(1) The rate of cellulose digestion in ruminal ingesta was studied both in vivo and in vitro by a new technique in which cotton threads were used
as test material.
(2) It was found that the rate of cellulose digestion was markedly
influenced by the diet.
(3) The appetite for either lucerne or grass hay was directly affected
by the rate of cellulose digestion.
(4) On a basic diet of poor quality grass hay both cellulose digestion
and appetite were stimulated by small amounts of sugar but markedly
depressed by excessive amounts. More sugar could be tolerated if protein
was also given. Optimal cellulose digestion necessitated a balance between
readily available carbohydrate and protein.
(5) Excess protein suddenly introduced after a period on a diet low in
both protein and carbohydrate caused marked inhibition of cellulose digestion
and inappetence. One case of sudden death was possibly associated with