A total of 1,099 pigs (PIC 1050 × 337; initially 75 lb) were used in a 104-d study to
determine the influence of a Bacillus product and diet type on growth performance,
carcass traits, fecal consistency, and pen cleaning time in growing-finishing pigs
raised under commercial conditions. Pens of pigs were balanced by initial weight and
randomly allotted to 1 of 6 dietary treatments in a completely randomized design with
26 to 27 pigs per pen and 7 replications per treatment. Treatments were arranged
as a 3 × 2 factorial with main effects of Bacillus product (0, 1x, or 10x) and diet type
(corn-soybean meal or a by-product diet with 30% dried distillers grains with solubles
[DDGS] and 20% bakery). The dose of Bacillus in the diet was approximately 200
million cfu/g feed for the 1x level and 2 billion cfu/g feed for the 10x level. Fecal consis-
tency and manure buildup in each pen was scored at the end of the trial by 3 observers
with the average value per pen used for analysis. Time required to wash each individual
pen was also recorded.
Overall (d 0 to 104), no differences were found in growth performance or carcass
composition for pigs fed the Bacillus product; however, pigs fed the 1x level of Bacillus
tended (quadratic, P = 0.10) to have the lowest ADG. Manure texture score tended to
increase (linear, P = 0.07) as Bacillus dose increased, indicating that pigs fed the Bacillus
product had firmer stools. For diet formulation, pigs fed the diet containing by-prod-
ucts had increased (P = 0.01) ADFI compared with pigs fed the corn-soybean meal diet.
With no difference in ADG, feed efficiency was poorer (P < 0.01) for pigs fed by-product
diets. Pens that contained pigs fed by-product diets required more (P < 0.01)
time to wash, which appeared to be the result of looser manure texture (P = 0.09) and
increased (P = 0.08) manure buildup in pens where pigs were fed by-product-based
diets. The Bacillus product tested did not improve growth performance, but altered
fecal consistency and barn wash time.
