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Studies of non-polio enterovirus prevalence and transmissibility in developing countries are limited and few studies have investigated specific risk factors for infection. An epidemiological survey of non-polio enterovirus among families in Mongolia was conducted in the late summer of 2003. Stools of 122 healthy persons were collected weekly for 5 weeks. Eight serotypes of non-polio enteroviruses (echovirus 30, 33, 12, 25, coxsackievirus A10, A2, A4, A24) were isolated from 62 persons, with an overall isolation rate of 51%, and 64% and 35% among children under 10 years and adults over age 21 years. Fifty-four per cent of isolations were due to intrafamilial infection. Analysis of risk factors for infection suggested contamination of indoor kitchen, bathroom, toilet, and waste disposal area. Hand washing after defecation was protective against infection. Our study findings stress the importance of hand washing and cleaning hygienic facilities to prevent infection by enteric viruses in the home environment.

By using a dentifrice or toothpaste for sensitive teeth, the brushing-induced effects on dentinal tubule occlusion and abrasion of human sound dentin were investigated with a scanning electron microscope and a scanning laser microscope. The dentifrice contained diatomaceous earth and silica as abrasives and strontium chloride hexahydrate as an active ingredient. Thirty dentin pieces of human premolar teeth with an average of 20% occluded dentinal tubules were attached to resin plates and exposed to the oral cavities of five adult subjects for 2, 4, and 8 weeks. Brushin with and without dentifrice was performed 1 min per day, respectively. Brushin with the dentifrice gradually decreased the mean average of occluded tubules from about 91 to 77% during 2 to 8 weeks, although there were no significant differences among the individual values. However, the mean abrasive loss of the dentin surfaces brushed with dentifrice significantly increased from about 52 to 143 µm in depth. The brushed surfaces of the dentin showed a rough topography with numerous toothbrush scratches but no organic pellicle was found. On the other hand, brushing without dentifrice caused about 99% of the dentinal tubules to occlude in 2 and 4 weeks and 100% in 8 weeks. The brushed dentin surfaces at 8 weeks were entirely covered with organic pellicle containing fine mineral granules derived from saliva, and the abrasive loss was about 1.4 µm in mean depth. Such results indicate that brushing with abrasive dentifrices for sensitive teeth remarkably erodes dentin, and suggest that the brushing should cause the dentinal tubules to open again for a certain period of time.

This study investigated whether or not endogenous cholecystokinin exerts satiety effects in chickens. After several doses (0, 1, 2 and 4 µg·kg body weight-1) of intravenous injection of caerulein, the bile flow was increased in a dose-dependent fashion. However, the pharmacological level of caerulein failed to suppress the food intake of chickens. Two potent stimulators of endogenous cholecystokinin, i.e., soybean trypsin inhibitor and phenylalanine were administered to chickens before feeding and food intake was determined over 2 h. The soybean trypsin inhibitor and phenylalanine did not alter food intake. Devazepide, a cholecystokinin-A receptor antagonist, significantly decreased amylase release from the dispersed chicken pancreatic acini stimulated by caerulein. However, devazepide did not improve food intake of the chicken. The results obtained suggest that endogenous cholecystokinin may not act as a satiety signal in chickens.

Whether ingestion of soya-bean trypsin inhibitor (SBTI) alters the release of cholecystokinin (CCK) was investigated in chickens. A meal of an adequate diet supplemented with SBTI (0, 100, or 1000 mg/kg) was given through a stomach tube, followed by CCK determination with specific CCK-8 antibody. The plasma CCK level increased from a basal level (control diet) of 9.6 ± 0.6 to 13.4 ± 0.6 and 18.1 ± 0.8 fmol/ml plasma at 90 min after feeding the diet supplemented with 100 and 1000 mg SBTI, respectively. Since the SBTI supplementation did not affect crop emptying rates significantly, it was concluded that SBTI by itself enhanced CCK release into circulation in a dose-dependent fashion.

1. The importance of linoleic acid (18:2n-6) itself and of dietary y-linolenic acid (18:3n-6) as essential fatty acids (EFA) in Japanese quail were investigated with regard to liver lipid metabolism. Experimental diets were made by adding of 0, 2 or 4 g γ-linolenic acid/kg, or 20 g linoleic acid/kg to an n-6 EFA-free diet. From 3 to 6 weeks of age, birds were fed equal amounts of experimental diets.2. liver weight and lipid content in birds fed the 2 and 4 g γ-linolenic acid/kg diet were significantly lower than those in birds fed the γ-linolenic acid-free diet. However, no significant difference was observed between the γ-linolenic acid- and linoleic acid-supplemented diets.3. In birds fed the 4 g γ-linolenic acid/kg diet, the proportion of arachidonic acid in the liver lipid was similar to that in quail fed the 20 g linoleic acid/kg diet, implying a conversion rate from linoleic acid to y-linolenic acid of approximately 20% of whole body content.4. It is concluded that linoleic acid itself is not essential for Japanese quail and that at least 2 g/kg of γ-linolenic acid in the diet completely prevents liver enlargement accompanied by lipid accumulation.

1. The aim of the present study was to determine if ovalbumin messenger RNA (mRNA) in the magnum of laying hens changes during the egg formation cycle.2. The concentration of ovalbumin mRNA in the magnum was measured by RNA:RNA hybridisation in solution. The concentration of ovalbumin mRNA was higher when an ovum was in the magnum than when it was in the infundibulum. These changes in ovalbumin mRNA were essentially parallel to those in ovalbumin synthesis during the egg formation cycle as reported by Muramatsu et al. (1991).3. The extent to which the ovalbumin mRNA was increased when an ovum moved down from the infundibulum to the magnum appeared to be too small to account for the expected increase in ovalbumin synthesis. This implies that in laying hens, translational rather than transcriptional regulation of ovalbumin synthesis is likely to be of primary importance.

1. Whole body protein synthesis was measured in chick embryos cultured in vitro. On day 7 of incubation chick embryos were cultured for 60 min in synthetic serum-free medium containing 4-[3H]phenylalanine. Specific radioactivities in free and protein-bound phenylaline in the whole embryo were measured, starting 2 min after commencement of the culture process.2. The values for fractional synthesis rate (FSR) estimated in vitro at 20, 30, 45 and 60 min during the embryo culture agreed well, ranging from 35 to 40%/d, suggesting that the method would serve as a useful model for studying the effect of growth promoters in chick embryos.3. Bovine insulin in the synthetic medium did not affect FSR of protein in chick embryos cultured in vitro.

1. The influence of feeding a high protein diet containing 400 g crude protein (CP)/kg on liver and breast muscle protein synthesis in chicks was investigated using a large dose injection of l-[4 -3H]phenylalanine.2. Liver weight of chicks fed on the high protein diet was significantly heavier than that of chicks fed on a control diet with 200 g CP/kg, and breast muscle weight was not affected by the treatment.3. Fractional and absolute protein synthesis rates, RNA and protein contents, and RNA:protein ratio of breast muscle were not influenced by feeding the high protein diet.4. Feeding the high protein diet decreased fractional synthesis rate of liver protein, an observation explained by reduced RNA:protein ratio. Liver protein content was elevated by feeding the high protein diet and this resulted in no change in the absolute synthesis rate of liver protein.

1. The effect of dietary medium chain triglyceride (MCT) on short-term food intake was compared with the effect of long chain triglyceride (LCT) in chickens. Maize oil was used as the LCT while glyceryl tricaprylate (C 8) and glyceryl tricaprate (C 10) were used as MCT. Cumulative food intake was determined during the 6 h after the start of feeding.2. Chicks were given diets containing 200 g C 8/kg diet, 200 g C 10/kg diet or 200 g LCT/kg diet in experiment 1. As early as 30 min after feeding, cumulative food intake in both MCT-supplemented diets decreased significantly compared with the diet containing LCT.3. To determine if endogenous cholecystokinin (CCK) was responsible for the decrease in food intake caused by MCT, birds were injected with the CCK-A receptor antagonist devazepide (DVZ, 1 mg/kg BW) before diet presentation. DVZ had no effect on food intake with either LCT- or MCT-supplemented diets.4. In experiment 3, chicks were given a choice between either diets containing LCT and C 8, LCT and C 10, or C 8 and C 10 to confirm whether or not the palatability of the diets was influenced by the dietary fat sources. There was no difference in food intake between C 8 and C 10-supplemented diets. However, chicks preferred the LCT-supplemented diet compared with either of the diets containing MCT.

1. To improve the influence of variation of ME intake, an experiment was carried out using equalised feeding to investigate the comparative effects on protein and energy utilisation in chicks of diets containing medium chain triglyceride (MCT) and long chain triglyceride (LCT). Experimental diets were given at 3 different food intakes, namely, 100, 120 or 147 g/bird/10 d. The diets contained MCT or LCT on an isoenergetic basis. Maize oil and caprylic acid triglyceride respectively, were used as LCT and MCT sources.2. Body weight gain and food efficiency of chicks significantly increased with the supplement of dietary MCT compared with dietary LCT at all food intakes. Protein retention and the efficiency of protein utilisation (protein retained/protein intake) at all food intakes also significantly increased with dietary MCT, while body fat and fat retention were significantly reduced. Chicks fed the LCT-supple-mented diet, on the other hand, had a lower protein retention, but significantly higher fat retention. The value for energy retention and the efficiency of energy utilisation (energy retained/ME intake) were not significantly different between MCT- and LCT-supplemented diets.3. It was concluded that supplementing MCT to the chick diet would improve body weight gain and protein utilisation while regulating fat deposition compared to the LCT supplemented diet, under equalised feeding conditions.

1. In experiment 1, the performance and tissue weights of germ-free (GF) and conventional (CV) chicks fed on diets containing 25'4 g acetic acid/kg diet (AD) or 25.4 g kaolin/kg diet (KD) were investigated. Body weight gain in GF chicks was significantly higher on the AD, but significantly lower on the KD compared with their CV counterparts. The values for food efficiency, protein retention and energy retention followed a similar pattern to that of the body weight gain.2. The weights of all sections of the intestine except the colon were significantly greater in CV chicks. In CV but not in GF birds the jejunum and ileum were heavier from birds fed on the AD than from those on the KD diet.3. In experiment 2, the influence of butyric acid administration on the weight of some organs in chicks was investigated. The weight of duodenum, jejunum and ileum was significantly increased by intra-peritoneal administration of butyric acid (2 ml of 100 mM solution/d) for 4 d, but no significant effect was observed by oral administration.4. It might be suggested that short chain fatty acids such as acetic and butyric acids formed by bacterial action in the crop and subsequently absorbed are at least partly responsible for the heavier gut weight in CV birds.

1. Prediction of the growth of young chicks was attempted by means of a computerised mathematical model, by fitting a 4 parameter kinetic equation (Mercer, 1982) to data obtained experimentally and from the literature. Amino acid antagonisms between arginine and lysine, and between branched-chain amino acids were taken into account.2. In order to pool the data, dietary concentrations of essential amino acids were standardised by expressing as percentages of requirements according to Japanese Feeding Standard (1984), and growth responses were expressed relative to growth at or above this requirement.3. The kinetic model gave an excellent fit (R2 = 0.92 -0.99) to independent growth data obtained experimentally and from the literature, validating the use of the equation.4. It was implied from predicted growth that the responses to alterations in dietary concentrations of different essential amino acids differed substantially, in a characteristic pattern, even when percentages of requirements were the same.5. The validity of the model was tested against data that were not used in its construction. It was found that the simulation model could predict the growth of young chicks satisfactorily from dietary amino acid patterns.

1. To evaluate the relative efficiency of energy utilisation of medium chain triglyceride (MCT) compared to long chain triglycer-ide (LCT), Single Comb White Leghorn 7-d-old male chicks were allocated into 4 experimental groups and one control of 5 birds per group. The chicks in the control group (Group 1) were given 5 g basal diet each day for 10 d. The birds in groups 2 and 3 received 5 g basal diet/d supplemented with MCT to provide 33-5 kj GE/d and 67-0 kj GE/d, and those in groups 4 and 5 were supplemented with LCT at 31-9 kj GE/d and 63-8 kj GE/d, respectively. Energy retained as protein and fat, and total energy retentions were measured.2. No significant differences were found in energy retention as protein between the four energy supplemented groups but significant differences in fat and total energy retentions were found between the different dietary energy contents but not between energy source. Net energy of MCT for production was calculated as 16-0 kJ/g which corresponds to about 74% of that of LCT (22-8 kJ/g).

1. The effect of different amounts of food, varying from below to above the rate of voluntary intake, was studied in chicks using a standard diet and diets containing only half the recommendation concentrations of leucine, isoleucine or valine.2. Irrespective of diet the body weight gain of the chicks increased with increasing food consumption. The body weight gain of chicks given the leucine-deficient diet was similar to that of chicks given the same amount of the standard diet.3. In contrast, the body weight gains of chicks given either the valine- or isoleucine-deficient diet were significantly less than that of chicks given the same amount of the standard diet.4. When the food intakes of the birds were similar the differences in body protein and water contents of the birds fed the different diets reflected differences in body weight gains, whereas body fat content was affected in the reverse manner.5. Retention and retention rate of dietary energy increased as food consumption increased. This was particularly evident in chicks given the isoleucine-deficient diet, followed by those given the valine-, leucine-deficient and standard diets.6. For all diets, the amounts of nitrogen retained and nitrogen retention rate (N retained/N consumed) increased in line with body weight gain.7. The metabolisable energy values of the diets were similar, except for the isoleucine-deficient diet which had a significantly higher metabolisable energy value than the standard valine-deficient diets.

1. Whole body protein turnover was measured in chick embryos during incubation to investigate whether or not there is a fall in fractional rates of protein synthesis and degradation during development.2. Stable isotopically labelled [15N]phenylalanine was injected intra-peritoneally into embryos on days 12 and 19. From 60 to 90 min after injection the isotope enrichment in free and protein-bound phenylalanine was measured with a selected-ion gas-chromatograph mass-spectrometer.3. The results showed that from days 12 to 19 of incubation, there was a remarkable reduction in fractional rates of protein synthesis and degradation in the whole body of chick embryos.4. During embryonic growth, protein synthesis per unit of RNA that is, the minimum amino acid translation rate of RNA, did not change significantly, whereas the RNA: protein ratio was reduced to one-third from days 12 to 19 of incubation.5. It was concluded, therefore, that the dramatic fall in fractional synthesis rate in chick embryos would be entirely attributable to the rapid increase in protein content, thereby changing the RNA: protein ratio in parallel with the fractional synthesis rate.

1. The nitrogen-sparing effect of methionine in chicks fed on a protein-free diet containing arginine was examined in three 10-d trials. Chicks received either a protein-free diet, this diet supplemented with arginine and methionine or diets containing arginine in which the methionine was replaced by various methionine-related compounds.2. Body-weight changes, nitrogen retentions and uric acid-nitrogen excretion indicated that the methyl moiety was unlikely to contribute to nitrogen sparing activity and that cysteine, or possibly glutathione, played an important role. The possible mechanism of the nitrogen-sparing effect is discussed.

1. The requirements for leucine, isoleucine and valine were determined in 8- to 18-d-old White Leghorn male chicks. The requirements were estimated from body-weight gains.2. The estimated requirements for leucine, isoleucine and valine were 200, 115 and 125 mg/bird d, or 12-0, 5.0 and 8.0 g/kg diet, respectively. In terms of concentration in the diet, they are broadly similar to results for broiler-type chicks.3. When body-weight gain was plotted against daily intakes of each amino acid, significant (P < 0.01) quadratic regression equations were obtained. The equations showed some characteristics of the individual amino acids.

1. In adult colostomised cockerels, the rates of urinary and faecal nitrogen loss were measured when feeding low- and high-energy, protein-free diets after a preliminary period during which diets of differing energy and protein contents had been fed.2. Urinary nitrogen excretion increased with increasing protein and decreasing energy in the preliminary diet.3. Urinary nitrogen excretion was high during the first 3 d of feeding a high-energy, protein-free diet, decreased rapidly during the next 3 d and thereafter become relatively constant. However, in the case of a low-energy, protein-free diet, urinary nitrogen excretion gradually declined throughout the trial period of 15 d, resulting in increased urinary nitrogen excretion.4. After a 3-d period of adjustment faecal nitrogen loss from birds fed on a protein-free diet was relatively constant under the conditions examined.

Abstract1. The effect of ketone bodies on crop emptying was studied in chickens in 2 experiments. In the first, the effect of β‐hydroxybutyrate, acetoacetate or acetone on relative crop content was measured. The effects of dietary medium and long chain triacylglycerols upon serum β‐hydroxybutyrate were investigated in the second.2. β‐Hydroxybutyrate, but not acetoacetate and acetone, delayed crop emptying in a dose dependent fashion. Serum β‐hydroxybutyrate concentration was high in chicks given medium chain triacylglycerol, when compared with long chain triacylglycerol.3. The results suggest that delayed crop emptying induced by medium chain triacylglycerol could partly be explained by an enhanced concentration of serum β‐hydroxybutyrate, which is the result of the rapid oxidation of medium chain fatty acids.

1. Protein, fat and energy retentions of chicks fed on diets containing medium chain triglyceride (MCT) and long chain trigly-ceride (LCT), at 100 and 200 g fat/kg diet, were investigated. Maize oil was used as the LCT source. The MCT used was glyceryl tricaprylate.2. Body weight gain and food intake were decreased with the diets containing MCT and these effects were greater at the higher fat concentration. Protein retention was also reduced by dietary MCT, although the efficiency of protein utilisation (protein retained/protein intake) was not altered.3. The values for fat and energy retentions were significantly lower in the chicks fed on the MCT-supplemented diets than in those receiving the LCT-containing diets. Dietary ME values and efficiencies for energy utilisation (energy retained/ME intake) were also reduced by dietary MCT.

1. The effect of dietary sorbitol on the performance of broilers was investigated. Male and female broilers were given a control diet or a sorbitol diet (100 g/kg diet) ad libitum from 29 to 57 d of age.2. Body weight gain, food intake, food efficiency and the ME values of the diets were not significantly different. Absolute and relative weights of abdominal fat were significantly reduced in birds given the sorbitol diet.3. Compared to the control diet, the diet containing sorbitol lowered the serum glucose, total cholesterol and very low density lipoprotein concentrations.

1. In experiment 1, growing conventional (CV) chicks were fed on diets containing graded amounts (0, 100, 200 and 300 g/kg diet) of sorbose from 4 to 14 d. Protein, fat and energy deposition were determined after carcase analysis. The values for growth, food efficiency, metabolisable energy (ME) and fat and energy depositions declined as the dietary sorbose content increased.2. In experiment 2, the performances of germ-free (GF) and CV chicks fed on diets with (100 g sorbose/kg diet) or without sorbose were investigated. On both diets, body weight gain, food consumption and protein accumulation in GF chicks were significantly higher than those in CV birds. No significant differences were observed between the dietary treatment except for ME values, which were significantly lower for the sorbose diet.3. It is suggested that dietary sorbose decreased energy utilisation, and that the microbial contribution to the utilisation of dietary sorbose was negligible in the chicken.

The importance of egg albumen content in whole-body protein synthesis was investigated in developing chicken embryos by using lines genetically selected for high and low albumen contents and by removing albumen from eggs before incubation.2. Whole-body protein synthesis was estimated by injecting l-[15N]-phenylalanine intravenously on day 12 of incubation.3. Embryos from high albumen eggs had higher whole-body protein synthesis rates than those from low albumen eggs.4. Whole-body protein synthesis was reduced by the removal of albumen from eggs before incubation.5. It was concluded that albumen content per se was of crucial importance in regulating whole-body protein synthesis in chicken embryos during incubation.

1. Whether or not there is a strain difference in embryonic whole-body protein turnover rates was tested using the chicken embryos of Rhode Island Red carrying a sex-linked dwarf gene (dwarf), White Leghorn (layer), and White Cornish x White Plymouth Rock (broiler) strains on day 12 of incubation.2. Whole-body protein synthesis was estimated by injecting l-[15N]-phenylalanine either intraperitoneally or intravenously on day 12 of incubation in order to investigate the effect of the route of isotope administration. The results showed that the values for fractional and absolute synthesis rates were approximately 13% higher by intravenous injection than by intraperitoneal injection.3. Whole-body protein turnover, both in terms of fractional and absolute rates, was significantly faster in dwarf than in broiler embryos, with intermediate values in layer embryos, although no growth differences were observed on day 12.4. Difference in egg weight, measured before incubation, did not affect protein turnover.5. It was concluded that the strain difference manifested in whole-body protein turnover of the chicken embryo would probably be a reflection of differences in genetic background.

1. Experiments were conducted to investigate whether or not varying dietary protein intake affects whole-body protein turnover rates in young chicks.2. Seven-d-old single comb White Leghorn male chicks were fed on diets with protein concentrations of 0, 100, 200 or 400 g/kg diet under conditions of ad libitum or equalised feeding. At the end of the experiments, the rate of protein synthesis and protein degradation in the whole body were measured in vivo.3. The results showed that both fractional and absolute rates of protein synthesis increased with increasing dietary protein up to 200 g/kg; above this concentration they remained almost constant when feeding was ad libitum.4. Similar responses were found with equalized feeding except that a significant reduction in protein synthesis was found when dietary protein was increased from 200 to 400 g/kg diet.5. Less sensitive and almost parallel changes in protein degradation rates were found.6. It was concluded that adaptation to varied dietary protein intake occurred primarily through changes in protein synthesis, accompanied by parallel alterations in protein degradation in the whole body.

1. The influence of the gut microflora on fasting heat production in chicks was investigated.2. Single Comb White Leghorn chicks were fed on an adequate diet from 2 to 12 d of age and then fasted for 3 d. Fasting heat production was estimated from changes in body composition and energy content of droppings from days 1 to 3 of fasting. Measurements of body temperature and plasma thyroxine concentration were also made.3. Body fat content was consistently higher in germ-free (GF) chicks than in conventional (CV) counterparts during the starvation period, whereas no difference was found in body protein content. The GF birds had a significantly higher body temperature than the CV controls with no change in plasma thyroxine concentration.4. It was concluded that estimated fasting heat production of chicks was increased by the absence of the gut microflora.

1. A procedure for colostomising birds from 3 weeks to 5 months of age is described.2. A plastic cannula was inserted into the fistula 10 d after surgery to keep it open.3. Provided that the cannula was changed regularly at 10-d intervals there was no constipation or dilation of the intestine.

1. The influence of the gut microflora on protein synthesis in individual tissues and in the whole body of young chicks was investigated by the large-dose injection of [3H]phenylalanine. 2. Growth of germ-free chicks was significantly better than that of conventional controls. Wet weights of liver, spleen, duodenum, jejunum + ileum and caeca were heavier in conventional birds than in germ-free counterparts. 3. Fractional rates of protein synthesis were higher in jejunum + ileum and whole body of conventional birds than in those of germ-free birds. Amounts of protein synthesized were larger in liver, jejunum + ileum and caeca in the presence of the gut microflora. 4. When tissues were classified into gut + liver and the remainder of the carcass, in the presence of the gut microflora an enhanced protein synthesis in fractional and absolute rate was found in the gut + liver, which is in direct contact or in close association with micro-organisms, whereas virtually no effect of the gut micro-organisms was detected in the remainder of the carcass. 5. The contribution of protein synthesis of gut + liver to that of the whole body was larger in conventional chicks than in germ-free birds, whereas the reverse was true for the remainder of the carcass.

The influence of the cholecystokinin (CCK)-A receptor antagonist, devazepide (DVZ), on the chicken digestive tract was investigated. The passage of food from the crops of birds treated with DVZ was not significantly different from that of the control. DVZ treatment did not inhibit the biliary flow stimulated by the CCK analogue, caerulein. Dispersed chicken pancreatic acini stimulated with CCK were treated with various concentrations of DVZ. At 10−5M, DVZ completely inhibited amylase release; this concentration was much higher than those reported to have similar effects in mammals. The results suggest that the action DVZ as a CCK antagonist in the chicken is very weak.

The influence of the cholecystokinin (CCK)-A receptor antagonist, devazepide (DVZ), on the chicken digestive tract was investigated. The passage of food from the crops of birds treated with DVZ was not significantly different from that of the control. DVZ treatment did not inhibit the biliary flow stimulated by the CCK analogue, caerulein. Dispersed chicken pancreatic acini stimulated with CCK were treated with various concentrations of DVZ. At 10−5 M, DVZ completely inhibited amylase release; this concentration was much higher than those reported to have similar effects in mammals. The results suggest that the action DVZ as a CCK antagonist in the chicken is very weak.

1. The effects of dietary or parenteral administration of ascorbic acid on the adverse effects of excess dietary tyrosine were investigated with young male White Leghorn chicks in a 2-week experiment.2. Addition of 10 g ascorbic acid/kg to the control diet (without excess tyrosine) produced no beneficial effects on performance. Excess dietary tyrosine caused depressions in all measures of performance.3. Adding 0.1, 1, 10 or 20 g ascorbic acid/kg to the diet containing excess tyrosine tended to improve performance.4. Subcutaneous injection of 50 mg ascorbic acid/bird d to chicks receiving excess tyrosine brought about a significant improvement in body-weight gain.5. The elevation of plasma free tyrosine caused by excess dietary tyrosine decreased as dietary ascorbic acid increased.6. Ascorbic acid can alleviate, though not completely counteract, the adverse effect of excess dietary tyrosine.

Abstract1. The effects of graded dietary concentrations of cholestyramine (CSTY, a bile acid binding polymer), which prevents micelle formation and bile acid reabsorption, on the lipid and energy metabolism of chicks given diets containing different dietary concentrations of medium chain triacylglycerol (MCT) and long chain triacylglycerol (LCT) were investigated.2. MCT‐ or LCT‐supplemented diets containing 100 or 200 g oil/kg diet and 0, 10 or 20 g CSTY kg were fed to 7 d old chicks for 10 d. As dietary CSTY concentration increased, a reduction in the metabolisable energy value was observed for both dietary lipid sources. Consequently, fat and energy retentions were also reduced as the dietary CSTY content increased.

To find out whether physiological concentrations of cholecystokinin (CCK), a gastrointestinal hormone in mammals, are also active in chickens, the pancreatic amylase secretory response to CCK-8 was investigated in vitro. Rat pancreatic acini responded to the physiological concentration of CCK-8, but in chickens amylase release was induced at a concentration of CCK-8 1000 times higher than that observed in rats. In another experiment, biliary flow was tested with several doses of CCK-8. The bile flow was stimulated in a dose-dependent fashion, but a significant enhancement was not obtained at a concentration of 0.5 μg CCK-8/kg body weight, which was considerably higher than physiological ones. It is concluded that endogeneous CCK does not have an important role in the digestive system in the chicken.

The present study was done to investigate the factors regulating the intestinal phase of exocrine pancreatic secretion in the turkey. The intestine of turkeys equipped with pancreatic fistulas was perfused with peptone solution, fat emulsion and hydrochloric acid (HCl), and pancreatic flow and protein output were measured. Neither peptone solution nor fat emulsion had any effects on pancreatic secretion. HCl enhanced the flow rate of pancreatic juice but not protein output. To clarify the neural mechanism of this phenomenon, the vagal postganglionic blocker atropine was continuously infused and pancreatic secretion in response to intestinal HCl was measured. Atropine completely suppressed both pancreatic flow and protein output. It is suggested that the avian intestinal phase of pancreatic secretion is mainly controlled by cholinergic action though HCl stimulation.

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