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 Experimental
 Results and discussion
 Summary
 Table 1 - Diet composition
 Table 2 - Performance of finishing...














Group Title: Department of Animal Science research report - Florida Agricultural Experiment Station ; AL-1982-6
Title: Effect of heating on the feeding value of aflatoxin contaminated corn for finishing swine
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Permanent Link: http://ufdc.ufl.edu/UF00073138/00001
 Material Information
Title: Effect of heating on the feeding value of aflatoxin contaminated corn for finishing swine
Series Title: Department of Animal Science research report
Physical Description: 5 leaves : ; 28 cm.
Language: English
Creator: Combs, G. E ( George Ernest ), 1927-
Harrison, Michael Dean, 1957-
University of Florida -- Dept. of Animal Science
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1982
 Subjects
Subject: Swine -- Feeding and feeds -- Florida   ( lcsh )
Corn as feed -- Florida   ( lcsh )
Corn -- Diseases and pests -- Control -- Florida   ( lcsh )
Aflatoxins   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: M.D.Harrison, and G.E.Combs
General Note: Caption title.
General Note: "August, 1982."
General Note: Leaves numbered 17-21.
Funding: Animal science research report (University of Florida. Dept. of Animal Science) ;
 Record Information
Bibliographic ID: UF00073138
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 81144446

Table of Contents
    Experimental
        Page 17
    Results and discussion
        Page 18
    Summary
        Page 18
        Page 19
    Table 1 - Diet composition
        Page 20
    Table 2 - Performance of finishing pigs fed diets containing heated and unheated aflatoxin contaminated corn
        Page 21
Full Text



Department of Animal Science 17 Florida Agricultural
Research Report AL-1982-6 Experiment Station
August, 1982 Gainesville, FL


EFFECTS OF HEATING ON THE FEEDING VALUE OF AFLATOXIN
CONTAMINATED CORN FOR FINISHING SWINE1

G. E. Combs and M. D. Harrison2


Previous research results3 indicated that heating aflatoxin infested
corn to a temperature of 1900C was effective in reducing aflatoxin content
without damaging the corn to the extent of adversely affecting pig perfor-
mance.

This study was conducted to confirm these findings and to verify re-
ports that folic acid supplementation was also effective in alleviating
the growth depression which accompanies the consumption of aflatoxin con-
taminated corn.


Experimental

Forty-two finishing pigs weighing approximately 68 kg were allotted on
the basis of weight, sex and litter to seven treatment groups. All pigs
were housed in semi-enclosed pens equipped with an aluminum slatted floor,
self-feeders and automatic watering devices.

The corn was purchased from a producer that had experienced considerable
death loss in pigs fed diets using this corn. Analyses from two laboratories
showed that this uncleaned corn contained 1955 ppb aflatoxin (1813 ppb as
B1 and 141 ppb as B2).

Heating this uncleaned corn in a Roast-A-Tron gas-fired roaster pro-
duced the following results:

Exit Temperature C

Aflatoxin, ppb 150 165 190
Bi 1175 1100 580
B2 120 115 65

Total 1295 1215 645

Heating to 1900C resulted in the largest amount of aflatoxin destruction.
However, subsequent attempts to duplicate these findings resulted in the corn
being reduced to a black gelatinized material which could not be used in
swine diets.


1Experiment 280.
2Combs, Animal Nutritionist and Harrison, Graduate Assistant, Animal Science
Department, Gainesville.
3Cereal Chem. 55:15, 1978.






- 18 -


Further experimentation showed that cleaning the contaminated corn re-
duced the aflatoxin content to a total of 1175 ppb (B1-975; B2-100 and
G1-100). When this cleaned corn was heated to an exit temperature of 1750C,
the aflatoxin content was further reduced to a total of 550 ppb (BI-450 and
B2-100). This corn and this temperature along with uncontaminated corn were
then used to form the following dietary treatments.

Treatment

No. Description

1 Uncontaminated corn (UC)
2 Uncontaminated corn heated to 1750C (UC-175)
3 Uncontaminated corn heated to 1750C + folic acid (UC-175 FA)
4 Aflatoxin corn (AC)
5 Aflatoxin corn heated to 1750C (AC-175)
6 Aflatoxin corn heated to 1750C + folic acid (AC-175 FA)
7 50% uncontaminated corn + 50% aflatoxin contaminated corn
heated to 1750C (50% UC-AC-1750C)

The composition of the basal diet is shown in table 1.

Results and Discussion

Performance data are summarized in table 2.

Comparison of average daily gain figures for pigs fed diets containing
uncontaminated corn and unheated aflatoxin corn (treatments 1 and 4) shows
that sufficient aflatoxin was present to cause a 22 percent depression in
this performance parameter. Further comparisons show that heating the afla-
toxin corn (treatment 5) resulted in an increased rate of gain. The addition
of folic acid to the heated corn (treatment 6) resulted in an additional in-
crease that surpassed that of pigs fed uncontaminated corn. The dilution of
the aflatoxin corn with uncontaminated corn (treatment 7) improved daily gain
over that obtained with unheated aflatoxin corn (treatment 4) but the improve-
ment was considerably less than that observed by heating the contaminated
corn to 1750C. The daily gain of pigs fed uncontaminated corn heated to 1750C
with and without supplemental folic acid (treatments 2 and 3) was depressed
when compared to pigs fed the uncontaminated control diet (treatment 1).

Feed efficiency comparisons show that with pigs fed diets containing
aflatoxin corn, improvement occurred only with the diet in which the corn was
heated and supplemented with folic acid (treatment 6). With the uncontaminated
corn, feed efficiency was not improved by either heat or heat plus folic acid.


Summary

An experiment was conducted with 42 finishing pigs to determine if
heating aflatoxin-infested corn was an effective procedure for reducing afla-
toxin content. The growth promoting effect of supplemental folic acid when
added to diets containing aflatoxin contaminated corn was also evaluated.
Performance data show that pigs fed diets containing aflatoxin contaminated






- 18 -


Further experimentation showed that cleaning the contaminated corn re-
duced the aflatoxin content to a total of 1175 ppb (B1-975; B2-100 and
G1-100). When this cleaned corn was heated to an exit temperature of 1750C,
the aflatoxin content was further reduced to a total of 550 ppb (BI-450 and
B2-100). This corn and this temperature along with uncontaminated corn were
then used to form the following dietary treatments.

Treatment

No. Description

1 Uncontaminated corn (UC)
2 Uncontaminated corn heated to 1750C (UC-175)
3 Uncontaminated corn heated to 1750C + folic acid (UC-175 FA)
4 Aflatoxin corn (AC)
5 Aflatoxin corn heated to 1750C (AC-175)
6 Aflatoxin corn heated to 1750C + folic acid (AC-175 FA)
7 50% uncontaminated corn + 50% aflatoxin contaminated corn
heated to 1750C (50% UC-AC-1750C)

The composition of the basal diet is shown in table 1.

Results and Discussion

Performance data are summarized in table 2.

Comparison of average daily gain figures for pigs fed diets containing
uncontaminated corn and unheated aflatoxin corn (treatments 1 and 4) shows
that sufficient aflatoxin was present to cause a 22 percent depression in
this performance parameter. Further comparisons show that heating the afla-
toxin corn (treatment 5) resulted in an increased rate of gain. The addition
of folic acid to the heated corn (treatment 6) resulted in an additional in-
crease that surpassed that of pigs fed uncontaminated corn. The dilution of
the aflatoxin corn with uncontaminated corn (treatment 7) improved daily gain
over that obtained with unheated aflatoxin corn (treatment 4) but the improve-
ment was considerably less than that observed by heating the contaminated
corn to 1750C. The daily gain of pigs fed uncontaminated corn heated to 1750C
with and without supplemental folic acid (treatments 2 and 3) was depressed
when compared to pigs fed the uncontaminated control diet (treatment 1).

Feed efficiency comparisons show that with pigs fed diets containing
aflatoxin corn, improvement occurred only with the diet in which the corn was
heated and supplemented with folic acid (treatment 6). With the uncontaminated
corn, feed efficiency was not improved by either heat or heat plus folic acid.


Summary

An experiment was conducted with 42 finishing pigs to determine if
heating aflatoxin-infested corn was an effective procedure for reducing afla-
toxin content. The growth promoting effect of supplemental folic acid when
added to diets containing aflatoxin contaminated corn was also evaluated.
Performance data show that pigs fed diets containing aflatoxin contaminated






19 -


corn that had been heated to 1750C gained 16 percent faster than pigs
given diets containing unheated aflatoxin infested corn. Pigs fed a
diet containing this heat treated corn plus supplemental folic acid
showed a 23 percent increase in rate of gain and a 13 percent increase
in feed efficiency when compared to pigs fed the unheated corn diets.






- 20 -


TABLE 1. DIET COMPOSITION1


Ingredient %

Ground yellow corn 78.75

Soybean meal 18.25

Dynafos 1.60

Limestone 1.00

Iodized salt 0.20

Trace minerals (CCC)2 0.10

Vitamin premix (UF)3 0.10


'Folic acid when used was added at the level of 2 grams/ton.
2Generously supplied by Calcium Carbonate Company, Quincy, IL. Contains
20% zinc, 10% iron, 5.5% manganese, 1.1% copper, 0.15% iodine, 0.10%
cobalt, and 2% calcium
3Contains 13,200 mg riboflavin; 44,000 mg niacin; 26,400 mg pantothenic
acid; 176,000 mg choline chloride; 22,000 mcg vitamin B12; 5,500,000 IU
vitamin A; 880,000 ICU vitamin D3 and 22,000 IU vitamin E per kg of premix.















FINISHING PIGS FED DIETS CONTAINING HEATED AND UNHEATED AFLATOXIN CONTAMINATED CORN1


Treatment no. 1 2 3 4 5 6 7
& description UC UC-1750C UC-1750C FA AC AC-1750C AC-1750C FA 50% UC-AC-1750C

Item

Avg. initial weight, kg 67.8 67.7 67.8 67.8 67.8 67.7 67.8

Avg. final weight, kg 99.8 97.6 95.8 92.6 97.4 100.0 95.1

Avg. daily gain, kg .76 .71 .67 .59 .70 .77 .65

Avg. daily feed, kg 2.78 2.55 2.25 2.01 2.38 2.29 2.38

Avg. feed/gain 3.66 3.59 3.36 3.41 3.40 2.97 3.66

'Experimental period 42 days.


TABLE 2. PERFORMANCE OF




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