Intake and digestibility by sheep of artificially dried forages in several physical forms

Abstract

In three experiments high quality, autumn-harvested dried Italian ryegrass and lucerne in the form of cobs and pellets and in one of these experiments in the chopped form were offered to mature castrated male sheep at a maintenance level of feeding. Only small differences were found between the physical forms of forage in digestibility of organic matter, retention of nitrogen and loss of energy in the urine, but the digestibility of crude fibre and the mean retention time of stained feed in the gut decreased with decreasing particle size. Increasing the level of feeding of cobs and of pellets from 800 g daily by three equal increments of 400 g caused a linear decline in digestibility but no difference was found between cobs and pellets in the rate of decline of digestibility. In three experiments the dried forages were offered ad libitum and in a fourth experiment a wide range of particle size was simulated by offering ad libitum five ratios of chopped and pelleted grass. Voluntary intake tended to increase as the particle size was reduced over the whole range, but there was no significant difference between the voluntary intakes of mixtures with a modulus of fineness of 4-4 or less. No difference was detected between the voluntary intake of cobs and pellets.

The effect of concentrate, barley and dried grass on the voluntary intake of different silages

“…However, the rate of passage of undigested residues of silage was less than that for residues of supplement and this agrees with previous findings (Milne and Campling, 1972;Mcllmoyle and Murdoch, 1977). The silage DM intake of mature steers offered unwilted and 'wilted' grass silages containing similar DM contents and whole-crop barley silage was therefore not significantly affected by type of supplement.…”

The performance of early-weaned calves offered concentrates or artificially dried grasses

“…Since DOM intakes of concentrate offered ad libitum in both experiments were significantly greater than maximum DOM intake of dried grass it is unlikely that intakes of dried grass DOM were limited by a chemostatic mechanism. Negative correlations have been found between intake and modulus of fineness of dried grass (Milne and Campling, 1972;Wilkins, Lonsdale, Tetlow and Forrest, 1972) but in the experiments reported here intake tended to decline as modulus of fineness decreased. Since both magnitude of, and ranges in, modulus of fineness in Experiments 1 and 2 were small it is unlikely that this parameter would have markedly affected intake.…”

“…The combined effects of field operations, high temperature drying and packaging may have a detrimental effect on OM digestibility of immature low fibre herbages. Packaging chopped dried herbages reduced their digestibility on average by 2 to 4 percentage units (Minson, 1963;Milne and Campling, 1972). There is, however, remarkably little quantitative information on the combined effects of field operations and high temperature drying on herbage digestibility.…”

Effect of rotary‐drum‐drier exit temperature and length of pre‐drying storage time on digestibility of dried grass cobs

“…A period of 30-45 min was allowed between the achievement of the desired exit temperature or the entry of pre-stored herbage 1972;Wilkins et al, 1972) by increasing the rate of passage of particles through the aliinentary tract (Milne and Campling, 1972). This effect is eliminated by digestion of the milled sample in vitro.…”