Use of waste paper as a feedstuff for ruminants

Abstract

The potential use of waste paper as a feedstuff for ruminants was investigated. Analyses of a range of types of paper showed that waste paper could be regarded only as a source of energy for animal production ; cellulose was the main chemical constituent. Levels of nitrogen (N) and soluble ash were very low in most samples. In vitro organic matter (OM) digestibilities ranged from a mean of 22 per cent for waste newspaper up to a mean of 63 to 65 per cent for high-quality office waste paper and computer printout. Individually penned mature crossbred wethers gained liveweight at a mean rate of 11 7 g day-1 when fed on pellets consisting of 65 per cent Gwernment waste paper (52.5 per cent in vitro digestibility), 32 per cent linseed meal and 3 per cent minerals, provided roughage as chaffed hay (50-300 g head-1 day-1) was fed as well. Mean daily dry matter (DM) intakes were about 1600 g. Without the chaffed hay, intakes fell to 1400 g DM head-1 day-1 and the sheep maintained weight. In a second experiment, crossbred ewes aged about seven months were offered ad libitum either lucerne pellets, Government waste paper pellets, or pellets containing equal proportions of Government waste paper and newspaper. The paper pellets contained 84 per cent paper, 8.4 per cent molasses, 3.6 per cent urea and 4 per cent minerals. During the first seven weeks, when 100-200 g head-1 day-1 of chaffed lucerne hay were offered in addition to the pellets, mean DM intakes (g day-1) and liveweight gains (g day-1) were 1522 and 144 for the lucerne-fed sheep, 950 and 60 for the sheep on Government paper pellets, and 450 and -27 for the sheep on the 42 per cent newspaper pellets. During the next two weeks, lucerne chaff was omitted; the sheep on lucerne pellets increased their mean DM intake and rate of gain, those on the Government waste paper pellets maintained their food intake but lost weight slowly, while sheep on the 42 per cent newspaper pellets reduced food intake and lost weight rapidly (-1 18 g day-1). OM digestibility of both paper diets was 56 to 60 per cent when fed with roughage, and decreased to 55 per cent when lucerne chaff was omitted. Ewes on both paper diets were consistently in negative N balance (-1.3 to -3.2 g N day-1) while those fed the lucerne pellets were in consistent positive balance (+3.3 g N day-1).