PRESERVATION AND FEEDING VALUE OF POTATO-HAY MIXTURES ENSILED IN WINTER

Abstract

Two experiments were conducted to determine if mixtures of potatoes and hay would preserve satisfactorily when ensiled in cold weather. The first experiment involved 3:1 (wt/wt) mixtures of pulped potatoes and chopped hay ensiled in plastic bags and stored for 4 wk at −18 °C, 2 °C or 20 °C. Very little fermentation took place at 2 °C and none at −18 °C as judged by subjective assessment and chemical analyses. Fermentation proceeded normally when the bags were moved from the two cold environments to the 20 °C heated room. Two concrete-stave upright silos (4.25 m diam.) were each partly filled with a 3:1 (wt/wt) mixture of potatoes and hay in February. The daytime temperature was about 0 °C during silo filling. Legume hay (28% ADF, 14% CP) was used in one silo and timothy hay (35% ADF, 8%CP) in the other. Temperatures recorded throughout the winter and spring showed that fermentation took place over an extended period. Temperatures near the center of the silos averaged 3–5 °C warmer than those near the edges. Both silages had desirable appearance, odor and chemical parameters when fed to yearling steers in June-August. There was little difference in the silage dry matter intake by steers fed the two silages and daily weight gains (0.97 kg/day) were not significantly different. Steers fed the potato-legume hay silage had a higher dressing percentage and carcass weight (P < 0.01). It was concluded that potato-hay mixtures ensiled in winter preserved satisfactorily and supported acceptable weight gains by steers when the silage was fed the following spring and summer. Key words: Potato, hay, silage, winter, cattle