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A New Description of Riboflavin Deficiency Syndrome in Chickens1,2
237
ENERGY RESTRICTION OF PULLETS
method of delaying maturity. The low-lysine or low-protein programs did not delay maturity appreciably or improve egg production over full-fed controls when all groups received constant daylength. REFERENCES
A New Description of Riboflavin Deficiency Syndrome in Chickens1'2 R. D. WYATT, H. T. TUNG, W. E. DONALDSON AND P. B. HAMILTON Department of Poultry Science and Department of Microbiology, North Carolina State University, Raleigh, North Carolina 27607 (Received for publication April 29, 1972)
ABSTRACT Day-old male broiler chickens were fed for three weeks with diets containing graded levels of riboflavin (0, 0.22, 0.52, 0.88, and 4.53 mg. added per kg. of basal diet). Curled-toe paralysis which is considered indicative of riboflavin deficiency occurred in less than 10% of the birds at the zero levels of added riboflavin while the mortality was about 25%. Commonly, the birds at the lower levels were paralyzed but with their legs spraddled out and without their toes curled downward and inward. The most senstive indicator of riboflavin deficiency was growth rate which was significantly (P < 0.05) reduced at 0.88 mg.Ag-, a level of added riboflavin which did not cause curled-toe paralysis or death. Another sensitive indicator was altered posture with the head, tail, and wings carried lower than normal. It appears that curled-toe paralysis is a minor aspect of riboflavin deficiency in the modern broiler chicken. POULTRY SCIENCE 52:
INTRODUCTION
T
HE current literature gives the impression that curled-toe paralysis is synonomous with riboflavin deficiency in "Paper Number 3743 of the Journal series of the North Carolina State University Agricultural Experiment Station, Raleigh, North Carolina. 2 The use of trade names in this publication does not imply endorsement by the North Carolina Experiment Station of the product named, nor criticism of similar ones not mentioned.
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chickens. In a report of the National Research Council (1971), it is stated that a lack of riboflavin in the diet of chickens brings about diarrhea, retarded growth, and paralysis of the legs, sometimes called "curled toe paralysis," which causes the chicks to walk on their hocks with toes curling inward and that this condition is the only obvious symptom. An earlier report of the National Research Council (1966) states that the nutritional paralysis
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Couch, J. R., R. E. Issacks, B. L. Reid, W. P. Crawford and J. H. Quisenberry, 1957. Feeding and management of replacement broiler stock. Feed Age, October: 34-39. Duncan, D. B., 1955. Multiple range and multiple F-tests. Biometrics, 11: 1-12. Fuller, H. L., D. K. Potter and W. M. Kirkland, 1969. Effect of delayed maturity and carcass fat on reproductive performance of broiler breeder pullets. Poultry Sci. 48: 801-809.
Harms, R. H. and P. W. Waldroup, 1962. Protein restriction. Another method of delaying sexual maturity of pullets. Feedstuffs, 34, ( 8 ) : 70. Kirkland, W. M., and H. L. Fuller, 1971. Methods of delaying sexual maturity of pullets 1. Water restriction. Poultry Sci. SO: 1761-1767. Peacock, R. G., E. Bossard and G. F. Combs, 1968. Methods of delaying sexual maturity of broiler breeder pullets and their effects of rearing and initial laying period performances. Proc. 1968 Maryland Nutrition Conference for Feed Manufacturers, p. 97. Singsen, E. P., J. Nagel, S. G. Patrick and L. D. Matterson, 1965. The effects of a lysine deficiency on growth characteristics, age at sexual maturity and reproductive performance of meat-type pullets. Poultry Sci. 44: 1467-1473. Snedecor, G. W., 1959. Statistical Methods. Fifth edition, Iowa State College Press, pp. 543.
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during riboflavin deficiency. The original description by Norris et al. (1930) stated that growth in general was not seriously interferred with until symptoms of paralysis had actually developed. Culton and Bird (1940) found evidence that the riboflavin requirement for the prevention of curledtoe paralysis is above that for maximum growth. Bethke and Record (1942) also found greater amounts of riboflavin to be required for the prevention of curled-toe paralysis than for promoting growth. Bird et al. (1946) found just the opposite, i.e. less riboflavin was required for prevention of curled-toe paralysis than was required for optimum growth. The object of this investigation was to study the symptoms of riboflavin deficiency. This was done by feeding diets with graded levels of riboflavin and observing the growth and symptoms of the chickens. MATERIALS AND METHODS
Day-old male chicks were obtained from commercial hatcheries. Three broiler strains (Peterson X Arbor Acres, Hubbard X Arbor Acres, and Indian River X Indian River) were used in separate experiments. They were housed in electrically heated batteries where feed and water were available ad libitum. The composition of the basal diet is given in Table 1. The sole source of riboflavin in the basal diet was the soybean meal and according to standard values (National Research Council, 1971) this supplied 1.4 mg. of riboflavin/ kg. of final diet. The dietary requirement of chickens for riboflavin is estimated to be 3.6 mg./kg. of diet (National Research Council, 1971). Pure riboflavin was added to the basal diet to give the desired level of riboflavin. The added levels of riboflavin used in these experiments were 0, 0.22, 0.52, 0.88 and 4.53 mg. of riboflavin/kg. of the diet. In each experiment, eight groups of ten birds each were fed from hatching
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is characterized by the sudden appearance of chicks walking on their hocks, with toes curling inward; otherwise, the chicks appear to be in excellent health. A similar though slightly less emphatic impression is given by standard textbooks in poultry science (Biester and Schwarte, 1965; Ewing, 1963). In a recent study, Chou et al. (1971) reported that curled-toe paralysis was a characteristic symptom of riboflavin deficiency. During experiments in our laboratory to study riboflavin deficiency, we were not able to obtain, to our surprise, curled-toe paralysis except in less than 10% of the deficient birds. Examination of the early literature on riboflavin deficiency revealed some inconsistencies, Norris et al. (1930) in the first report of riboflavin deficiency^ observed curled-toe paralysis in 70% of the deficient chicks. Bethke et al. (1931) found the incidence to vary from 10-70% in different experiments while Bethke and Record (1942) had an incidence of 60-98% in different experiments. Culton and Bird (1940) obtained an incidence of up to 80%. Bird et al. (1946) observed curled-toe paralysis in no more than 20% of their experimental birds. On the other hand, Lepkovsky and Jukes (1936) made no mention of curledtoe paralysis and stated that the symptoms of deficiency in chicks were slow growth, diarrhea, and emaciation without dermatitis. Stokstad and Manning (1938) in agreement with the impressions of Norris et al. (1936) found the incidence to be dependent upon the dose-level; no curled-toe occurred at the zero level or a high level of riboflavin addition while up to 53% of the birds were affected at the intermediate level. However, Bird et al. (1946) did not confirm this differential effect and observed little curled-toe paralysis in their experiments. Another inconsistency is the relation of growth retardation to curled-toe paralysis
RIBOFLAVIN DEFICIENCY
until 3 weeks of age at each level of riboflavin, and the experimental designs were completely randomized. The body weights and mortality were recorded weekly and the birds were observed daily for overt symptoms. The body weights were submitted to an analysis of variance in which the F-ratio was calculated. If it were significant, the least significant difference among treatment means was calculated. The statistical analyses were done as outlined in Bruning and Kintz (1968).
TABLE 1.—Composition of basal diet deficient in riboflavin Ingredient
%
Glucose Soybean meal (dehulled, 50% protein) Cellulose2 Refined cottonseed oil Defluorinated rock phosphate 3 Ground limestone Trace mineralized salt4 DL-methionine Vitamin mix6
45.00 44.00 3.00 3.00 2.50 0.64 0.50 0.36 1.00
1
1
Cerelose Solka-floc, Brown Co., Boston. » Contained 34% Ca and 14.5% P. 4 Contained the following minerals, % : manganese, 0.6; iron, 0.25; copper, 0.062; cobalt, 0.015; iodine, 0.013 and zinc, 0.01. 6 Supplied the following amounts/Kg. of diet: vitamin A, 8800 I.U.; vitamin D 3 , 880 I.C.U.; vitamin E, 18 I.U.; vitamin Ki, 2.2 mg.; thiamine, 8.8 mg.; panthothenic acid, 15.4 mg.; niacin, 52.8 mg.; pyridoxine, 6.6 mg.; biotin, 0.15 mg.; choline, 1980 mg.; folic acid, 1.54 mg.; vitamin Bi 2 ,0.02 mg. 2
TABLE 2.—Effect of graded doses of dietary riboflavin on body weight, mortality, and curled-toe incidence oj three-week old chickens Added riboflavin (mg./kg.)
Body weight (grams)
Mortality
0
205.1» 279.7 350.4 417.0 493.9
28/80b 9/80 3/80 3/80 0/80
0.22 0.52 0.88 4.53
Curled-toe incidence 6/80° 4/80 3/80 0/80 0/80
a Each number in this column is significantly different (P<0.05) from every other number. b This number means that 28 of 80 birds on this treatment died. 0 This number means that 6 of 80 birds on this treatment exhibited curled-toe paralysis.
of curled-toe paralysis was 7.5%. At 0.22 mg. of riboflavin/kg. of diet the figures were 1 1 % and 5% respectively. The incidence of curled-toe paralysis was 4% at 0.52 mg./kg- and zero at 0.88 mg./kg. which was not sufficient for optimum growth. This particular experiment which was repeated four times used Hubbard X Arbor Acres chickens. Similar results were obtained with Peterson X Arbor Acres and Indian River X Indian River crosses. The incidence of curled-toe paralysis ranged from 0-9% and the incidence never exceeded the mortality. This low incidence of curled-toe paralysis does not mean that the deficient birds were free of visible symptoms. The majority of the birds fed deficient diets underwent a series of progressively more severe symptoms that, depending upon the extent of deficiency, led to prostration and death but did not include curled-toe paralysis. Indeed, there is a problem of deciding what is (curled-toe paralysis. We used the criteria stated and illustrated explicitly in the literature,.(Norris et al., 1931; Bethke et al., 1931; National Research Council, 1971). The toes must curl downwards and inwards and the birds must walk with part of their weight on their hocks. An example is shown
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RESULTS
The effects of graded levels of dietary riboflavin on body weight, mortality, and incidence of curled-toe paralysis in threeweek old chickens are shown in Table 2. Body weight was increased significantly (P < 0.0S) at each step in the graded addition of riboflavin. Gradations were seen in mortality and incidence of curled-toe paralysis at the lower levels of dietary riboflavin. At the zero level of added riboflavin the mortality was 35% while the incidence
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in Fig. 1. For comparative purposes, a control bird fed a riboflavin-sufficient diet is shown in Fig. 2. The first noticeable symptoms of riboflavin deficiency were a lowering of the head from its normal erect position, a drooping of the tail feathers, and a slight lowering of the wings from the normal position high on the side of the bird. These symptoms (Fig. 3) typified the birds receiving 0.88 mg./kg. of added riboflavin for three weeks. The next degree of severity is demon-
strated in Fig. 4 and Fig. 5. The birds rested on their hocks and breast with lowered heads but without curled toes (Fig. 4). These birds were able to walk but usually their weight was borne on their hocks (Fig. 5). If they were able to stand at all, the hocks were only about 1 cm. from the floor. Once again the head was depressed toward the floor and the wings and tail drooped. In addition a concave depression frequently occurred in the middle of the back. These symptoms were characteristic
FIG. 2. Picture of a chicken fed the control diet which contained 4.53 mg. of added riboflavin/kgof diet. Note the erect posture with the head, wings, and tail held high.
FIG. 4. Picture of a resting chicken with a moderately severe riboflavin deficiency. This chicken received 0.52 mg./kg. of added dietary riboflavin. Note the low position of the head, wing, and tail and the concave depression in the back.
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FIB. 1. Picture of a chicken displaying typical symptoms of curled-toe paralysis. The toes are curled downward and inward and the weight is supported mainly on the hocks.
FIG. 3. Picture of a chicken showing the first visible symptoms of riboflavin deficiency. Note the head, tail, and wings which are carried lower than in control chickens. This chicken received 0.88 mg.Ag- of added dietary riboflavin.
RIBOFLAVIN DEFICIENCY
FIG. 5. Picture of a walking chicken with a moderately severe riboflavin deficiency. This chicken received 0.52 mg./kg. of added dietary riboflavin. The weight is borne on the hocks, the toes are not curled, the head, tail, and wings are carried low, and there is a concave depression in the back.
FIG. 6. Picture of a chicken severely affected by riboflavin deficiency. The chicken was on the zero level of added dietary riboflavin. The legs and toes are out to the side of the body with the weight borne on the breast.
boflavin and to a certain extent those on 0.22 mg./kg. level. It should be mentioned that some birds raised on wire-screen floors showed a false curled-toe symptom in which the toes were curled downward. This was the result of their gripping the wire with their toes while propelling themselves about the cage. The false curled-toe symptom disappeared when the birds were placed on a solid floor for a few minutes. They quickly learned that a flat-toe rather than a curled-toe was advantageous here. This, of course, proves that the curled-toe in these cases was not the result of paralysis. The effect of the duration of riboflavin
FIG. 7. Picture of a chicken with an extremely severe case of riboflavin deficiency. The chicken was on zero level of added dietary riboflavin. Note the spraddled legs with one forward and the other backwards, the wings and tail resting on the floor, and the toes which are not curled.
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of birds receiving 0.52 mg./kg. of added riboflavin for three weeks. The next degree of severity is shown in Fig. 6. The birds rested on their breasts with their legs out to the side of their body. If their toes curled at all it was outward as shown here. Note that the head, wings and tail drooped. These birds were capable of movement but with their breasts on the floor and the propelling force was applied by backward thrusts of the legs and by the wings. An example of the most severely affected birds is shown in Fig. 7. This posture usually preceded death. The legs were spraddled, usually with one forward and the other backward, and both at a small angle from the axis of the body. The head here was slightly erect with the wings and tail resting on the floor. The toes were straight, not curled, and could be described as "bunched" if anything. Surprisingly these birds were capable of considerable movement and they could get to the feed and water troughs in the batteries. Movement was largely undirected and was achieved by a rapid fluttering of wings which resulted in a gliding and scraping motion across the floor. The birds shown in Fig. 6 and Fig. 7 typify those on the zero level of added ri-
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E. DONALDSON AND P. B. HAMILTON
TABLE 3.—Effect of duration of riboflavin deficiency on body weight Added riboflavin (mg./kg.)
Age (weeks) 0 0 1 2 3
41.8» 88.5 117.8 146.0
0.88 42.2 113.9 232.4 374.5
TABLE 5.-—Effect of duration of riboflavin deficiency
on mortality Added riboflavin (mg./kg.)
Age (weeks)
0
0.88
4.53
1 2 3
4/80" 10/80 22/80
2/80 2/80 2/80
0/80 1/80 1/80
4.53 43.8 115.8 261.5 400.8
a
This number means that 4 out of 80 birds died.
* This number is the mean body weight in grams of 8 groups of 10 chickens.
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ommended level and when it occurred the morbidity was less than 10% (Tables 2 and 4). Death was a more frequent sympTABLE 4.—Effect of duration of riboflavin deficiency on incidence of curled-toe paralysis tom which occurred in about 25% of the birds on the zero level of added riboflavin Added riboflavin (mg./kg.) Age (Tables 2 and 5). This high mortality at the (weeks) 0 0.88 4.53 zero level of added riboflavin indicated that the basal diet was truly deficient in ribofla1 0/80° 0/80 0/80 2 0/80 0/80 0/80 vin as was calculated from standard values 3 3/80 0/80 0/80 (National Research Council, 1971). The ° This number means that none of 80 birds had most sensitive indicator of riboflavin deficurled-toe paralysis. ciency was impaired growth rate (Tables 2 and 3). Another sensitive indicator of riboflavin deficiency was the slight variations deficiency on these parameters was considfrom the erect posture and carriage of the ered next. At the zero level of added ribonormal bird. In particular, the head, wings, flavin, the growth rate was significantly (P and tail were carried lower than normal < 0.01) depressed at the end of one week (Fig. 3). (Table 3) while curled-toe paralysis reIn the current experiments, riboflavin dequired at least two weeks to develop (Taficiency was characterized mainly by a seble 4). When the basal diet contained 0.88 ries of visible symptoms of progressive semg./kg. of added riboflavin the growth deverity and intensity which culminated in pression did not occur until the end of two death rather than curled-toe paralysis. The weeks (Table 3) and at this level of added severity and frequency of these symptoms riboflavin, curled-toe paralysis never de(Figs. 2 through 7) varied with the duraveloped (Table 4). The mortality assocition and degree of deficiency. For example, ated with diets very deficient in riboflavin only slight modifications in the carriage of occurred throughout the experiment, but the birds occurred with marginal (0.88 mg. the majority occurred between the second /kg.) diets while at the zero level hardly and third weeks (Table 5). any of the birds were able to stand and DISCUSSION walk (Figs. 6 and 7) despite their relative The present experiments suggest that freedom from curled-toe paralysis. It curled-toe paralysis is a minor symptom of should be mentioned that the locomotion of riboflavin deficiency in the modern broiler birds such as those in Figures 6 and 7 was chicken. It occurred only in very deficient more severely affected than those with diets containing about one-third of the rec- curled-toe paralysis (Fig. 1). Indeed, our
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RIBOFLAVIN DEFICIENCY
with commercial broiler cockerels. However, they did not state their criteria for curled-toe paralysis. The occurrence of a false curled-toe symptom and different degrees of paralysis recorded in our results would appear to necessitate a statement of criteria before valid comparisons can be made. At any rate, these considerations would seem to be ample justification for reinvestigation of other nutritional diseases with modern strains of birds and nutrition. It seems clear from the current results that while riboflavin deficiency can cause curled-toe paralysis such a deficiency does not cause it obligatorily and that curled-toe paralysis is a minor aspect of riboflavin deficiency in the modern broiler chicken. ACKNOWLEDGEMENTS
We thank Sharon West, Rini Hardjopranjoto, and Nancy Goodwin for technical assistance. REFERENCES Bethke, R. M., P. R. Record and D. C. Kennard, 1931. A type of nutritional leg paralysis affecting chicks. Poultry Sci. 10: 355-368. Bethke, R. M., and P. R. Record, 1942. The relation of riboflavin to growth and curled-toe paralysis in chicks. Poultry Sci. 2 1 : 147-154. Biester, H. E., and L. H. Schwarte, 19S6. Diseases of Poultry (5th ed.). The Iowa State University Press, Ames, Iowa. Bird, F. H., V. S. Asmundson, F. H. Kratzer and S. Lepkovsky, 1946. The comparative requirements of chicks and turkey poults for riboflavin. Poultry Sci. 25: 47-S1. Bruning, J. L., and B. L. Kintz, 1968. Computational Handbook of Statistics. Scott, Foresman, and Co., Glenview, 111. Chou, S. T., J. L. Sell and P. A. Kondra, 1971. Interrelationships between riboflavin and dietary energy and protein utilization in growing chicks. Br. J. Nutr. 26: 323-333. Culton, T. G., and H. R. Bird, 1940. The effect of some riboflavin supplements on chick growth and curled-toe paralysis. Poultry Sci., 19: 424430. Ewing, W. R., 1963. Poultry Nutrition (5th ed.). The Ray Ewing Company, Pasadena, Calif.
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impression was that birds with curled-toes were larger and less likely to die although these impressions were not quantitated. These impressions agree with those stated in Biester and Schwarte (1965) that curled-toe paralysis is not the most advanced stage of the deficiency. The reason for the conflicting literature about riboflavin deficiency is not certain. In the present experiments which utilized about 5000 birds over a two year period, curled-toe paralysis occurred in only a small percentage of the deficient birds and impaired growth rate was a much earlier and more sensitive indicator of deficiency. This is directly contrary to the earlier reports (Norris et al., 1930; Culton and Bird, 1940; Bethke and Record, 1942). However, it is interesting and perhaps instructive that the present findings agree with a later report (Bird et al., 1946) on these points. Great changes have occurred in the poultry industry during and after World War II since the original description of riboflavin deficiency, particularly in the strains of birds, the diets fed them, and in the knowledge of their nutrition. These changes are also reflected in laboratory experiments and practice and they would seem to be possible explanations for the conflicting reports about the symptoms of riboflavin deficiency. Of particular interest, the riboflavin requirement of chickens is a heritable trait (Hutt, 1958). Also, Norris et al. (1936) advanced a hypothesis that two different vitamins were responsible for the growth promotion and nutritional paralysis now associated with riboflavin. While this seems unlikely in view of current nutritional knowledge, the possibility that curled-toe paralysis is the result of multiple deficiencies or imbalances would appear to merit consideration. Other contrary results are those of Chou et al. (1971) who observed a curled-toe incidence of 60% and above in only 16 days
244
R. D. WYATT, H. T. TUNG, W. E. DONALDSON AND P. B. HAMILTON poultry due to the presence of a new vitamin? Poultry Sci. 9 : 133-140. Norris, L. C , G. F. Heuser, H. S. Wilgus and A. T. Ringrose, 1931. The occurrence in chicks of a paralysis of nutritive origin. Poultry Sci. 10: 93-97. Norris, L. C , H. S. Wilgus, A. T. Ringrose, V. Heiman and G. F. Heuser, 1936. The vitamin G requirement of poultry. Bulletin 660, Cornell University Agricultural Experiment Station, Ithaca, New York. Stokstad, E. L. R., and P. D. V. Manning, 1938. The effect of riboflavin on the incidence of curled toe paralysis in chicks. J. Nutr. 16: 279-283.
Effects of Electrolyte Treatments and Dry-Chilling' on Yields and Tenderness of Broilers K. K. HALE, JR. 2 AND W. J. STADELMAN Department of Animal Sciences, Purdue University, Lafayette, Indiana 47907 (Received for publication May 1, 1972)
ABSTRACT Commercially available electrolyte preparations, when administered in the drinking water of broiler chickens, did not significantly alter the live weights or eviscerated weights of the birds. Although these electrolytes significantly increased weight gains during wet-chilling, most of this gain was lost as drip during storage with fresh product or upon thawing of the frozen product. The net loss from eviscerated to cooked weight of drychilled broilers was less than the corresponding net loss of wet-chilled broilers. The hot cutting and rapid chilling by crust freezing (dry chilling) did not significantly alter shear values of breast meat as compared to broilers that had been wet-chilled. Small but statistically higher shear values were recorded in the thigh muscle {biceps femoris) of the dry-chilled birds. POULTRY SCIENCE 52:
INTRODUCTION
M
OST broiler chickens are chilled in ice-water with mechanical agitation. The basic purpose of this wet-chilling is to rapidly lower the temperature of the freshly eviscerated carcass from about 37° C. to 4°C. in order to retard microbial growth, particularly salmonella. This process results in five to eight percent moisture uptake by the whole carcass (Kotula et al., 'Journal paper No. 4726 Purdue Agricultural Experiment Station, Lafayette, Indiana 47907. 'Present address: Department of Poultry Science, University of Georgia, Athens, Georgia.
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1960). However, this moisture is not tightly bound and most of it leaches out during market distribution. This detracts from the appearance of the packaged product. In the dry-chill process the chicken is packaged and chilled in a — 35°C. blast freezer long enough to crust freeze the outer layer and lower the internal temperature to 4°C. One processing plant in the United States currently using the dry-chill process is also hot-cutting the freshly eviscerated carcasses for packaging of parts. Based on work on cold shortening, such
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Hutt, F. B., 1958. Genetic Resistance to Disease in Domestic Animals. Comstock Publishing Associates, Ithaca, New York. Lepkovsky, S., and T. H. Jukes, 1936. The response of rats, chicks and turkey poults to crystalline vitamin G (flavin). J. Nutr. 12: 515526. National Research Council, 1966. Nutrient Requirements of Poultry (5th ed.). National Academy of Sciences, Washington, D.C. National Research Council, 1971. Nutrient Requirements of Poultry (6th ed.). National Academy of Sciences, Washington, D.C. Norris, L. C , G. H. Heuser and H. S. Wilgus, 1930. Is the chief value of milk for feeding
ENERGY RESTRICTION OF PULLETS
method of delaying maturity. The low-lysine or low-protein programs did not delay maturity appreciably or improve egg production over full-fed controls when all groups received constant daylength. REFERENCES
A New Description of Riboflavin Deficiency Syndrome in Chickens1'2 R. D. WYATT, H. T. TUNG, W. E. DONALDSON AND P. B. HAMILTON Department of Poultry Science and Department of Microbiology, North Carolina State University, Raleigh, North Carolina 27607 (Received for publication April 29, 1972)
ABSTRACT Day-old male broiler chickens were fed for three weeks with diets containing graded levels of riboflavin (0, 0.22, 0.52, 0.88, and 4.53 mg. added per kg. of basal diet). Curled-toe paralysis which is considered indicative of riboflavin deficiency occurred in less than 10% of the birds at the zero levels of added riboflavin while the mortality was about 25%. Commonly, the birds at the lower levels were paralyzed but with their legs spraddled out and without their toes curled downward and inward. The most senstive indicator of riboflavin deficiency was growth rate which was significantly (P < 0.05) reduced at 0.88 mg.Ag-, a level of added riboflavin which did not cause curled-toe paralysis or death. Another sensitive indicator was altered posture with the head, tail, and wings carried lower than normal. It appears that curled-toe paralysis is a minor aspect of riboflavin deficiency in the modern broiler chicken. POULTRY SCIENCE 52:
INTRODUCTION
T
HE current literature gives the impression that curled-toe paralysis is synonomous with riboflavin deficiency in "Paper Number 3743 of the Journal series of the North Carolina State University Agricultural Experiment Station, Raleigh, North Carolina. 2 The use of trade names in this publication does not imply endorsement by the North Carolina Experiment Station of the product named, nor criticism of similar ones not mentioned.
237-244,
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chickens. In a report of the National Research Council (1971), it is stated that a lack of riboflavin in the diet of chickens brings about diarrhea, retarded growth, and paralysis of the legs, sometimes called "curled toe paralysis," which causes the chicks to walk on their hocks with toes curling inward and that this condition is the only obvious symptom. An earlier report of the National Research Council (1966) states that the nutritional paralysis
Downloaded from http://ps.oxfordjournals.org/ at Brunel University on June 5, 2015
Couch, J. R., R. E. Issacks, B. L. Reid, W. P. Crawford and J. H. Quisenberry, 1957. Feeding and management of replacement broiler stock. Feed Age, October: 34-39. Duncan, D. B., 1955. Multiple range and multiple F-tests. Biometrics, 11: 1-12. Fuller, H. L., D. K. Potter and W. M. Kirkland, 1969. Effect of delayed maturity and carcass fat on reproductive performance of broiler breeder pullets. Poultry Sci. 48: 801-809.
Harms, R. H. and P. W. Waldroup, 1962. Protein restriction. Another method of delaying sexual maturity of pullets. Feedstuffs, 34, ( 8 ) : 70. Kirkland, W. M., and H. L. Fuller, 1971. Methods of delaying sexual maturity of pullets 1. Water restriction. Poultry Sci. SO: 1761-1767. Peacock, R. G., E. Bossard and G. F. Combs, 1968. Methods of delaying sexual maturity of broiler breeder pullets and their effects of rearing and initial laying period performances. Proc. 1968 Maryland Nutrition Conference for Feed Manufacturers, p. 97. Singsen, E. P., J. Nagel, S. G. Patrick and L. D. Matterson, 1965. The effects of a lysine deficiency on growth characteristics, age at sexual maturity and reproductive performance of meat-type pullets. Poultry Sci. 44: 1467-1473. Snedecor, G. W., 1959. Statistical Methods. Fifth edition, Iowa State College Press, pp. 543.
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during riboflavin deficiency. The original description by Norris et al. (1930) stated that growth in general was not seriously interferred with until symptoms of paralysis had actually developed. Culton and Bird (1940) found evidence that the riboflavin requirement for the prevention of curledtoe paralysis is above that for maximum growth. Bethke and Record (1942) also found greater amounts of riboflavin to be required for the prevention of curled-toe paralysis than for promoting growth. Bird et al. (1946) found just the opposite, i.e. less riboflavin was required for prevention of curled-toe paralysis than was required for optimum growth. The object of this investigation was to study the symptoms of riboflavin deficiency. This was done by feeding diets with graded levels of riboflavin and observing the growth and symptoms of the chickens. MATERIALS AND METHODS
Day-old male chicks were obtained from commercial hatcheries. Three broiler strains (Peterson X Arbor Acres, Hubbard X Arbor Acres, and Indian River X Indian River) were used in separate experiments. They were housed in electrically heated batteries where feed and water were available ad libitum. The composition of the basal diet is given in Table 1. The sole source of riboflavin in the basal diet was the soybean meal and according to standard values (National Research Council, 1971) this supplied 1.4 mg. of riboflavin/ kg. of final diet. The dietary requirement of chickens for riboflavin is estimated to be 3.6 mg./kg. of diet (National Research Council, 1971). Pure riboflavin was added to the basal diet to give the desired level of riboflavin. The added levels of riboflavin used in these experiments were 0, 0.22, 0.52, 0.88 and 4.53 mg. of riboflavin/kg. of the diet. In each experiment, eight groups of ten birds each were fed from hatching
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is characterized by the sudden appearance of chicks walking on their hocks, with toes curling inward; otherwise, the chicks appear to be in excellent health. A similar though slightly less emphatic impression is given by standard textbooks in poultry science (Biester and Schwarte, 1965; Ewing, 1963). In a recent study, Chou et al. (1971) reported that curled-toe paralysis was a characteristic symptom of riboflavin deficiency. During experiments in our laboratory to study riboflavin deficiency, we were not able to obtain, to our surprise, curled-toe paralysis except in less than 10% of the deficient birds. Examination of the early literature on riboflavin deficiency revealed some inconsistencies, Norris et al. (1930) in the first report of riboflavin deficiency^ observed curled-toe paralysis in 70% of the deficient chicks. Bethke et al. (1931) found the incidence to vary from 10-70% in different experiments while Bethke and Record (1942) had an incidence of 60-98% in different experiments. Culton and Bird (1940) obtained an incidence of up to 80%. Bird et al. (1946) observed curled-toe paralysis in no more than 20% of their experimental birds. On the other hand, Lepkovsky and Jukes (1936) made no mention of curledtoe paralysis and stated that the symptoms of deficiency in chicks were slow growth, diarrhea, and emaciation without dermatitis. Stokstad and Manning (1938) in agreement with the impressions of Norris et al. (1936) found the incidence to be dependent upon the dose-level; no curled-toe occurred at the zero level or a high level of riboflavin addition while up to 53% of the birds were affected at the intermediate level. However, Bird et al. (1946) did not confirm this differential effect and observed little curled-toe paralysis in their experiments. Another inconsistency is the relation of growth retardation to curled-toe paralysis
RIBOFLAVIN DEFICIENCY
until 3 weeks of age at each level of riboflavin, and the experimental designs were completely randomized. The body weights and mortality were recorded weekly and the birds were observed daily for overt symptoms. The body weights were submitted to an analysis of variance in which the F-ratio was calculated. If it were significant, the least significant difference among treatment means was calculated. The statistical analyses were done as outlined in Bruning and Kintz (1968).
TABLE 1.—Composition of basal diet deficient in riboflavin Ingredient
%
Glucose Soybean meal (dehulled, 50% protein) Cellulose2 Refined cottonseed oil Defluorinated rock phosphate 3 Ground limestone Trace mineralized salt4 DL-methionine Vitamin mix6
45.00 44.00 3.00 3.00 2.50 0.64 0.50 0.36 1.00
1
1
Cerelose Solka-floc, Brown Co., Boston. » Contained 34% Ca and 14.5% P. 4 Contained the following minerals, % : manganese, 0.6; iron, 0.25; copper, 0.062; cobalt, 0.015; iodine, 0.013 and zinc, 0.01. 6 Supplied the following amounts/Kg. of diet: vitamin A, 8800 I.U.; vitamin D 3 , 880 I.C.U.; vitamin E, 18 I.U.; vitamin Ki, 2.2 mg.; thiamine, 8.8 mg.; panthothenic acid, 15.4 mg.; niacin, 52.8 mg.; pyridoxine, 6.6 mg.; biotin, 0.15 mg.; choline, 1980 mg.; folic acid, 1.54 mg.; vitamin Bi 2 ,0.02 mg. 2
TABLE 2.—Effect of graded doses of dietary riboflavin on body weight, mortality, and curled-toe incidence oj three-week old chickens Added riboflavin (mg./kg.)
Body weight (grams)
Mortality
0
205.1» 279.7 350.4 417.0 493.9
28/80b 9/80 3/80 3/80 0/80
0.22 0.52 0.88 4.53
Curled-toe incidence 6/80° 4/80 3/80 0/80 0/80
a Each number in this column is significantly different (P<0.05) from every other number. b This number means that 28 of 80 birds on this treatment died. 0 This number means that 6 of 80 birds on this treatment exhibited curled-toe paralysis.
of curled-toe paralysis was 7.5%. At 0.22 mg. of riboflavin/kg. of diet the figures were 1 1 % and 5% respectively. The incidence of curled-toe paralysis was 4% at 0.52 mg./kg- and zero at 0.88 mg./kg. which was not sufficient for optimum growth. This particular experiment which was repeated four times used Hubbard X Arbor Acres chickens. Similar results were obtained with Peterson X Arbor Acres and Indian River X Indian River crosses. The incidence of curled-toe paralysis ranged from 0-9% and the incidence never exceeded the mortality. This low incidence of curled-toe paralysis does not mean that the deficient birds were free of visible symptoms. The majority of the birds fed deficient diets underwent a series of progressively more severe symptoms that, depending upon the extent of deficiency, led to prostration and death but did not include curled-toe paralysis. Indeed, there is a problem of deciding what is (curled-toe paralysis. We used the criteria stated and illustrated explicitly in the literature,.(Norris et al., 1931; Bethke et al., 1931; National Research Council, 1971). The toes must curl downwards and inwards and the birds must walk with part of their weight on their hocks. An example is shown
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RESULTS
The effects of graded levels of dietary riboflavin on body weight, mortality, and incidence of curled-toe paralysis in threeweek old chickens are shown in Table 2. Body weight was increased significantly (P < 0.0S) at each step in the graded addition of riboflavin. Gradations were seen in mortality and incidence of curled-toe paralysis at the lower levels of dietary riboflavin. At the zero level of added riboflavin the mortality was 35% while the incidence
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E. DONALDSON AND P. B. HAMILTON
in Fig. 1. For comparative purposes, a control bird fed a riboflavin-sufficient diet is shown in Fig. 2. The first noticeable symptoms of riboflavin deficiency were a lowering of the head from its normal erect position, a drooping of the tail feathers, and a slight lowering of the wings from the normal position high on the side of the bird. These symptoms (Fig. 3) typified the birds receiving 0.88 mg./kg. of added riboflavin for three weeks. The next degree of severity is demon-
strated in Fig. 4 and Fig. 5. The birds rested on their hocks and breast with lowered heads but without curled toes (Fig. 4). These birds were able to walk but usually their weight was borne on their hocks (Fig. 5). If they were able to stand at all, the hocks were only about 1 cm. from the floor. Once again the head was depressed toward the floor and the wings and tail drooped. In addition a concave depression frequently occurred in the middle of the back. These symptoms were characteristic
FIG. 2. Picture of a chicken fed the control diet which contained 4.53 mg. of added riboflavin/kgof diet. Note the erect posture with the head, wings, and tail held high.
FIG. 4. Picture of a resting chicken with a moderately severe riboflavin deficiency. This chicken received 0.52 mg./kg. of added dietary riboflavin. Note the low position of the head, wing, and tail and the concave depression in the back.
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FIB. 1. Picture of a chicken displaying typical symptoms of curled-toe paralysis. The toes are curled downward and inward and the weight is supported mainly on the hocks.
FIG. 3. Picture of a chicken showing the first visible symptoms of riboflavin deficiency. Note the head, tail, and wings which are carried lower than in control chickens. This chicken received 0.88 mg.Ag- of added dietary riboflavin.
RIBOFLAVIN DEFICIENCY
FIG. 5. Picture of a walking chicken with a moderately severe riboflavin deficiency. This chicken received 0.52 mg./kg. of added dietary riboflavin. The weight is borne on the hocks, the toes are not curled, the head, tail, and wings are carried low, and there is a concave depression in the back.
FIG. 6. Picture of a chicken severely affected by riboflavin deficiency. The chicken was on the zero level of added dietary riboflavin. The legs and toes are out to the side of the body with the weight borne on the breast.
boflavin and to a certain extent those on 0.22 mg./kg. level. It should be mentioned that some birds raised on wire-screen floors showed a false curled-toe symptom in which the toes were curled downward. This was the result of their gripping the wire with their toes while propelling themselves about the cage. The false curled-toe symptom disappeared when the birds were placed on a solid floor for a few minutes. They quickly learned that a flat-toe rather than a curled-toe was advantageous here. This, of course, proves that the curled-toe in these cases was not the result of paralysis. The effect of the duration of riboflavin
FIG. 7. Picture of a chicken with an extremely severe case of riboflavin deficiency. The chicken was on zero level of added dietary riboflavin. Note the spraddled legs with one forward and the other backwards, the wings and tail resting on the floor, and the toes which are not curled.
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of birds receiving 0.52 mg./kg. of added riboflavin for three weeks. The next degree of severity is shown in Fig. 6. The birds rested on their breasts with their legs out to the side of their body. If their toes curled at all it was outward as shown here. Note that the head, wings and tail drooped. These birds were capable of movement but with their breasts on the floor and the propelling force was applied by backward thrusts of the legs and by the wings. An example of the most severely affected birds is shown in Fig. 7. This posture usually preceded death. The legs were spraddled, usually with one forward and the other backward, and both at a small angle from the axis of the body. The head here was slightly erect with the wings and tail resting on the floor. The toes were straight, not curled, and could be described as "bunched" if anything. Surprisingly these birds were capable of considerable movement and they could get to the feed and water troughs in the batteries. Movement was largely undirected and was achieved by a rapid fluttering of wings which resulted in a gliding and scraping motion across the floor. The birds shown in Fig. 6 and Fig. 7 typify those on the zero level of added ri-
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E. DONALDSON AND P. B. HAMILTON
TABLE 3.—Effect of duration of riboflavin deficiency on body weight Added riboflavin (mg./kg.)
Age (weeks) 0 0 1 2 3
41.8» 88.5 117.8 146.0
0.88 42.2 113.9 232.4 374.5
TABLE 5.-—Effect of duration of riboflavin deficiency
on mortality Added riboflavin (mg./kg.)
Age (weeks)
0
0.88
4.53
1 2 3
4/80" 10/80 22/80
2/80 2/80 2/80
0/80 1/80 1/80
4.53 43.8 115.8 261.5 400.8
a
This number means that 4 out of 80 birds died.
* This number is the mean body weight in grams of 8 groups of 10 chickens.
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ommended level and when it occurred the morbidity was less than 10% (Tables 2 and 4). Death was a more frequent sympTABLE 4.—Effect of duration of riboflavin deficiency on incidence of curled-toe paralysis tom which occurred in about 25% of the birds on the zero level of added riboflavin Added riboflavin (mg./kg.) Age (Tables 2 and 5). This high mortality at the (weeks) 0 0.88 4.53 zero level of added riboflavin indicated that the basal diet was truly deficient in ribofla1 0/80° 0/80 0/80 2 0/80 0/80 0/80 vin as was calculated from standard values 3 3/80 0/80 0/80 (National Research Council, 1971). The ° This number means that none of 80 birds had most sensitive indicator of riboflavin deficurled-toe paralysis. ciency was impaired growth rate (Tables 2 and 3). Another sensitive indicator of riboflavin deficiency was the slight variations deficiency on these parameters was considfrom the erect posture and carriage of the ered next. At the zero level of added ribonormal bird. In particular, the head, wings, flavin, the growth rate was significantly (P and tail were carried lower than normal < 0.01) depressed at the end of one week (Fig. 3). (Table 3) while curled-toe paralysis reIn the current experiments, riboflavin dequired at least two weeks to develop (Taficiency was characterized mainly by a seble 4). When the basal diet contained 0.88 ries of visible symptoms of progressive semg./kg. of added riboflavin the growth deverity and intensity which culminated in pression did not occur until the end of two death rather than curled-toe paralysis. The weeks (Table 3) and at this level of added severity and frequency of these symptoms riboflavin, curled-toe paralysis never de(Figs. 2 through 7) varied with the duraveloped (Table 4). The mortality assocition and degree of deficiency. For example, ated with diets very deficient in riboflavin only slight modifications in the carriage of occurred throughout the experiment, but the birds occurred with marginal (0.88 mg. the majority occurred between the second /kg.) diets while at the zero level hardly and third weeks (Table 5). any of the birds were able to stand and DISCUSSION walk (Figs. 6 and 7) despite their relative The present experiments suggest that freedom from curled-toe paralysis. It curled-toe paralysis is a minor symptom of should be mentioned that the locomotion of riboflavin deficiency in the modern broiler birds such as those in Figures 6 and 7 was chicken. It occurred only in very deficient more severely affected than those with diets containing about one-third of the rec- curled-toe paralysis (Fig. 1). Indeed, our
243
RIBOFLAVIN DEFICIENCY
with commercial broiler cockerels. However, they did not state their criteria for curled-toe paralysis. The occurrence of a false curled-toe symptom and different degrees of paralysis recorded in our results would appear to necessitate a statement of criteria before valid comparisons can be made. At any rate, these considerations would seem to be ample justification for reinvestigation of other nutritional diseases with modern strains of birds and nutrition. It seems clear from the current results that while riboflavin deficiency can cause curled-toe paralysis such a deficiency does not cause it obligatorily and that curled-toe paralysis is a minor aspect of riboflavin deficiency in the modern broiler chicken. ACKNOWLEDGEMENTS
We thank Sharon West, Rini Hardjopranjoto, and Nancy Goodwin for technical assistance. REFERENCES Bethke, R. M., P. R. Record and D. C. Kennard, 1931. A type of nutritional leg paralysis affecting chicks. Poultry Sci. 10: 355-368. Bethke, R. M., and P. R. Record, 1942. The relation of riboflavin to growth and curled-toe paralysis in chicks. Poultry Sci. 2 1 : 147-154. Biester, H. E., and L. H. Schwarte, 19S6. Diseases of Poultry (5th ed.). The Iowa State University Press, Ames, Iowa. Bird, F. H., V. S. Asmundson, F. H. Kratzer and S. Lepkovsky, 1946. The comparative requirements of chicks and turkey poults for riboflavin. Poultry Sci. 25: 47-S1. Bruning, J. L., and B. L. Kintz, 1968. Computational Handbook of Statistics. Scott, Foresman, and Co., Glenview, 111. Chou, S. T., J. L. Sell and P. A. Kondra, 1971. Interrelationships between riboflavin and dietary energy and protein utilization in growing chicks. Br. J. Nutr. 26: 323-333. Culton, T. G., and H. R. Bird, 1940. The effect of some riboflavin supplements on chick growth and curled-toe paralysis. Poultry Sci., 19: 424430. Ewing, W. R., 1963. Poultry Nutrition (5th ed.). The Ray Ewing Company, Pasadena, Calif.
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impression was that birds with curled-toes were larger and less likely to die although these impressions were not quantitated. These impressions agree with those stated in Biester and Schwarte (1965) that curled-toe paralysis is not the most advanced stage of the deficiency. The reason for the conflicting literature about riboflavin deficiency is not certain. In the present experiments which utilized about 5000 birds over a two year period, curled-toe paralysis occurred in only a small percentage of the deficient birds and impaired growth rate was a much earlier and more sensitive indicator of deficiency. This is directly contrary to the earlier reports (Norris et al., 1930; Culton and Bird, 1940; Bethke and Record, 1942). However, it is interesting and perhaps instructive that the present findings agree with a later report (Bird et al., 1946) on these points. Great changes have occurred in the poultry industry during and after World War II since the original description of riboflavin deficiency, particularly in the strains of birds, the diets fed them, and in the knowledge of their nutrition. These changes are also reflected in laboratory experiments and practice and they would seem to be possible explanations for the conflicting reports about the symptoms of riboflavin deficiency. Of particular interest, the riboflavin requirement of chickens is a heritable trait (Hutt, 1958). Also, Norris et al. (1936) advanced a hypothesis that two different vitamins were responsible for the growth promotion and nutritional paralysis now associated with riboflavin. While this seems unlikely in view of current nutritional knowledge, the possibility that curled-toe paralysis is the result of multiple deficiencies or imbalances would appear to merit consideration. Other contrary results are those of Chou et al. (1971) who observed a curled-toe incidence of 60% and above in only 16 days
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R. D. WYATT, H. T. TUNG, W. E. DONALDSON AND P. B. HAMILTON poultry due to the presence of a new vitamin? Poultry Sci. 9 : 133-140. Norris, L. C , G. F. Heuser, H. S. Wilgus and A. T. Ringrose, 1931. The occurrence in chicks of a paralysis of nutritive origin. Poultry Sci. 10: 93-97. Norris, L. C , H. S. Wilgus, A. T. Ringrose, V. Heiman and G. F. Heuser, 1936. The vitamin G requirement of poultry. Bulletin 660, Cornell University Agricultural Experiment Station, Ithaca, New York. Stokstad, E. L. R., and P. D. V. Manning, 1938. The effect of riboflavin on the incidence of curled toe paralysis in chicks. J. Nutr. 16: 279-283.
Effects of Electrolyte Treatments and Dry-Chilling' on Yields and Tenderness of Broilers K. K. HALE, JR. 2 AND W. J. STADELMAN Department of Animal Sciences, Purdue University, Lafayette, Indiana 47907 (Received for publication May 1, 1972)
ABSTRACT Commercially available electrolyte preparations, when administered in the drinking water of broiler chickens, did not significantly alter the live weights or eviscerated weights of the birds. Although these electrolytes significantly increased weight gains during wet-chilling, most of this gain was lost as drip during storage with fresh product or upon thawing of the frozen product. The net loss from eviscerated to cooked weight of drychilled broilers was less than the corresponding net loss of wet-chilled broilers. The hot cutting and rapid chilling by crust freezing (dry chilling) did not significantly alter shear values of breast meat as compared to broilers that had been wet-chilled. Small but statistically higher shear values were recorded in the thigh muscle {biceps femoris) of the dry-chilled birds. POULTRY SCIENCE 52:
INTRODUCTION
M
OST broiler chickens are chilled in ice-water with mechanical agitation. The basic purpose of this wet-chilling is to rapidly lower the temperature of the freshly eviscerated carcass from about 37° C. to 4°C. in order to retard microbial growth, particularly salmonella. This process results in five to eight percent moisture uptake by the whole carcass (Kotula et al., 'Journal paper No. 4726 Purdue Agricultural Experiment Station, Lafayette, Indiana 47907. 'Present address: Department of Poultry Science, University of Georgia, Athens, Georgia.
244-252,
1973
1960). However, this moisture is not tightly bound and most of it leaches out during market distribution. This detracts from the appearance of the packaged product. In the dry-chill process the chicken is packaged and chilled in a — 35°C. blast freezer long enough to crust freeze the outer layer and lower the internal temperature to 4°C. One processing plant in the United States currently using the dry-chill process is also hot-cutting the freshly eviscerated carcasses for packaging of parts. Based on work on cold shortening, such
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Hutt, F. B., 1958. Genetic Resistance to Disease in Domestic Animals. Comstock Publishing Associates, Ithaca, New York. Lepkovsky, S., and T. H. Jukes, 1936. The response of rats, chicks and turkey poults to crystalline vitamin G (flavin). J. Nutr. 12: 515526. National Research Council, 1966. Nutrient Requirements of Poultry (5th ed.). National Academy of Sciences, Washington, D.C. National Research Council, 1971. Nutrient Requirements of Poultry (6th ed.). National Academy of Sciences, Washington, D.C. Norris, L. C , G. H. Heuser and H. S. Wilgus, 1930. Is the chief value of milk for feeding