Group Title: Department of Animal Science mimeograph series - University of Florida Agricultural Experiment Station ; 61-12
Title: Effects of cobalt-60 irradiation on animal feedstuffs
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 Material Information
Title: Effects of cobalt-60 irradiation on animal feedstuffs
Series Title: Department of Animal Science mimeograph series
Physical Description: 4 leaves : ; 28 cm.
Language: English
Creator: Combs, G. E ( George Ernest ), 1927-
Feaster, J. P
Wallace, H. D ( Harold Dean )
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1961
Subject: Feeds -- Research -- Florida   ( lcsh )
Irradiation -- Research -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: G.E. Combs, J.P. Feaster and H.D. Wallace.
General Note: Caption title.
General Note: "May, 1961."
 Record Information
Bibliographic ID: UF00072912
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 77080155

Full Text

Department of Animal Science Florida Agricultural
Mimeograph Series No. 61-12 Experiment Station
May, 1961 Gainesville, Florida


G. E. Combs, J. P. Feaster and H. D. Wallace 1I

Numerous investigations have shown that the nutritive value of various
foods are altered upon exposure to high energy radiation. Exposure to radi-
ation has also produced objectional odors, flavors, discoloration and texture
changes in many foods. However, the effects of irradiation on the palat-
ability and nutritive value of animal feedstuffs has received only limited

The experiments reported herein were preliminary in nature and were
designed primarily to determine if the palatability of swine rations was
altered by irradiation. The influence of gamma radiation upon solutions and
mixtures of sugar and urea was also studied.


Experiment I. Solvent extracted soybean meal was irradiated at a dos-
age level of 5 X 106 rep. This meal was then incorporated into the rations
of growing-finishing swine so as to form 10% of the total ration (table I).
Nine pigs weighing approximately 134 pounds were divided among 3 treatment
groups. Pigs in group I were given the ration containing the non-irradiated
soybean meal, group 2 received the ration containing the irradiated meal and
group 3 was given access to rations containing either the non-irradiated or
irradiated meal.

Experiment 2. The composition of the ration fed was identical to that
used in Experiment I (taule I). The three ration treatments were as follows:
(I) basal ration containing non-irradiated soybean meal, (2) entire basal
ration irradiated at IX 106 rep. and (3) basal ration containing soybean
meal irradiated at I X 106 rep. Treatment 2 was fortified with vitamins and
an antibiotic following Irradiation. Each of these treatments was fed to
replicated lots of 4 pigs each for a 2 week period.

Experiment 3. Aqueous solutions of sucrose and urea end dextrose and
urea were irradiated at 5 X 105, I X 106, 5 X 10I, 10 X 106 and 20 X 106 rep.
The irradiated and non-irradiated samples were analyzed for total nitrogen
and urea nitrogen. Paper chromatograms were made with each irradiated and
non-irradiated sample. Dry mixtures of urea and sucrose or dextrose were
also irradiated at 5 X 106 and 10 X 106 rep. : .

S". 5 l '
I/ Combs, Feaster, Wallace, Assistant Animal Nutritionist'.,;5ssociate Bi-
chemist and Associate Animal Nutritionist respectively, Department of
Animal Science. -

Results and Discussion

The results of Experiments I and 2 are summarized in table 2. The feed
consumption data for Experiment I indicated that the soybean meal irradiated
at 5 X 106 rep. suffered a slight palatability Impairment. Pigs that were
given a choice of rations (treatment 3 ) perferred the ration which did not
contain the irradiated meal approximately 3 to I over the irradiated meal
ration. However, as evidenced by the similarity in feed consumed by pigs
on treatments I end 2 irradiation at the dosage used did not severely affect

In Experiment 2 the performance of pigs fed the non-irradiated ration
(treatment I) was slightly superior to those pigs on treatment 2 and 3.
The feed consumption data again dcmonstrted that the effect of irradiation
on palatability was small. Although the experimental period was relatively
short, 14 days, the rate and efficiency of gain of pigs fed the irradiated
feedstuffs indicated that some nutrient loss had occurred.

The results of Experiment 3 are summarized in table 3. Previous studies
elsewhere have shown that exposure of amino acids to gamma radiation results
in deamination and the breaking of the benzene ring present in such amino
acids as tryptophan and phenylalanine. Therefore, high-level radiation
could possibly complex the nitrogen present in urea with other compounds so
as to alleviate or eliminate the toxicity encountered when urea is fed to
swine. However, the urea nitrogen or percentage urea present in the non-
irradiated and irradiated samples were similar for both sugar solutions at
the 3 lower radiation levels. At both the 10 and 20 million rep. level
there was a reduction of approximately 7.5 percent in urea nitrogen in the
irradiated urea-sucrose sample. With the urea-dextrose sample only the
highest radiation dosage resulted in a reduction of urea nitrogen. A simi-
lar reduction was also obtained with dry mixtures of urea and sucrose or
dextrose irradiated at 5 X 106 or 10 X 106 rep. The urea nitrogen present
in the control and irradiated samples of urea-sucrose and urea-dextrose
respectively were as follows: (5 X 10 rep.) 5.38 and 4.59, 4.43 and 4.17;
(10 X 106 rep.) 4.57 and 4.04, 5.32 and 4.96. The paper chromatograms
obtained from the non-irradiated and irradiated samples were similar.


Ration acceptance was not markedly influenced by including soybean meal
irradiated at either 5 X 106 rep. or I X 106 rep. in the rations of swine.
The quantity of feed consumed by pigs fed a ration in which all ingredients
had been irradiated (I X 106 rep.) was also similar to that of pigs fed the
non-irradiated ration. Rate and efficiency of gain were adversely affected
by feeding the irradiated (I X 106 rep.) feedstuffs.

Solutions and mixtures of urea with sucrose and dextrose exhibited a
reduction in urea nitrogen when subjected to high levels of cobalt-60 radi-


TABLE I. Composition of Basal Ration


Ground yellow corn 85.4
Soybean meal 10.00
Ground limestone 1.0
Steamed bone meal 1.0
Iodized salt .5
Trace minerals .1
Vitamin-antibiotic premix 2.0

TABLE 2. Results of Feeding Cobalt-60 Irradiated Feeds to Swine

Experiment I

Lot No. I 2 3
Treatment Control Irrad. SBOM Control Irrad. SBOM
(5 X 106 rep.) (5 X 106 rep.)

Total feed
consumed, Ibs. 64 64.5 64 23

Experiment 2

Lot No. I 2 3
Treatment Control Complete Ration SBOM Irrad.
Irrad. (I X 106 rep.) (I X 106 rep.)

No. pigs 8 8 8
Av. init. wt., Ibs. 26.9 26.9 27.0
Av. final wt., Ibs. 38.4 36.3 37.6
Av. daily gain, Ibs. 0.82 0.67 0.76
Av. daily feed, Ibs. 2.82 2.72 2.70
Feed/gain, Ibs. 3.43 4.06 3.55


_ ___

Table 3. Effects of Cobalt-60 Irradiation
on Aqucous Solutions of Urea and Sugars

Urea and Sucrose Urea and Dextrose
... I c I

5 x 10 reo.

Proteinb/ 11.86 11.21 9.23 8.66
Urea Nit. 1.85 1.87 1.47 1.49
Urea 5 3.97 4.01 3.15 3.20

Ix 106 ren.

Protein 11.78 11.78 9.41 8.84
Urea Nit. 1.86 1.79 1.49 I.50
Urea ; 3.99 3.84 3.20 3.22

5 x 106 rep.

Protein 10.51 11.78 8.75 9.41
Urea Nit. 1.86 1.84 1.47 1.47
Urea i 3.99 3.95 3.15 3.15

10 x 106 rep.

Protein 11.73 11.47 8.92 9.01
Urea Nit. 1.85 1.71 1.50 1.50
Urea 3.97 3.67 3.22 3.22

20 x 106 ren.

Protein 11.21 11.29 8.40 9.01
Urea Nit. 1.86 1.70 1.50 1.36
Urea 5 3.99 3.65 3.22 2.92

a/ C = Non-irradiated control sample, I = irradiated sample.

y/ Protein = N. x 6.25.


1000 copies

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