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The effect of environmental temperature on potassium concentrations in the blood of the domestic fowl.

The effects of environmental temperature on the blood potassium concentration of chickens of different ages were studied. The mean environmental temperatures used were 8 degrees, 19 degrees and 30 degrees C. There were no statistically significant differences in blood potassium concentration between age groups within a given temperature. Birds acclimated to an environmental temperature of 30 degrees C., had a lower mean blood potassium concentration than birds acclimated to an environmental temperature of 8 degrees C. There was no significant difference between the birds at 19 degrees C. and the other groups. Birds transferred from the 8 degrees to the 30 degrees C. environmental temperature showed a significant decrease in whole blood potassium concentrations as early as six hr. following transfer. In birds transferred from the 30 degrees to the 8 degrees C. environmental temperature, the blood potassium concentrations before and after transfer did not differ significantly. The results of this study indicate that blood potassium concentrations change with acclimation by the domestic fowl.

Acclimatization↗

Histophysiological studies on the postovulatory follicles of the fowl ovary.

A histochemical study has been made of the postovulatory follicles of fowl (Gallus domesticus) during their various stages of development and degeneration. The lumen of postovulatory follicle shows granulosa cells at their initial formative stages and both thecal and stromal cells at the later regressive stages. The granulosa and thecal cells develop diffuse lipoproteins, cholesterol-positive lipids and various enzyme activities (delta5-3beta-HSDH, NAD-NADP-diaphorases and alkaline phosphatase), which are indicative of steroidogenesis.

Animals↗

Preliminary observations on northern fowl mite infestations on estrogenized roosters and in relation to initial egg production in hens.

Treatment of normal male Leghorn chickens with doses of estradiol ranging from .1 to 1.0 mg per week caused only a slight increase in resistance to infestation with northern fowl mites. The resistance phenomenon did not increase linearly with estradiol dose. Pullets were initially resistant to mite infestation; however, susceptibility was noted to increase markedly near the time of initial egg-production. These data indicate that sex hormones may be related to mite resistance in chickens, but that estrogen alone is probably not responsible for the difference in mite susceptibility between male and female birds.

Animals↗

Effects of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on fertility and hatchability of eggs from artificially inseminated White Leghorn hens.

Egg production of White Leghorn hens infested with the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), was as much as 15% lower than egg production of control hens. However, when these hens were artificially inseminated with semen from mite infested roosters, fertility nor hatchability was affected by the mite infestation.

Animals↗

The effect of sodium pentobarbital on the fertility of fowl spermatozoa.

The effect of three levels of sodium pentobarbital in modified glycine-citrate extender on the preservation of the fertilizing capacity of fowl spermatozoa was tested. Extended semen samples were stored for 24 and 48 hr at 2 C before insemination. Insemination with semen stored for 24 hr in the extender containing 120 mg of sodium pentobarbital provided the best results (73.9%).

Animals↗

The effects of the northern fowl mite, Ornithonyssus sylivarium on egg production and body weight of caged White Leghorn hens.

Egg production of caged White Leghorn hens with heavy (greater than 1000) populations of the northen fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), was 5 to 15% less than egg production of control hens. Body weight was depressed in hens infested with mites before the hens came into full egg production but not when hens were infested after that time. Feed consumption was not affected by mite populations.

Animals↗

Systemic activity of coumaphos, famphur, crufomate, ronnel, and phosmet given orally to hens for control of the northern fowl mite, Ornitbonyssus sulviarum (Canestrini and Fanzago).

Coumaphos (O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl)O,O-diethyl phosphorothioate), famphur (O-[p-(dimethylsulfamoyl)phenyl] O,O-dimethyl phosphorothioate). crufomate (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate), ronnel (O,O-dimethyl O-(2,4,5-trichlorophenyl) phosphorothioate) and phosmet (O,O-dimethyl phosphorodithioate S-ester with N-(mercaptomethyl) phthalimide) were administered as systemic acaricides (either single or multiple oral doses or as feed additives) for control of the nortnern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on caged White Leghorn hens. None of the treatments controlled the mites, but some hens were poisoned.

Animals↗

Control of northern fowl mite with permethrin and fenvalerate, two synthetic pyrethroid compounds.

Trials were conducted to evaluate the efficacy of permethrin and fenvalerate, two synthetic pyrethroid compounds, for the control of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on White Leghorn hens. Fenvalerate at .0125%, .025%, and .05% active ingredient (ai) were as effective as carbaryl at .5% ai for 56 days posttreatment. Permethrin at .01%, .025%, and .05% ai were as effective, or better than, malathion at .27% ai for 56 days posttreatment. All treatments were applied to the birds as high pressure sprays.

Animals↗

A nonchemical method of controlling the northern fowl mite, Ornithonyssus sulviarum (Canestrini and Fanzago), on caged White Leghorn hens.

Populations of the northern fowl mite on hens but not on roosters were significantly reduced relative to normally feathered chickens when feathers in the vent area were clipped to 2 to 3 mm length. The average difference in egg production between the control (no mites) and the clipped mite-infested hens was only 2.6% during the 22-week study, but the average difference between the control and the unclipped mite-infested hens was 7.6%, which was significantly different (P less than .01). Egg weight, hen body weight, and feed consumption of the three groups of hens were not significantly different.

Animals↗

Acquired immune response of white leghorn hens to populations of northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago).

Three levels (high, low and control) of northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), were maintained on White Leghorn hens for 24 weeks. The hens were then treated with carbaryl to eradicate the mites, were induced to molt, and were reinfested with mites 9 weeks later. Subsequent levels of mites on the three groups showed that the degree of acquired immunity was related to the initial level of mite infestation.

Animals↗

Histological changes in the testis of the domestic fowl after partial adenohypophysectomy.

The effects of partial adenohypophysectomy on comb size, testicular weight, and histology 20 or 30 days after the operation are described and discussed in relating these observed changes with the volume of remaining adenohypophyseal tissue. From the present observation, it is concluded that 1) the response of the domestic fowl to partial deficiency of adenohypophyseal tissue may be more sensitive than that of some mammals, 2) the decrease in testicular weight and tubular diameter precedes the histological change in testis and comb regression, and 3) to maintain fully active testicular function, more than 75% of the adenohypophysis is needed. About 40% of the adenohypophyseal tissue including a remnant of cephalic lobe can stimulate spermatogenesis, but the spermatozoa produced were partially abnormal. The critical amount of adenohypophyseal tissue for normal spermiogenesis may exist between 55 and 75%. All histological change is initially observed in the center of testis and then extended toward the periphery. It is suggested that the cephalic lobe contains at least a trace of ICSH in addition to FSH.

Animals↗

Storage and evacuation of spermatozoa from the uterovaginal sperm-host glands in domestic fowl.

Autoradiography with 3H-labeled spermatozoa was utilized to study spermatozoal oviductal interrelationships. Results demonstrated that sperm displacement from the uterovaginal sperm-host glands did not occur in domestic fowl. Furthermore, there was no indication that phagocytosis of labeled spermatozoa by sperm gland epithelium occurred. Associated studies demonstrated that extensive head-to-head agglutination occurred between freshly ejaculated spermatozoa, but the ability to agglutinate was lost as the sperm cells aged. On the basis of these observations, it was proposed that agglutination may be the basic mechanism controlling sperm storage and release from the uterovaginal sperm-host glands. A working model to this effect was presented.

Animals↗

An evaluation of permethrin, carbaryl, and amitraz for the control of northern fowl mites on caged chickens.

In two trials at the University poultry farm, two formulations of the synthetic pyrethroid permethrin (Ectiban 5.0% EC and Ectiban .25% Livestock Dust) were compared against carbaryl and amitraz sprays for the control of northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on caged birds. Under continuous reinfestation pressure, birds treated with dust did not support live mites in the vent region until 7 weeks posttreatment in comparison to 4 weeks with the permethrin 0.5% spray. Initially, both carbaryl (.5%) and amitraz (0.5%) sprays were as effective in controlling mites as the permethrin spray but did not provide protection for as long a period. Individual birds were either had dusted or treated with low pressure sprays.

Animals↗

Effects of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on egg quality of White Leghorn hens.

Interior egg quality and shell thickness of eggs from hens infested with the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), were compared with eggs from mite free hens. Egg shells of mite infested hens were significantly thicker (P greater than or equal to .05) but within the normal biological range. There were no differences in either Haugh units or yolk color between the two groups of hens.

Animals↗

Residues of stirofos (rabon) in eggs of laying hens treated for northern fowl mite control by dipping.

Laying hens were treated with a wettable powder formulation of stirofos [Rabon, 2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethylphosphate] by dipping in a .5 or 1.0% actual ingredient (AI) water suspension of a 50% wettable powder (WP) stirfos formulation. Stirofos residues were detected in eggs within 1 day after treatment and reached maximum levels 3 days after dipping (.021 and .035 ppm in the low- and high-dose birds, respectively). After that time, levels of residues in eggs declined rapidly and no sample contained detectable quantities (less than .004 ppm) of stirofos after 21 days. Dipping may be a practical control method for the northern fowl mite on chickens, because stirofos dips effectively control this mite on laying hens for at least 6 weeks and because resulting residues in eggs are well below established tolerances.

Administration, Topical↗

Effects of gradation in protein-calorie restriction on the hypothalo-pituitary-gonadal axis in young domestic fowl.

The effect of protein-calorie restriction on the circulating concentration of luteinizing hormone (LH) was investigated in the young domestic fowl. Two-week-old broiler chicks were fed isocaloric synthetic diets with varying levels of soy protein for a period of 14 days. Growth rate, as indicated by body weight, was decreased as the level of protein in the diet was reduced. Body weights of birds on a 3% protein diet were only 29.7% that of birds on a 24% protein diet. Severe protein-calorie restriction was also associated with depressed plasma LH levels in birds of both sexes, with male birds appearing to be more sensitive to this deficiency. A reduction of protein in the diet from 24% to 3% was associated with a 69% decrease in LH in males and a 43% decrease in females. In addition to lower circulating concentrations of LH, protein-calorie restriction was associated with a reduction in gonadal weight. Testes weights in birds on a 3% protein diet were only 16% of those on a 24% protein diet. Studies with synthetic luteinizing hormone releasing hormone (LHRH) indicated that protein-calorie restriction alters luteinizing hormone secretion via a hypothalamic effect.

Animals↗

Starch digestion in fowl.

Starch is usually the largest single nutrient in feed and provides the greatest proportion of metabolizable energy. Amylose and amylopectin comprise starch and are packed by plants in granular form. Granule stability is a function of the proportions of each polymer and the manner in which they are crystallized. Plant source determines granule size and stability. Grains generally have granules that are smaller and less stable than tuber or legume sources. Pancreatic alpha-amylase is the only enzyme elaborated by fowl that digests starch. Avian and mammalian sources are very similar, and inhibitors would not ordinarily be encountered in practice. The primary products of amylose digestion are maltose and maltotriose which further include alpha-limit dextrins when amylopectin is the substrate. Having starch in granule form reduces polymer access by the enzyme, and digestion difficulties occur in proportion to stability of structure. Moisture combined with heat destabilize granule structure and their use at one time or another in the manufacture of most feeds alleviates digestibility problems. Large amounts of the enzyme are present with the chick at hatch, and the pancreas is more than capable of synthesis commensurate with need. Gelatinization, enzyme adequacy, predominance of starch from grain, and lack of inhibitors account for the relative absence of practical problems involving this nutrient.

Amylopectin↗