Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FOWLS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46Linked to original sources
PubMed2000

Active spermiophagy in the initial part of the proximal efferent duct of the epididymis of normal domestic fowl (Gallus domesticus).

In a study of the absorptive activities of the excurrent ducts of the testis of birds, six adult cocks of the Ovambo breed of domestic fowl were deeply anaesthetised and intravascularly perfused with buffered 3 per cent glutaraldehyde. Epididymal tissue was prepared conventionally for electron microscopy. In favourable sections in three of these birds avid ingestion of spermatozoa was revealed in the non-ciliated (Type I) cells of the epithelial lining of the initial part of the proximal efferent duct, at and a little beyond its junction with the rete testis. No obvious defects were detected in luminal spermatozoa. The testicular excurrent ducts were neither distended nor obstructed, and mononuclear cell mobilisation was absent in both the ductal and periductal tissue. The significance of this observation with regard to the specific segment of the efferent duct system involved and how certain spermatozoa are identified for elimination from the duct lumen, must await precise studies.

Animals↗
PubMed2001

Effects of anti-inflammatory steroid drugs on pain coping behaviours in a model of articular pain in the domestic fowl.

The optimum dose rates of betamethasone, dexamethasone (sodium phosphate) and methylprednisolone (acetate salt) were determined for the treatment of inflammatory pain in domestic fowl using the microcrystalline sodium urate model of articular pain. The response criteria were the changes in behavioural profiles and pain-related activity over 60 minutes commencing 1 hour after an intra-articular injection of sodium urate and a course of intramuscular injections of a range of doses of each drug on the previous 2 days. The optimum dose rates for betamethasone, dexamethasone and methylprednisolone respectively were 0.04, 0.06 and 2 mg kg(-1)and are in the range of the recommended doses for these drugs in mammals.

Animals↗
PubMed1969

Organ-specific estrogen-induced RNA synthesis resolved by DNA-RNA hybridization in the domestic fowl.

In the domestic fowl and other oviparous vertebrates, estrogens induce hepatic synthesis of yolk proteins. The oviduct also increases in size and produces ovalbumin when estrogens are administered. DNA-RNA hybridization assays indicate that within 105 minutes following treatment with estrone the liver of immature pullets contains most, if not all, of the liver RNA species that are present in the livers of the laying hen. Because of limitations of the nucleic acid hybridization technique, which remain to be clearly defined, it is not known whether the hepatic RNA populations in estrone-treated pullets and laying hens are completely homologous or differ in some important way. The results indicate that the genomic response in the avian liver to exogenous estrone is "normal" (relative to the laying hen) and further suggest that the hepatic response to estrogen is primarily pertinent to vitellinogenesis.DNA-RNA hybridization assays on total RNA also indicate that estrogen-induced RNA species in the liver are not homologous to estrogen-evoked RNA species of the oviduct. Therefore, in these two target organs estrogen-evoked RNA synthesis appears to be in part organ-specific. These data indicate that the specificity of hormone action can be explained in part on the basis of induced synthesis of specific RNA molecules. Whether these alterations in transcription are due to indirect hormonal action or are the result of a primary action of estrogens or estrogen-binding site complexes on the genome and/or its repressors remains a basic question.

Animals↗
PubMed1995

Crystal structure of a cross-reaction complex between Fab F9.13.7 and guinea fowl lysozyme.

The crystal structure of the complex between the cross-reacting antigen Guinea fowl lysozyme and the Fab from monoclonal antibody F9.13.7, raised against hen egg lysozyme, has been determined by x-ray diffraction to 3-A resolution. The antibody interacts with exposed residues of an alpha-helix and surrounding loops adjacent to the lysozyme active site cleft. The epitope of lysozyme bound by antibody F9.13.7 overlaps almost completely with that bound by antibody HyHEL10; the same 12 residues of the antigen interact with the two antibodies. The antibodies, however, have different combining sites with no sequence homology at any of their complementarity-determining regions and show a dissimilar pattern of cross-reactivity with heterologous antigens. Side chain mobility of epitope residues contributes to confer steric and electrostatic complementarity to differently shaped combining sites, allowing functional mimicry to occur. The capacity of two antibodies that have different fine specificities to bind the same area of the antigen emphasizes the operational character of the definition of an antigenic determinant. This example demonstrates that degenerate binding of the same structural motif does not require the existence of sequence homology or other chemical similarities between the different binding sites.

Amino Acid Sequence↗
PubMed1992

Gastrointestinal morphology and absorption of monosaccharides in fowls conditioned to different types and levels of dietary fibre.

To test a possible influence of dietary fibre on intestinal sugar uptake, rates of absorption of 10 mM-D-[U-14C] glucose and 10 mM-D-[U-14C] xylose were measured in either jejunum or (distal) caecum, by in vivo lumen perfusion, in immature female fowls preconditioned to a standard diet containing (g/kg) either 0, 100, 200 or 400 added dried grass, 200 powdered cellulose, or 200 grass with a polysaccharidase enzyme supplement. When birds were killed after perfusion, dimensions of (unperfused) parts of their alimentary tracts were determined, and recoveries of 14C radioactivity in some body tissues were compared with measured activities absorbed. On average, absorption of glucose was 1.9 and 1.2 times faster than xylose in jejunum and caecum respectively, although these differences varied with dietary treatment and order of perfusion. Increasing grass in the diet caused significant changes in xylose absorption rate in both jejunum and caecum, but only when it was perfused before glucose. With any one sugar and intestinal segment, mean rates of absorption were correlated positively with corresponding mean rates of fluid loss from perfusate. Although their influence on sugar absorption was not well defined, the dietary fibre treatments had more pronounced effects on gross dimensions of parts of the alimentary tract and, hence, potentially on total rates of absorption. Compared with the basal diet, addition of 100, 200 or 400 g grass/kg or 200 g cellulose/kg caused significant increases in small intestine length while 200 g grass/kg with supplementary enzyme did not, and combined caecal length increased with the 400 g grass/kg and the supplementary enzyme treatments. Absorbed 14C activity was recovered in plasma after jejunal perfusions but not caecal ones, whereas it was recovered in liver and in the flushed perfused segment after both types of perfusion. Since there was overlap in absorption rates between jejunum and caecum, this result suggests that the liver may be able to distinguish and treat differently compounds absorbed in the two regions.

Animals↗
PubMed1992

Metabolic fates of U-14C-labelled monosaccharides and an enzyme-treated cell-wall substrate in the fowl.

A major benefit of supplementing non-ruminant feedstuffs with exogenous enzymes is presumed to be the degradation of plant cell-wall polysaccharides to metabolizable monosaccharide residues. In the present study, metabolic fates of (U-14C-labelled, 10 mM) glucose, galactose, mannose, xylose and arabinose were compared in the fowl, by measuring recoveries of 14C radioactivity in exhaled carbon dioxide excreta and body tissues after administration either by wing vein (iv) or into the crop (ic). A further comparison was made with a tube-fed, enzyme-treated, U-14C-labelled cell-wall substrate, Festuca arundinacea, and a final experiment tested possible competition for absorption between different cell-wall residues. Delays between iv and ic treatments in recovery of 14C in CO2, which were assumed to reflect intestinal absorption, indicated that xylose was absorbed more slowly than glucose and galactose, but faster than mannose and arabinose. Total recoveries of 14C in CO2 and excreta over the whole test period indicated that metabolizabilities were highest with glucose, galactose and mannose, and lowest with arabinose. After testing, 14C recovery in caecal contents was highest with ic arabinose, and recoveries in body tissues, with all sugar treatments, were in the order liver greater than breast and leg muscle greater than abdominal fat greater than plasma. Results with the Festuca substrate showed similar patterns of recovery in body tissues and confirmed an increase in metabolizability with addition of enzyme. The timing of the 14CO2 response with Festuca and a wet enzyme pretreatment was broadly similar to a 'predicted Festuca' response, based on the composition of the substrate and the measured responses with individual (ic) monosaccharides. There was no evidence of any competition for absorption or metabolism among cell-wall residues. It was concluded that glucose release from cellulose is potentially the most important product of cell-wall degradation to contribute to enzyme enhancement of metabolizable energy.

Animals↗
PubMed1992

Energy and nitrogen intake, expenditure and retention at 32 degrees in growing fowl given diets with a wide range of energy and protein contents.

Heat production (HP) and the intake and retention of energy and nitrogen were measured in growing broiler fowl kept at 32 degrees and given diets with metabolizable energy contents from 8 to 15 MJ/kg and crude protein (N x 6.25; CP) contents of 130 and 210 g/kg. The temperature of 32 degrees was chosen for comparison with earlier measurements at 20 degrees to minimize heat produced for the maintenance of body temperature. The effects of diet composition were observed when the same birds were taken from 20 to 32 degrees. The tendency for energy intake to increase with dietary energy concentration was less at 32 than at 20 degrees. The lower heat increments measured for the high-fat diets did not, therefore, confer an increased ability to sustain higher energy intake at 32 degrees. HP was about 17% lower at 32 than at 20 degrees; the change in HP between 20 and 32 degrees was not significantly influenced by diet composition. The absence of significant effects of diet composition on HP, combined with the significant trend in energy intake, produced significant differences (related both to dietary energy and dietary protein concentrations) in total energy retention and in the partition of retained energy between protein and fat. As at 20 degrees, variation in energy retention and in the composition of retained energy were the main responses to variation in dietary CP concentration and energy intake; a significantly higher energy cost of unit protein accretion on the low-CP diets was insufficient to produce an elevation in total HP because the higher unit energy cost was balanced by a lower absolute rate of protein accretion.

Animal Nutritional Physiological Phenomena↗
PubMed2004

Responses of domestic fowl to excess iodine: a review.

Typically, poultry diets contain 1-2 mg I/kg, but higher concentrations are sometimes used to enhance the I content of eggs. In addition to an increased deposition of I in the yolk, other often adverse responses occur, especially at exceptionally high concentrations. Excess I in grower diets can prevent sexual maturation in male and female fowl, and in layer diets will progressively reduce egg production until, by about 2500 mg I/kg diet, ovulation is inhibited and egg production ceases. Most I accumulates in the thyroid gland, and it is likely that the mechanism responsible for these reproductive disorders involves a modification of thyroid hormone activity. Simultaneous with the declining rate of lay, feed intake declines, egg weight and yolk-cholesterol contents decrease and body weight increases. Whereas fertility is unaffected in female breeders, hatch of fertile eggs is reduced, hatch time extended and embryonic mortality and dead-in-shell proportions increased. In contrast, male fertility is decreased because of an increased incidence of dead spermatozoa, although hatchability of eggs from normally fed hens is unaffected. All reproductive variables, together with feed intake and body weight, are normalised within about 7 d of returning to a diet with normal I levels. Excess I suppresses growth in meat-type chickens, but does not affect feed conversion efficiency. There are transient increases in plasma I and cholesterol concentration during excess I intake in all types of bird. The evidence for varying responses to different I sources is equivocal, but the consensus is that source is probably not important.

Animal Feed↗
PubMed2001

Discrimination between individual humans by domestic fowl (Gallus gallus domesticus).

1. We demonstrate that Barred-Rock and Isa-Brown hens can discriminate between the presence of 2 different humans and use this information as a cue for whether or not to make an operant response. 2. This demonstration in domestic fowl, the first of its kind in any avian subject, is consistent with a growing body of evidence that many species, including agricultural animals, are surprisingly adept at differentiating between humans. 3. Such a discriminative ability carries considerable implications for issues related to husbandry, production and welfare.

Animal Husbandry↗
PubMed2003

Genetic variation for egg production, egg quality and bone strength in selected and traditional breeds of laying fowl.

1. A multi-breed experiment was conducted with 25 commercial and traditional lines of laying fowl to determine the extent of between-breed genetic variation for adult body weight, sexual maturity, rate of lay, egg weight and egg composition to 55 weeks of age. The genetic variability for bone strength and eggshell strength was determined at 55 weeks of age and a comparison of commercially selected and traditional breeds was performed. 2. The proportion of the total variation that was associated with breed or line of origin was high (> 0.8) for body weight, sexual maturity and shell colour; moderately high (0.4 to 0.7) for rate of lay, early and late egg weight, weights of egg yolk, albumen and shell at 55 weeks; and low (< 0.4) for egg weight at 42 to 45 weeks, albumen quality and the number of egg inclusions. 3. There were no detectable differences between breed within category (traditional and commercial lines) for rate of lay, and estimates of breed variation for egg weight and egg components were substantially decreased within category compared with the overall analysis. 4. Commercial lines displayed earlier sexual maturity, greater rates and persistency of lay, and higher egg weights at earlier (32 to 35 weeks) and later (52 to 55 weeks) ages. At 55 weeks, the larger eggs from commercial birds contained more albumen of higher quality and paler yolks of similar weight to those from traditional breeds. The relative weight of the eggshell was similar in both categories. 5. There was considerable genetic variation between commercial lines for bone density and a moderate proportion of genetic variability for bone strength. Commercial lines had very weak bones compared with traditional lines but there was relatively little genetic variation for eggshell strength. The results suggest that eggshell quality is maintained in genetically selected lines at the expense of bone strength and bone radiographic density.

Animals↗
PubMed2004

Immunohistochemical demonstration of myoid cells in the testis and its excurrent ducts in the domestic fowl.

(1) Immunohistochemical methods and three antibodies (against actin, desmin and smooth muscle actin) were used to demonstrate the myoid cells in the domestic fowl testis and its excurrent ducts. (2) A positive reaction to actin, smooth muscle actin and desmin was found in the myoid cells of peritubular tissue of the testis and in rete testis, ductuli efferentes and ductus epididymidis. (3) In the testis myoid-reactive cells form a single layer. In the rete testis, ductuli efferentes and the ductus epididymidis reactive myoid cells form a main component of the stroma. (4) Positive reaction to actin, smooth muscle actin and desmin was also observed in the myoid cells of the tunica albuginea and in the wall of blood vessels in the testis and epididymis, indicating a contractile function for the testicular capsule.

Actins↗
PubMed1975

Obesity induced by force-feeding and accompanying changes in body temperature and fertility in the male domestic fowl.

1. Excessive amounts of food (two-fold more than the ad libitum intake) introduced into the gastro-intestinal tract of three adult male fowls, for 5 weeks, caused a marked increase in body weight resulting mainly from fat deposition. 2. The induced obesity was accompanied by an increase of the rectal temperature (0-2 to 0-3 degrees C) and a decrease of the skin and comb temperatures, a cessation in the growth of the comb, a reduction in the blood packed cell volume, an eight-fold reduction in the number of spermatozoa in the vasa deferentia and a concomitant depression in their motility. 3. A decrease of the testosterone and an increase of luteinising hormone concentrations in the blood plasma was obtained in two of the three treated birds.

Animal Feed↗
PubMed1977

Biochemical, physiological and production indices related to fat metabolism in the laying fowl at various stages of physiological development.

The significance of fat accumulation during physiological development of layers was studied using White Leghorn X Australorp pullets from 12 weeks of age. 2. Liver fat, carcass fat, liver weight and body weight increased markedly at the onset of sexual maturity. 3. Within the liver, the protein to DNA ratio did not alter significantly during development; glycogen was not consistently depleted by egg production. 4. Liver fat content was significantly correlated with carcass fat, liver weight and DNA concentration, and plasma total lipid and cholesterol, independent of stage of development; with body weight, liver protein, moisture, and protein to DNA ratio, excluding the period prior to commencement of sexual maturation; and with plasma phospholipid during lay. 5. Obesity was a feature of faster growing fowls which matured earlier, consumed more, utilised food less efficiently for egg production and produced fewer saleable eggs.

Adipose Tissue↗
PubMed1978

Preservation of fowl semen in liquid nitrogen--an improved method.

1. An improved method of storing fowl semen in liquid nitrogen is described. It uses glycerol as a cryopotectant and the degree of fertility obtained with semen stored for up to 2 1/4 years was very promising. 2. The essential features of the method are a slow freezing rate, a reduction of temperature to - 35 degrees C before the semen is plunged into liquid nitrogen and insemination within 15 min of thawing and removing the glycerol from the diluent. 3. It seems likely that further improvements in the technique may be expected through better control of the injection of liquid nitrogen into the freezing chamber, thereby minimising localised, rapid temperature changes around the ampoules during freezing. 4. Preliminary results suggest that it may prove possible to select males for the ability of their spermatozoa to withstand freezing. 5. The importance of recognising differences between males in the initial quality of semen and between females in the physiology of the reproductive organs in determining the fertilising ability of stored semen is discussed.

Animals↗
PubMed1978

The relative importance of sunrise and sunset for entrainment of oviposition in the fowl.

1. A series of four "sunset" signals, without associated sunrises, was given to laying hens by reducing light intensity in steps from 190 lx to 63, 21, 7 and 2 lx at 24-h intervals. Four "sunrises" were given by reversing the process. Treatments involving single "sunrises", single "sunsets" and combinations of sunrises and sunsets at 12-h intervals were also tested. 2. Only treatments which included one or more sunset signals were found to give full entrainment of oviposition, as judged by the proportion of eggs laid in a modal 8-h segment of each 24-h cycle. Full entrainment was achieved if the sunset occurred between 16.00 h and midnight, but not if the sunset occurred in the morning hours. Treatments involving only sunrise signals did not fully entrain oviposition but did have effect on the timing and distribution of ovipositions. Sunrises given in association with sunsets increased the degree of entrainment achieved, as compared with the sunset signal alone. 3. This study indicates that sunset is a potent synchronising agent for phase setting oviposition and, presumably, for phase setting the endogenous circadian rhythm of the fowl. Sunrise can also exert a modifying influence.

Animals↗
PubMed1979

The localisation of beta-N-acetyl-glucosaminidase in the oviduct of the domestic fowl.

1. Beta-N-acetylglucosaminidase [EC 3.2.1.30] activity in the oviduct of the domestic fowl has been studied using biochemical and histochemical methods. 2. The principal source of the enzyme was the isthmus, where the enzyme was localised within the less dense region of the dual density granules which characterise this portion of the oviduct.

Acetylglucosaminidase↗