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Feeding a 13% CP diet based on corn and soybean meal and supplemented with methionine to laying hens results in reduced egg weight in comparison with hens fed a corn and soybean meal methionine-supplemented diet containing 16% CP. An experiment was conducted to determine whether the egg weight reduction could be eliminated by supplementing the low-protein diet with additional lysine, methionine, and tryptophan or by adding glycine and glutamic acid to increase the amino nitrogen to a level equivalent to 16% CP. The influence of the dietary treatments on the weight of the major egg components was also determined. In a second experiment, the influence of time of day of feeding the 13 or 16% CP diets on egg weight and egg components was determined. Adding additional amino nitrogen in the form of glycine and glutamic acid or increasing the levels of lysine, methionine, or tryptophan individually or in combination failed to prevent the depression in egg weight of hens fed the lower protein diet. Measurement of egg components demonstrated that the reduction in egg weight was primarily associated with a reduction in albumen content of the egg. Feeding a high-protein diet from 1400 to 0800 h and a low-protein diet from 0800 to 1400 h resulted in egg weight equivalent to that from hens continuously fed the high-protein diet. The lower weight of the albumen in eggs from hens fed a 13% CP diet may be due to a lower availability of amino acids for protein synthesis during the 3- to 4-h period when the ovum is in the magnum.

Experiments were conducted to determine whether age of hen, weight of the egg, and sex of the chick affected fat retention and growth of the broiler chick. Chicks were fed a corn and soybean meal diet containing 5% supplemental poultry fat. In the first study, eggs from two ages of hens were compared (30 and 52 wk) with six egg weight classes per age. The second experiment consisted of three hen ages (31, 37, and 47 wk) with three egg weight classes per age. The results indicated that as hen age and egg weight increased, BW gain of the chicks increased but feed efficiency and fat retention were not affected. Females had improved fat retention when compared with males. When analyzed within each egg weight class, there was no age effect on fat retention, BW gain, or feed efficiency.

Three experiments were conducted to determine the effects of dietary orotic acid (OA) on laying hen performance, liver lipid content, and plasma and egg cholesterol levels. Laying hens were fed a basal diet supplemented with 0, .5, 1.0, and 2.0% OA for 8 wk. Performance of the hens and cholesterol levels were measured at biweekly intervals. In all three experiments, OA decreased (P less than .05) BW in a linear manner. In two experiments, OA caused a linear decrease in total liver lipid (P less than .05), and in a third experiment OA resulted in a quadratic effect (P less than .01) on liver lipid content. There were no effects observed by OA supplementation on egg weight, yolk weight, percentage yolk, or egg production. Orotic acid failed to influence egg cholesterol content in any of the biweekly measurements of the three experiments. In two experiments, total plasma cholesterol content was not influenced by OA supplementation. Orotic acid significantly reduced (P less than .05) free and total plasma cholesterol in a third experiment when measured at Weeks 4, 6, and 8 of the experiment. The data indicate that OA is an ineffective dietary supplement for reducing egg cholesterol levels in laying hens.

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 passive biomechanical wall properties of the esophagus were studied in rabbits with esophageal varices and controls using a four-electrode impedance technique. Stepwise pressure inflation and deflation was done for analysis of esophageal cross-sectional area, compliance, and hysteresis monthly during six months. At sacrifice, the esophageal collagen content was determined. A small but statistically insignificant increase in compliance was observed during the six-month observation period in both groups. No differences were observed between the groups (P greater than 0.3). No change in hysteresis was observed in either group. The group with esophageal varices had significantly higher collagen content in the distal esophagus when compared to controls (P less than 0.05). No difference was demonstrated in the proximal part. No correlation was demonstrated between the collagen content and esophageal compliance. The study demonstrated that the method allows measurement of luminal cross-sectional area and tissue elasticity. No relationship was found, however, between the collagen content and compliance of the rabbit esophagus.

Experiments were conducted to investigate the effect of feeding cimetidine (CIMET), ranging from 0 to 750 mg/kg, on vitamin D3 metabolism and eggshell calcification in laying hens fed two levels of vitamin D3 (500 and 2,000 ICU/kg). Final BW and feed intake were not significantly affected by either CIMET or vitamin D3 level. Feeding 500 and 750 mg of CIMET significantly decreased total egg production in hens fed either level of vitamin D3, but no differences were observed at lower CIMET levels. Tibia ash decreased significantly in hens fed 150 to 750 mg of CIMET, regardless of the vitamin D3 level. Plasma Ca and inorganic P concentrations were decreased in hens fed high CIMET levels (500 and 750 mg/kg) at Week 2, but no differences were observed at Week 4. Feeding CIMET (500 and 750 mg/kg) significantly decreased plasma 25-hydroxycholecalciferol (25-OHD3) levels at Week 2 in hens fed both vitamin D3 diets but not at Week 4. Eggshell breaking force, shell thickness, and percentage shell weight were decreased significantly by CIMET in all experiments; however, in one experiment, shell quality recovered by Week 8. These results suggest that the CIMET-induced reduction in bone mineralization, eggshell quality, and plasma 25-OHD3 levels could be due to interference of CIMET with vitamin D3 metabolism in vitamin D3-replete laying hens. Shell quality decreased in CIMET-treated hens fed the higher vitamin D diet even though 250-HD3 plasma levels were three times higher than in hens fed the lower vitamin D diet, suggesting that CIMET affected shell quality through some mechanism other than inhibition of 250-HD3 synthesis.

Four experiments were conducted with White Leghorn laying hens to estimate their requirement for tryptophan for optimal egg production and other parameters. In the first two experiments, the hens were fed a 14.5% protein diet supplemented with 0, .025, .05 and .075% L-tryptophan. The first experiment was conducted for 12 wk and the second for 55 wk. In the third and fourth experiments, the influence of protein concentration on tryptophan requirement was investigated. Diets formulated to contain 14, 16, and 18% protein were supplemented with 0, .02, .04, .06, or .08% L-tryptophan. Protein concentration in Experiment 3 was increased by increasing only soybean meal; in Experiment 4, it was increased by increasing all protein concentrates, resulting in the same ratio of tryptophan to protein. These experiments were conducted for 6 wk. Rate of egg production was significantly improved by tryptophan supplementation in Experiments 1 and 2, but production was inferior to that expected for commercial laying hens. The estimated tryptophan requirements were .137% of the diet and 123 mg/day per hen in Experiment 1 and .118% of the diet and 95 mg/day per hen in Experiment 2. Egg production was significantly increased by adding tryptophan to the 14% protein diet in Experiment 3 but not to the higher protein diets. The estimated requirement was .164% of the diet and 168 mg/day per hen. In Experiment 4, tryptophan supplementation significantly increased egg production at all protein percentages, and the requirement increased as the protein increased. Egg weight was not significantly affected by tryptophan supplementation in any of the four experiments. Hepatic lipid accumulation was generally not decreased by tryptophan supplementation.

Performance of broiler chicks fed low protein diets supplemented with several essential amino acids (EAA) is generally inferior to that of birds fed a higher protein diet composed primarily of intact protein. Two experiments were conducted to determine whether lowering the minimum requirements of the EAA in proportion to the lowered protein concentration or equalizing the dietary amino nitrogen content by use of glutamic acid would prevent the reduction in performance. Chicks were fed the experimental diets from 7 to 21 days of age, and body weight gain, feed consumption, and feed efficiency were determined. In the first experiment, the chicks were fed diets with 23, 20, or 17% CP with minimum EAA set at 100% of the 1984 National Research Council (NRC) suggested requirements. Other groups were fed the 20% CP diet with EAA set at 93.5% or the 17% CP diet set at either 93.5 or 87.5% of the NRC requirements. In the second experiment, the 23% and 17% CP diets were fed, and glutamic acid was added at 3, 6, or 9% to provide the amino nitrogen equivalent of 23% protein with the minimum EAA set at 100% of 1984 NRC requirements. In the first experiment, body weight gain and feed efficiency, but not feed intake, were depressed by lowering CP content. Reducing the minimum EAA requirements in proportion to the reduction in CP failed to correct the difference in performance between the high and low CP diets. In Experiment 2, body weight gain and feed intake were reduced as intact CP decreased and glutamic acid increased, but feed efficiency was unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Three experiments were conducted to estimate the arginine requirement of male broiler chicks from 0 to 3 wk of age. The experiments were conducted in battery brooders with wires floors, and the birds received water and feed ad libitum. In the first experiment, chicks were fed a diet based on corn, soybean meal, casein, and corn-gluten meal containing 3,200 kcal ME per kg and either 20 or 23% crude protein. Regression analysis indicated an arginine requirement of 1.22% for maximum growth rate and feed efficiency with the 20% protein diet. For chicks fed the 23% protein diet, neither growth rate nor feed efficiency was significantly different among the diets containing arginine ranging from 1.13 to 1.43%. In the second experiment, a basal diet was used containing 17.5% casein and 22.5% protein with arginine ranging from 1.03 to 1.43%. An arginine requirement of 1.18% for maximum body weight gain was estimated by regression analysis, but no significant response to arginine above the basal level was observed for feed efficiency. Performance of chicks fed the basal diet was somewhat reduced because of a difficulty with adherence of feed to the beaks. In a third experiment, three basal diets containing 21, 22, or 23% protein were formulated from practical ingredients without use of casein. The requirement for maximum growth rate and feed efficiency was estimated to be 1.24 to 1.28% for the three diets. The results of these investigations indicate that the arginine requirement for starting chicks suggested by the National Research Council in 1984 of 1.44% in diets containing 3,200 kcal ME per kg is too high for practical diets. The data presented here support an arginine requirement of 1.25%.

Because previous studies indicated that cimetidine (CIMET) and isoniazid (ISON) may inhibit vitamin D metabolism in both rats and humans, experiments were conducted to evaluate the influence of these drugs on growth and bone development in male broiler chicks. Chicks were fed a corn and soybean meal basal diet containing various levels of the drugs for 21 days. Body weight gain (BWG), feed consumption per bird (FB), tibia ash (TA), tibia breaking force (TBF), and plasma calcium levels were measured. In birds fed a diet supplemented with 1,100 ICU D3/kg, CIMET at up to 300 ppm resulted in a significant linear decrease in TA as the drug level increased. Birds fed ISON up to 405 ppm had inconsistent responses in TA and TBF. Body weight gain was only depressed with the highest level of ISON (405 ppm). The effects of feeding 0, 150, or 300 ppm CIMET were also investigated when chicks were fed 200 or 1,000 ICU per kg vitamin D3. The interaction between vitamin D3 and CIMET was significant for BWG, FCB, TA, and TBF. These were significantly reduced as the CIMET level increased for birds fed the low vitamin D3 diet but were not significantly affected when fed the high D3 diet. In another study in which chicks were fed a diet with 1,100 ICU vitamin D3, lowering the dietary Ca, or P, or both did not result in any effect of CIMET on the chicks. The results indicate that CIMET possibly interferes with normal bone formation in chicks by altering vitamin D3 metabolism.

Four experiments were conducted to investigate if the degree of activation of the microsomal mixed-function oxidase (MFO) system was related to the degree of growth depression associated with the addition of monensin to the diet. The experiments were conducted with broiler chicks in battery brooders in which the chicks were fed diets of various composition and containing monensin at 0 to 160 ppm. In all experiments, the activity of the MFO system was estimated by the change in the content of cytochrome P-450 in the hepatic microsomes. Activities of some microsomal enzymes were also measured in some of the experiments. Feeding a diet with 24% protein containing fish meal, alfalfa meal, and torula yeast significantly increased the activity of the MFO system in comparison with feeding an isonitrogenous and isoenergetic corn and soybean diet, but there was no difference between the diets in the toxicity of monensin as measured by growth rate. Supplementing a 16% protein but not a 24% protein diet with monensin significantly reduced growth rate. In none of the four experiments was there a statistically significant change in the hepatic content of cytochrome P-450 as a result of feeding monensin. Thus, variation in the magnitude of growth depression caused by monensin in diets of different protein concentration or ingredient composition does not appear to be explained on the relative degree of the activation of the MFO system.

Two experiments were conducted with White Leghorn laying hens to determine the influence of the dietary CP concentration on the requirement for TSAA. Supplements of 0, .05, .1, or .15% of DL-methionine (Experiment 1) and 0, .025, .05, .075, .1, or .125% of DL-methionine (Experiment 2) were each added to corn-soybean meal diet with 13, 16, or 19% CP. Experiment 1 was conducted for 4 wk (four groups of 10 hens, 32 wk of age per treatment). Experiment 2 was conducted for 5 wk (three groups of 9 hens, 59 wk of age per treatment). Methionine supplementation significantly improved egg production in Experiment 2, and in Experiment 1, the increase in egg production approached significance (P = .077). Egg production was highly significantly improved by increasing the protein level in both experiments. Egg weight was increased by methionine supplementation at all protein levels. For Experiments 1 and 2, respectively, the estimated requirement for TSAA in order to achieve maximum egg mass (grams of egg per day) was .61 and .54% for 13% CP, .61 and .65% for 16% CP, and .68 and .73% for 19% CP. The methionine requirement for maximum egg mass in Experiment 2 was .29%, .36 and .41% for 13, 16, and 19% CP, respectively, but was not improved in Experiment 1 by increasing the concentration of protein. Feed per gram of egg, but not feed per dozen eggs, was improved by methionine supplementation at all CP levels. Body weight gain generally increased along with the CP levels and with methionine supplementation, but the methionine requirement for maximum body weight did not appear to increase along with the increase in protein concentration. The results of the present study show that the concentration of dietary protein should be considered when determining the requirement of laying hens for TSAA.

Four experiments were conducted to investigate further the effects of V on hen performance and egg quality as well as on the ability of ascorbic acid and Cr to counteract the deleterious effects of V on interior egg quality. At 10 ppm, added V significantly reduced albumin quality as measured by Haugh units; and at 30 ppm and 100 ppm, respectively, significantly reduced rate of lay and feed consumption and also increased body weight loss. As measured by shell breaking strength or shell thickness, shell quality was not affected significantly by V (added to a maximum of 100 ppm). Ascorbic acid (100 to 5,000 ppm) effectively protected the hens from the reduction in albumen quality resulting from the addition of 10 ppm of V to the basal diet. Hen performance and egg quality were not significantly affected by adding 10 or 50 ppm of Cr to a diet with 10 ppm of added V, nor by adding 30 or 150 ppm of Cr to a diet with 30 ppm of added V. The added Cr failed to counteract the depressing effects of V on the Haugh units recorded, regardless of the composition of the basal diet.

In a randomized prospective controlled trial involving 311 patients undergoing acute or elective colorectal surgery, the efficacy and safety of two different single dose and one triple dose regimen of antibiotic prophylaxis, as well as the influence of blood transfusion on postoperative infectious complications, were studied. Postoperative infectious complications occurred in a total of 59 patients (19.0 per cent). There were no major differences between the three treatment groups. Thirty-four patients (10.9 per cent) developed abdominal wound infection, 17 patients (5.5 per cent) intra-abdominal abscess and 16 patients (5.1 per cent) anastomotic leakage. Of 202 patients (65.0 per cent) requiring blood transfusion during hospitalization 57 (28.2 per cent; 95 per cent confidence limits of 23-36 per cent) developed infectious complications, whereas two non-transfused patients (1.8 per cent; 95 per cent confidence limits of 0.2 to 6 per cent; P less than 0.001) developed infectious complications. It is concluded that one single dose of antibiotic prophylaxis in acute and elective colorectal surgery is as protective as a triple dose regimen. The development of infectious complications despite antibiotic prophylaxis is strongly related to blood transfusion.

In 29 patients admitted with their first bleeding episode from oesophageal varices the varices were obliterated within 6 months by treatment with serial endoscopic sclerotherapy and propranolol or with sclerotherapy only. The patients were checked regularly during 18 months after the varices had been obliterated. Variceal recurrence was found in 11 patients (73%; 95% confidence limits, 45-92%) treated with sclerotherapy only and in 2 patients (15%; 95% confidence limits, 2-43%; p less than 0.01) treated with sclerotherapy and propranolol. In nine patients (69%) with recurrence significant variceal bleeding occurred. All recurrences were observed within 12 months after the initial obliteration. Variceal recurrence occurred in 3 Child A patients and in 10 Child B or C patients. All bleeding occurred in Child B or C patients. It is concluded that obliteration of oesophageal varices by endoscopic sclerotherapy and propranolol may be more effective in the long-term control of variceal recurrence than treatment with sclerotherapy only.

Three experiments were conducted for the purpose of determining the effect of feeding isoenergetic diets with and without fish meal or its fractions on hepatic lipid deposition in estrogenized chicks. The chicks were fasted for 48 hr before being fed the experimental diets and were injected with estradiol three times during the experiment. After 4 days, hepatic lipid content was determined. In the first experiment, the quantity of hepatic lipid deposited per unit of liver and per 100 g body weight was significantly less for chicks fed 10% fish meal and an ethanol extract of fish meal equivalent to 10% than for chicks fed an unsupplemented corn-soy diet. In a second experiment a significant reduction in hepatic lipids deposited per 100 g body weight was observed with 10% fish meal but only a numerical reduction with ethanol extracts of fish meal equivalent to 10 or 20% and the ash of ethanol extract equivalent to 20%. In a third experiment a highly significant reduction in hepatic lipid deposition was observed in birds refed a diet containing fish meal, alfalfa, and torula yeast but feeding this before the starvation-refeeding period did not affect liver lipids. These results show that fish meal contains hepatic lipid lowering activity in refed estrogenized chicks and suggest that the activity may be extracted with ethanol.

Temporal effects of feeding isocaloric and isonitrogenous diets with and without 10% menhaden fish meal (FM) on plasma estradiol and thyroxine concentrations, hepatic fatty acid synthetase and hepatic lipid content were investigated. Hepatic fatty acid synthetase activity and lipid content were significantly increased at 7 days and 14 days, respectively, after feeding the corn-soybean meal (CS) diet. Plasma thyroxine concentration was significantly reduced at 3 days after feeding the FM diet. Plasma estradiol concentration was immediately and gradually elevated after feeding the CS diet and reduced after changing from the CS to the FM diet. A significant positive correlation was observed between plasma estradiol, but not plasma thyroxine, and hepatic fatty acid synthetase activity. These findings suggest that tissue estradiol concentration responds early to dietary changes followed by stimulated hepatic lipogenesis, and steatosis in laying hens.

A laboratory model with chicks is described that is suggested as an assay for dietary factors affecting liver lipid accumulation in laying hens. The model utilizes growing White Leghorn male chicks injected with estrogen. Diets to be tested were fed ad libitum for 4 days following 2 days starvation. Liver lipid deposition was increased with increasing level of estradiol injected. Lipid deposition in livers of estrogenized chicks fed a diet containing fish meal, alfalfa meal, and torula yeast (FAY) was significantly less than that in chicks fed a corn-soybean meal (CS) diet. This correlated with a similar response in laying hens fed ad libitum FAY and CS diets for 30 days, suggesting the response of livers to dietary changes in fasted-refed-estrogenized chicks reflects the responses obtained with laying hens. Using the proposed laboratory model, fish meal, distillers dried grains with solubles, and alfalfa meal were shown to contain activity that reduced liver lipid deposition.

1. Myographic and histological techniques were used to study the mechanical and morphological properties of oesophageal and mesenteric veins from rabbits subjected to 0, 4, 14 and 90 days of partial portal vein stenosis. 2. The stenosis caused an immediate increase in portal pressure from 10.5 mmHg (1.4 kPa) to 20.5 mmHg (2.7 kPa); the pressure returned to the control level by 90 days. 3. The lumen diameter of oesophageal veins was increased by 76% after 4 days and by 147% after 90 days, while that of the mesenteric veins was unchanged. The media thickness in both veins increased rapidly, reaching a maximum at 14 days (82%, oesophageal; 56%, mesenteric) and thereafter decreasing. 4. The contractility of oesophageal veins was transiently decreased (at 4 days), while that of the mesenteric veins was transiently increased (at 14 days). 5. In further experiments, sclerosing of the oesophagus, which is believed to restrict flow without reducing pressure, restricted the increase in lumen diameter of oesophageal veins caudal to the sclerosing site, but did not affect the media thickness. 6. The results suggest that, in oesophageal and mesenteric veins, portal pressure is a primary determinant of media thickness but not of lumen diameter.

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.

The purpose of this study was to determine whether diet composition would influence calcium and phosphorus metabolism in chicks administered estrogen. At 1 day of age, broiler chicks were fed either a corn-soybean meal diet (CS), or an isoenergetic and isonitrogenous diet containing 5% fish meal, 5% alfalfa meal and 10% torula yeast (FAY). At 21 days equivalent numbers were implanted with one of two lengths of Silastic tubing containing estradiol dipropionate, while the remaining birds served as nonimplanted controls. Significant increases were observed in liver weight, liver lipid, plasma total calcium and inorganic phosphate in chicks that were implanted, while concomitant declines were seen in body weight. Implanted chicks fed the CS diet had significantly higher liver weight, liver lipid, plasma phosphorus and plasma calcium and lower tibial bone ash than those fed the FAY diet. Furthermore, liver lipid values were very highly correlated with plasma phosphorus and calcium. In an identical study with slower growing White Leghorn chicks, the same trends were observed but were less well defined. These data show that the inclusion of certain ingredients into corn-soybean diets balanced for the major nutrients affects the response of chicks to estrogenization. Liver lipid deposition, calcium and phosphorus metabolism are all subject to diet and estrogen interactions.

The properties of isolated small oesophageal and mesenteric veins were investigated in a rabbit model subjected to a 4-week period of portal vein stenosis. The animals developed oesophageal varices and these together with the small mesenteric veins were mounted on a myograph. Compared with sham-operated controls portal hypertension resulted in an increased normalized inner radius and media thickness of the oesophageal veins resulting in a non-significant increase in the media to lumen ratio, while the inner radius decreased as media thickness increased in mesenteric veins resulting in a significant (P less than 0.01) increase in the media to lumen ratio. When activated, the active wall tension of both the oesophageal and mesenteric veins was increased following portal hypertension, but the active media stress was unchanged. The EC50 for noradrenaline and angiotensin II did not change in portal hypertensive vessels compared with controls and was equal in oesophageal and mesenteric vessels. The ability of isoprenaline and serotonin to relax pre-contracted vessels of both types was reduced by the portal hypertension. The results of these studies suggest that the development of oesophageal varices is not only due to increased portal venous pressure.

Three experiments were conducted to study the effect of varying levels of dietary copper on fatty acid composition of adipose and liver tissue of male broiler chicks. Chicks were fed the experimental diets to 4 weeks at which time leg adipose and liver samples were obtained for fatty acid determination. Adding 500 or more p.p.m. copper to either a practical or corn starch-soy basal diet caused significant changes in fatty acid composition but the differences were variable perhaps due to a depression of growth caused by these levels of copper. Fatty acid composition of the tissue was not greatly affected by adding 250 p.p.m. of copper to the practical diet which contained 1.5% poultry fat. When a corn starch-soy diet was fed with 0, 2, or 8% added corn oil, the ratio of 16:0 + 18:0 to 16:1 to 18:1 was not lowered in leg adipose lipids by copper supplementation (250 p.p.m.) with any level of added corn oil. With liver lipids copper appeared to reduced the ratios in birds fed the diets with 0 or 2% added corn, but the differences were not statistically significant. The results indicate that using copper levels in practical diets that do not depress growth rate will not have much effect on fatty acid composition of carcass lipids and probably not on physical characteristics of the fat.

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.

Two experiments were conducted with laying hens fed a corn-soy basal diet or diets containing fish meal, distillers dried grains with solubles (DDGS) or torula yeast formulated to be isocaloric and isonitrogenous with the basal diet. One half of the hens were kept at a temperature range of 13-24 degrees and the other half at 24-35 degrees for 49 days in experiment 2. Liver lipid content was significantly lower in hens fed DDGS (experiment 1) and DDGS or fish meal (experiment 2) than in hens fed the corn-soy basal diet, but it was not influenced by environmental temperature. Feeding DDGS or fish meal reduced lipoprotein lipase activity in adipose tissue. High temperature reduced plasma estradiol level but not thyroid hormone levels. Plasma estradiol in the hens fed DDGS or fish meal (experiment 1) and DDGS, fish meal or torula yeast (experiment 2) an plasma thyroxine and triiodothyronine in hens fed the DDGS or fish meal at 24-35 degrees in experiment 2 were significantly lower than that of hens fed the corn-soy basal diet. Significant correlations were observed between liver lipid content and plasma estradiol or thyroxine concentrations. These findings show that plasma estrogen and thyroxine levels were influenced by diet composition and that these hormones have a close relation to induction of fatty livers in laying hens.

Experiments were conducted to investigate the effect of isocaloric diets varying in protein and fat content or diluted with a combination of cellulose and sand during the 1st wk of life on subsequent abdominal fat pad size in male broiler chicks. In the first experiment chicks were fed diets containing 2,850 kcal metabolizable energy (ME)/kg with 23% protein and low or high total fat (23/LF) or 28% protein with low fat (28/LF) for the 1st 7 days and diets with varying protein and fat levels during the next 19 days. Abdominal fat was significantly higher in chicks fed 28/LF for 7 days followed by 23/HF than for the other treatments. In a second experiment chicks in battery brooders were fed diets with 18, 23, or 28% protein with or without added fat. They were then intermingled and placed in floor pens where they were fed corn-soy starter grower and finisher diets to 7 wk. Body weight at 4 and 7 wk and abdominal fat at 4 wk were not significantly different among treatments, but abdominal fat at 7 wk was significantly higher for chicks fed the 28/LF or 28/HF diets. Effects of feeding the same 18/LF, 23/LF, and 28/LF diets or practical diets containing 3,150 kcal ME/kg with various protein levels during the first week were examined in another experiment. Chicks all received the same diets from 7 to 49 days. No significant differences in size of abdominal fat pad was observed within each diet series.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of this study was to determine if plasma mineral levels and plasma or hepatic ascorbic acid would be affected by the composition of the diet fed to chickens with higher circulating estrogen levels. Three-week-old broiler chicks were implanted with estradiol dipropionate to give estimated release rates of 0, 3.2, and 8.0 micrograms/bird/day. The chicks were fed a corn-soy diet (CS) or a diet containing 5% fish meal, 5% alfalfa meal and 10% torula yeast (FAY). The FAY diet resulted in significantly lower hepatic lipid and plasma iron, copper, manganese, and zinc in chicks administered the highest level of estrogen. In two experiments laying hens were fed either CS or diets containing fish meal (FM), alfalfa meal (AM), distillers dried grains with solubles (DDGS) or wheat-soy (WS) for 4 weeks. In the first experiment, liver lipid content was not significantly affected by diet composition, but plasma iron was significantly reduced by the AM, DDGS, and WS diets. No significant effects on copper, manganese, and zinc in plasma were observed among the dietary treatments. In the second experiment, relative liver weight was significantly reduced with the AM, DDGS, and WS diets and liver lipid by the AM diet. Plasma iron levels were significantly reduced by feeding all diets compared with the CS diet, but no significant differences in total iron binding capacity were observed. Plasma and hepatic ascorbic acid were significantly increased by the AM, DDGS, and WS diets, but no significant differences in hepatic ascorbic acid were observed when calculated per unit of fat-free dry matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Experiments were conducted to study the effect of chromiun and selenium on liver lipid deposition and incidence of liver hemorrhage in caged layers. Commercial strains of layers were fed ad libitum equicaloric and isonitrogenous diets. Corn-torula dried yeast diets containing added selenium (.1 microgram/g) with or without supplementary chromium (10 microgram/g) significantly reduced total liver lipid and liver hemorrhage. The effects of protein source (soybean meal vs. yeast) and selenium were separated in a factorial experiment which showed that the hepatic lipid response to selenium results from an interaction of selenium with an unidentified factor in torula yeast. The addition of selenium to diets with each protein source significantly elevated glutathione peroxidase (GSHPx) activity. Inclusion of 5% brewers yeast in the corn-soy diet or vitamin E (50 IU/kg) to the corn-torula dried yeast reduced liver lipid similar to that seen in birds fed the torula-yeast diet containing .1 microgram Se/g. Comparison of oral glucose tolerance of birds fed corn-soy and corn-soy brewers yeast diets showed no significant difference. None of the dietary treatments significantly altered body weight, egg production, egg weight, or feed consumption. The results indicate that the metabolic role of selenium in relation to its role in hepatic lipid metabolism is mediated through an interaction with a dietary factor(s) present in yeast.

Three experiments were conducted to investigate the effect of diet and estradiol (E2) administration on hepatic microsomal mixed function oxidase (MFO) activity, E2 metabolism, and liver lipid content in male broiler chicks. Broiler chicks (3 weeks of age) were fed either a corn-soybean (CS) diet or a diet containing fish meal, alfalfa meal, and torula yeast (FAY) for 19 days in Experiments 1 and 3 and for 14 days in Experiment 2, respectively. Half of the chicks were implanted with tubes containing E2. In all experiments when the chicks were estrogenized, feeding FAY significantly lowered liver lipid content and plasma E2 concentration. Activity of hepatic microsomal aniline hydroxylase and content of cytochrome P-450 were significantly increased by feeding FAY with or without E2 administration. The chicks fed the CS diet had a significantly lower content of cytochrome P-450 when E2 was administered. Activities of aminopyrine demethylase and nicotinamide adenine dinucleotide phosphate, reduced (NADPH)-cytochrome C reductase did not differ significantly between the diets. In in vitro studies, conversion of 14C-E2 into the water soluble fraction was significantly increased in microsomes from chicks fed the FAY diet as compared to ones from chicks fed the CS diet. The results suggest that some of the hepatic microsomal functions on the CS diet are modified by the change in diet composition and that these modifications are probably associated with E2 metabolism and occurrence of fatty liver.

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.

Two experiments were conducted with Large White male turkeys to investigate the lysine requirement from 12 to 22 weeks of age. Six pens of 20 turkeys were fed each of the experimental diets. In experiment 1, a basal diet containing wheat, meat meal, cottonseed meal and distillers dried grains with solubles was supplemented with four levels of L-lysine. Lysine at 4.27% of protein and 2.31 g./mcal. of metabolizable energy from 16 to 20 weeks of age, and 1.83 g. from 20 to 22 weeks of age was inadequate for optimum growth and feed efficiency (16-22 weeks). Supplementing the diet with lysine from soybean meal gave performance equivalent to synthetic lysine, indicating that it was fully available. Performance of turkeys fed a diet containing 88% triticale from 16 to 20 weeks of age, and 72% from 20 to 22 weeks of age was equivalent to that of turkeys fed a more complex ration with an equivalent level of lysine. In experiment 2, Large White male turkeys were fed a basal diet composed largely of triticale and soybean meal from 12 to 20 weeks of age with different levels of added lysine. From 12 to 16 weeks of age, 3.11 g. lysine/mcal. of M.E. (4.9% of protein) was adequate for optimum growth and feed efficiency. From 16-20 weeks of age 2.36 g. lysine/mcal. of M.E. (4.3% of protein) was adequate for optimum performance. Although the estimated requirement from 16 to 20 weeks of age based on the two experiments differs (perhaps because of differences in lysine availability), the results suggest that the current N.R.C. recommendation may be higher than necessary.

The interrelationships among dietary composition, environmental temperature, and level of estradiol (E2) administration on hepatic lipid deposition in chicks were studied. Two levels of E2 were injected at three intervals over a 4-day period, in 3-week-old male Leghorn chicks fed either a corn-soybean meal (CS) diet or a diet containing fish meal (FM) after 2 days fasting. The chicks were subjected to temperature ranges of 15 to 24 C (low) or 24 to 35 C (high) at 2 weeks of age. The E2 (in silastic tubes) was also implanted subcutaneously in 3-week-old broiler chicks fed either the CS diet or a diet containing fish meal, alfalfa meal, and torula yeast (FAY) from day of age to 6 weeks. They were subjected to the high and low temperature ranges at 3 weeks. Liver lipid deposition markedly increased with E2 administration among chicks fed all diets within both temperature ranges. Liver lipid was significantly greater at 24 to 35 C than at 15 to 24 C among estrogenized chicks. Feeding the FM or the FAY diet decreased hepatic lipid accumulation as compared to feeding the CS diet, but the ameliorative effect of the FM diet on hepatic lipid deposition was not observed at the low temperature or at the lower level of implantation. It was concluded that a range for estrogen administration exists wherein dietary effects are expressed. These data indicate that environmental temperature, dietary composition, estrogen level, and their interactions influence hepatic lipid deposition and also suggest that high temperature augments liver response to estrogen.

Two experiments were conducted to determine if differences in response of livers to estradiol administration in male broiler chicks would be observed if fed isonitrogenous and isocaloric diets of different composition. A polymethylsiloxane tube filled with estradiol dipropionate was implanted under the neck skin to ensure a constant release of hormone. Different tube sizes were implanted in two- to three-week-old chicks fed a basal corn-soybean meal (CS) diet or a diet containing fish meal, alfalfa meal, and torula yeast (FAY) o distiller's dried grains with solubles (DDGS). Body weight gains were significantly reduced by the highest level of estradiol in chicks fed the CS diet but not chicks fed FAY or DDGS. Liver weight, deposition of lipid in liver and plasma lipid were markedly increased in proportion to the size of estradiol tube in chicks fed all diets. Increase of liver weight and lipid deposition by the highest level of estradiol in chicks fed the CS diet was significantly greater than that in chicks fed the FAY diet. Liver weight and the liver lipid response to estradiol in chicks fed the CS diet were significantly greater than that in chicks fed the FAY diet when dose response equations were compared among diets. These data show that the response on deposition of lipid in liver to estrogen administration was modified by the type of ingredients included in diets with similar energy and nutrient profiles.

The influence of dietary cereal on hepatic lipid metabolism was studied in adult Japanese quail and mature female chickens fed isoenergetic and isonitrogenous corn-soy and wheat-soy diets ad libitum. Hepatic lipid accumulation and rate of biosynthesis were significantly higher in birds fed the corn-soy diet. The differential response to the cereals was seen in ovipositing females but not in mature male quail. There were no significant concomitant changes in body composition, egg production, egg weight, body weight, feed, and energy intake. Results of sequential changes in hepatic lipid metabolism showed that reduction in liver fat was significant 2 to 3 weeks after feeding the wheat diet and was due to a significant reduction in rate of lipogenesis and the amount of triacylglycerols deposited. Plasma levels of free fatty acids and glucose were not significantly altered by the dietary regimes in laying hens. In Japanese quail fed the corn-soy diet, plasma glucose was elevated and there was evidence of impaired glucose tolerance. In vitro rate of oxidation of labeled palmitate was significantly higher in liver homogenates from birds fed the corn-soy diet. Addition of carnitine to the incubation mixtures resulted in an increase of equivalent magnitude for both treatments. Liver hemorrhages were observed in laying hens but not in Japanese quail. Addition of myo-inositol to the corn diet for Japanese quail failed to significantly alter hepatic lipid accumulation. These studies show that differences in liver lipid accumulation due to corn and wheat diets are related to changes in rate of lipogenesis.

Sixteen rabbits with oesophageal varices were randomized to no treatment (n = 8) or endoscopic paravenous sclerotherapy of the varices (n = 8). Eight other rabbits served as sham-operated controls. Four months after sclerotherapy the animals were killed, and the mechanical strength and collagen content of the oesophagus were determined at proximal, middle, and distal levels. In animals treated by sclerotherapy there was a 15% increase in collagen content at the distal level when compared with controls and non-treated animals (2p less than 0.05). This was not accompanied by changes in the mechanical strength. At middle and proximal levels there were no differences between the groups. It is concluded that the late effect of one single session of paravenous sclerotherapy of oesophageal varices is a slight fibrosis in the distal oesophagus, with no changes in the mechanical properties of the oesophageal wall.

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.

The purpose of this study was to determine if length of time of feed withdrawal of broilers prior to slaughter could affect the lipid content of their livers. Seven-week-old male broilers were allocated to three treatments: 1) no feed and water, 2) no feed, and 3) feed and water ad libitum. Those in the first treatment were held in plastic coops and those in the latter two treatments were kept in floor pens. Eight birds were randomly sampled initially and eight birds from each treatment at 4, 8, 12, 16, and 24 hr after the start of the study. The birds were weighed, killed, and the livers removed and analyzed for lipid content. The regression slopes of the two treatments without feed for body weight, liver weight, liver weight per unit body weight, and liver fat per unit body weight were significantly different from the control treatment. The slopes for liver fat were not significantly different among treatments. No obvious differences in the gross appearance of the livers were detected. The occasional problems with fatty livers in commercial broilers apparently cannot be accounted for by the length of time of feed withdrawal before slaughter.

Experiments were conducted to study the effect of marginal levels of selenium and vitamin E on plasma thyroid hormones of meattype chicks. Plasma thyroxine (T4) was significantly increased when a semipurified diet was supplemented with either selenium or vitamin E. Triiodothyronine (T3) was also significantly increased by vitamin E and in one experiment with selenium supplementation. No significant increase in these hormones was observed in birds fed a corn-soybean-meal diet supplemented with these nutrients. Plasma corticosterone level was reduced and weight of the bursa of Fabricius increased by selenium or vitamin E supplementation. These nutrients may be necessary for providing the optimum thyroid conditions for activity of thyroid peroxidase.

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.

The effect of long-term propranolol administration on esophageal varices, portocollateral shunting, portal pressure, hepatosplanchnic hemodynamics, and liver function was studied in a pig model with experimentally induced prehepatic portal hypertension and esophageal varices. Five pigs were treated with 160 mg propranolol daily from week 5 to week 24 after portal-vein banding, and five pigs served as nontreated controls. Administration of propranolol caused an initial, significant reduction (20%) of portal venous pressure, followed by a gradual increase to levels not different from control pressures. In contrast, a marked reduction of the caliber of the coronary vein and size of the esophageal varices was noticed. Twenty weeks of propranolol treatment did not change liver blood flow or liver function. We conclude that the size of the varices rather than portal venous pressure depicts the effect of propranolol treatment and suggest that the beneficial effect of propranolol on variceal bleeding can be explained by a reduction in the wall tension of the varices, initiated and maintained by a diminution of splanchnic blood flow.