396
THE AMERICAN SOCIETY OF ANIMAL PRODUCTION
ENERGY VALUES OF CORN BRAN, RICE POLISH, RICE
BRAN A N D RYE FLOUR AS MEASURED BY
EXPERIMENTS ON BABY CHICKS
G. S. FRAPS and E. C. CARLYLE
Texas Agricultural Experiment Station
Individual feeding experiments with the use of baby chicks, in which
representative chicks are analyzed at the beginning of the experiment,
and the chicks on experiment at the end, have been used to to study the
utilization of food energy. In Texas Bulletin 571 we published a preliminary determination of the productive energy of corn meal. In the
Journal of Nutrition October 1939, we compared the energy values of
corn meal with that of wheat gray shorts, wheat bran and wheat flour.
It is our intention to study poultry feeds so as to set up a system of
energy values for all poultry feeds. W e also expect to study human
foods by this method of procedure and to check the values so secured by
such other procedures as is possible.
The method of procedure has been given in detail in the publications
just referred to. About 60 baby chicks were fed for a week on the
standard ration, weighed, and divided into five groups of equal total
weight. One group of four was analyzed. The other chicks in 4 groups of
6 chicks each were fed individually. One group was fed on the standard
ration, consisting of 56.8 percent white corn meal, 6 percent alfalfa leaf
meal, 12 percent casein, 2 percent yeast, 20 percent wheat gray shorts,
1 percent calcium carbonate, 1 percent tricalcium phosphate, 1 percent
salt and 0.2 percent of a fortified fish oil containing approximately 400
units of vitamin D per gram.The other three groups were fed on similar
rations, containing 50 percent of the feed to be tested in place of corn
meal. At the end of 3 weeks, each chick was weighed, ground up and
analyzed. The energy content was calculated by multiplying the percentage of protein (N x 6.25) by 5.66 and the fat by 9.35. Comparison of the
composition of the chicks analyzed at the beginning of the experiment
with those at the end enabled the gain in energy to be calculated. Digestion experiments were made on the 4 rations with use of the baby chicks
not needed in the other work.
The average composition of the feeds compared is given in Table 1.
Table 2 contains the data from which the relative values of the feeds
tested were compared with corn meal in which table the work has been
combined to save space. The productive energy of the standard corn
meal ration per 100 grams was assumed to be 2.78 times the effective
digestible nutrients of this ration, as found by the digestive tests, which
THE AMERICAN SOCIETY OF ANIMAL PRODUCTION
397
would be 1.909 Calories per gram in Experiment 13 and 1.925 Calories
in Experiment 16. The value of 2.78 Calories per gram of the effective
digestible nutrients was secured in work reported in Texas Bul. ~71. The
calculated productive energy of the corn meal ration eaten, less the energy
stored up in the chicks, gives the Calories of productive energy of the
corn meal ration used for maintenance, which was calculated to maintenance requirements per 100 grams of live weight of chick. These maintenance requirements were then used to calculate the Calories used for
maintenance by the chicks fed on the rations being tested. The sum of the
Calories in the gain and the Calories used for maintenance, gives the
productive energy of the ration tested, and is calculated to 100 grams of
ration eaten, as shown in Table 2.
TABLE 1--PERCENTAGE COMPOSITION OF FEEDS
Exp.
Corn meal ( A)
Corn meal (B)
Corn bran (A)
Corn bran (B)
Corn bran (C)
Rice polish
Rice bran
Rye flour
13
16
13
13
13
16
16
16
Nitrogen
Ether Crude Free
Protein Extract Fibre Extract Water
10.52
I0.69
9.40
10.49
6.34
13.17
13.10
12.61
2.67
3.23
6.~7
8.16
3.95
15.31
11.17
1.90
1.01
1.12
12.54
10.20
14.79
2.10
6.78
2.16
74.3Y
73.97
62.06
61.70
65.70
52.ll
50.77
69.77
Ash
10.04
1.41
9.74
7.21
6.92
7.73
9.53
8.98
11.75
1.25
2.22
2.53
1.49
7.78
9.20
1.81
Digestion experiments were made with the rations and the results are
summarized as "effective digestible nutrients", which is the sum of the
digestible protein, the digestible ether extract multiplied by 2.25 and
the digestible nitrogen-free extract. The effective digestible nutrients of
the feeds were secured by substracting those of the constant part of the
ration from the total ration and multiplying by 2 and are given in Table 3.
The metabolizable energy was calculated from the heats of combustion
of the rations fed and of the excrement secured in the digestion experiments, measured in a bomb calorimeter, and the metabolizable energy
of the feed as given in Table 3 calculated by a method similar to that used
for the total digestible nutrients. Details are given in the articles previously mentioned.
The calculated productive energy of the corn meal and the productive
energy of the other feeds as compared with corn meal, are given in Table
3.
Examination of Table 3 shows wide differences in the productive energy
per 100 grams of feed. The 3 samples of corn bran have values of 63,
103, and 132 Calories per 100 grams, as compared with 225 for corn
398
T H E A M E R I C A N S O C I E T Y OF A N I M A L P R O D U C T I O N
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THE AMERICAN SOCIETY OF ANIMAL PRODUCTION
399
meal. T h e r y e flour, rice bran and rice polish have values of 134, 181,
and 216 compared with 225 for corn meal.
TABLE 3--DIGESTIBLE NUTRIENTS, METABOLIZABLE ENERGY AND
PRODUCTIVE ENERGY OF FEEDS TESTED
Productive energy
~.~z
Corn meal standard
Corn bran (A)
Corn bran (B)
Corn bran (C)
Corn meal standard
Rice polish
Rice bran
Rye flour
Exp.
Exp.
Exp.
Exp.
Exp.
Exp.
Exp.
Exp.
13
13
13
13
16
16
16
16
79.6
34.5
43.1
20.9
82.8
83.~
65.1
60.4
~
338.3
135.1
184.2
91.3
347.8
351.4
264.~
256.1
~ ~
222
103
132
63
225
216
181
134
~
~'7,
279
299
306
301
272
259
278
222
~ -~
66
76
72
69
65
61
68
52
W h e n the productive energy for 100 grams of effective digestible
nutrients is considered, the differences are less apparent, except with rye
flour. T h e differences between the value of 279 Calories for corn meal
and the values of 301, 306, and 299 Calories per 100 grams of effective
digestible nutrients for the three samples of corn bran may be in the limit
of error. T h e values for 100 grams of the effective digestible nutrients
of 259 for rice polish and 278 for rice bran are close to that of 272 for
corn meal. T h e value of 222 for rye flour, however, shows that its digestible nutrients have much lower values than those of corn meal. There
are likewise small differences per 100 grams of metabolizable energy, except with the rye flour.
Summary
Compared with corn meal at 225 Cal. per 100 grams, the productive
energy of some other feeds were: rice polish 216, rice bran 181, rye
flour 133, and three lots of corn bran, 103, 132 and 63 calories per gram.
The productive energy per unit of effective digestible nutrients and
for metabolizable energy are reasonably close for all the feeds tested except rye flour, which had an appreciably lower value and in this respect
resembled wheat bran and wheat gray shorts reported in previous work.
Literature Cited
1. Fraps, G. S. and E. C. Carlyle. 1939. The utilization of the energy of feed
by growing chicks. Texas Agricultural Experiment Station Bulletin 571.
2. Fraps, G. S. and E. C. Carlyle. 1939. The utilization of corn and wheat
products by chickens. Journl of Nutrition. 18, 385-398.