Decreasing egg weight by energy or protein restriction and energy required for repletion 1     

J. A. Oluyemi  R. H. Harms 《British poultry science》1978,19(1):85-91

1. A diet containing 110 g crude protein/kg caused smaller losses in egg weight, numbers and body weight in Babcock B300 layers than diets containing 90 g protein/kg, 6.56 MJ ME/kg or 7.90 MJ/kg.

2. The sequence of repletion of depleted birds was body weight, egg weight and egg number. For the first alone more than 420 kJ/d was required, for body weight and egg weight more than 630 kJ/d and for all three more than 1170 kJ/d.  相似文献   

Calcium involvement in luteinizing hormone-releasing hormone release from the bovine infundibulum     

W. W. Dippel  P. L. Chen  N. H. McArthur  P. G. Harms   《Domestic animal endocrinology》1995,12(4):349-354

Bovine infundibular (stalk median eminence) explants were incubated in vitro to test the hypothesis that calcium (Ca) is involved in the release of luteinizing hormone-releasing hormone (LHRH) from LHRH neuron terminals in cattle. Right and left infundibular halves from individual heifers and/or steers were randomly assigned to either control or treated (EGTA [a Ca chelator] or verapamil [an L-type Ca channel antagonist]) groups. Each half was incubated in 600 μl of KrebsRinger bicarbonate medium (KRB) in the presence or absence of a treatment agent for 180 min. At 30-min intervals, 500-μl samples were removed from each incubate and replaced with fresh media. Spontaneous (basal) and depolarization-induced (60 mM potassium) LHRH release was evaluated by radioimmunoassay of the LHRH content in the media incubated from 91 to 120 and 121 to 150 min of culture, respectively. The effect of treatment on depolarization-induced LHRH release was analyzed by comparing the differences between spontaneous and depolarization-induced LHRH release in control and treated groups. Spontaneous LHRH release was not different between control and 1.25 mM EGTA- or 100 μM verapamil-treated halves from steers. In contrast, steer infundibular halves incubated with EGTA (replacing Ca in KRB and chelating any Ca in the media) released less LHRH during depolarization than did control halves. In addition, verapamil-treated (to block Ca uptake by the terminal) infundibular halves from steers or heifers released less LHRH in response to depolarization than did control halves. In conclusion, these results: 1) support the hypothesis that Ca is involved in LHRH release from the bovine infundibulum, 2) suggest that the involvement of Ca may be independent of the reproductive state, and 3) demonstrate that bovine infundibular halves incubated in vitro are useful for studying selected mechanisms regulating bovine hypothalamic neurohormone release (exocytosis) from neuron terminals.  相似文献   

Three cases of gastric prolapse through the gill slit in sand tiger sharks, Carcharhinus taurus (Rafinesque)     

Tuttle AD  Burrus O  Burkart MA  Scott PW  Stoskopf MK  Harms CA 《Journal of fish diseases》2008,31(4):311-315

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Subsystems,flowpaths, and the spatial variability of nitrogen in a fluvial ecosystem     

David Bruce Lewis  Nancy B. Grimm  Tamara K. Harms  John D. Schade 《Landscape Ecology》2007,22(6):911-924

Nutrient dynamics in rivers affect biogeochemical fluxes from land to oceans and the atmosphere. Fluvial ecosystems are thus important environments for understanding spatial variability in nutrient concentrations. At the San Pedro River in semi-arid Arizona, USA, we investigated how variability in dissolved inorganic nitrogen (DIN) was regulated by subsystem type and hydrological flowpaths. The three subsystems we compared were the riparian zone, parafluvial (gravel bar) zone, and surface stream. DIN concentration was greater in the riparian zone than in the surface stream, suggesting that the riparian zone retains DIN and is a source of N for the surface stream. Parafluvial zones were too variable to generalize how they regulate DIN. Our hypothesis that subsystem type regulates DIN oxidation was too simple. The riparian and parafluvial zones host a mosaic of oxidizing and reducing conditions, as they exhibited highly variable ammonium to nitrate (NH₄⁺:NO₃⁻) ratios. Surface stream DIN was dominated by NO₃⁻. Along a subsurface flowpath in the riparian zone, we did not observe spatial covariation among the N forms and transformations involved in mineralization. We also compared spatial variability in solute concentrations between flowpaths and non-flowpath reference areas. Our mixed results suggest that spatial variability is regulated in part by flowpaths, but also by solute-specific processing length along a flowpath. To understand the distribution of N in fluvial ecosystems, subsystem type and flowpaths are readily discernable guides, but they should be coupled with other mechanistic factors such as biota and soil type.  相似文献   

Immunohistochemical Localization of Vascular Endothelial Growth Factor (VEGF) and its Two Receptors (Flt-I and KDR) in the Endometrium and Placenta of the Mare During the Oestrous Cycle and Pregnancy     

WR Allen  S Gower  S Wilsher 《Reproduction in domestic animals》2007,42(5):516-526

Polyclonal antisera for vascular endothelial growth factor (VEGF) and its two main receptor molecules, VEGF-I (Flt) and VEGF-II (KDR), were used in a conventional immunocytochemical staining method to localize these angiogenic ligand molecules in the endometrium and placenta of the mare during the oestrous cycle and pregnancy. The anti-VEGF and anti-Flt sera both labelled the lumenal and glandular epithelia of the endometrium throughout the oestrous cycle and both the invasive trophoblast cells of the endometrial cups and the non-invasive trophoblast of the allantochorion in pregnancy. The anti-KDR serum likewise stained the maternal and foetal epithelial layers during the oestrous cycle and pregnancy and it also labelled fibroblast-like cells in the endometrial and allantoic stromas and the endothelium of foetal and maternal capillaries. The results demonstrated that constant supplies of the principal vasculogenic and angiogenic factor, VEGF, and its two major receptors, Flt and KDR, are available on both the maternal and foetal sides of the placental barrier throughout gestation in the mare. They are presumed to facilitate the continuing development of the extensive foetal and maternal capillary networks that are such prominent features within the microplacentomes of the diffuse, epitheliochorial equine placenta.  相似文献   

Intraocular pressure of juvenile loggerhead sea turtles (Caretta caretta) held in different positions.     

B Chittick  C Harms 《The Veterinary record》2001,149(19):587-589

The intraocular pressure of 12 apparently healthy juvenile loggerhead sea turtles (Caretta caretta) was determined by applanation tonometry while the turtles were held in dorsoventral, ventrodorsal, and head-down suspended positions. The median intraocular pressures were 5 mmHg (range 4 to 9 mmHg) in the dorsoventral position, 7 mmHg (range 5 to 12 mmHg) in the ventrodorsal position, and 23 mmHg (range 17 to 33 mmHg) in the suspended position.  相似文献   

Quantitative determination of chewing and rumination activities in dairy cows]     

S Nagel  K Harms  E Mahnke  B Piatkowski 《Archives of Animal Nutrition》1975,25(1):21-26

A device is described (RMBZ) which allows to register the movements of the lower jaws of cattle during food consumption and rumination. A microfeeler is connected to the device which is fastened to the halter. With the use of this device following data can be obtained separately: the total number of chewing movements; the number of bits of food swallowed and the length of chewing period in this way it has become possible to avoid the laborious and time-consuming work that is necessary to analyze strip charts. Trials were performed with varying patterns of food ration showing that this device is particularly suited for studies of this kind especially when compared with other devices using strip charts. Average deviations, e.g. in the number of rumination activities, from those registered with the recorder device were +/- 5%. The measuring technique and the operating principle of the RMBZ device are described in some detail.  相似文献   

Abnormalities of erythrocytes and renal tubules of chicks poisoned with lead     

C F Simpson  B L Damron  R H Harms 《American journal of veterinary research》1970,31(3):515-523

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Prostaglandin involvement in hypothalamic control of gonadotropin and prolactin release   总被引：1，自引：0，他引：1  

P G Harms  S R Ojeda  S M McCann 《Science (New York, N.Y.)》1973,181(101):760-761

Prostaglandin E(2) (PGE(2)) injected into the third ventricle of ovariectomized rats increased plasma luteinizing hormone dramatically and follicle stimulating hormone slightly. PGE(1) elevated prolactin; PGF(1alpha) or PGF(2alpha) had no effect. PGE(2) or PGE(1) injected directly into the anterior pituitary were ineffective. These results suggest that specific prostaglandins act at the hypothalamus to control pituitary hormone release.  相似文献   

Pharmacokinetics of fluconazole in loggerhead sea turtles (Caretta caretta) after single intravenous and subcutaneous injections, and multiple subcutaneous injections.     

Kate M Mallo  Craig A Harms  Gregory A Lewbart  Mark G Papich 《Journal of zoo and wildlife medicine》2002,33(1):29-35

Superficial and systemic mycotic infections are common among clinically ill sea turtles, which places growing importance on the establishment of pharmacokinetic-based dosage regimens for antifungal drugs. The pharmacokinetic properties of the antifungal drug fluconazole, after intravenous (i.v.) and subcutaneous (s.c.) injections, were studied in juvenile loggerhead sea turtles (Caretta caretta) housed at 23.0-26.5 degrees C. Fluconazole pharmacokinetic properties were further assessed in a multiple-dose s.c. regimen derived from the pharmacokinetic parameters determined in the single-dose study. Pharmacokinetic parameters were calculated, using a two-compartment model, from plasma concentration-time data obtained after single i.v. and s.c. administrations of fluconazole at a dosage of 2.5 mg/ kg body weight in six juvenile sea turtles. Blood samples were collected at intervals through 120 hr after each dose, and the concentration of fluconazole in plasma was measured by reverse-phase high-performance liquid chromatography. The i.v. and s.c. elimination half-lives were 139.5 +/- 36.0 and 132.6 +/- 48.7 hr (mean +/- SD), respectively. Systemic clearance of fluconazole was 8.2 +/- 4.3 ml/kg x hr, and the apparent volume of distribution at steady state was 1.38 +/- 0.29 L/kg. A multiple-dose regimen was derived, which consisted of a loading dose of 21 mg/kg body weight and subsequent doses of 10 mg/kg administered through s.c. injection every 120 hr (5 days). This regimen was administered to four juvenile sea turtles for 10 days, and blood samples were taken to determine peak and trough plasma concentrations of fluconazole. The mean concentrations for the two peak concentrations were 16.9 +/- 1.1 and 19.1 +/- 2.8 microg/ml 4 hr after dosing, and the mean concentrations for the three trough concentrations were 7.2 +/- 2.2, 10.4 +/- 2.7, and 10.7 +/- 2.9 microg/ml 120 hr after dosing. The terminal half-life after the last dose was calculated at 143 hr. Throughout the multiple dosing, fluconazole concentrations remained above approximately 8 microg/ml, a concentration targeted when treating mycotic infections in humans. The results of this study suggest that fluconazole can be effectively administered to sea turtles at a dosage of 10 mg/kg every 5 days after a loading dose of 21 mg/kg.  相似文献