Epidemiological Study of Hepatitis E Virus Infection in Pigs in Zhejiang Province

<正>The study was aimed at establishing an indirect ELISA for epidemiological investigation of hepatitis E viral(HEV) infection in pigs from the major pig-producing regions of Zhejiang Province. The gene fragment covering the immunogenic epitopes of HEV ORF2 was synthesized and expressed in Escherichia coli.Western blot analysis revealed that the purified protein reacted to HEV positive sera,but not to positive sera from some other common viruses that infect pigs.An indirect ELISA system was then developed using truncated HEV ORF2 protein as the coating antigen and had diagnostic accuracy of 91.5% as compared with a diagnostic kit for HEV antibodies.A total of 1 330 serum samples were collected from 46 pig farms in Zhejiang Province from 2005-2008 and tested for sero-prevalence of HEV using the indirect ELISA.The average HEV-positive rate was 55.7%(741/1 330).The positive rate of 2005 and 2006 was 62.7%(175/279) and 61.4%(301/490) respectively,much higher than those of 2007(43.0%,59/137) and 2008(48.6%,206/424).Pigs aged 66-100 days had a statistically higher positive rate(58.2%,110/189) when compared to that of pigs aged 30-65 days(39.7%,73/184) or 101-160 days(44.1%,83/188).Only three herds in the study were HEV antibody-negative,indicating high sero-prevalence of HEV in the pig populations in Zhejiang Province.     

Feed Output in China to Rebound

The output of animal teed is poised to rebound after seeingits first contraction in 20 years, as demand for feed increases on greater demand for meat and increased production at fish farms in the country.     

Dietary requirements of synthesizable amino acids by animals:a paradigm shift in protein nutrition

Amino acids are building blocks for proteins in all animals.Based on growth or nitrogen balance,amino acids were traditionally classified as nutritionally essential or nonessential for mammals,birds and fish.It was assumed that all the "nutritionally nonessential amino acids(NEAA)" were synthesized sufficiently in the body to meet the needs for maximal growth and optimal health.However,careful analysis of the scientific literature reveals that over the past century there has not been compelling experimental evidence to support this assumption.NEAA(e.g.,glutamine,glutamate,proline,glycine and arginine) play important roles in regulating gene expression,cell signaling,antioxidative responses,fertility,neurotransmission,and immunity.Additionally,glutamate,glutamine and aspartate are major metabolic fuels for the small intestine to maintain its digestive function and to protect the integrity of the intestinal mucosa.Thus,diets for animals must contain all NEAA to optimize their survival,growth,development,reproduction,and health.Furthermore,NEAA should be taken into consideration in revising the "ideal protein" concept that is currently used to formulate swine and poultry diets.Adequate provision of all amino acids(including NEAA) in diets enhances the efficiency of animal production.In this regard,amino acids should not be classified as nutritionally essential or nonessential in animal or human nutrition.The new Texas A&M University’s optimal ratios of dietary amino acids for swine and chickens are expected to beneficially reduce dietary protein content and improve the efficiency of their nutrient utilization,growth,and production performance.     

Grading Index(GI)∶A New Integrated Technique for Evaluation of Forage Quality

IntroductionForage quality can be defined as the extent to which forage has the potential to produce a desired animal response or level of performance,for example,daily gain or milk production.Due to forage quality is a function of both animal and plant factors.It is difficult and complex to completely evaluate forage quality.Recently,an new integrated index,Grading index (GI),was proposed by Chinese scholar Lu Dexun.Grading index (GI) method has been appraised officially as the national standard of forage quality evaluation in China,which was implemented in 2009.On basis of briefly overview the development of forage quality evaluation technology,this paper is to emphasize on introducing forage grading index and its application in dairy cattle feeding.     

Gut health benefit and application of postbiotics in animal productionOA

Gut homeostasis is of importance to host health and imbalance of the gut usually leads to disorders or diseases for both human and animal. Postbiotics have been applied in manipulating of gut health, and utilization of postbiotics threads new lights into the host health. Compared with the application of probiotics, the characteristics such as stability and safety of postbiotics make it a potential alternative to probiotics. Studies have reported the beneficial effects of components derived from ...     

Ministry of Agriculture Intensifying the Supervision of Animal Drugs to Ensure Animal Drug Quality and Safety of Animal Products

Recently, the Veterinary Bureau of Ministry of Agriculture publicized the plan on animal drug supervision in the latter half of 2010, requiring more stringent measures to be taken by the veterinary departments at all levels in an all-round way. Work should focus on the guaranteed quality of key vaccines for animal diseases and quality safety of animal products, so as to ensure the healthy development of animal husbandry and safeguard the safety of public hygiene.     

Ministry of Agriculture Intensifying the Supervision of Animal Drugs to Ensure Animal Drug＇s Quality and Safety of Animal Products

Recently, the Veterinary Bureau of Ministry of Agriculture publicized the plan on animal drug supervision in the latter half of 2010, requiring more stringent measures to be taken by the veterinary departments at all levels in an all-round way, focusing on the guaranteed quality of key vaccines for animal diseases and quality safety of animal products, so as to ensure the healthy development of animal husbandry and safeguard the safety of public hygiene.     

GMOs in animal agriculture: time to consider both costs and benefits in regulatory evaluations

In 2012, genetically engineered （GE） crops were grown by 17.3 million farmers on over 170 million hectares. Over 70% of harvested GE biomass is fed to food producing animals, making them the major consumers of GE crops for the past 15 plus years. Prior to commercialization, GE crops go through an extensive regulatory evaluation. Over one hundred regulatory submissions have shown compositional equivalence, and comparable levels of safety, between GE crops and their conventional counterparts. One component of regulatory compliance is whole GE food/feed animal feeding studies. Both regulatory studies and independent peer-reviewed studies have shown that GE crops can be safely used in animal feed, and rDNA fragments have never been detected in products （e.g. milk, meat, eggs） derived from animals that consumed GE feed. Despite the fact that the scientific weight of evidence from these hundreds of studies have not revealed unique risks associated with GE feed, some groups are calling for more animal feeding studies, including long-term rodent studies and studies in target livestock species for the approval of GE crops. It is an opportune time to review the results of such studies as have been done to date to evaluate the value of the additional information obtained. Requiring long-term and target animal feeding studies would sharply increase regulatory compliance costs and prolong the regulatory process associated with the commercialization of GE crops. Such costs may impede the development of feed crops with enhanced nutritional characteristics and durability, particularly in the local varieties in small and poor developing countries. More generally it is time for regulatory evaluations to more explicitly consider both the reasonable and unique risks and benefits associated with the use of both GE plants and animals in agricultural systems, and weigh them against those associated with existing systems, and those of regulatory inaction. This would represent a shift away from a GE evaluation process that currently focuses only on risk assessment and identifying ever diminishing marginal hazards, to a regulatory approach that more objectively evaluates and communicates the likely impact of approving a new GE plant or animal on agricultural production systems.     

Improving the nutritional values of yellow mealworm Tenebrio molitor(Coleoptera: Tenebrionidae) larvae as an animal feed ingredient: a reviewOA

Yellow mealworm larvae(YML; Tenebrio molitor) are considered as a valuable insect species for animal feed due to their high nutritional values and ability to grow under different substrates and rearing conditions. Advances in the understanding of entomophagy and animal nutrition over the past decades have propelled research areas toward testing multiple aspects of YML to exploit them better as animal feed sources. This review aims to summarize various approaches that could be exploited to maximi...     

Heat stress in pigs and broilers:role of gut dysbiosis in the impairment of the gut-liver axis and restoration of these effects by probiotics,prebiotics and synbioticsOA

Heat stress is one of the most challenging stressors for animal production due to high economic losses resulting from impaired animal’s productivity,health and welfare.Despite the fact that all farm animal species are susceptible to heat stress,birds and pigs are particularly sensitive to heat stress due to either lacking or non-functional sweat glands.Convincing evidence in the literature exists that gut dysbiosis,a term used to describe a perturbation of commensal gut microbiota,develops in br...     

Fecal microbiota dynamics and its relationship to diarrhea and health in dairy calvesOA

Background: Diarrhea is a major cause of morbidity and mortality in young calves, resulting in considerable economic loss for dairy farms. To determine if some gut microbes might have resistance to dysbiotic process with calf diarrhea by dictating the microbial co-occurrence patterns from birth to post-weaning, we examined the dynamic development of the gut microbiota and diarrhea status using two animal trials, with the first trial having 14 Holstein dairy calves whose fecal samples were collec...     

Effects of Chrysanthemum coronarium Extract on Fermentation Characteristics and Biohydrogenation of Polyunsaturated Fatty Acids in vitro Batch Culture

IntroductionCis-9,trans-11 CLA has been shown to be potentially healthpromoting CLA in many animal models.The C18∶1 trans-11 fatty acid (VA) is also desirable as a product flowing from the rumen,because the flow from the rumen of VA play a more important role than CLA in determining CLA concentration in animal tissues.The factors which affect CLA content in milk have been studied mainly in dairy cows and most factors are basically dietary factors,especially fat source(e.g.,plant oils,fish oil,et al.).Recently some researches showed that some plants or plant extracts could increase cis-9,trans-11 -CLA content in milk.The purpose of this experiment was to evaluate the effects of Chrysanthemum coronarium extract on in vitro Biohydrogenation of polyunsaturated fatty acids and fermentation characteristics of mixed rumen microorganisms.     

Gama-aminobutyric acid(GABA) alleviates hepatic inflammation via GABA receptors/TLR4/NF-kB pathways in growing-finishing pigs generated by super-multiparous sows

The offspring of super-multiparous sows face problems such as decreased growth performance, poor meat quality and even diseases in animal husbandry. Gama-aminobutyric acid(GABA) has long been known to promote growth and suppress inflammation, but little is known about the mechanisms. A total of 72 growing-finishing pigs from the 8th generation were randomly allotted to 2 groups with 6 replicates per treatment to receive a corn-soybean basal diet or the basal diet supplemented 20 mg/kg GABA for 6...     

Epigenetics and transgenerational inheritance in domesticated farm animals

Epigenetics provides a molecular mechanism of inheritance that is not solely dependent on DNA sequence and that can account for non-Mendelian inheritance patterns. Epigenetic changes underlie many normal developmental processes, and can lead to disease development as wel. While epigenetic effects have been studied in wel-characterized rodent models, less research has been done using agricultural y important domestic animal species. This review wil present the results of current epigenetic research using farm animal models(cattle, pigs, sheep and chickens). Much of the work has focused on the epigenetic effects that environmental exposures to toxicants, nutrients and infectious agents has on either the exposed animals themselves or on their direct offspring. Only one porcine study examined epigenetic transgenerational effects; namely the effect diet micronutrients fed to male pigs has on liver DNA methylation and muscle mass in grand-offspring(F2 generation). Healthy viable offspring are very important in the farm and husbandry industry and epigenetic differences can be associated with production traits. Therefore further epigenetic research into domestic animal health and how exposure to toxicants or nutritional changes affects future generations is imperative.     

Feed-and feed additives-related aspects of gut health and development in weanling pigs

The development of new/different management and feeding strategies to stimulate gut development and health in newly-weaned pigs, in order to improve growth performance while minimizing the use of antimicrobial compounds such as antibiotic growth promotants (AGP) and heavy mineral compounds, is essential for the long-term sustainability of the pig industry. Factors including the sub-optimal intake of nutrients and energy, inappropriate microbiota biomass and (or) balance, immature and compromised immune function, and psychosomatic factors caused by weaning can compromise both the efficiency of digestion and absorption and intestinal barrier function through mucosal damage and alteration of tight junction integrity. As a consequence, pigs at weaning are highly susceptible to pathogenic enteric conditions such as post-weaning diarrhea that may be caused by serotypes of enterotoxigenic Escherichia coli. Many dietary components, e.g., protein, fiber, feed additives and minerals, are known to influence microbial growth in the gastrointestinal tract that in turn can impact upon pig growth and health, although the relationships between these are sometimes not necessarily apparent or obvious. In a world climate of increased scrutiny over the use of antibiotics per se in pig production, certain feed additives are seen as alternatives/replacements to antibiotics, and have evolved in some cases to have important roles in everyday commercial pig nutrition. Nevertheless and in general, there remains inconsistency and variability in the efficacy of some feed additives and in cases of severe disease outbreaks, for example, therapeutic antibiotics and/or heavy minerals such as zinc oxide (ZnO) are generally relied upon. If feed ingredients and (or) feed additives are to be used with greater regularity and reliability, then it is necessary to better understand the mechanisms whereby antibiotics and minerals such as ZnO influence animal physiology, in conjunction with the use of appropriate challenge models and in vitro and in vivo techniques.     

New horizons for selenium in animal nutrition and functional foods

Selenium(Se), one of the indispensable nutrients for both human health and animal growth, participates in various physiological functions, such as antioxidant and immune responses and metabolism. The role of dietary Se, in its organic and inorganic forms, has been well documented in domestic animals.Furthermore, many feeding strategies for different animals have been developed to increase the Se concentration in animal products to address Se deficiency and even as a potential nutritional strateg...     

Uterine biology in pigs and sheep

There is a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling, implantation, regulation of gene expression by uterine epithelial and stromal cells, placentation and exchange of nutrients and gases. The uterus provide a microenvironment in which molecules secreted by uterine epithelia or transported into the uterine lumen represent histotroph required for growth and development of the conceptus and receptivity of the uterus to implantation. Pregnancy recognition signaling mechanisms sustain the functional lifespan of the corpora lutea (CL) which produce progesterone, the hormone of pregnancy essential for uterine functions that support implantation and placentation required for a successful outcome of pregnancy. It is within the peri-implantation period that most embryonic deaths occur due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. With proper placentation, the fetal fluids and fetal membranes each have unique functions to ensure hematotrophic and histotrophic nutrition in support of growth and development of the fetus. The endocrine status of the pregnant female and her nutritional status are critical for successful establishment and maintenance of pregnancy. This review addresses the complexity of key mechanisms that are characteristic of successful reproduction in sheep and pigs and gaps in knowledge that must be the subject of research in order to enhance fertility and reproductive health of livestock species.     

睡眠嗜血杆菌复合体病研究进展

Haemophilus somnus has long been associated with thrombotic meningoencephalomyelitis but has also been identified as the agent responsible for other clinical diseases including respiratory disease, reproductive problems, myocarditis, otitis, conjunctivitis, mastitis, and polyarthritis. Exposure to the bacteria is widespread and infection may occur via the respiratory tract from urogenital excretions and secretions.Diagnosis and treatment of hemophilosis may be easy or difficult depending on the manifestation presented, and special procedures must be taken to facilitate isolation of the organism. vaccination is the only preventive measure demonstrating a beneficial effect.     

Dual potential of microalgae as a sustainable biofuel feedstock and animal feed

The rise in global population has led to explorations of alternative sources of energy and food. Because corn and soybean are staple food crops for humans, their common use as the main source of dietary energy and protein for food-producing animals directly competes with their allocation for human consumption. Alternatively, de-fatted marine microalgal biomass generated from the potential biofuel production may be a viable replacement of corn and soybean meal due to their high levels of protein, relatively well-balanced amino acid profiles, and rich contents of minerals and vitamins, along with unique bioactive compounds. Although the full-fatted （intact） microalgae represent the main source of omega-3 （n-3） polyunsaturated fatty acids including docohexaenoic acid （DHA） and eicosapentaenoic acid （EPA）, the de-fatted microalgal biomass may still contain good amounts of these components for enriching DHA/EPA in eggs, meats, and milk. This review is written to highlight the necessity and potential of using the de-fatted microalgal biomass as a new generation of animal feed in helping address the globa energy, food, and environmental issues. Nutritional feasibility and limitation of the biomass as the new feed ingredient for simple-stomached species are elaborated. Potential applications of the biomass for generating value-added animal products are also explored.     

Current status and future perspectives for sequencing livestock genomes

Only in recent years, the draft sequences for several agricultural animals have been assembled. Assembling an individual animal’s entire genome sequence or specific region(s) of interest is increasingly important for agricultural researchers to perform genetic comparisons between animals with different performance. We review the current status for several sequenced agricultural species and suggest that next generation sequencing (NGS) technology with decreased sequencing cost and increased speed of sequencing can benefit agricultural researchers. By taking advantage of advanced NGS technologies, genes and chromosomal regions that are more labile to the influence of environmental factors could be pinpointed. A more long term goal would be addressing the question of how animals respond at the molecular and cellular levels to different environmental models (e.g. nutrition). Upon revealing important genes and gene-environment interactions, the rate of genetic improvement can also be accelerated. It is clear that NGS technologies will be able to assist animal scientists to efficiently raise animals and to better prevent infectious diseases so that overall costs of animal production can be decreased.