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Effects of Diets Containing Helminthosporium maydis Blighted Corn on Growth Rate, Feed Conversion, Mortality and Blood Clotting Time of Broilers
Effects of Diets Containing Helminthosporium maydis Blighted Corn on Growth Rate, Feed Conversion, Mortality and Blood Clotting Time of Broilers K. W. WASHBURN AND W. M. BEITTON Department of Poultry Science, University of Georgia, Athens, Georgia 30601 (Received for publication January 9, 1971)
T
HE severe infection of corn by Helminthosporium maydis has resulted in blighted corn of questionable value as the main food ingredient in poultry rations. There are a number of areas involving the blighted corn that need to be studied, but the question of most immediate importance is whether or not blighted corn of otherwise good quality can be incorporated into broiler rations without deleterious effects on growth. The present study was designed to determine if the feeding of diets containing moderately blighted corn (25% of kernels visibly infected with Helminthosporium maydis) would have a deleterious effect on growth rate or feed conversions of broiler chicks under field growing conditions. In addition, its possible effect on coagulation time was studied, since various toxins produced by microorganisms, particularly aflatoxins, (Forgacs et al., 1962) may interfere with blood coagulation and result in a hemorrhagic syndrome-type disease.
The moisture content of the control and blighted corn was similar, but the protein content was increased in the blighted corn. There was little difference in the gross energy values of the blighted and control corn (Table 3). The proximate analysis and gross energy were determined using the methods of A.O.A.C. (1960). Fifty commercial broiler chicks were placed in each of forty floor pens. Females were placed in 20 pens on one side of the house and males in 20 pens on the other. Within each sex, ten pens of chicks fed blighted corn were alternated with ten pens of chicks fed the control corn. The diets were fed ad libitum from 1 day to 7 weeks of age. Body weights by pens were obtained at 2, 4, 6, and 7 weeks of age. Feed TABLE 1.—Composition of experimental, diets
(%) Ground yellow corn Soybean meal Poultry by-products meal Poultry fat Deny, alfalfa Defl. phosphate Limestone Salt (NaCl) Vitamin and2 Amino acid mix1 Mineral mix
MATERIALS AND METHODS
The experimental diets (Table 1) used in this study contained 55.75% corn which showed no evidence of blight or 55.75% blighted corn (Table 2) in which 25-30% of the kernels were infected with Helminthosporium maydis. The weight per unit volume of the blighted corn was 10.7% less than that of the control non-blighted corn. University of Georgia, College of Agriculture Experiment Station, College Station, Athens, Georgia. Journal Series Paper Number 951.
1
55.75 32.23 5.00 2.50 1.50 1.50 0.60 0.40 0.40 0.10
Vit. and A.A. mix (per kg. diet) : Vitamin A (I.U.) 4400.0 Vitamin D 3 (I.C.U.) 880.0 Vitamin K (mg.) 2.2 Vitamin B12 (meg.) 6.6 Riboflavin (mg.) 4.4 Ca pantothenate (mg.) 8.8 Niacin (mg.) 44.0 Choline CI (mg.) 220.0 DL-methionine (gm.) 1.0 2 Mineral mix supplied (per kg. diet): 60 mg. Mn, 20 mg. Fe, 2 mg. Cu, 20 mg. Zn, 1.2 mg. I.
1161
1162
K. W. WASHBURN AND W. M. BRITTON
TABLE 2.—Severity of fungi infection of blighted corn used in experimental diets1
Fungus
Percent grains infected
Helminthosporium maydis Helminlhosporium rostratum Fusarium moniliforme Rhinolrichum tennellum Rhizoctonia solani Bacteria alone Nothing
24 2 74 8 2 2 2
1 Random sample of 50 grains surface sterilized by dip in alcohol and 3-minute immersion in 10% bleach (sodium hypochlorite). Plated on water agar. Dr. E. S. Luttrell, Plant Pathology, University of Georgia. Visual observation of the blighted corn indicated 26% of kernels appeared damaged.
conversions were obtained for the period 02, 2-4, and 4-6 weeks of age. Plasma prothrombin time was determined at 3 and 5 weeks of age by the use of a lyophilized chick embryo extract as the source of thromboplastin. The detailed methods are given by Soliman and Huston (1971). Mortality was recorded, but birds were not autopsied due to very low mortality and lack of differences between the groups. Frequent visual observations of the appearance of the birds showed that all chicks appeared very healthy, well feathered with no evidence of morbidity during any part of the experimental period. RESULTS AND DISCUSSION As shown in Figure 1 and Tables 4 and 5 there were no significant differences in growth rate between the groups fed the diet containing blighted or control corn. The blighted corn appeared to result in a growth depression at 4 weeks but by 6 weeks this effect was completely lost. By 7 weeks the weight of the groups fed the blighted corn was higher than that of the groups fed the control diet. These differences between the 2 diets (treatments) at the different age periods resulted in a highly
significant treatment-age effect (Table 5), but there were essentially no differences between the groups in mean body weight averaged over the entire experimental period. This interaction effect is illustrated in Figure 1. There were no significant differences between the groups in feed conversion (Table 5). The feed conversion ratios (Table 4) showed a depression at 4 weeks of age for the blighted corn similar to that for body weight, but the differences between the treatments at the different time periods were not significant. The feeding of the diet containing blighted corn did not cause any increased mortality. The total mortality of the birds receiving the blighted corn was 0.9% compared to 1.6% in the control birds. No differences in appearance of the groups could be detected by visual observations. The effect of feeding diets containing blighted corn on prothrombin time (P.T.) are presented in Table 6. In group 1 the P.T. was increased to 44.3 seconds compared to the control values of 40.6 seconds. This difference was not significant and similar differences were not noted in the second group of birds. The increases in P.T. of the birds fed blighted corn in group 1 were primarily due to two individuals in that
TABLE 3.-
-Proximate analysis of blighted and control corn
H20
Whole corn control blighted x severely moderately nondamaged
Ash
Protein
Fiber
Ether extract
Gross energy
%
%
%
%
%
Kcal./k.
HI .62 10 .57 11)..93 10 .12
1.68 1.78 1.98 1.83
9, 95 12 .01 12. 28 12..21
1.81 2.67 3.08 2.50
3.74 2.42 1.88 2.44
3977.0 3953.9 3945.2 3967.5
10 .07
1.55
11..55
2.43
2.94
3949.0
Ground com control blighted
12 .01 11 .27
1.67 1.45
9 23 11 .68
2.32 1.74
2.86 2.12
3881.2 3923.6
Diets control blighted
9 .37 9 .78
6.18 5.60
22 .39 25 .84
2.64 2.98
5.96 5.24
4124.6 4147.4
1163
BLIGHTED CORN FOR BROILERS
FEMALES 3.0
2.5-
2.0
— SLIGHTED CORN —CONTROL
O I
1.5 -BLIGHTED CORN -CONTROL
>-
>o
a O
s
1.0
i.o-
0-5
4
6
4
AGE ( w . . k . )
6
AGE (wwkt)
FIG. 1. Effects of feeding diets containing blighted corn on growth rate of male and female broiler chicks.
group which had extremely high P.T. rather than uniform elevation of the values of all birds in this group. These results demonstrate that the feeding of a diet containing approximately 55% corn that was affected with Helminthosporium maydis to the extent that ap-
proximately 25% of the kernels were affected did not have a detrimental effect on growth rate, feed conversion, mortality or blood clotting time. It should be emphasized that the corn was of otherwise excellent quality. The blighted corn used in this trial weighed 11 % less per unit volume and
TABLE 4.—Effects of feeding diets containing blighted corn on) conversion (F.C.) ratio and body weight (B.W.)
Blighted Male Female X
Control Male Female X
1
AGE (wks.) F.C. B.W.
F.C.
B.W.
X
6
4-6
7
F.C.
(1-70) (1.75) (1.73)
2.10 1.84 1.97
(2.07) (2.071 (2.07)
2.68 2.31 2.50
1.74*1
(1.63) (1.65) (1.64)
1.99 1.83 1.91
(1.99) (2.05) (2.02)
2.61 2.24 2.42
1.68»
B.W.
F.C.
B.W.
2
0-2
4
2-4
0.36 0.37 0.36
(1.42) (1.42) (1.42)
1.09 0.98 1.04
0.37 0.40 0.38
(1.37) (1.43) (1.40)
1.15 1.08 1.11
Those means with the same superscript are not significantly different (P<0.05).
1164
K. W. WASHBURN AND W. M. BEITTON
TABLE 5.—Analysis of variance for growth rate and feed conversion Feed conversions
Body weight d.f. Sex (S) Treatment (T) Age (A) SXT SXA TXA SXTXA Error Total
Mean Squares
1 1.323** 1 .004 3 34.039** 1 .002 3 .028* 3 .050** .001 3 144 .007 159
TABLE 6.—Effects of feeding diets containing blighted corn on prothrombin time {seconds)
d.f.
Mean Squares
S 1 T 1 A 2 SXT 1 SXA 2 TXA 2 SXTXA 2 Error 107 Total 119
0.01 0.06 2.72** 0.07 0.00 0.01 0.23 0.73
Group l 1 Blighted 3 wk. 5 wk. Male Female
the protein content was higher than the control corn used. The formulation of a ration containing equal amounts by weight of this corn apparently did not upset the dietary balance to the extent that an observable detrimental effect was experimentally produced. REFERENCES Association of Official Agricultural Chemist, 1960. Official Methods of Analyses. 9th Edition.
49.6 44.6
45.9 42.7 44.3a
Control 3 wk. 5 wk. 37.2 37.2
Group 2 Blighted 3 wk. 5 wk. Male Female
**P<.01. *P<.05.
42.2 40.8
x
35.6 36.4
31.8 32.3
x 33.7 34.2 34.0s
44.3 43.6
x 40.7 40.4 40.6°
Control 3 wk. 5 wk. 36.6 34.0
29.0 31.5
x 32.8 32.7 32.7"
1 Each group consisted of 15 birds of each sex and diet. Those means within a group with the same superscript are not significantly different at the P<0.05.
Washington, D.C. Forgacs, J., H. Koch, W. T. Carll and R. H. White-Stevens, 1962. Mycotoxicosis I. Relationship of toxic fungi to moldy-feed toxicosis in poultry. Avian Diseases, 6: 363-380. Soliman, K., and T. M. Huston, 1971. Effect of dietary protein and fat on changes of prothrombin time in chickens under different ambient temperatures. Poultry Sci. (In press).
Susceptibility of Broilers to Coccidiosis Following Early Coccidiostat Withdrawal 1 L. R. MCDOUGALD AND W. M. REID Department of Poultry Science, University of Georgia, Athens 30601 (Received for publication January 11, 1971)
T
HE use of preventive medication for coccidiosis protection is now virtually universal in management of commercial broiler flocks. This is accomplished by mixing a coccidiostatic drug into the feed. Medication may be discontinued before marketing for several different reasons. Because of Food and Drug Administration regulations on certain drugs, it is some-
1 University of Georgia College of Agriculture Experiment Station, Journal Series Paper No. 941, College Station, Athens. Institute of Comparative Medicine Contribution No. 832.
times necessary to withdraw the drug several days before the birds are marketed to allow tissue residues of the drug to diminish to permitted levels. This is particularly true if the drug is used in combination with an arsenical growth-promoting agent. Other drugs have no withdrawal requirements, however, they can be withdrawn for reasons of economy and convenience. In one broiler feeding program starter ration is fed for 28 days, grower ration from 29-53 days, then "withdrawal ration," which does not contain the medication, is fed until birds are marketed. In other feeding pro-
T
HE severe infection of corn by Helminthosporium maydis has resulted in blighted corn of questionable value as the main food ingredient in poultry rations. There are a number of areas involving the blighted corn that need to be studied, but the question of most immediate importance is whether or not blighted corn of otherwise good quality can be incorporated into broiler rations without deleterious effects on growth. The present study was designed to determine if the feeding of diets containing moderately blighted corn (25% of kernels visibly infected with Helminthosporium maydis) would have a deleterious effect on growth rate or feed conversions of broiler chicks under field growing conditions. In addition, its possible effect on coagulation time was studied, since various toxins produced by microorganisms, particularly aflatoxins, (Forgacs et al., 1962) may interfere with blood coagulation and result in a hemorrhagic syndrome-type disease.
The moisture content of the control and blighted corn was similar, but the protein content was increased in the blighted corn. There was little difference in the gross energy values of the blighted and control corn (Table 3). The proximate analysis and gross energy were determined using the methods of A.O.A.C. (1960). Fifty commercial broiler chicks were placed in each of forty floor pens. Females were placed in 20 pens on one side of the house and males in 20 pens on the other. Within each sex, ten pens of chicks fed blighted corn were alternated with ten pens of chicks fed the control corn. The diets were fed ad libitum from 1 day to 7 weeks of age. Body weights by pens were obtained at 2, 4, 6, and 7 weeks of age. Feed TABLE 1.—Composition of experimental, diets
(%) Ground yellow corn Soybean meal Poultry by-products meal Poultry fat Deny, alfalfa Defl. phosphate Limestone Salt (NaCl) Vitamin and2 Amino acid mix1 Mineral mix
MATERIALS AND METHODS
The experimental diets (Table 1) used in this study contained 55.75% corn which showed no evidence of blight or 55.75% blighted corn (Table 2) in which 25-30% of the kernels were infected with Helminthosporium maydis. The weight per unit volume of the blighted corn was 10.7% less than that of the control non-blighted corn. University of Georgia, College of Agriculture Experiment Station, College Station, Athens, Georgia. Journal Series Paper Number 951.
1
55.75 32.23 5.00 2.50 1.50 1.50 0.60 0.40 0.40 0.10
Vit. and A.A. mix (per kg. diet) : Vitamin A (I.U.) 4400.0 Vitamin D 3 (I.C.U.) 880.0 Vitamin K (mg.) 2.2 Vitamin B12 (meg.) 6.6 Riboflavin (mg.) 4.4 Ca pantothenate (mg.) 8.8 Niacin (mg.) 44.0 Choline CI (mg.) 220.0 DL-methionine (gm.) 1.0 2 Mineral mix supplied (per kg. diet): 60 mg. Mn, 20 mg. Fe, 2 mg. Cu, 20 mg. Zn, 1.2 mg. I.
1161
1162
K. W. WASHBURN AND W. M. BRITTON
TABLE 2.—Severity of fungi infection of blighted corn used in experimental diets1
Fungus
Percent grains infected
Helminthosporium maydis Helminlhosporium rostratum Fusarium moniliforme Rhinolrichum tennellum Rhizoctonia solani Bacteria alone Nothing
24 2 74 8 2 2 2
1 Random sample of 50 grains surface sterilized by dip in alcohol and 3-minute immersion in 10% bleach (sodium hypochlorite). Plated on water agar. Dr. E. S. Luttrell, Plant Pathology, University of Georgia. Visual observation of the blighted corn indicated 26% of kernels appeared damaged.
conversions were obtained for the period 02, 2-4, and 4-6 weeks of age. Plasma prothrombin time was determined at 3 and 5 weeks of age by the use of a lyophilized chick embryo extract as the source of thromboplastin. The detailed methods are given by Soliman and Huston (1971). Mortality was recorded, but birds were not autopsied due to very low mortality and lack of differences between the groups. Frequent visual observations of the appearance of the birds showed that all chicks appeared very healthy, well feathered with no evidence of morbidity during any part of the experimental period. RESULTS AND DISCUSSION As shown in Figure 1 and Tables 4 and 5 there were no significant differences in growth rate between the groups fed the diet containing blighted or control corn. The blighted corn appeared to result in a growth depression at 4 weeks but by 6 weeks this effect was completely lost. By 7 weeks the weight of the groups fed the blighted corn was higher than that of the groups fed the control diet. These differences between the 2 diets (treatments) at the different age periods resulted in a highly
significant treatment-age effect (Table 5), but there were essentially no differences between the groups in mean body weight averaged over the entire experimental period. This interaction effect is illustrated in Figure 1. There were no significant differences between the groups in feed conversion (Table 5). The feed conversion ratios (Table 4) showed a depression at 4 weeks of age for the blighted corn similar to that for body weight, but the differences between the treatments at the different time periods were not significant. The feeding of the diet containing blighted corn did not cause any increased mortality. The total mortality of the birds receiving the blighted corn was 0.9% compared to 1.6% in the control birds. No differences in appearance of the groups could be detected by visual observations. The effect of feeding diets containing blighted corn on prothrombin time (P.T.) are presented in Table 6. In group 1 the P.T. was increased to 44.3 seconds compared to the control values of 40.6 seconds. This difference was not significant and similar differences were not noted in the second group of birds. The increases in P.T. of the birds fed blighted corn in group 1 were primarily due to two individuals in that
TABLE 3.-
-Proximate analysis of blighted and control corn
H20
Whole corn control blighted x severely moderately nondamaged
Ash
Protein
Fiber
Ether extract
Gross energy
%
%
%
%
%
Kcal./k.
HI .62 10 .57 11)..93 10 .12
1.68 1.78 1.98 1.83
9, 95 12 .01 12. 28 12..21
1.81 2.67 3.08 2.50
3.74 2.42 1.88 2.44
3977.0 3953.9 3945.2 3967.5
10 .07
1.55
11..55
2.43
2.94
3949.0
Ground com control blighted
12 .01 11 .27
1.67 1.45
9 23 11 .68
2.32 1.74
2.86 2.12
3881.2 3923.6
Diets control blighted
9 .37 9 .78
6.18 5.60
22 .39 25 .84
2.64 2.98
5.96 5.24
4124.6 4147.4
1163
BLIGHTED CORN FOR BROILERS
FEMALES 3.0
2.5-
2.0
— SLIGHTED CORN —CONTROL
O I
1.5 -BLIGHTED CORN -CONTROL
>-
>o
a O
s
1.0
i.o-
0-5
4
6
4
AGE ( w . . k . )
6
AGE (wwkt)
FIG. 1. Effects of feeding diets containing blighted corn on growth rate of male and female broiler chicks.
group which had extremely high P.T. rather than uniform elevation of the values of all birds in this group. These results demonstrate that the feeding of a diet containing approximately 55% corn that was affected with Helminthosporium maydis to the extent that ap-
proximately 25% of the kernels were affected did not have a detrimental effect on growth rate, feed conversion, mortality or blood clotting time. It should be emphasized that the corn was of otherwise excellent quality. The blighted corn used in this trial weighed 11 % less per unit volume and
TABLE 4.—Effects of feeding diets containing blighted corn on) conversion (F.C.) ratio and body weight (B.W.)
Blighted Male Female X
Control Male Female X
1
AGE (wks.) F.C. B.W.
F.C.
B.W.
X
6
4-6
7
F.C.
(1-70) (1.75) (1.73)
2.10 1.84 1.97
(2.07) (2.071 (2.07)
2.68 2.31 2.50
1.74*1
(1.63) (1.65) (1.64)
1.99 1.83 1.91
(1.99) (2.05) (2.02)
2.61 2.24 2.42
1.68»
B.W.
F.C.
B.W.
2
0-2
4
2-4
0.36 0.37 0.36
(1.42) (1.42) (1.42)
1.09 0.98 1.04
0.37 0.40 0.38
(1.37) (1.43) (1.40)
1.15 1.08 1.11
Those means with the same superscript are not significantly different (P<0.05).
1164
K. W. WASHBURN AND W. M. BEITTON
TABLE 5.—Analysis of variance for growth rate and feed conversion Feed conversions
Body weight d.f. Sex (S) Treatment (T) Age (A) SXT SXA TXA SXTXA Error Total
Mean Squares
1 1.323** 1 .004 3 34.039** 1 .002 3 .028* 3 .050** .001 3 144 .007 159
TABLE 6.—Effects of feeding diets containing blighted corn on prothrombin time {seconds)
d.f.
Mean Squares
S 1 T 1 A 2 SXT 1 SXA 2 TXA 2 SXTXA 2 Error 107 Total 119
0.01 0.06 2.72** 0.07 0.00 0.01 0.23 0.73
Group l 1 Blighted 3 wk. 5 wk. Male Female
the protein content was higher than the control corn used. The formulation of a ration containing equal amounts by weight of this corn apparently did not upset the dietary balance to the extent that an observable detrimental effect was experimentally produced. REFERENCES Association of Official Agricultural Chemist, 1960. Official Methods of Analyses. 9th Edition.
49.6 44.6
45.9 42.7 44.3a
Control 3 wk. 5 wk. 37.2 37.2
Group 2 Blighted 3 wk. 5 wk. Male Female
**P<.01. *P<.05.
42.2 40.8
x
35.6 36.4
31.8 32.3
x 33.7 34.2 34.0s
44.3 43.6
x 40.7 40.4 40.6°
Control 3 wk. 5 wk. 36.6 34.0
29.0 31.5
x 32.8 32.7 32.7"
1 Each group consisted of 15 birds of each sex and diet. Those means within a group with the same superscript are not significantly different at the P<0.05.
Washington, D.C. Forgacs, J., H. Koch, W. T. Carll and R. H. White-Stevens, 1962. Mycotoxicosis I. Relationship of toxic fungi to moldy-feed toxicosis in poultry. Avian Diseases, 6: 363-380. Soliman, K., and T. M. Huston, 1971. Effect of dietary protein and fat on changes of prothrombin time in chickens under different ambient temperatures. Poultry Sci. (In press).
Susceptibility of Broilers to Coccidiosis Following Early Coccidiostat Withdrawal 1 L. R. MCDOUGALD AND W. M. REID Department of Poultry Science, University of Georgia, Athens 30601 (Received for publication January 11, 1971)
T
HE use of preventive medication for coccidiosis protection is now virtually universal in management of commercial broiler flocks. This is accomplished by mixing a coccidiostatic drug into the feed. Medication may be discontinued before marketing for several different reasons. Because of Food and Drug Administration regulations on certain drugs, it is some-
1 University of Georgia College of Agriculture Experiment Station, Journal Series Paper No. 941, College Station, Athens. Institute of Comparative Medicine Contribution No. 832.
times necessary to withdraw the drug several days before the birds are marketed to allow tissue residues of the drug to diminish to permitted levels. This is particularly true if the drug is used in combination with an arsenical growth-promoting agent. Other drugs have no withdrawal requirements, however, they can be withdrawn for reasons of economy and convenience. In one broiler feeding program starter ration is fed for 28 days, grower ration from 29-53 days, then "withdrawal ration," which does not contain the medication, is fed until birds are marketed. In other feeding pro-