Animal Science Department Florida Agricultural
Mimeograph Report AN66-10 Experiment Station
DRIED BAKERY PRODUCT FOR RUMINANTS: NUTRIENT DIGESTIBILITY
AND RUMEN FERMENTATION
J. E. Moore, L. R. Arrington, R. L. Shirley and T. J. Cunhal/
The nutritive value of dried bakery product (DBP) for livestock
has been the subject of several studies with various species of animals.
DBP replaced corn meal as 10, 20 and 30% of the total diet of growing
pigs with no marked change in the overall performance of the pigs (6).
When used in the diet of early weaned pigs, DBP economically replaced
dried skimmilk at 20% of the total diet (5). In studies with laboratory
animals, rats fed diets containing 66.5% DBP performed as well as those
fed corn meal and feed efficiency was generally improved when the diets
included DBP (2). DBP was inadequate as a source of B-vitamins for rats
(2) and swine (6).
In studies with ruminants, lactating dairy cows utilized 30% DBP
in the diet as a source of energy (7). Fattening beef steers fed 2.37
Ibs. of DBP per day in replacement of ground snapped corn gained as
fast and efficiently as steers fed no DBP (3).
To gain additional information about the feeding value of DBP for
ruminants, two experiments were conducted with sheep to evaluate (1)
nutrient digestibility and (2) rumen fermentation of rations containing
DBP. Sheep were selected as experimental animals because of their more
convenient size and since sheep and cattle have similar digestive powers
(1). In addition to DBP, a bakery product with added fermentation
solubles (Nujets) was also evaluated for nutrient digestibility.
EXPERIMENT I. NUTRIENT DIGESTIBILITY
Five mature Florida native wethers, averaging 95 lbs. in weight,
were individually fed five rations in a 5 x 5 Latin square design. The
composition of the five concentrate mixtures is shown in Table 1. Each
sheep was fed daily 710 gm of one of the concentrates and 90 gm of
chopped bermudagrass hay. Water was provided ad libitum. The nutrient
composition of the five concentrates and the hay is shown in Table 2.
-/ Moore, Asst. Animal Nutritionist; Arrington, Assoc. Animal Nutritionist;
Shirley, Animal Nutritionist; Cunha, Animal Nutritionist and Head of
Total collection digestion trial procedures were used, with .14 day
preliminary feeding and 5 day fecal collections in each of the 5
periods. Rations and feces were analyzed for dry matter, protein and
energy and digestion coefficients calculated. Data were analyzed for
statistical significance by analysis of variance and Duncan's multiple
The digestion coefficients of dry matter, protein and energy are
shown in.Table 3 for each of the five rations. These values do not
represent the digestion coefficients of the nutrients in dried bakery
products alone, but indicate nutrient digestibility of the total rations
with or without dried bakery products. There were no differences among
the digestion coefficients for dry matter and protein. The digestibility
of energy was significantly lower (P<.05) in rations D and E which
included the dried bakery product with added fermentation solubles
(Nujets). However, the digestibility of energy was at an acceptable
level in the latter rations. These data suggest that dried bakery
products are equivalent to corn meal in providing digestible nutrients
EXPERIMENT II. RUMEN FERMENTATION
Fifteen mature Florida Native wethers, weighing 95-125 lbs., were
divided randomly, by weight, to one of three groups, five animals per
group. All groups received the same ration (Ration F, Table 4, 50% corn
meal) for a preliminary period of 14 days. .Each animal received 800 gn
daily and water ad libitum. At the end of the preliminary period the
rumen fluid of each animal was sampled by stomach tube. After sampling,
the animals in group 1 were continued on Ration F, but the animals in
groups 2 and 3 were fed Rations G (25% corn meal, 25% dried bakery
product) and H.(50o5 dried bakery product) (Table 4), respectively.
Rumen samples were taken from all animals 12 and 19 days after groups
2 and 3 were started on Rations G and H.
Rumen fluid samples were analyzed for volatile fatty acids by gas
chromatography. The concentration of total volatile fatty acids (TVTA),
the molar percentages of acetate (C2), propionate (03), butyrate (C4),
isovalerate (ic5) and valerate (C5), and the acetate:propionate ratio
(C2/c3) were calculated. TVFA and acetate:propionate (C2/C3) ratios
were analyzed statistically by analysis of variance at each sampling
Some difficulty was encountered in maintaining the 800 gm daily
feed intake level with sheep receiving the 50CQ dried bakery product
(Ration H). However, after the first 12 days on the ration, only one
of the five sheep went off feed before the last sampling.
- 3 -
The volatile fatty acid compositions of the rumen fluids taken
from sheep in this experiment are shown in Table 5. No differences
were observed in TVFA levels at any time. The average rumen acetate:
propionate ratios (02/C3) were lower in sheep fed DBP than in those
fed no DBP at both the 12 and 19 day sampling times. Differences among
rations were statistically significant (P<.05) only at the 12 day
sampling time. There was an apparent increase in rumen C2/03 ratio of
animals in group 1 between the preliminary and 12 day sampling even
though these animals were continued on the same ration (F, 50% corn
meal). The ratio declined at 19 days to the preliminary level. This
variation is not explained, but is typical of that encountered in other
Even though the average 02/03 ratios were statistically different
at 12 days and apparently different at 19 days between those animals
receiving only corn meal and those receiving bakery product, there was
large variability among the individual animals receiving the 50fo bakery
product ration. Whereas at 12 days the range in C2/C3 ratios among the
five animals on Ration F (50% corn meal) was only 1.06 and for Ration G
(25% corn meal, 25% bakery product) was only 1.20, the range for Ration
H (50% bakery product) was 2.68. The ranges were even greater at 19
days, and this may have accounted for the lack of statistically signi-
ficant differences at that time. The wide range in rumen 02/03 ratios
and the lower acceptability of the 50% DBP ration may indicate some
instability of rumen digestion in those animals fed the 50o DBP ration.
Digestibilities of dry matter, protein and energy in rations con-
taining.5 and 30% of dried bakery products (DBP) replacing corn meal
were equal to those of a ration containing no DBP. Perhaps higher
levels of DBP could be fed to ruminants unless palatability problems
would be encountered as occurred in the rumen fermentation trial when
a ration containing 50o% DBP was fed.
Although the energy digestibility of DBP was apparently similar
to that of corn meal, the data on rumen volatile fatty acids (VFA)
suggest that a different rumen fermentation may occur with DBP as
compared to corn meal. Considering that lower rumen acetate:propionate
ratios have been related to increased feed efficiency (4), the VFA data
suggest that the digestible energy of DBP might be more efficiently
utilized by the fattening ruminant than that of corn meal. Feeding
studies are required to investigate this hypothesis. DBP may have no
effect on rumen VFA with other types of rations or when included at
less than 25% of the total ration.
Two experiments were conducted with sheep to evaluate (1) nutrient
digestibility and (2) rumen fermentation of rations for ruminants con-
taining various levels of dried bakery product (DBP). Dry matter, protein
and energy digestibilities of rations containing 0, 5 and 30% DBP were
essentially similar. A decrease in the acetate:propionate ratio of rumen
volatile fatty acids occurred when DBP constituted 25 or 50% of the total
ration as a replacement for corn meal.
- I -
Table 1. Composition of Concentrate Mixtures Fed in Digestion Trial
(Amount per 100 lbs.)
Ingredient A B C D E
Corn meal (lb.) 60.0 55.0 30.0 55.0 30.0
Dried Bakery Product (Ib.) 5.0 30.0 --
Nu.etsl/(lb.) 5.0 30.0
Ground snapped corn (Ib.) 15.0
Soybean meal (44% protein) (lb.) 23.5
Trace Mineralized Salt (Ib.) 0.5
Defluorinated phosphate (lb.) 1.0
Vit. A. palmitate (10,000 lU/gm) (gm) 30.0
Vit. D2 (9,000 IU/gm) (gm) 10.0
1/ Trade name for dried bakery product with fermentation solubles added.
S ame amount included in Rations A to E.
Table 2. Nutrient Composition of Concentrate Mixtures and Hay
Fed in Digestion Triall/
1/ Average of five determinations; as fed.
Table 3. Digestion Coefficients of Dry Matter, Protein and Energy in
Rations Containing Dried Bakery Productsl/
Nutrient A B C D E
Dry Matter 81.8 81.6 81.1 78.9 79.8
Protein 83.4 83.1 83.3 82.6 81.5
Energy 82.3a3/ 82.2ab 82.5a 79.8c 80.1bc
/ Average of five determinations.
2/ Refer to Table 1 for composition of Rations A to E.
3/ Values with different superscript letters are significantly dif-
Table 4. Composition of Rations Fed in Rumen Fermentation Trial
(Amount per 100 lbs.)
Ingredient F G H
Corn meal (lb.) 50.0 25.0 --
Dried Bakery Product (Ib.) 25.0 50.0
Ground snapped corn (Ib.) 16.5
Ground hay 20.0
Soybean meal (44l protein) (lb.) 12.0
Trace Mineralized Salt (Ib.) 0.5
Defluorinated phosphate (Ib.) 1.0
Vit. A (10,000 IU/gm) (gm) 2.0
Vit. D2 (9,000 IU/gm) (gm) 5.0
-/ Same amount included in Rations F to H.
Table 5. Rumen Fluid Volatile Fatty Acids in Sheep Fed Rations
Containing Corn Meal or Dried Bakery Products
..... Volatile Fatty Acid3/
Sampe Group; Ration!/ TVFA C2 C3 C4 iC5 C5 C2/C3
mM/1_/ ----Molar percentage-----
Prelim. 1 F 62.6 57.6 25.1 13.7 2.6 1.0 2.33
2 F 75.9 56.9 25.9 13.2 2.9 1.1 2.27
3 .F 80.7 58.2 26.4 11.7 2.5 1.2 2.33
12 days 1 F 64.5 61.5 20.8 14.6 2.0 1.1 3.C0
2 G 94.4 49.7 31.7 14.9 1.9 1.8 1.88
3 H 77.4 50.6 36.5 10.1 1.1 1.7 1.47
19 days 1 F .75-9 57.3 25.6 14.3 1.9 0.9 2.36
2 G 90.7 48.6 37.1 11.5 1.3 1.5 1.51
3 H 81.8 52.9 32.9 10.7 1.5 2.0 1.78
/ Refer to Table 4 for composition of Rations F to H.
2/ Concentration of total volatile fatty acids, millimoles per liter of
3/ C2, acetate; C3, propionate; C4, butyrate; iC5, isovalerate; C5,
4/ Acetate:Propionate Ratio.
1. Alexander, R. A., J. F. Hentges, Jr., J. T. McCall and W. 0. Ash.
1962. Comparative digestibility of nutrients in roughages by
cattle and sheep. J. Animal Sci. 21: 373.
2. Arrington, L.
T. J. Cunha.
R., Roberto Ancalmo, D. E. Raulerson, J. E. Moore and
1964. Feeding value of dried bakery products for rats
Fla. Agr. Exp. Sta. Mineo Report AN65-7, November.
3. Baker, F. S., Jr. 1964. Steer fattening trial. North Florida
Exp. Sta. Mimeo Report 64-7, May 25.
4. Blaxter, K. L. 1962. The Energy Metabolism of Ruminants. Charles
C. Thomas, Publisher, Springfield, Ill.
5. Combs, G. E., H. D. Wallace and T. H. Berry. 1964. Dried bakery
product as a replacement for dried skim milk in starter rations.
Fla. Agr. Exp. Sta. Mimeo Report AN65-1, July.
6. Wallace, H. D., G. E. Combs
product as a substitute for
the growing-finishing pig.
and R. G. Conness. 1964. Dried bakery
corn and as a source of B-vitamins for
Fla. Agr. Exp. Sta. Mimeo Report AN164-15.
7. Wing, J. M. 1964. Preliminary evaluation of dried bakery product
in dairy cattle rations. Fla. Agr. Exp. Sta. Dairy Sci. Mimeo
Report 64-2, April 28.