current research into alternative uses for the whey, such as the production of food yeast (Chapman, 1966), will make significant inroads into the very large whey surpluses. It is clear that the conversion of these surpluses into pigmeat is still the most profitable single outlet for a large amount of the whey produced. On the basis of calculations similar to those made by Owtram, (1961) full utilization of the whey produced in 1966 if fed alone, could yield up to 19,000 tons of pigmeat. Needless to say, under the more normal feeding systems in which 1 lb meal daily, is also fed, production levels even higher could be envisaged.