|Abstract or Summary
- Methods to improve the efficacy of swine barley rations were
evaluated. A literature review pertaining to the subject, three feeding
trials involving 104 swine, and a laboratory investigation were
used in the study.
The effects of pelleting with a new modified pellet die that
produces a dense pellet; supplementation with 5 percent stabilized
beef tallow or with a cellulase preparation¹; adding water to the
ration at the time of feeding; soaking the ration 9 to 15 hours prior
to feeding; the use of temperature control with mash rations, and
several interactions of these methods have been evaluated.
Pelleting barley rations significantly (P < .01) improved the
feed conversion over similar rations fed as meal, but had no significant
(P > .10) effect on daily feed consumption or average daily gains. Meal rations were 7 percent bulkier than pellets, and it is
suggested that the increased density of pellets is responsible for the
improvement in feed conversion due to pelleting. Fat supplementation
was additive with pelleting when the modified pellet die was
used; together the two significantly (P < .05) improved the feed conversion
of the control ration.
Supplementation with 5 percent stabilized beef tallow brought
about no significant (P > .05) changes in average daily gains, feed
consumption, or feed conversion. However, fat supplementation tended to improve the utilization of barley rations more than pelleting or cellulase supplementation. Fat additions apparently lowered
cellulase activity as determined in vitro, but fat apparently was not
detrimental to cellulase activity in vivo except in pelleted rations.
Cellulase 4000 did not bring about any significant (P > .10)
changes in average daily gains, feed consumption or feed efficiency
although there was a slight but consistently favorable trend to do so.
Carcass shrinkage was significantly (P < .05) lower following cellulase
feeding, whether the ration was soaked or dry. Backfat was
significantly (P < .05) thicker on soaked rations, but not on dry
rations, when Cellulase 4000 was supplemented. The use of this
enzyme apparently increases the average daily gains but not the feed
efficiency of soaked rations, at least in the absence of temperature
control. Soaking the ration 9 to 15 hours prior to feeding or simply wetting
the ration at the time of feeding tended to increase the average
daily gains and feed consumption, but lowered the efficiency of feed
utilization. When temperature control was applied to the mash rations,
average daily gains were significantly (P < . 05) improved
over the controls, shrinkage losses apparently increased (P < .05
with the "soaked" group), but the feed efficiency tended to decrease
as did the backfat thickness and the iodine numbers of the backfat
(P < .05 with the "soaked" group).
The laboratory study provided some evidence that Cellulase
4000 brought about reduction in cellulose, but that the pH of barley
rations was not optimum for cellulase activity. Reducing sugars and
crude fiber were found to increase with the ration soaking time. ¹ Cellulase 4000, supplied gratis by Miles Laboratories, Elkhart, Indiana.