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排序方式: 共有153条查询结果,搜索用时 15 毫秒
1.
Comparative evaluation of the effect of two maternal diets on fatty acids, vitamin E and carotenoids in the chick embryo. 总被引:1,自引:0,他引:1
1. The fatty acid profile of egg yolk and vitamin E and carotenoid accumulation in the egg yolk and embryonic tissues were investigated in relation to the maternal diet. 2. Two hundred fertile eggs (Ross 308 Broiler Breeder), obtained from hens fed on a maize-based (M-diet) or a wheat-based diet (W-diet), were incubated using standard conditions. 3. The egg yolk and embryo tissues (residual yolk, yolk sac membrane, liver, kidney, lung, muscles, adipose tissue and plasma) were collected on d 18 of incubation and on d 21 (newly-hatched chicks) and analysed for fatty acids, vitamin E and carotenoids. 4. The diets did not differ in terms of fatty acid or alpha-tocopherol concentrations. The concentration of carotenoids in the M-diet was 11.8 mg/kg and in the W-diet was 5.6 mg/kg with lutein and zeaxanthin being major carotenoids. 5. Eggs from the M-group contained higher (P<0.01) concentrations of beta+gamma-tocopherols, total carotenoids, lutein and zeaxanthin. Chickens hatched from those eggs were characterised by the increased concentrations of total carotenoids and zeaxanthin in all the tissues studied. The concentration of beta+gamma-tocopherol was enhanced only in the liver and yolk sac membrane. 6. It is concluded that the maternal diet plays an important role in antioxidant systems formation during chick embryonic development; the M-diet can increase the antioxidant potential of the egg yolk and embryonic tissues compared to the antioxidant potential provided by parent birds fed the W-diet. 相似文献
2.
1. When a solution of ferric ammonium sulphate was added to shell membranes of the domestic fowl, iron infiltrated the mantle (cortex) surrounding the cores of the individual fibres of the membranes.
2. Contraction of warm eggs in ice‐cold colloidal iron caused flooding of pore canals and contamination of the underlying shell membranes with this element.
3. Appreciable contamination of the inner shell membrane with iron persisted for 25 d in infertile eggs stored at 37.5 °C. 相似文献
3.
Twenty-seven compounds were screened as potential inhibitors of juvenile hormone esterases. Of these compounds O-ethyl-S-phenyl phosphoramidothiolate provided the best inhibition for the cabbage looper, Trichoplusia ni (Hubner), and the yellow mealworm, Tenebrio molitor L., while the juvenile hormone esterases of the house fly, Musca domestica L., were best inhibited by a juvenoid carbamate (1-(m-phenoxy-N-ethyl carbamate)-3,7-dimethyl-7-methoxy-2E-octene). The inhibition patterns of T. ni and T. molitor are similar, while those of M. domestica are relatively different. Further studies on the juvenile hormone and α-napthyl acetate esterases of T. ni showed that they could be differentially inhibited. Diisopropyl phosphorofluoridate and an alkyl trifluoromethyl ketone selectively inhibit the hydrolysis of α-naphthyl acetate and juvenile hormone, respectively, while O-ethyl-S-phenyl phosporamidothiolate inhibits both enzymes. The juvenile hormone esterases of T. ni also appear to be unique enzymes that are selective for juvenile-hormone-like molecules. The in vivo inhibition of T. ni juvenile hormone esterases by O-ethyl-S-phenyl phosphoramidothiolate slows the in vivo hydrolysis of juvenile hormone and results in delayed pupation and malformed larvae that resemble larval-pupal intermediates. Thus, the esterases involved in juvenile hormone metabolism appear to be important in juvenile hormone regulation. 相似文献
4.
Questionnaire‐based Analysis of Owner‐reported Scratching and Pain Signs in Cavalier King Charles Spaniels Screened for Chiari‐like Malformation and Syringomyelia 下载免费PDF全文
C.R. Sparks S. Cerda‐Gonzalez E.H. Griffith B.D.X. Lascelles N.J. Olby 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(1):331-339
Background
Chiari‐like malformation (CM) and syringomyelia (SM) cause a pain syndrome in Cavalier King Charles spaniels (CKCS). Clinical signs are not consistently apparent on neurologic examination, and owner reporting of signs provides vital clinical history. However, owner questionnaires for this disease are not well developed.Objectives
To develop a tool to capture owner‐reported clinical signs for use in clinical trials and to compare owner‐reported signs with the presence of pain on neurologic examination and SM on magnetic resonance imaging (MRI).Animals
Fifty client‐owned CKCS.Methods
Owners completed a questionnaire and pain/scratch map. Each dog underwent a neurologic examination and craniocervical magnetic resonance imaging (MRI). Questionnaire responses were developed into scores, area of shading for pain/scratch maps was measured, and consistency of responses between these tools was assessed. Owner‐reported findings were compared with neurologic examination findings and presence and severity of SM on MRI.Results
Thirty‐three dogs were symptomatic and 17 asymptomatic; 30 had SM. The most common sign of pain was crying out when lifted (n = 11). Extent of shaded areas on maps positively correlated with questionnaire scores for pain (r2 = 0.213, P = 0.006) and scratch (r2 = 0.104, P = 0.089). Owner‐reported findings were not significantly associated with presence or severity of SM or neurologic examination findings. Owner‐reported lateralization of signs was significantly associated with SM lateralization (P < 0.0001).Conclusions
The questionnaire and maps may be useful for clinical trials. Lack of association of owner‐reported signs with SM highlights our lack of understanding of the pathophysiology of pain in this disease. 相似文献5.
V. Sandilands F. Whyte L. K. Williams T. S. Wilkinson N. H. C. Sparks T. J. Humphrey 《British poultry science》2018,59(6):698-702
ABSTRACT1. Chicken-associated Campylobacter spp. are the cause of most food poisoning cases in Europe. In order to study the host–pathogen interactions, a reliable and reproducible method of colonising chickens with the bacteria is required.2. This study aimed to identify a more appropriate and less invasive method of colonisation (cf. gavaging) by seeding bedding material (litter) that commercial chickens are kept on with a mixture of Campylobacter spp., broth and faeces.3. The first phase of the study tested the longevity of Campylobacter spp. recovery in seeded litter over 24 h: significantly more Campylobacter spp. was recovered at 0 or 3 h post-seeding than at 6 and 24 h post-seeding, indicating that the pathogen can survive to detectable levels for at least 3 h in this environment.4. In the second phase, three groups of 10 broiler chickens (negative for Campylobacter spp. prior to exposure) were exposed at 21 days of age to one of three different Campylobacter jejuni and C. coli mixes (A, B, C), using the method above. At 28 days of age, birds were euthanised by overdose of barbiturate or cervical dislocation, and livers and caeca removed for Campylobacter spp. assessment.5. All liver and 28/30 caeca samples tested positive for Campylobacter spp., with mix A and C giving higher counts in the caeca than mix B. The method of euthanasia did not affect Campylobacter spp. counts.6. In conclusion, a successful method for reliably colonising broiler chickens with Campylobacter spp. has been developed which negates the need for gavaging and is more representative of how contamination occurs in the field. 相似文献
6.
Clayton T Larue Michael Goley Lei Shi Artem G Evdokimov Oscar C Sparks Christine Ellis Andrew M Wollacott Timothy J Rydel Coralie E Halls Brook Van Scoyoc Xiaoran Fu Jeffrey R Nageotte Adewale M Adio Meiying Zheng Eric J Sturman Graeme S Garvey Marguerite J Varagona 《Pest management science》2019,75(8):2086-2094
7.
Clayton T Larue Joel E Ream Xuefeng Zhou Farhard Moshiri Arlene Howe Michael Goley Oscar C Sparks Steven T Voss Erin Hall Christine Ellis Janice Weihe Qungang Qi Daniela Ribeiro Xiaoping Wei Shirley Guo Artem G Evdokimov Marguerite J Varagona James K Roberts 《Pest management science》2020,76(3):1031-1038
8.
Tissue-specific accumulation of tocopherols and tocotrienols in turkey tissues during embryonic development and their susceptibility to lipid peroxidation were investigated. Fertile turkey eggs were incubated using standard commercial conditions. Embryonic tissues were collected at 16, 22, 25 d of incubation and from day-old poults (referred to as day 29) and alpha-; beta- + gamma- and delta-tocopherols and respective tocotrienols were analysed by HPLC. A turkey diet provided to the parent hens contained the complete range of tocopherols and tocotrienols. Between days 16 and 22 of embryo development, the alpha-tocopherol concentration in the liver remained constant and then increased significantly (P<0.01) reaching a maximum just after hatching. Similar changes were observed for the other tocopherols and tocotrienols. The accumulation of alpha-tocopherol in the yolk sac membrane (YSM) started after day 20 of development and at hatching the alpha-tocopherol concentration in the YSM was twice that of beta- + gamma-tocopherols and 15 times greater than that of alpha-tocotrienol. In the kidney, heart, lung, muscle and adipose tissues a gradual increase in tocopherol and tocotrienol concentrations took place between days 20 and 25 of development with a sharp increase in particular of alpha-tocopherol between days 25 and 29. There was a discrimination between tocopherols and tocotrienols during their assimilation from the diet by the parent hen and during metabolism by the developing turkey embryo. Tissue-specific features in the susceptibility to lipid peroxidation were found with the brain being the most susceptible to lipid peroxidation at day 25 and in day-old poults. 相似文献
9.
10.
Impact of an experimental PRRSV and Streptococcus suis coinfection on the pharmacokinetics of ceftiofur hydrochloride after intramuscular injection in pigs 下载免费PDF全文
D. N. Day J. W. Sparks L. A. Karriker K. J. Stalder L. W. Wulf J. Zhang J. M. Kinyon M. L. Stock R. Gehring C. Wang J. Ellingson J. F. Coetzee 《Journal of veterinary pharmacology and therapeutics》2015,38(5):475-481
This study determined the impact of porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis coinfection on the pharmacokinetic (PK) profile of ceftiofur hydrochloride in pigs after intramuscular (i.m.) injection. Eighteen clinically normal crossbred gilts were assigned by weight into a challenge group (10 pigs) and control group (eight pigs). Pigs in both groups received a single i.m. injection of ceftiofur hydrochloride (Excenel RTU Sterile Suspension; Zoetis) at a 5 mg/kg BW dose. Serial blood samples were collected to characterize the plasma concentration curve. After a 10 days drug washout period, the challenge group was inoculated with 2 mL of PRRSV isolate VR‐2385 (105.75 50% tissue culture infective doses per mL) intranasally and 8 days later inoculated S. suis. When clinical disease was evident, the second PK assessment began in both challenge and control groups. Coinfected pigs demonstrated lower values of AUC and CMAX, but higher values of Cl/F and Vz/F indicating drug kinetics were altered by infection. The data from this study have implications on ceftiofur treatment regimens in diseased pigs. 相似文献