The role of rodents in avian influenza outbreaks in poultry farms: a review

Wild migratory birds are associated with global avian influenza virus (AIV) spread. Although direct contact with wild birds and contaminated fomites is unlikely in modern non-free range poultry farms applying biosecurity measures, AIV outbreaks still occur. This suggests involvement of other intermediate factors for virus transmission between wild birds and poultry. This review describes current evidence of the potential role of rodents in AIV transmission from wild birds to poultry and between poultry houses. Rodents can be abundant around poultry houses, share their habitat with waterfowl and can readily enter poultry houses. Survival of AIV from waterfowl in poultry house surroundings and on the coat of rodents suggests that rodents are likely to act as mechanical vector. AIVs can replicate in rodents without adaptation, resulting in high viral titres in lungs and nasal turbinates, virus presence in nasal washes and saliva, and transmission to naïve contact animals. Therefore, active AIV shedding by infected rodents may play a role in transmission to poultry. Further field and experimental studies are needed to provide evidence for a role of rodents in AIV epidemiology. Making poultry houses rodent-proof and the immediate surroundings unattractive for rodents are recommended as preventive measures against possible AIV introduction.     

The relevance of glycine and serine in poultry nutrition: a review

ABSTRACT

1. Dietary glycine equivalents (Gly_equi) for glycine and serine represent the first-limiting non-essential amino acid in poultry diets. Targeted adjustment of essential amino acids and Gly_equi in diets can considerably decrease crude protein (CP) in poultry diets below the limit of CP reduction when only essential amino acids are adjusted.

2. The level to which CP can be reduced in diets adequate in Gly_equi depends on the objective; which includes reducing dietary CP without affecting performance and increasing nitrogen utilisation efficiency. Dietary CP can be reduced to ~15–16% in diets for up to 21 d old broiler chicken without affecting growth performance compared to responses to diets with currently common CP concentrations by considering Gly_equi in the diet formulation. Dietary CP can be further reduced to maximise nitrogen utilisation efficiency; however, this leads to reduced growth performance.

3. The dietary Gly_equi requirement of poultry varies depending on other dietary constituents. In broiler chickens up to 21 days of age, the dietary Gly_equi requirement is estimated to be between 11 and 20 g/kg. This estimate is influenced by the concentrations of Cys and the endogenous Gly_equi precursors, threonine and choline. Urinary nitrogen excretion seems to be a major determinant of the response to dietary Gly_equi, because it is needed for uric acid formation.

4. The variable requirement for dietary Gly_equi means that its static recommendation in poultry diets would lead to high safety margins in Gly_equi supply or the risk of Gly_equi deficiency. Variable recommendations for dietary Gly_equi concentrations would help to supply birds based on their specific requirements and could reduce nitrogen emissions originating from poultry farming.     

The effect of inulin supply to high‐fat diet rich in saturated fatty acids on pork quality and profile of sarcoplasmic protein in meat exudate

The aim of the study was to evaluate the influence of inulin supply to high‐fat diet rich in saturated fatty acids (SFA) on pork quality and profile of sarcoplasmic protein in drip loss. At 50 days of age, twenty cross‐bred pigs (gilts) were randomly allotted to four groups: the control (C) group fed a standard diet, and three experimental (D1, D2 and D3) groups fed a high‐fat diet rich in SFA. Moreover, pigs from the groups D2 and D3 consumed an extra inulin supply (7% of daily feed intake) from 85 to 120 days of age (for 5 weeks) and from 50 to 120 days of age (for 10 weeks) respectively. The addition of inulin to the diet reduced meaty odour and flavour significantly, improved tenderness and overall sensory quality of pork and additionally influenced ultimate pH, L* colour parameter, lactate level and protein content in meat. The diets also affected the profile of sarcoplasmic proteins. Significant effects were observed for the following enzymes—PK/PGI (pyruvate kinase/phosphoglucose isomerase) and ALD (aldolase), which are related to the intensity of post‐mortem glycolysis. Presented data indicate that long‐term inulin supply to high‐fat diet has a positive effect on technological and sensory quality as well as protein profile of pork.     

Diagnosis and treatment of copper poisoning caused by accidental feeding on poultry litter in a sheep flock

We report a case of chronic copper poisoning in a flock of 182 grazing dairy sheep in Thessaly, Central Greece. Five ewes were found dead during the course of a week. The diagnosis of copper poisoning was confirmed by necropsy examination, blood test results, and abnormally high copper levels in liver and kidney samples. A field investigation revealed the source of copper as a litter heap from a broiler farm to which the sheep had accidental access during their movement between the milking parlour and the grazing area. Access to the litter was subsequently blocked and all sheep were provided with 50 g of a salt/gypsum/sodium molybdate mixture (90.0: 9.8: 0.2, w/w) mixed in 500 g of concentrate feed daily, for a period of 5 weeks. Follow-up blood samples were taken 3 and 8 wk after the initial diagnosis. A reduction in aspartate aminotransferase activity indicated the source of copper had been eliminated and the subsequent treatment was successful.     

Supplementation of Selenium Nanoparticles-Loaded Chitosan Improves Production Performance,Intestinal Morphology,and Gut Microflora in Broiler Chickens

The current study aimed to evaluate the efficacy of selenium nanoparticles (SeNPs), combined or loaded with chitosan (COS), in broiler chickens reared under standard management protocols. The parameters under investigation were production performance, organ development, components of the intestinal barrier, and ileal microbial count. Two hundred and forty day-old chicks were raised in five groups, with each group containing eight replicates (n=6/replicate). The control group received a basal diet whereas the other four groups received basal diets supplemented with SeNPs (0.5 mg/kg), COS (200 mg/kg), SeNPs+COS (0.5 mg/kg SeNPs + 200 mg/kg COS), and SeNPs-loaded COS (SeNPs-L-COS) (200 mg/kg) respectively. On day 35, two birds/replicate were sampled to collect the viscera under investigation. The results revealed that dietary inclusion of SeNPs-L-COS increased (p<0.05) the body weight gain and improved (p<0.05) feed conversion ratio. Similarly, SeNPs-L-COS supplementation increased (p<0.05) the small intestinal villus surface area as well as the count of acidic goblet cells and intraepithelial lymphocytes when compared with the control group. Whereas the total goblet cell count was higher (p<0.05) in the small intestines of both the SeNPs+COS and SeNPs-L-COS groups. Microbial analysis of ileal contents also revealed an increase (p<0.05) in Lactobacilli species count with a concurrent decrease (p<0.05) in Escherichia coli count in the SeNPs-L-COS group when compared with the COS and control groups. Based on the results of the current trial, we can conclude that supplementation with SeNPs-L-COS is a superior combination for promoting the gut health and performance of broilers.     

The use of a pen-size optimization workbook for experiment research design using the Visual Basic for Applications in Excel for poultry

Researchers often seem to choose the number of birds per pen and replications per treatment somewhat arbitrarily on the basis of cost, availability of animals, housing considerations, convenience, tradition, and so on. Statistical simulation, performed while designing an experiment, will provide a researcher with an objective estimate of the number of birds per pen and replicates needed for an experiment of known Type I and II errors. In most cases, the time for making power calculations should be before, not after, an experiment is conducted. Here we present a Microsoft Excel workbook to explore the statistical and economic ramifications of different combinations of birds per replicate and replicates per treatment for research with poultry.     

In vitro effects of inulin and soya bean oligosaccharide on skatole production and the intestinal microbiota in broilers

The experiment was conducted to investigate the in vitro effects of inulin and soya bean oligosaccharide (SBO) on the metabolism of L‐tryptophan (L‐try) to skatole production, and the intestinal microbiota in broilers. Treatments were as follows: caecal microbiota control (Cc), Cc + inulin, Cc + SBO, rectal microbiota control (Rc), Rc + inulin and Rc + SBO. Microbial suspensions were anaerobically incubated at 38°C for 24 hr. The results showed that concentrations of skatole and acetic acid were significantly lower in caecal microbiota fermentation broth (MFB) than those in rectal MFB (p < .05). Addition of inulin or SBO significantly decreased the concentrations of indole and skatole and rate of L‐try degradation (p < .05). Inulin groups had lower indole than SBO groups (p < .05). PCR‐DGGE analysis revealed that addition of inulin or SBO decreased the microbiota richness (p < .05), but no significant differences in Shannon index (p > .05). Four distinct bands were detected in inulin and SBO groups, which were related to two of Bacteroides, one of Firmicutes and Bifidobacteria. Six bands were detected only in control groups, which represented uncultured Rikenellaceae, Roseburia, Escherichia/Shigella dysenteriae, Bacteroides uniformis (T), Parabacteroides distasonis and Enterobacter aerogenes. Populations of Lactobacilli, Bifidobacteria and total bacteria in inulin groups were higher than those in control groups (p < .05). For SBO groups, only population of total bacteria increased (p < .05). However, there were no significant differences in Escherichia coli population among treatments (p > .05). These results suggest that reduced concentrations of skatole and indole in the presence of inulin and SBO may be caused by decrease in L‐try degradation rate, which were caused by change in microbial ecosystem and pH value. Uncultured B. uniformis (T) and E. aerogenes may be responsible for degradation of L‐try to skatole.     

In ovo feeding of carbohydrates for broilers—a systematic review

The purpose of this systematic review was to evaluate the evidence that the injection of carbohydrate‐based solutions into embryonated eggs improves broiler performance. A literature search was conducted in April 2017 using the keywords broiler, carbohydrate, in ovo, nutrition and poultry. Only papers that involved in ovo carbohydrate injections in poultry were used in this study. After specific selection criteria, 17 papers were selected. The quality scoring system of the selected studies was based on the injection methodology, use of control groups, type of solution injected, period of injection, egg and hens characteristics, number of variables analysed and the statistical design. Among papers, there was no standardised procedure in to inoculate the solutions. Nevertheless, in general, in ovo feeding of carbohydrates decreases the hatch rate, improves the hatch weight, but it does not seem to influence the post‐hatch performance of broilers. The inoculation of 75 mg of glucose in the albumen seems to bring better results. Further studies are needed to improve the technical methodology of in ovo injections for commercial use.     

我国禽肉产业发展现状和对策

HE Yang;LIU Chousheng(National Animal Husbandry Service,Chaoyang,Beijing 100125,China)     

蘑菇类原料在家禽生产中的应用

近期人们对食用蘑菇的潜力及其在预防和治疗方面的应用越来越感兴趣.食用蘑菇具有抗氧化、免疫刺激、抗炎、抗菌、抗病毒和降胆固醇等特性.本文综述了食用蘑菇作为饲料添加剂在肉鸡和蛋鸡中的应用现状,并对食用蘑菇的营养和健康促进作用进行综述.     

植酸酶在家禽饲养中的应用

植酸酶能够水解植酸盐,释放出能被动物利用的磷和多种微量元素。它不仅消除植酸的抗营养作用,还提高动物胃肠道消化酶的活性,提高饲料的利用率,减少饲料中添加高水平磷所造成的环境污染。本文综述了植酸酶在禽类饲料中的应用效果和近年来的研究进展。     

牛磺酸的生物学功能及其在家禽生产中的应用

牛磺酸是一种条件性必需氨基酸,具有广泛的生物学功能。本文从脂质代谢、脂质过氧化、神经内分泌系统、免疫功能等方面重点讨论牛磺酸的生物学功能及其在家禽生产中的应用。     

Aortic rupture in poultry: a review

Mortality in poultry due to aortic rupture is characterized by sudden death. The condition is seen in fast-growing male turkeys but has also been described in chickens, ostriches, and waterfowl. Losses in affected flocks usually only reach 1-2%. Post-mortem examination shows a large blood clot in the abdominal cavity subsequent to a dissecting aneurysm. Fragmentation of elastic fibres and degenerative changes of smooth muscle cells are seen in the region of the rupture. Intimal sclerotic plaques are present adjacent to the site of rupture. Copper deficiency, hypertension, hormonal influences, diet, lathyrism, zinc deficiency, pharmaceuticals, and parasites are precipitating factors for aortic rupture. Field studies suggest that favourable results are obtained with reserpine and copper as treatment for ruptured aorta.     

多胺在畜禽营养中的作用

本文就畜禽体内多胺的来源及代谢,多胺对畜禽小肠形态、功能以及畜禽生长性能的影响进行综述。     

调控家禽肌肉和肝脏代谢的胰岛素信号

本文综述了胰岛素通过受体对鸡肝脏和肌肉的一般代谢和基因表达的调控作用。与哺乳动物相比,家禽血液循环中具有相似的胰岛素浓度,但仍然可以维持高血糖水平,这可能是家禽对外源性胰岛素敏感性低的结果。为了确定这种低敏感性是否是家禽与哺乳动物之间胰岛素受体信号差异的结果,家禽组织中的胰岛素受体已经得到了验证,并在肝脏和肌肉组织发现了两种胰岛素受体底物(胰岛素受体底物-1和结构域蛋白C)。与哺乳动物相比,目前我们对家禽胰岛素信号传导的认识还不全面。当考虑到参与胰岛素级联反应的成分异构体数量时,这一点尤其明显,许多异构体可能尚未在家禽中得到验证。尽管现有数据存在一些不足,但鸡肝脏中的胰岛素信号与哺乳动物相似,但肌肉与哺乳动物不同。在腿部肌肉中,鸡与哺乳动物在胰岛素信号级联的早期阶段不同,其中,鸡的磷脂酰肌醇-3激酶(PI3K)活性大约是大鼠的30倍,这种肌肉PI3K的高活性可能过度刺激鸡的反馈抑制通路,从而使鸡肌肉对胰岛素不敏感。     

Tryptophan in poultry nutrition: Impacts and mechanisms of action

Many studies have shown that productivity, immune system, antioxidant status, and meat and egg quality can be optimized by dietary supplementation with amino acids that are not usually added to poultry diets. Understanding the effects of these amino acids may encourage feed manufacturers and poultry producers to include them as additives. One of these amino acids is tryptophan (Trp). The importance of Trp is directly related to its role in protein anabolism and indirectly related to its metabolites such as serotonin and melatonin. Thus, Trp could affect the secretion of hormones, development of immune organs, meat and egg production, and meat and egg quality in poultry raised under controlled or stressed conditions. Therefore, this review discusses the main roles of Trp in poultry production and its mode (s) of action in order to help poultry producers decide whether they need to add Trp to poultry diets. Further areas of research are also identified to address information gaps.