The influence of varying amounts of a supplement consisting of starch,
casein, brewers yeast and minerals, alone and in conjunction with one of
green feed, on the digestibility of the cellulose in a basal ration of poor
veld hay, containing only 2.2 per cent. protein, has been tested in a series
of digestion trials with sheep. It is concluded that:
(1) The ability of sheep to digest cellulose was impaired when kept
for any length of time on the basal diet of veld hay only.
(2) Daily supplements of 20, 50 or 85 grams of the concentrate
mixture per sheep did not improve the digestion of the cellulose
of the basal ration. Unlike the lowest one, the two higher
supplements had, however, the effect of preventing deterioration
of the digestive powers and appetites of the sheep.
(3) The highest supplement of concentrate, 170 grams per animal
per day, more than compensated for the energy deficiency of
the basal ration but depressed the digestion of its cellulose.
(4) Ability to digest cellulose, which had been temporarily weakened,
as under (1) and (3) above, was restored by an additional supplement
of green feed.