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肉鸡日粮中添加植酸酶的新认识   总被引:1,自引:0,他引:1  
加入饲料中的植酸酶可提高氨基酸、蛋白质和能量的消化率植酸盐,即植酸(肌醇六磷酸)的复合盐类物质,主要以植酸镁复合物的形式存在于所有植物性饲料原料中。植酸盐大约以10.0g/kg的浓度或以大约2.8g/kg的植酸磷浓度普遍存在于肉鸡日粮中。在家禽营养上,植酸盐很难被消化,所以植酸盐中的磷仅部分可被利用,并且植酸盐也有抗营养特性。植酸盐是一种多阴离子分子,  相似文献   

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Equine colic, a disorder manifested in abdominal pain, is the most frequent cause of emergency treatment and death in horses. Colic often requires intestinal surgery, subsequent hospitalisation and post operative care, with a strong risk of complications arising from surgery. Therefore strategies that explore approaches for preventing the condition are essential. To this end, a better understanding of the factors and mechanisms that lead to the development of colic and related intestinal diseases in the horse allows the design of preventive procedures. Colic is a multifactorial disorder that appears to be induced by environmental factors and possibly a genetic predisposition. One factor that seems to influence the risk of developing colic is the excessive consumption of diets containing high levels of carbohydrates. Therefore, major efforts have been made by various laboratories and institutions across the world to study the type and digestibility of various feed in order to formulate accurate and safe feed components and proportions. However, relatively little work has been carried out to characterise, in detail, the carbohydrate digestive and absorptive capacity and mechanisms underlying the potential adaptive response of equine gut epithelium to a changing diet. This review focuses on advances made towards understanding the molecular and cellular mechanisms involved in digestion and absorption of dietary carbohydrates in the equine gastrointestinal tract and the implication of these processes for the whole body physiology. It addresses the underlying mechanisms that may govern the adaptive response of equine small intestine to increased dietary hydrolysable carbohydrates. Furthermore, it describes changes that occur in the equine large intestinal microbiology and host tissue biology brought about by alterations in diet and in colic. It is hoped that a better understanding of the molecular and cellular processes that play important roles in the physiology and pathology of the equine gastrointestinal tract will assist the development of effective strategies to prevent equine colic.  相似文献   

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A foetal cat exhibiting multiple congenital malformations and meeting the criteria for being considered as a case of true schistosoma reflexum (SR) is described. SR in animals is briefly compared with relatively similar malformation entities in humans. Murine gene mutations producing severe ventral body wall defects associated with anomalies of internal organs and other structures are briefly reviewed. New insights into aetiopathogenic mechanisms possibly implicated in the development of SR are suggested. This is probably the first case of true SR reported in the cat.  相似文献   

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During routine chemical analyses of the stalked ibliform barnacle Chaetolepas calcitergum Buckeridge & Newman 2006, peaks of more than 7% (by dry mass) of bromine were detected. Although bromine ions occur in seawater (up to 66 ppm), this level of accumulation, in the soft tissue of the barnacle, is extraordinary. Organic concentration of bromine compounds occurs in a number of invertebrates, such as algae and sponges, but this is the first record of elevated bromine in goose barnacles. The high accumulation of bromine compound(s) is most likely a defense mechanism. The present paper includes a review of the mechanisms deployed by barnacles to repel predators.
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New insights into the epidemiology of bovine piroplasmoses in Italy   总被引:1,自引:0,他引:1  
Few studies have been published on bovine piroplasmoses in Italy, and therefore a clear picture of the epidemiology of these infections is difficult to obtain. Vertebrate and invertebrate hosts in Central and Northern Regions of Italy were investigated in 2005 and 2006, when microscopy, molecular tools and serological tests were applied to 468 blood samples drawn from cattle in order to evaluate the presence of these protozoa and identify possible risk factors. Ticks were also collected, identified and analyzed by molecular techniques.Microscopy identified 6.5% of the animals as positive, whereas PCR detected piroplasm DNA in 21.6%. BLAST analysis showed 67 amplicons (17.0%) referable to the Theileria sergenti/buffeli/orientalis group, 17 (4.3%) to Theileria annae, and 1 to Babesia divergens. Serology evidenced a prevalence of 45.4% for Babesia bovis, 17.4% for Babesia bigemina, and 34.9% for B. divergens. The 127 collected ticks were identified as belonging to 5 species, mostly represented by Rhipicephalus bursa, Hyalomma marginatum and Ixodes ricinus. Molecular analyses evidenced the presence of B. bovis and B. bigemina, in 3 and 5 ticks, respectively.Our findings suggest that different species of piroplasms are circulating in bovine populations in Central and Northern Italy, and provide new insights into the complex epidemiology of bovine piroplasmoses in Italy.  相似文献   

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Previous epidemiological studies on EBLVs indicated a distinct geographical distribution of EBLV-1 in Germany. In this study, 48 isolates were selected to further investigate the spatial and temporal distribution of EBLV-1 variants in Germany. The nucleoprotein-gene (N), the nucleoprotein-phosphoprotein spanning untranslated region (NP-UTR) and the UTR between G- and L-gene of each isolate were sequenced using direct cycle sequencing. Results of the subsequent phylogenetic analysis of the N-gene confirmed previous studies on EBLVs, showing a high sequence identity among German EBLV-1a isolates, and a correlation between genetic and temporal and spatial distance, respectively, was shown. Our results indicate that the GL-UTR is not suitable for phylogenetic analyses. Interestingly, 6 nt insertions in two isolates as well as a single nucleotide insertion in a different isolate were detected in the N-P UTR. Within the UTR between G- and L-gene one isolate showed a 35 nt deletion. The effect of those changes on viral properties remains elusive as such mutations have not been described for lyssaviruses before.  相似文献   

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细菌生物被膜(bacterial biofilms)是由细菌互相粘连、不可逆地固着于生物机体或物体表面并由细菌分泌的胞外基质包裹的微生物群落。生物被膜为细菌提供了一种保护性生活方式,其形成有利于微生物持续定植,抵抗宿主免疫系统清除,提高对抗生素的耐受性以及遗传物质的交换。细菌生物被膜的存在对生物医学、食品加工等方面极为不利,因此,迫切需要研发能够去除生物被膜的新技术。目前,噬菌体被认为是控制生物被膜的一种有效方法。本文综述了应用噬菌体防控生物被膜的最新进展。  相似文献   

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Degenerative mitral valve disease (DMVD) is the most common cardiac disease in dogs. Although the disease is frequently described in the veterinary literature, many aspects are still unknown or controversial. Based on recent research findings, this article addresses the etiology, pathogenesis, inheritance, diagnosis of early DMVD, diagnosis of mild decompensated heart failure, and efficacy of early medical intervention in clinically compensated dogs.  相似文献   

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With the growing emergence of antibiotic resistance and rising consumer demands concerning food safety, vaccination to prevent bacterial infections is of increasing relevance. Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease leading to severe economic losses in the swine industry. Despite all the research and trials that were performed with A. pleuropneumoniae vaccination in the past, a safe vaccine that offers complete protection against all serotypes has yet not reached the market. However, recent advances made in the identification of new potential vaccine candidates and in the targeting of specific immune responses, give encouraging vaccination perspectives. Here, we review past and current knowledge on A. pleuropneumoniae vaccines as well as the newly available genomic tools and vaccination strategies that could be useful in the design of an efficient vaccine against A. pleuropneumoniae infection.  相似文献   

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Adipose tissue-derived stem cells (ADSCs) represent a promising subpopulation of adult stem cells for tissue engineering applications in veterinary medicine. In this study we focused on the morphological and molecular biological properties of the ADSCs. The expression of stem cell markers Oct4, Nanog and the surface markers CD90 and CD105 were detected using RT-PCR. ADSCs showed a proliferative potential and were capable of adipogenic and osteogenic differentiation. Expression of Alkaline phosphatase (AP), phosphoprotein (SPP1), Runx2 and osteocalcin (OC) mRNA were positive in osteogenic lineages and peroxisome proliferator activated receptor (Pparγ2) mRNA was positive in adipogenic lineages. ADSCs show stem cell and surface marker profiles and differentiation characteristics that are similar to but distinct from other adult stem cells, such as bone marrow-derived mesenchymal stem cells (BM-MSCs). The availability of an easily accessible and reproducible cell source may greatly facilitate the development of stem cell based tissue engineering and therapies for regenerative equine medicine.  相似文献   

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The Ruminant Nutrition Symposium titled "Acidosis: New insights into the persistent problem" was held at the Joint Annual Meeting of the American Dairy Science Association, American Society of Animal Science, Poultry Science Association, Asociación Mexicana de Producción Animal, Western Section-ASAS, and the Canadian Society of Animal Science in Denver, Colorado, July 11 to 15, 2010. The objective of the symposium was to provide the ruminant nutrition community with new insights and perspectives from recent research findings on acidosis. Under modern production systems, ruminants are fed high-grain diets to maximize their energy intake and productivity. However, feeding highly fermentable diets often causes excess fermentation and results in accumulation of fermentation acids in the rumen, leading to a decrease in feed intake, poor feed efficiency, liver abscesses, and lameness in feedlot cattle or lactating dairy cows. Although our understanding of nutritional factors (i.e., effects of type and processing method of grains and importance of physically effective fiber) affecting rumen pH have increased substantially over the past few decades, rumen acidosis has continued to be a common problem in the ruminant livestock industry. The symposium program was organized to review recent research findings in acidosis with more emphasis on physiological aspects, and provide novel insights into the persistent problem.  相似文献   

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