The Influence of a Diet Containing Helminthosporium maydis Blighted Corn on Laying Hen Performance

EMULSIFYING

adjust pH may have merit in controlling the variability of mechanically deboned meat. Also, salt preblending could possibly be used in conjunction with pH adjustment to improve emulsifying ability of mechanically deboned meat sources. REFERENCES Acton, J. C , and R. L. Saffle, 1969. Preblended and prerigor meat in sausage emulsions. Food Technol. 23:367-371. Association of Official Agricultural Chemists, 1965. Official Methods of Analysis. 10th Ed. Washington, D.C.

CHARACTERISTICS

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Froning, G. W., 1970. Poultry meat sources and their emulsifying characteristics as related to processing variables. Poultry Sci. 49: 16251631. Froning, G. W., and S. Neelakantan, 1971. Emulsifying characteristics of prerigor and postrigor poultry muscle. Poultry Sci. SO: 839-84S. Swift, C. E., and R. Ellis, 1957. Action of phosphates in sausage products. II. Pilot plant studies of the effects of some phosphates on binding and color. Food Technol. 11: 450-456. Townsend, W. E., L. P. Witnauer, J. A. Riloff and C. E. Swift, 1968. Comminuted meat emulsions: Differential thermal analysis of fat transitions. Food Technol. 22: 319-323.

W. M. BRITTON

Department of Poultry Science, University of Georgia, Athens, Georgia 30601 (Received for publication January 23, 1971) INTRODUCTION

J TELMINTHOSPORIUM MAYDIS, •^ J- the fungus which causes the disease of corn called southern corn leaf blight, was first identified in Japan (Nisikado and Miyake, 1926). Prior to 1969 southern corn leaf blight was not considered to be of any major economic importance in the United States. In 1969 the extreme susceptibility to southern corn leaf blight of corn possessing "Texas male-sterile (Tms) cytoplasm" was observed in Iowa, Illinois, Indiana and Minnesota (Scheifele et al., 1970). The hypersusceptibility of corn possessing Tms cytoplasm to Helminthosporium maydis was first reported in the Philippines by Mercado and Lantican (1961), but no attempt was made to solve this problem. The epiphytotic in 1970 was brought University of Georgia College of Agriculture Experiment Station Journal Series Paper Number 972, College Station, Athens, Georgia.

about by the widespread planting of hybrids containing Tms cytoplasm, by weather conditions favorable for disease development and dissemination by wind of large quantities of inoculum. The first report of an outbreak in 1970 was in the Belle Glade, Florida area during late February and early March, but by September reports of the disease were made throughout the eastern half of the United States (Moore, 1970). The corn blight epidemic resulted in a reduced corn crop in 1970. The U. S. Department of Agriculture placed the 1970 crop at 4.1 billion bushels, about 10% below the original estimate in July, 1970 and 15% below the crop of 1969 (Clough, 1971). The problem was not just one of a reduction in the amount of corn. Since poultry feeds usually contain large amounts of corn, it became important to know if the blight-infected corn contained any toxic

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The Influence of a Diet Containing Helminthosporium maydis Blighted Corn on Laying Hen Performance

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W. M. BRITTON TABLE 1.—Control diet Ingredient

Yellow corn Soybean meal (50% protein) Alfalfa meal (17% protein, deny.) Poultry by-product meal Poultry fat ' NaCl Defluorinated phosphate Ground limestone Vitamin premix1 Trace mineral premix2

% 67.50 15.00 3.75 5.00 1.00 0.50 1.25 5.75 0.15 0.10

Provided/kg. diet: vitamin A, 2200 I.U.; vitamin D, 880 I.C.U.; riboflavin, 2.2 mg.; Ca pantothenate, 4.4 mg.; niacin, 9.9 mg.; choline chloride, 99 mg.; and vitamin B12,6.6 Aig. 2 Provided mg./kg. diet: Mn, 60; Co, 0.4; Fe, 25; Cu, 2; Zn, 35; and I, 1.2.

EXPERIMENTAL

Three hundred White Leghorn hens, 16 months of age, housed two in a cage, were divided into six equal groups. Prior to the experiment the laying hens were subjected to the normal commercial practices for layers and were fed a commercial type laying mash shown in Table 1. This diet was the control diet and was fed to three groups of the hens. The other three groups of hens were fed the blighted corn diet which was prepared exactly the same as the control diet except corn known to be infected with Helminthosporium maydis was substituted for the control corn on a weight basis. The fungal content of the control and blighted corn was determined on random samples of 50 grains of corn. The grains were surface sterilized by dipping in 95% ethanol followed by a three minute immersion in 10% sodium hypochlorite. The

RESULTS The fungal content, of the blighted corn is shown in Table 2. Helminthosporium TABLE 2.—Fungal infection of blighted corn used in experimental diet

Microorganism Helminthosporium maydis Helminthosporium rostratum Fusarium moniliforme Rhinotrichum tenellum Rhizoctonia solani Bacteria alone No fungi or bacteria

Percent grains positive 24 2 74 8 2 2 2

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substance for laying hens. It also was important to determine the nutritive value of corn which was known to be infected with Helminthosporium maydis. This report describes a study conducted to test the toxicity and nutritive value of Helminthosporium maydis infected corn in the laying hen.

grains were then plated on water agar and fungal growth determined. The fungi were identified by visual and microscopic examination by a mycologist. Proximate analysis and gross energy were determined for the control and blighted corn and their respective diets using the methods of the A.O.A.C. (1960). The weight per volume of the control and blighted corn was determined by weighing one liter samples of corn. The control or blighted corn diets were available ad libitum throughout the nine weeks experimental period. Individual egg production and mortality were recorded. Total feed consumed by all control and all blighted corn fed birds was determined at the end of the experimental period. Average body weight was determined for each group at the end of the experiment. Egg size was evaluated by weighing all eggs laid on the first day of each week. Egg quality was determined by candling all eggs laid the first day of each week, and Haugh unit scores were determined each week using 20 eggs from hens fed the control diet and 20 eggs from hens fed the blighted corn diet. Analysis of variance was used to determine statistical significance of differences in the data obtained.

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BLIGHTED CORN AND LAYERS

TABLE 5.—Weekly egg production of laying hens fed control or blighted corn diets

TABLE 3.—Proximate analysis and gross energy of corn and diets Moisture Ash Corn Control Blighted Layer Diet Control Blighted

Protein Fiber

Ether

Gross energy Kcal./kg.

%

%

%

%

%

12.01 11.27

1.67 1.45

9.23 11.68

2.32 1.74

2.86 2.12

3929 3924

8.08 8.57

16.93 18.49

2.84 2.97

4.61 4.10

3748 3741

9.40 9.55

Percent Egg Production Control1

Blighted1

55 56 48 54 47 44 44 44 38 34

50 52 49 52 51 44 44 48 42 40

Week prior to expt. 1 2 3 4 3

Weekly egg production of the hens fed the control or blighted corn diets is shown in Table 5. There were no statistically significant differences in egg production throughout the experiment, although there was a trend to slightly higher egg production in the hens fed the blighted corn diet during the last three weeks of the experiment. Mortality was 1.6% in the controls and 2.6% in the blighted corn fed birds, but the difference was not statistically significant.

6 7 8 9 1

Each value a mean of 3 groups of 50 birds each.

To determine the effect of blighted corn on egg quality, weekly determinations of candling quality, egg weight and albumen quality, as measured by Haugh units, were made. Table 6 shows that blighted corn in the diet had no influence on egg quality as determined by candling. Egg weight and Haugh unit scores were not significantly different in the hens fed the blighted corn diet (Table 7). The Haugh unit scores for week three and week eight were lower because the eggs were stored at 22°C. for five and three days, respectively. Visual examination of eggs from hens fed the blighted corn diet showed no differences in shell or yolk color. For the nine week experimental period the birds fed the control diet consumed 3.63 kg. of feed per dozen eggs and the birds fed the blighted corn diet consumed 3.22 kg. of feed per dozen eggs. The average body weight after nine weeks of feeding TABLE 6.— Candling quality of eggs from laying hens fed control or blighted com diets

TABLE 4.—The influence of blight on the •weight per unit volume of corn

Downgrades Diet

1

Type of corn

Grams per liter

Control BUghted

721.4 1 643.9 1

Each value is mean of 10 samples.

Control1 Blighted1 1

A grade

76.9 76.8

% Checks

% Blood spots

17.2 18.2

5.9 5.0

Each value is a mean of 9 weekly observations.

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maydis was present on 24% of the grains. The other fungi found are normally found on corn. The blighted corn was found to have 26% of the grains damaged upon visual observation. Proximate analysis (Table 3) of the control and blighted corn showed an increase of about 2.5%, on a wet-weight basis, in the protein content of the blighted corn to be the only change of any significance. The increase in protein content of the blighted corn was also reflected in the diet. The blighted corn diet was about 1.5% higher in protein. The weight per unit volume of the blighted corn was 10.7% less than that of the control corn (Table 4).

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W. M.

TABLE 7.—Egg weight and Haugh units of eggs from hens fed control of blighted corn diets Week fed diet

1 23 3 4 5 6 7 8" 9

Egg weight (g.)1

Haugh units 2

Control

Blighted

Control

Blighted

64 65 65 66 67 67 67 67 68

63 65 65 66 66 66 66 67 67

— 63 46 65 63 57 53 49 61

— 69 47 67 65 59 64 54 66

1 3

the control or blighted corn diets was 1757 and 1743 grams, respectively. These data indicate that the blighted corn diet does not have a detrimental effect on feed per dozen eggs or body weight. DISCUSSION When the corn in the layer diet (67.5% corn) was supplied by corn known to be infected with Helminthosporium maydis, no detrimental effects were observed during the nine weeks of the experiment. The nutritive value of the diet, as shown by chemical analysis, was not reduced by the use of the blighted corn. The protein content was actually higher. The effect of the blighted corn diet on performance of laying hens was tested in hens nearing the end of the laying cycle. The reasoning was that the older hen would be more responsive to any stress imposed by the diet. The results show that the blighted corn diet did not have a detrimental effect on performance of the hens as measured by egg production, mortality, egg size, quality or feed per dozen eggs. The blighted corn was found to weigh about 11 % less per unit volume. Since corn is often obtained on a volume basis (the bushel) and feed is made on a weight basis, a problem does exist. The results of these

experiments would indicate that blighted corn showing the degree of infection (24% of grains infected) of the corn used in these experiments can be used in place of an equal weight of non-infected corn without harming performance. SUMMARY A laying hen diet containing corn infected with Helminthosporium maydis did not have a detrimental effect on egg production, mortality, egg size, egg quality (interior or exterior), feed per dozen eggs or body weight when fed for a nine week period. The blighted corn weighted 11% less per unit volume and the protein content was 2.5% higher than the non-infected corn. ACKNOWLEDGMENT The author wishes to thank Dr. E. S. Luttrell, Plant Pathology Department, University of Georgia for performing the fungal analysis of the corn. REFERENCES Association of Official Agricultural Chemists, 1960. Official Methods of Analysis. 9th Edition. Washington, D.C. Ciough, M., 1971. Outlook for feed. National Agricultural Outlook Conference. Feb. 24, 1971, Washington, D.C. p. 4. Mercado, A. C , and R. M. Lantican, 1961. The susceptibility of cytoplasmic male-sterile lines of corn to Helminthosporium maydis Nisikado and Miyake. Philippine Agriculturist, 45: 235243. Moore, W. F., 1970. Origin and spread of southern corn leaf blight in 1970. Plant Disease Reporter, 54: 1104-1108. Nisikado, Y., and C. Miyake, 1926. Studies on two Helminthosporium diseases of maize caused by H. turcicum Passerini and Ophiobolus herterostrophus Drechsler. Ohara Inst. f. Landevirt. Forsch., Ber., 3 : 221-266. Scheifele, G. L., W. Whitehead and C. Rowe, 1970. Increased susceptibility to southern leaf spot (Helminthosporium maydis) in inbred lines and hybrids of maize with Texas male-sterile cytoplasm. Plant Disease Reporter, 54: 501-503.

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Each value is a mean of 50 eggs. Each value is a mean of 20 eggs. Eggs stored for 5 days at 22°C. 4 Eggs stored for 3 days at 22°C. 2

BEITTON