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Copper sulfate was added to the diet of broiler chickens from 1 day to 3 weeks of age at the rate of 0.05% to 0.20% in order to evaluate its influence on the incidence of oral lesions. Both the incidence and severity of oral lesions showed a significant linear increase as the concentration of copper sulfate increased. Adding a level of sulfate equivalent to that produced by the highest level of copper sulfate failed to induce oral lesions. The severity of gizzard erosion also increased as the concentration of copper increased. Dietary copper sulfate supplementation should be considered a possible cause of oral lesions seen during the necropsy of avian species.

The effects of broiler strain and various additives to practical corn-soy diets on the incidence of tibial dyschondroplasia (TD) were studied using broiler chicks maintained in battery brooders. At the termination of each experiment, birds were killed and examined for TD by cutting longitudinally along the tibia. No significant difference in the incidence of TD was found among the nine broiler strains compared. While the incidence of twisted legs was higher than TD among the nine strains there was no apparent correlation between the two leg disorders. Studies conducted using the following additives did not significantly increase the incidence of TD in broilers when compared to controls: monensin, sodium chloride, copper sulfate, magnesium sulfate, potassium sulfate, roxarsone, gentian violet, erythromycin, vitamin K, or vitamin D3. However, dietary ammonium chloride (1.5 or 30%) did increase the incidence of TD, whereas adding various fermentation products at levels of 10 and 20% either in the absence or presence of ammonium chloride failed to reduce the incidence of the disease. The incidences of TD among broiler chicks fed high dietary fluoride were nonsignificant; no evidence of the disease was found in Leghorn chicks fed the same diets. Chicks maintained in battery brooders in these studies, generally had a lower incidence of TD than that reported for commercial flocks in the field. Furthermore, manipulation of feed additives or ingredients in practical rations for broiler chickens did not increase the incidence of the disease.

Dietary furazolidone (500 ppm or higher) significantly slowed the growth of chicks fed either a conventional or a purified diet and of turkeys fed a conventional diet. Deaths were significantly increased in turkeys fed 500 ppm and in chicks fed 700 ppm in the purified diet. Ratio of heart to body weight was significantly increased by furazolidone in turkeys, but not in chicks. Furazolidone did not induce anemia in either species. Turkeys and chicks differed markedly in cardiac response to toxic levels of furazolidone.

Vitamin E and/or selenium supplementation of a corn-soybean diet fed to broiler chicks in floor pens ameliorated the effect of an outbreak of pale bird syndrome diagnosed when the chicks were 3 weeks old. Supplementation significantly reduced both mortality and the effects of disease on body weight gain. The added nutrients only partly overcame the effect of the disease on body weight gain when infected chicks were compared with uninfected chicks.

Six experiments were conducted with male broiler chicks kept in battery brooders to investigate the effects of feeding diets high in copper on the integrity of the gizzard lining. Conventional and corn starch-soy basal diets were used. Slight improvements in body weight gain and/or feed efficiency were observed when the diets were supplemented with 250 p.p.m. copper as as CuSO4-5HSO, but higher levels (500 to 1000 p.p.m.) depressed growth and decreased feed efficiency. Little or no gizzard erosion was seen in birds fed the practical ration without added copper. Gizzard erosion was observed with 250 p.p.m. copper and the severity of the condition increased with higher levels. With the same level of copper supplementation, severity of gizzard erosion was greater when chicks were fed the corn starch-soy diet than when fed the practical diet. Adding 0.5 p.p.m. selenium to the practical diet containing 1000 p.p.m. copper slightly improved the appearance of the gizzard lining, although the subjective scoring index was significantly (P less than 0.05) lower in only one of two experiments. The addition of zinc, vitamin E, and vitamin B12 did not prevent the gizzard damage caused by high copper levels. Severity of gizzard erosion was significantly reduced by adding 0.35% cholic acid to the semipurified diet with 500 p.p.m. copper, but not to the practical diet with 100 p.p.m. copper. There was no correlation between acidity of the gizzard contents and severity of the erosion.

Energy utilization and lipid absorption were studied in chickens having the symptoms of the pale bird syndrome (PBS). Chicks with PBS and also ones that appeared "normal" were taken from a commercial farm and compared to control chicks raised at the University of Georgia (UGA). The PBS chicks utilized dietary energy and absorbed lipids substantially less than the normal birds from the commercial farm. Differences in lipid absorption alone did not account for the discrepancy in metabolizable energy between the two groups, suggesting that absorption of non-lipid dietary components was also affected. Both of the commercial groups of chicks showed a lesser ability to utilize dietary energy and absorb lipid than the UGA control chicks, indicating that the normal chicks may also have been affected by the disease.

Four experiments were conducted using broiler chicks to study the effects of feeding a semipurified diet on coccidial infection. Chickens fed a semipurified diet and inoculated with E. tenella had a very mild infection with little or no mortality and no effect on body weight gain, feed intake, feed conversion ratio, and blood cell loss as judged by hematocrit. At necropsy the infected chickens had light cecal lesions. However, no difference in response was observed between chickens fed either the corn-soybean meal or the semipurified diet and inoculated with a mixture of E. acervulina, E. maxima, and E. brunetti. Chickens fed a diet composed of 25% of the corn-soybean meal diet plus 75% of the semipurified diet and inoculated with E. tenella had the same mortality as chickens fed the corn-soybean meal diet. Feeding chickens the semipurified diet as early as 6 days before inoculation did not affect the severity of E. tenella infection. No difference was observed in the intestinal or cecal pH or food passage time of noninfected chickens fed either the corn-soybean meal or the semipurified diet. No differences were found in the number of oocysts discharged between 2 and 9 hr after inoculation expressed as a percentage of the infective dose. The results of these studies show that a semipurified diet ameliorates infection of chickens with the cecal parasite E. tenella but not coccidial infections of the small intestine.

The Oily Bird Syndrome (OBS) was successfully reproduced in broilers under laboratory conditions which included elevated temperatures simulating summer conditions and feeding high energy diets with a relatively wide calorie to protein ratio. No significant difference in incidence of the syndrome was detected in broilers fed a corn-soy diet, or one with 13% animal protein concentrates and 7.5% bakery product, or with a diet containing 10% distillers dried gains with solubles. Substituting animal tallow for poultry oil significantly (P less than .05) increased the incidence of the syndrome. Feeding diets with a more narrow calorie to protein ratio significantly reduced incidence in one experiment, and feeding an unpelleted diet from 3 to 7 weeks of age also significantly reduced the incidence below that of birds fed the same diet in pelleted form. Incidence of OBS was significantly less for birds housed in a separate building with lower temperature conditions than those maintained in a house with a higher environmental temperature. The OBS could best be observed under commercial processing conditions. Results of these experiments show that growing broilers at a high environmental temperature and feeding diets with wide calorie to protein ratios provide conditions conducive to the development of OBS. Further studies will be necessary to determine the specific etiology of the syndrome.

Experiments were designed to study environmental factors that affect incidence of tibial dyschondroplasia (TD) in broiler chickens. A significant higher frequency of TD was observed in birds reared in floor pens vs. those maintained in a battery brooder with wire floors and fed the same diet. Incorporating either 5% raw or autoclaved broiler litter in the diet produced no significant effect on the incidence of the disease in chicks reared in floor pens covered with wood shavings or wire frames. During the first six months of 1979, the incidence of TD declined markedly in market-age broilers of the same strain fed similar diets and maintained on litter in the same broiler house.

Experiments were conducted to study the effect of addition of natural feedstuffs to a semi-purified (SP) diet on Eimeria tenella infection of chickens. Chicks were fed the experimental diet throughout the experimental period and were orally inoculated with 200,000 sporulated oocysts of E. tenella at 14 days of age. Addition of corn, but not soybean meal, to a SP diet increased mortality and decreased body weight gain due to the coccidial infection in comparison with chickens fed the SP diet. Addition of corn gluten meal or replacement of poultry fat by corn oil or glucose by corn starch in the SP diet did not significantly change any of the parameters studied. Addition of 20% of corn fermentation solubles (CFS)-but not 20% of distillers dried grains with solubles, wheat bran, or rice bran-to the SP diet, resulted in significantly higher mortality from the coccidial infection. Addition of 5 or 10% of CFS to the SP diet significantly increased mortality in chicks compared to those fed the SP diet, but feeding the residue of CFS after extraction with chloroform-methanol followed by water did not increase mortality. These studies show that corn and CFS contain factors that enhance E. tenella infection in chicks fed a semi-purified diet, but other natural feedstuffs such as soybean meal do not.

Five experiments were conducted with Large White poults to determine the effect of methionine and other sulfur-containing compounds on the incidence and severity of dermatitis and on growth and feed efficiency to three or four weeks of age. The poults were housed in battery brooders with wire screen floors in four experiments" and in floor pens with litter in one experiment. Male turkeys were used in four experiments and female turkeys in one experiment. Either a corn-soy diet or a cornstarch-soy diet was used as the basal diet in the various studies. A high incidence of foot-pad dermatitis was observed in poults fed the basal diets unsupplemented with methionine. A high incidence of a dermatitis on the upper part of the beak was also observed in poults maintained in battery brooders but not in floor pens. Adding methionine to the diets significantly lowered the incidence and severity of dermatitis, but cystine and potassium sulfate failed to modify dermatitis. Some foot-pad dermatitis was still observed in poults fed levels of methionine more than adequate to meet the requirements for optimum growth and feed efficiency. The incidence and severity of foot-pad dermatitis generally increased with age during the experiment among poults fed methionine-supplemented diets. Although methionine deficiency is a major cause of foot-pad dermatitis in poults, other environmental or dietary factors also appeared to be involved in the development of the condition. The methionine requirement for optimum growth, feed efficiency, and prevention of dermatitis was approximately 0.6% or 2.1 g. per mcal. of metabolizable energy (M.E.). This is higher than the present recommendation of the National Research Council. With corn-soybean meal diets the requirement for total sulfur amino acids is approximately 1.05% or 3.7 g. per mcal. of M.E.

Twenty-one samples of water were collected from commercial egg production farms in Georgial with or without a history of fatty liver syndrome. These samples plus a sample of water from the University of Georgia Poultry Farm were analyzed for various mineral elements by atomic absorption, direct reading emission spectroscopy and by neutron activation. Water samples from farms with a history of fatty liver syndrome had signficantly more calcium, magnesium, strontium, sodium, iron and barium than water samples from farms reporting no significant problem with fatty liver syndrome. Levels of manganese, boron, copper zinic and aluminum were not significantly different. Although the results do not prove that water quality is the cause of the disease, they do demonstrate an association of hardness of water with fatty liver syndrome that should be further investigated.

Susceptibility to vitamin A (vit A) toxicosis was compared in Single Comb White Leghorn chicks, broilers, and turkey poults by giving an aqueous vit A solution of varying concentrations by crop intubation. Results of these studies indicate a differential response to vit A toxicosis within breeds and across species. Pair-fed treatments clearly demonstrated that the effects of excess vit A on bone calcification were independent of anorexia. A comparison between turkey poults receiving either a constant dietary level of vit A or vit A by gavage showed that the latter markedly increased the severity of vit A. toxicosis.

Six experiments were conducted using broiler chickens to study the effect of selenium (Se) or vitamin E supplementation of a corn-soybean meal diet on the immune response to coccidiosis. Immunized chickens fed diets supplemented with .25 ppm Se or 100 IU vitamin E/kg of diet had increased body weight gain and feed intake and a tendency for lower feed conversion ratio than chickens fed unsupplemented diet after a challenge with 150,000 oocysts of Eimeria tenella. In two experiments, chickens fed .25 and .50 ppm of Se and immunized against E. tenella had higher body weight gain and a tendency for higher feed intake and lower feed conversion ratio than unsupplemented chickens when challenged with 150,000 oocysts of E. tenella. Except for a reduction on cecal lesion scores and blood packed cell volume in Experiments 1 and 4, respectively, no dietary effect was observed on cecal lesion score or blood packed cell volume of immunized chickens. Dietary supplementation with selenium or vitamin E reduced mortality and increased body weight gain of nonimmunized chickens infected with E. tenella in three of four experiments. These studies suggest that immunization of chickens against coccidiosis is enhanced by Se or vitamin E supplementation.

Four experiments were conducted with commercial strains of White Leghorns. Experimental corn-soy diets with (CSW) and without (CS) minor feed ingredients significantly elevated liver and plasma lipids when compared to a standard layer diet (UGA) used at the University of Georgia. The response was not due to difference in vitamin and mineral premix or level of energy and protein in the diets. Inclusion of 5% alfalfa in a low protein (13.5%) diet with energy and amino acid profile similar to diet CS significantly reduced liver lipid. Comparison of diet CS to isocaloric and isonitrogenous diets with 20% brewers dried grains, soybean mill feed, or wheat bran showed that layers fed diets with these supplements had significantly lower liver and plasma lipids. In all experiments a higher incidence of liver hemorrhage was associated with feeding the experimental diets CS and CSW. There were no significant differences in egg production, egg weight, or body weight change due to dietary treatment in the experiments. Results of the experiments show that hens with equivalent ME intake and egg output exhibit differences in liver and plasma lipids due to diet composition. The data suggest that mill feeds and fermentation by-products contain an essential factor for control of lipid metabolism in caged layers.

Two experiments were conducted with chicks to compare the effectiveness of vitamin E,selenium and cystine in preventing the deleterious effects of dietary silver. Adding 900 p.p.m. silver to a diet marginal in vitamin E and selenium significantly depressed growth and caused a high mortality during the four-week experiment. Most of the mortality was due to exduative diathesis. Including either 1 p.p.m. selenium or 100 I.U. vitamin E per kg. in the diets with silver prevented the growth depression and mortality. Adding 0.15% cystine stimulated growth, but failed to rpevent mortality. In a second experiment, chicks were grown on the diet containing silver with and without cystine to 15 days of age, at which time approximately 50% of the chicks exhibited signs of exudative diathesis. At that time they were either continued on the same diet of fed diets supplemented with selenium or vitamin E. Both vitamin E and selenium reduced mortality during the following two-week period, but vitamin E. was more effective than selenium.

Three experiments determined if the methionine requirement of broiler chicks was affected by coccidial infection. Chicks were fed a corn-soy or a corn-soy-pea basal diet containing 0.73% and 0.62% total sulfur amino acids (TSAA), respectively. Levels of 0 to 0.45% DL-methionine were added, with and without 0.01% monensin sodium. In two experiments, the chicks were inoculated at two weeks of age with a mixture of oocysts of E. acervulina, E. maxima, E. tenella, E. necatrix and E. brunetti. Lesion scores on the intestines and ceca, and blood carotenoid levels were determined at three weeks. The experiments were terminated at four weeks. A level of methionine greater than 0.47% and of TSAA greater than 0.83% was necessary to obtain maximum growth rate in uninoculated chicks. No evidence of dermatitis was observed. Growth rate and feed efficiency of chicks infected with coccidiosis were more severly depressed when the diet was not supplemented with methionine. Infections of coccidia and low levels of methionine, which in themselves did not produce any significant change in weight gain, did give a significant weight depression in combination. Adding monensin to the diet prevented a reduction in growth rate and feed efficiency of inoculated chicks fed adequate methionine. Monensin did not completely prevent the adverse effects of a coccidial infection, based on feed efficiency, when chicks were fed diets inadequate in methionine. Blood carotenoid levels were not affected by methionine level, but were significantly lowered by coccidial infection in the absence of monensin. Intestinal and cecal lesions in inoculated chicks were significantly reduced by including monesin in the diet. Although the coccidial infection more severly affected the performance of chicks fed diets deficient in methionine, satistical analysis of pooled data indicated no difference in the quantitative requirement of chicks for methionine. Therefore, a level of methionine and cystine adequate for optimum growth under the coccidial-free conditions should be adequate for chicks when infected with coccidia.

Growth rate of Single Combe White Leghorn cockerels fed a casein-gelatin-glucose diet was significantly depressed at two weeks when 10 p.p.m. or more selenium was added to the diet. When 20% linseed meal was included in the diet, growth was not reduced with 10 p.p.m. selenium and only slightly reduced with 20 p.p.m. selenium. Including 20% soybean meal failed to modify the toxicity. Levels of 5 and 10% linseed meal were less effective in counteracting selenosis than was 20%. Fractionation studies showed that a protective factor in linseed meal was extracted by methanol and ethanol and was not destroyed by autoclaving. Ashing the ethanol extract destroyed its activity. The factor was readily extracted by chlorform:methanol (2:1) but less effectively by acetone and diethyl ether. Washed chloroform:methanol extract was inactive but the washings contained the factor. Concentrates of the factor were active at less than 1% of the dry matter of the diet. The results of these studies show that linseed meal contains a heat stable, organic, polar factor that modified selenium toxicity in the chick.

The interaction between malabsorption syndrome (MAS) and dietary vitamins A and D was studied in broiler chicks reared in floor pens for 4 weeks. The chicks were naturally infected with MAS, whereas hatchmates fed the same diets but in a separate facility (battery brooder) did not exhibit signs of MAS and, therefore, were considered controls. MAS significantly reduced body weights, bone ash, serum calcium and phosphorus concentrations, and liver lipids and increased the incidence of skeletal abnormalities (tibial dyschondroplasia and rickets). Rather than ameliorating the effects of MAS, vitamin A caused a further reduction in body weight and bone ash. A possible nutrient interaction between vitamin A and vitamin D or vitamin E in birds with MAS may account for the exacerbative effect of vitamin A.

High mortality and a high incidence of exudative diathesis and muscular dystrophy were observed in chicks fed a diet supplemented with either 800 or 1600 ppm copper. Adding 0.5 ppm selenium to a basal diet containing 0.2 ppm prevented mortality and selenium deficiency signs. Dietary zinc levels of 2100 to 4100 ppm also resulted in high mortality, exudative diathesis, and muscular dystrophy. A selenium supplement of 0.5 ppm completely prevented the deficiency signs and markedly reduced mortality. The results demonstrate that both copper and zinc can induce a selenium deficiency in chicks when a diet relatively low in this element is fed.

Experiments were conducted to study the effects of dietary selenium (Se) on peripheral blood leucocytes of chickens infected with coccidia. Primary coccidial infection significantly increased blood leucocyte number at 6 days postinfection (PI) in three of four experiments when chicks were fed a corn-soy diet, and in all four experiments at 11 days PI. When chickens were fed a semipurified (SP) diet, coccidial infection did not affect the blood leucocytes number at 6 days PI but significantly increased blood leucocyte number at 11 days PI. In the primary infection, Se significantly decreased blood leucocyte number in four of six experiments at 6 days PI and significantly increased the blood leucocyte number in three of five experiments at 11 days PI. In the secondary infection, chickens had significantly more blood leucocytes than chickens given a primary infection at 8 or 24 hr after challenge. Selenium significantly increased blood leucocyte number at 8 hr after challenge in one experiment and produced numerically higher leucocyte number in three other experiments. The results of these studies indicate that dietary Se supplementation modifies the number of peripheral blood leucocytes in chickens infected with coccidia.

Three experiments were conducted using commercially available broiler chicks to study the influence of high levels of pyridoxine on incidence of twisted legs. Chicks were grown in wire floored battery brooders to two weeks of age when they were weighed and visually scored for twisted legs. Supplementation of a diet containing 2.2 mg synthetic vitamin B6/kg with 10 and 20 mg/kg pyridoxine resulted in a significant decrease (P less than or equal to .05) in incidence of twisted legs in Experiment 1. In Experiment 2, supplementation with 30, 60, or 100 mg/kg numerically reduced incidence, but the differences were not statistically significant. Incidence of twisted legs was significantly increased by injecting chicks with .5 ml physiological saline at 1 and 7 days of age in comparison to noninjected controls. Including 10 mg pyridoxine HCl in the saline reduced the incidence but it was still numerically higher than the noninjected controls. Factors other than vitamin B6 nutrition appear to play a more important role in the etiology of twisted legs in broiler chicks.