Enhanced release of cholecystokinin by dietary amino acids in chicks (Gallus domesticus)

1. The effect of dietary amino acids and protein on cholecystokinin (CCK) release into plasma was investigated in chicks by feeding a meal through a stomach tube, followed by the CCK determination with specific CCK-8 antibody. 2. The results showed that both isolated soya protein and an amino acid mixture simulating the amino acid composition of the soya protein increased the release of CCK, though to a lesser extent with a delayed response in the former, when added to a protein-free diet. 3. Among amino acids added singly to the protein-free diet, phenylalanine was more efficient than arginine and valine, exerting a response almost identical to the complete amino acid mixture.     

Interaction of lead toxicity and riboflavin status in chicks (Gallus domesticus)

Chicks (Gallus domesticus) were fed diets containing 0 or 2000 ppm lead (Pb) and adequate, marginal or deficient levels of riboflavin. In comparison to adequate, marginal riboflavin depressed growth at 2000 ppm Pb but not at 0 ppm Pb. Deficient riboflavin depressed growth at both Pb levels, and Pb depressed growth at all riboflavin levels. Hepatic glutathione reductase activity was reduced by riboflavin deficiency, but Pb was without effect. Hepatic non-protein sulfhydryl concentrations were increased by Pb, and the increases were greater at the lower riboflavin levels. Dietary Pb appears to increase the level of riboflavin required in chick diets.     

Responses of the pancreatic digestive enzyme secretion to various combinations of amino acids and cholecystokinin in chicks (Gallus domesticus)

1. Effect of amino acid administration on pancreatic secretion of digestive enzymes, amylase, trypsinogen and chymotrypsinogen was studied after wing vein injection of an amino acid (AAs) mixture (Thr, Lys, Phe, Leu, Ile, Glu, Val, His, and Met) or combinations of selected amino acids, i.e. Thr + Phe + Ile, Thr + Phe, Thr + Ile or Phe + Ile, in the presence of cholecystokinin (CCK) in chicks. 2. Time course changes of enzyme output were similar in all treatment groups having a peak within 10-30 min, except for Phe + Ile that resulted in delayed induction of the enzyme release as shown by significant increases in the last 20 min compared with those in the rest. 3. When increases in enzyme outputs for the first 30 min were compared, it was shown that the three enzyme responses brought about by the administration of the AAs mixture was almost entirely accounted for by the combined injection of Thr + Phe. 4. Neither Thr + Ile nor Phe + Ile was as effective as Thr + Phe in inducing the output of these pancreatic enzymes. 5. The present results suggest that Thr and Phe may have a specific regulatory role in the secretion of pancreatic digestive enzymes in chicks when administered simultaneously.     

Effect of dietary protein and fat content on tri-iodothyronine-induced thermogenesis in young chicks (Gallus domesticus)

1. The effect of dietary protein and fat content on tri-iodothyronine (T3) induced thermogenesis was studied in young chicks (Gallus domesticus). 2. Irrespective of dietary protein and fat contents employed, energy and fat retained were consistently decreased and heat production was increased, but protein retained was not affected by the T3 administration throughout the experiments. 3. Little or no effect of dietary protein and fat contents on T3-induced thermogenesis was observed. 4. Increased heat production by the T3 administration was primarily brought about by a reduction in retained fat which served as fuel to give rise to extraneous heat.     

Implication of iron in seizure syndrome of mutant chicks (Gallus domesticus)

1. An investigation was made of systemic iron in paroxysmal (px) chicks. 2. Serum transferrin levels in px chicks are greatly increased (P less than 0.05) over control levels, but iron-binding capacity is decreased (P less than 0.05). 3. The delayed (by 10 days) increase in px hemoglobin (P less than 0.01) may be due to the general debilitation seen in px syndrome. 4. An attempt to determine brain iron showed no deposits comparable to mammalian brain iron distribution, but this was consistent with inability of others to locate iron in adult chicken brain tissue.     

Responses of domestic chicks (Gallus gallus domesticus) to multimodal aposematic signals

Many aposematic prey combine their visual warning signals withadditional signals. Together, these signals constitute a multimodalor multicomponent warning display. The additional signals arethought to increase the effects of the visual signals on predators.Olfactory signals are much emphasized, but later studies haveshown that also auditory signals like the buzzing of certaininsects might have multimodal effects. The wasp displays typicalvisual aposematic signals, black and yellow stripes, but doesalso emit a characteristic buzzing. We wanted to test if, andin what way, the visual and acoustic display of the wasp hasan aversive function on the predators. We therefore conducteda 12-trial discrimination-learning task on inexperienced chicksto study whether there are innate biases toward these signalsand how they affect the speed of avoidance learning. We alsoperformed three extinction-learning trials to study how memorablethe signals were to the chicks. We show that the visual signalsin the display of the wasp contribute to the protection frompredators but in different ways; the yellow color had an aversiveeffect on inexperienced predators, while the striped patternimproved the aversion learning. The sound did not enhance theinnate aversions but increased the aversion learning of stripesin green prey.     

Ultrastructure of the subfornical organ of the chicken (Gallus domesticus)

Summary The SFO of the chicken is divided in half by a large central blood sinus; ventrally it is covered by a thin layer of ependyma (including tanycytes, dendrites, and axons) which connects the two lateral halves and protrudes as a midsagittal crest into the lumen of the third ventricle. The ependyma consists predominantly of tanycytes with long basal processes which terminate upon perivascular spaces. These cells have an extensive Golgi apparatus and abundant lysosomes; their cellular apices containing polyribosomes and a few vesicles frequently protrude into the ventricle. In addition to astrocytes, oligodendrocytes, and microglial cells, there is another glial cell population that is distinguished by the presence of parallel stacks or spherical to ovoid conglomerates of rough ER and their unique location, i.e., limited to areas ventral and ventral-lateral to the large blood sinus. Two types of neurons are present: neurons in which there is a paucity of granulated vesicles and occasional vacuoles in both the cytoplasm and nuclei, the second type of neuron elaborates many granulated vesicles. Numerous puncta adhaerentia are observed between adjacent neuronal perikarya and between glial processes and neuronal perikarya.Diverse axon types are found within the chicken SFO. Axo-dendritic and axo-somatic axon terminals and presynaptic axon dilations contain assorted combinations of electron-lucent and granulated vesicles of different maximal diameters. Based on the morphology of these axons, cholinergic, peptidergic, and serotoninergic fibers are described. There are two additional groups of axons whose classification awaits further investigation.The chicken SFO differs from the mammalian SFO in several respects: it possesses an ependyma with secretory and/or absorptive tanycytes predominating; it is divided midsagittally by a central blood sinus; its lateral and dorsal limits are nebulous; a previously undescribed peculiar type of glial cell is found in a limited portion of the organ; supraependymal neurons are lacking.Dedicated to Prof. H. Grau at the occasion of his 80th birthdayWe gratefully acknowledge the technical help of Susan Woroch and secretarial assistance of Diana Hapes and Debbie Harrison     

Plasma lipoprotein profiles in broiler chicks (Gallus domesticus): effects of early overfeeding

1. Twenty-eight day old broiler chicks gavage fed for 22 days consumed 40% more feed and gained 100-110 g more than control birds. 2. Normal feeding resumed on day 41, by day 63 feed intakes and body weights of overfed and control birds were equal. 3. Moderate differences in lipid compositions of LDL and VLDL were observed at 41 and 50 but not at 63 days. 4. In contrast to mammals where early over feeding predisposes to adult obesity, lipoprotein profiles and ad lib feeding patterns of chicks are not readily altered by dietary measures.     

Ultradian activity rhythms in large groups of newly hatched chicks (Gallus gallus domesticus)

A clutch of young chicks housed with a mother hen exhibit ultradian (within day) rhythms of activity corresponding to the brooding cycle of the hen. In the present study clear evidence was found of ultradian activity rhythms in newly hatched domestic chicks housed in groups larger than natural clutch size without a mother hen or any other obvious external time-keeper. No consistent synchrony was found between groups housed in different pens within the same room. The ultradian rhythms disappeared with time and little evidence of group rhythmicity remained by the third night. This disappearance over time suggests that the presence of a mother hen may be pivotal for the long-term maintenance of these rhythms. The ultradian rhythm of the chicks may also play an important role in the initiation of brooding cycles during the behavioural transition of the mother hen from incubation to brooding. Computer simulations of individual activity rhythms were found to reproduce the observations made on a group basis. This was achievable even when individual chick rhythms were modelled as independent of each other, thus no assumptions of social facilitation are necessary to obtain ultradian activity rhythms on a group level.     

The distribution of lice (Phthiraptera) on poultry (Gallus domesticus)

The distribution of three amblyceran (Menacanthus stramineus, Menacanthus cornutus, Menopon gallinae) and five ischnoceran species (Lipeurus lawrensis tropicalis, Lipeurus caponis. Goniocotes gallinae, Goniodes gigas, Goniodes dissimilis) on poultry was determined. The preferred sites of these species on the host body were recorded.     

Tissue glycogen and lactate levels in starved and in protein-fed domestic fowl chicks (Gallus domesticus)

The levels of glycogen, protein and lactate in the tissues of 3- and 5-day-old domestic fowl chicks either starved or fed a protein diet (hard-boiled egg white) have been studied. The patterns of change in the parameters studied were much similar in both experimental groups compared to fed controls. Tissue and circulating levels of lactate were very low in protein-fed chicks, they are lowest in the starved ones. Plasma glucose levels were diminished in starved and protein-fed groups vs. controls, as were their tissue glycogen levels, the latter being lowest in starved chicks. The availability of dietary amino acids could not prevent the effects of the lack of dietary carbohydrate observed in starved chicks, as the weight of liver, circulating glucose and lactate levels were significantly lowered in these animals compared with controls.     

Effect of phenylalanine on pancreatic amylase secretion in chicks (Gallus domesticus).

1. Effect of phenylalanine (Phe) on pancreatic amylase secretion in growing chicks was investigated in four experiments. 2. In Experiment 1, birds were injected through a wing vein with 0.25 ml Phe at 0, 0.1, 0.5, 2.5 and 12.5 mM in physiological saline. No significant difference was observed in amylase secretion among treatments. 3. Effect of various concentrations of Phe with cholecystokinin (CCK, 0.31 Crick unit) on amylase secretion was investigated in Experiment 2. Amylase secretion increased with time, although no significant effect was detected in Phe treatment. 4. Efficacy of Phe and tyrosine (Tyr) injection with CCK on amylase secretion was compared. There was no significant difference between Phe and Tyr treatments. 5. Birds were injected intraperitoneally with dl-p-chlorophenylalanine (p-CP), which is an inhibitor of phenylalanine hydroxylase, or saline 1 day before the collection of pancreatic amylase in Experiment 4. Both chicks showed increased amylase secretion with CCK (0.31 Crick unit), whereas the response was at a drastically reduced rate in chicks with the p-CP treatment.     

Effect of Escherichia coli infection on growth and protein metabolism in broiler chicks (Gallus domesticus)

1. A controlled experimental Escherichia coli infection was developed in broiler chicks. 2. Infection with E. coli significantly reduced feed intake, altered growth of the whole body, eviscerated carcass, skeletal muscles, heart and liver. Organ weight and/or the proportions of organs within the body were affected. 3. Protein accumulation in the eviscerated carcass, extensor digitorum communis and sartorius muscles was severely inhibited by infection, and to a greater extent than body weight. 4. Failure of muscle tissue to accumulate protein was associated with a significant decline in protein synthesis, when measured in vitro (-48%; P less than 0.05) and in vivo (-42%; P less than 0.001). Protein degradation also declined (-28.7%), but to a smaller extent than protein synthesis. 5. Although the infected chicks showed no viable bacteria at day 12 after infection, chicks did not reach the same body weight as controls by day 30 after infection.     

Dexamethasone facilitates lipid accumulation and mild feed restriction improves fatty acids oxidation in skeletal muscle of broiler chicks (Gallus gallus domesticus)

Effects of dexamethasone (DEX) and mild feed restriction on the uptake and utilization of fatty acids in skeletal muscle of broiler chicks (Gallus gallus domesticus) were investigated. Male Arbor Acres chicks (7-days old, n = 30) were injected with DEX or saline for 3 days, and a feed restriction group was included. DEX enhanced circulating very low density lipoprotein (VLDL) level and the lipid accumulation in both adipose and skeletal muscle tissues. Compared with the control, liver-carnitine palmitoyltransferase 1 (L-CPT1) and AMP-activated protein kinase (AMPK) α2 mRNA level of M. biceps femoris (BF) were down-regulated significantly by DEX, while mRNA expression of lipoprotein lipase (LPL), fatty acid transport protein 1 (FATP1), heart-fatty acid binding protein (H-FABP), long-chain acyl-CoA dehydrogenase (LCAD), activities of LPL and AMPK in both skeletal muscles were not obviously affected. Feed restriction increased the mRNA expression of LPL, L-CPT1 and LCAD of M. pectoralis major (PM), and FATP1, H-FABP, L-CPT1 and LCAD of BF. In conclusion, DEX retards the growth of body mass but facilitates lipid accumulation in both adipose and skeletal muscle tissues. In contrast to the favorable effect of mild feed restriction, DEX did not alter the uptake of fatty acids in the skeletal muscle. The result suggests that DEX may promote intramyocellular lipid accumulation by suppressed fatty acid oxidation while mild feed restriction improved fatty acid oxidation in skeletal muscle, especially in red muscle. Glucocorticoids (GCs) regulated muscle fatty acid metabolism in a different way from energy deficit caused by mild feed restriction.     

Development of responsiveness to the individual maternal “clucking” by domestic chicks (Gallus gallus domesticus)

Sixty-nine chicks, brooded by hens, were given the choice of approaching the clucking sound of the familiar hen or another clucking source. The effects of age and prenatal experience of clucking on the responsiveness to their hen's clucking were also investigated. Eighty-three percent of all chicks tested chose the familiar hen clucking after a certain age. By 4 days of age, 29% of artificially incubated chicks approached the clucking of a familiar hen. Seventy-four percent of naturally incubated chicks and 89% of chicks artificially incubated until pipping and then naturally incubated, showed this discrimination. This corresponds well to the natural situation, in which the hen remains in the nest with the chicks for up to 3 days after hatching. The results also indicate that late prenatal experience of the maternal call is of importance for the later responsiveness to this call.     

The ultrastructure of the paratympanic organ (Vitali) in Gallus domesticus: preliminary studies

The sensory epithelium of the paratypanic organ (Vitali) was studied by means of the electron microscope. Two kinds of cells are present. One type extends from the basement membrane to the surface of the epithelium; their nuclei are arranged close to the connective tissue and are surrounded by a pale cytoplasm. The distal part of these cells, which are denser and richer in organelles, possess microvilli. The cells of the second type are located above the basement membrane and are found between the upper parts of the cells of the first type. Their cytoplasm is rich in small round vesicles, free ribosomes and cisternae of rough endoplasmic reticulum are present especially in the infranuclear zone. The apical part contains a Golgi apparatus lysosomes and multive sicular bodies. At the apex each cell possesses a cuticular plate numerous stereocilia and one kinocilium. The stereocilia become increasingly longer from one side of the cell surface to the other and the kinocilium is situated on the side where the stereocilia are longest. Nervous fibers are present in the epithelium and are in close contact with the cells of the second type. The cells we have described are remarkably similar to the supporting and hair cells of the vestibular sensory epithelium.