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1.
维生素D3是一种新的神经内分泌-免疫调节剂,主要表现为对单核/巨噬细胞、T淋巴细胞、B淋巴细胞、胸腺细胞的增殖分化及细胞功能具有重要影响。维生素D3与T淋巴细胞、B淋巴细胞和巨噬细胞分泌抗体、淋巴因子、补体和单核因子等功能紧密相关。但关于维生素D3对家禽免疫细胞、免疫因子调节的研究甚少。本文就维生素D3的免疫功能及其对家禽T淋巴细胞、抗原呈递细胞(APC)和免疫因子调节的研究现状和展望作一综述。  相似文献   

2.
文章综述了25-羟基维生素D(325-OH D3)在动物(主要是家禽)营养中的研究进展:①25-OH D3改善肉鸡生长性能,但会受到基础饲粮钙、磷和维生素D(3VD3)水平的影响;②25-OH D3改善肉鸡骨骼质量,降低TD(胫骨软骨发育不良)发病率,但受到肉鸡品系的影响;③25-OH D3增加肉鸡植酸磷回肠末端消化率,但未影响肠道(内源)植酸酶活性;④25-OH D3调节肉鸡肠道形态和免疫机能;⑤25-OH D3改善产蛋鸡产蛋后期蛋壳质量;⑥以家禽骨骼和蛋壳质量为评价指标,25-OH D3生物学活性为VD3的1~2.5倍;⑦以家禽肾脏钙化评价,25-OHD3的毒性约为VD3的5~10倍。  相似文献   

3.
在过去几十年中,由于肉用仔鸡的快速生长,骨骼畸形问题也日益突出。家禽骨骼畸形会降低肉用仔鸡的生产性能,提高家禽死亡率,难以加工并影响胴体品质,给家禽生产厂、加工厂造成巨大经济损失。影响家禽骨骼畸形发生的因素很多,营养因素是其中一个非常重要的因素。研究表明:日粮中的8种维生素、13种矿物元素、6种氨基酸以及日粮能量和蛋白质水平都与家禽骨骼畸形有关。在过去20~30年间,研究主要集中于维生素D、钙、磷、氯、锌、铜、胱氨酸、半胱氨酸、同型半胱氨酸、脂肪酸等营养因素。近5~6年,国内外关于维生素D代谢及其与家禽骨骼畸形之间  相似文献   

4.
一、维生素维生素是家禽维持生命、生长发育、正常生理机能和新陈代谢所必需的一类特殊的低分子有机化合物。当维生素缺乏时,会引起维生素缺乏症,造成禽体物质代谢紊乱、生长停滞以致发生各种疾病,严重时甚至可以引起死亡。引起家禽维生素缺乏的原因主要有:(1)维生素来源不足,饲料中维生素不足或因加工储存不当而造成损失、破坏过多,长期使用抗菌药物使家禽肠道细菌合成维生素受到抑制,家禽对饲料摄取量不足;(2)家禽对维生素的需要量增加,如幼禽、产蛋禽对各种维生素(特别是维生素A、D)的需要量增加,感染性疾病、中毒、高热或处应激状态下…  相似文献   

5.
25-羟D3不同添加水平对罗曼父母代种鸡生产性能的影响   总被引:2,自引:0,他引:2  
25-羟基维生素D3是维生素D3的代谢物,它与维生素D3不同,更容易吸收,很少受肠道中脂肪和胆汁存在与否的影响,是维生素D3的一种活性产物。它能有效的降低蛋鸡的破蛋率、腿病发病率,提高鸡的生产性能,种蛋的受精率、孵化率和健雏率。维生素D3彼家禽或动物采食后,需要在肝脏经羟化作用转变为25-羟基维生素D3,25-羟D3经血液运送到肾脏后,在1-α-羟化酶作用下,转变为1,25-二羟基维生素D3,1,25-二羟基维生素D3为维生素D3的活性形式,可调节钙和磷结合蛋白的合成,继而调节钙和磷自小肠的吸收、运送血液钙和磷的浓度.  相似文献   

6.
美国国家标准(NRC)中规定家禽维生素要求量,是用实验得出的预防其缺乏症的最低需要量,家禽饲养者都希望获得最佳成绩(骨骼强度、肌肉产量、皮肤状况等),为此在其饲料中需要添加NRC要求量2~10倍的维生素,此实用家禽饲料添加维生素量被家禽营养学家称为“最适维生素营养”。实践表明不会因此导致维生素中毒(维生素A、D有可能引起肝脏障碍和组织石灰化例外,V_A摄入量为NRC3~4倍、V_D为12~14倍时这种例外有可能发  相似文献   

7.
维生素对于家禽的生长和发育具有重要的促进作用,同时也是家禽繁殖所需的重要营养物质,一旦出现大量缺乏的情况,就会引起维生素缺乏症,从而影响到家禽机体的紊乱,影响家禽正常生长。本文主要对家禽维生素E缺乏症的病因、特点和症状进行分析,提出了防治该病的措施,希望能够促进家禽的正常生长和发育。  相似文献   

8.
维生素D2主要存在于植物性饲料中,如麦角和酵母;而维生素D3则主要由存在于动物的皮肤、血液、神经和脂肪组织中的7脱氢胆固醇在紫外线照射下生成。维生素D2与维生素D3对哺乳动物的活性基本相同;对于包括家禽在内的鸟类,维生素D3的活性远高于D2,前者约为后者的20~40倍;奶牛维生素D2的效价可能只有维生素D3的1/2~1/4。近年来,对活性维生素D的研究有了进一步的认识,逐渐发现活性维生素D除具有经典的钙磷调节作用以外,还参与调节许多细胞的代谢过程,对机体的免疫功能、生殖等方面均有着十分重要的意义。作者就近年来国内外对维生素D在动…  相似文献   

9.
家禽营养代谢病的病因及诊治   总被引:1,自引:0,他引:1  
1 家禽营养代谢病的种类 脂溶性维生素A、维生素D、维生素E、维生素K缺乏或代谢障碍病;水溶性维生素B1、维生素B2、泛酸、烟酸、生物素、胆碱、叶酸、维生素B12以及维生素C的缺乏或代谢障碍病。  相似文献   

10.
维生素C是家禽维持生命和正常生理机能所必不可少的营养元素,在家禽的免疫反应、激素形成和其他健康状况的维持上都扮演着某种角色。维生素C缺乏会造成某些代谢障碍和紊乱,进而影响家禽的生长、产蛋和健康。一般饲养条件下,普通家禽的饲料中不需要添加维生素C,这是因为家禽的肾脏能够自身合成维生素c。  相似文献   

11.
Mites can be important sources of airborne allergens, especially on farms. Two dust samples from pig farms and three dust samples from poultry farms were investigated for mites. House-dust mites were present in the poultry-dust samples, but not in the pig-dust samples. Furthermore, storage mites and predatory mites also were found in the poultry-dust samples. Specifically, the house-dust mite Dermatophagoides evansi was found in the dust samples from two poultry farms. Subsequently, a dust sample was collected from five other poultry farms. Again, D. evansi was present in dust from these farms. This is the first time that D. evansi is reported in dust from poultry farms in Western Europe outside Norway. If D. evansi cross-reacts with other Dermatophagoides spp., then poultry farmers and their families, but also other professionals working in the poultry industry, such as veterinarians, may be exposed to house-dust mites with potential clinical consequences, both domestic and occupational.  相似文献   

12.
The poultry red mite Dermanyssus gallinae is a major pest and widespread ectoparasite of laying hens and other domestic and wild birds. Under optimal conditions, D. gallinae can complete its lifecycle in less than 10 days, leading to rapid proliferation of populations in poultry systems. This paper focuses on developing a theoretical model framework to describe the population dynamics of D. gallinae. This model is then used to test the efficacy and residual effect of different control options for managing D. gallinae. As well as allowing comparison between treatment options, the model also allows comparison of treatment efficacies to different D. gallinae life stages. Three different means for controlling D. gallinae populations were subjected to the model using computer simulations: mechanical cleaning (killing once at a given time all accessible population stages), sanitary clearance (starving the mite population for a given duration, e.g. between flocks) and acaricide treatment (killing a proportion of nymphs and adults during the persistence of the treatment). Simulations showed that mechanical cleaning and sanitary clearance alone could not eradicate the model D. gallinae population, although these methods did delay population establishment. In contrast, the complete eradication of the model D. gallinae population was achieved by several successive acaricide treatments in close succession, even when a relatively low treatment level was used.  相似文献   

13.
The poultry red mite, Dermanyssus gallinae (De Geer) is a serious ectoparasitic pest of layer hens that can survive for long periods in the poultry house sub-structure without taking a blood meal from its host. The research undertaken in this study found that 'time since last blood meal' had a notable effect on how toxic a selection of plant essential oils were to D. gallinae under laboratory conditions. In general, the essential oils had a greater toxic effect on D. gallinae if mites had been starved of a blood meal for around 3 weeks, than if they had been more recently fed 3-13 days prior to tests. This result was consistent across the four essential oils used (thyme, palmarosa, caraway and juniper leaf). This suggests that plant essential oils may be of use in management schemes for D. gallinae, particularly if used to sanitise houses between flocks, when mites will have been starved.  相似文献   

14.
苏氨酸是家禽第三限制性氨基酸,在家禽体内发挥多种重要的生物学功能,如平衡饲粮氨基酸比例,提高营养物质利用效率,改善家禽生长性能和产蛋性能;促进肠道组织发育、维持肠道屏障功能,提高家禽免疫力等。文章从苏氨酸的代谢途径及其对家禽的生物学作用方面进行综述,为苏氨酸在家禽生产中的合理应用提供理论依据。  相似文献   

15.
纤维曾被视为家禽饲粮所含的一种抗营养因子,但适量的饲粮纤维可有效改善家禽的营养与健康。饲粮纤维成分复杂,不同纤维源的营养功能与作用机制不尽相同。本文介绍饲粮纤维的概念与性质,探讨其对家禽消化生理、肠道健康及生产的影响,阐释其调控家禽营养的机制,为其在家禽生产中高效利用提供科学依据。  相似文献   

16.
Infectious bronchitis (IB) is a highly contagious viral disease and is responsible for considerable economic losses in the poultry industry, worldwide. To mitigate the IB-associated losses, multiple vaccines are being applied in the sector with variable successes and thus necessitating the development of a potent vaccine to protect against the IB in the poultry. In the present study, we investigated a bivalent live attenuated vaccine consisting of IB virus (IBV) strain H120 (GI-1 lineage) and D274 (GI-12 lineage) to evaluate its protection against heterologous variant of IBV (GI-23 lineage) in chicken. Protection efficacy was evaluated based on the serology, clinical signs, survival rates, tracheal and kidney histopathology and the viral shedding. Results demonstrated that administering live H120 and D274 (named here Classivar®) vaccine in one day-old and 14 days-old provided 100 % protection. We observed a significant increase in the mean antibody titers, reduced virus shedding, and ameliorated histopathology lesions compared to routinely used vaccination regimes. These results revealed that usage of different IBV vaccines combination can successfully ameliorate the clinical outcome and pathology in vaccinated chicks especially after booster vaccination regime using Classivar®. In conclusions, our data indicate that Classivar® vaccine is safe in chicks and may serve as an effective vaccine against the threat posed by commonly circulating IBV strains in the poultry industry.  相似文献   

17.
Infestations with the poultry red mite Dermanyssus gallinae represent a major ectoparasite problem in poultry and can affect egg layers worldwide. There is presently a lack of an ectoparasiticide in Europe for poultry which can assure a 0-day withholding period for eggs. In this study, ByeMite (phoxim 50%, Bayer HealthCare, Animal Health Division) was administered to treat a D. gallinae infestation in a poultry house stocked with egg-laying hens kept in a cage system. A layer house was sprayed twice within a 7-day interval using a solution containing 2000 ppm phoxim and a similar layer house was used as an untreated control unit. Specially developed D. gallinae traps made of cardboard were used to assess the mite density in both layer houses during a 49-day period after the treatment. In order to collect mites, the traps were placed on days--1, 2, 6, 9, 13, 20, 34 and 48 and always removed after 24 h. The collected mites were counted and differentiated according to their developmental stage (mite eggs, larvae, nymphs, adults). Three days after the first spray treatment, the efficacy against all mite stages (larvae, nymphs, adults) was 96.1%, and from day 7 post-treatment until the end of the trial (day 49) the efficacy exceeded 99%. In contrast, in the untreated layer house (negative control group) the mite population showed a 400% increase. No treatment-related side effects in chickens were detectable. It is concluded that two administrations of ByeMite within a 7-day interval are highly effective against D. gallinae infestations in a stocked poultry house.  相似文献   

18.
Eighty per cent of Enterobacteriaceae isolates from battery poultry exhibited drug resistance in a survey among university and commercial poultry flocks. These birds, being a source of human food, may serve as an important reservoir for human pathogenic drug-resistant enteric organisms. Feeds used on University and Commercial poultry farms were found to be inhibitory to standard test organisms--Oxford strain of Staphylococcus aureus and Escherichia coli K 12 J5 NA+ Lac-. Feed additives, which purportedly were mineral and vitamin supplements, were found to be highly laden with antibacterials, a quantitative estimation of which revealed that one of them, termed A & D Crumbles contained as much as 3000 (three thousand) micrograms of antibiotic per g, while another feed additive known as ADVIT contained 130 micrograms of antibiotic per g of the feed supplement. These are routinely added to poultry feeds, a practice which may easily lead to development of drug resistance among enteric pathogens that may, in turn, reach humans and complicate therapy of human bacterial infections. This may be of a considerable public health significance.  相似文献   

19.
家禽业正在努力寻求减少对抗生素促生长剂和抗菌剂依赖的方法,以避免耐药菌的产生和药物残留等问题。这就促使一些天然物质,如益生菌、益生元、共生菌、有机酸、饲料酶和植物源性提取物等的开发为家禽饲料添加剂的相关研究逐渐成为热点。就上述抗生素替代物作为饲料添加剂应用于家禽养殖时的有益作用、作用机制及注意事项等进行详细阐述,以期为家禽生产实践奠定理论基础。  相似文献   

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