Thermotolerant Campylobacter during Broiler Rearing: Risk Factors and Intervention

Thermotolerant Campylobacters are one of the most important bacterial causative agents of human gastrointestinal illness worldwide. In most European Union (EU) member states human campylobacteriosis is mainly caused by infection with Campylobacter jejuni or Campylobacter coli following consumption or inadequate handling of Campylobacter‐contaminated poultry meat. To date, no effective strategy to control Campylobacter colonization of broilers during rearing is available. In this review, we describe the public health problem posed by Campylobacter presence in broilers and list and critically review all currently known measures that have been researched to lower the numbers of Campylobacter bacteria in broilers during rearing. We also discuss the most promising measures and which measures should be investigated further. We end this review by elaborating on readily usable measures to lower Campylobacter introduction and Campylobacter numbers in a broiler flock.     

试验预混料对肉仔鸡增重和肌肉品质影响的研究

选择1日龄商品代艾维茵(Avian)混合健雏180只为试验动物,随机分为2组,即试验组和对照组,进行49 d的饲养对比试验.在试验基础日粮中,试验组添加1.5%的自行研制的肉鸡用复合预混料,对照组添加1.0%的市售肉鸡用复合预混料,观察其增重效果和肌肉品质.结果表明:试验全期试验组、对照组肉鸡的平均增重分别为2 655和2 698 g(P＞0.05);平均料肉比分别为1.89和1.84(P＞0.05);试验组肉鸡肌肉中水分、粗蛋白质、肌内脂肪酸、氨基酸总量和不饱和脂肪酸总量分别优于对照组3.05%、8.40%、12.94%、9.58%和11.06%,差异显著(P＜0.05).     

日粮蛋氨酸和赖氨酸水平对肉鸡生长性能及肌肉和肝脏组织DNA甲基化含量的影响

研究日粮中添加不同氨基酸水平对肉鸡生长性能和不同日龄阶段肉鸡各组织中DNA甲基化含量的影响。结果表明:①日粮中添加不同赖氨酸和蛋氨酸水平,显著影响了肉仔鸡的生长和屠宰性能;②肉鸡肌肉和肝脏组织DNA甲基化含量随日龄增加均成降低趋势;55日龄肉鸡肌肉和肝脏组织中,蛋氨酸过量组DNA甲基化含量均大于蛋氨酸缺乏组,且两两差异显著;③肉鸡肌肉甲基化含量与55日龄肉鸡总活体重、胴体重成显著正相关,与屠宰率、半净膛率和全净膛率成负相关;肉鸡肝脏甲基化含量与55日龄肉鸡总活体重、半净膛重、全净膛重成显著正相关,与屠宰率和半净膛率成负相关。     

Common structure in the heterogeneity of plant-matter decay

Carbon removed from the atmosphere by photosynthesis is released back by respiration. Although some organic carbon is degraded quickly, older carbon persists; consequently carbon stocks are much larger than predicted by initial decomposition rates. This disparity can be traced to a wide range of first-order decay-rate constants, but the rate distributions and the mechanisms that determine them are unknown. Here, we pose and solve an inverse problem to find the rate distributions corresponding to the decomposition of plant matter throughout North America. We find that rate distributions are lognormal, with a mean and variance that depend on climatic conditions and substrate. Changes in temperature and precipitation scale all rates similarly, whereas the initial substrate composition sets the time scale of faster rates. These findings probably result from the interplay of stochastic processes and biochemical kinetics, suggesting that the intrinsic variability of decomposers, substrate and environment results in a predictable distribution of rates. Within this framework, turnover times increase exponentially with the kinetic heterogeneity of rates, thereby providing a theoretical expression for the persistence of recalcitrant organic carbon in the natural environment.     

不同湿度条件对肉鸡浓缩料中霉菌污染的影响

研究了室温条件下不同湿度(RH)贮存饲料的霉菌污染情况,在湿度条件分别为65%RH、75%RH、85%RH,利用国标检测法进行霉菌总数、产毒菌种类及毒素含量分析。结果表明,在20℃、65%RH条件下,饲料存放到第17天前就应该采取防霉措施。在75%RH条件下,存放到第10天前就应该采取防霉措施。在85%RH条件下,在生产饲料的时候就应该采取防霉措施。     

Effect of reconstitution of sorghum with or without enzymes on production performance and immunocompetence in broiler chicken

BACKGROUND: The presence of tannins and phytic acid in sorghum causes anti‐nutritional effects that include reduced growth rate, feed intake, feed efficiency and nutrient digestibility in broiler chicken. Therefore, in the present investigation efforts were made to reveal the effect of reconstitution of sorghum with or without enzymes on production performance and immunocompetence in broiler chicken. RESULTS: The body weight gain, feed conversion ratio, energy and protein utilization efficiency were better in birds fed reconstituted sorghum in comparison to those fed untreated sorghum. The intake of feed in different treatments did not vary in comparison to the control group. The feed cost per unit weight gain or meat yield apparently reduced due to reconstitution. There was significant improvement in nitrogen corrected apparent metabolizable energy (AMEn) of diets containing reconstituted sorghum. The serum biochemical parameters such as total cholesterol, triglycerides and uric acid were not affected due to dietary treatments. The cell‐mediated immune response to phytohaemagglutinin‐P was better in sorghum‐fed groups. However, the humoral response to sheep red blood cells remained unaffected owing to the substitution of the maize by sorghum or its processed form. CONCLUSION: The results suggest that the reconstitution of sorghum was beneficial in improving the growth performance and nutrient utilization in broiler chicken. However, supplementation of enzymes to raw sorghum‐based diets or addition of enzymes during reconstitution of sorghum did not further improve the growth performance of broilers. Copyright © 2009 Society of Chemical Industry     

虫草饲料添加剂对肉仔鸡肌肉营养成分的影响

将一种虫草无性型菌株P5深层液体发酵菌丝体作为饲料添加剂,在日粮中按0.25%的添加量喂养土杂商品肉用仔鸡,56日龄屠宰,取同一部位的胸肌和腿肌进行主要营养成分的测定,考察虫草饲料添加剂对肉仔鸡肌肉营养成分的影响。研究结果表明:与对照组相比,在日粮中添加0.25%的虫草饲料添加剂不仅可显著提高肉仔鸡胸肌和腿肌中蛋白质和氨基酸的总含量(P<0.05),并且可显著提高肉仔鸡肌肉中人体必需氨基酸和风味氨基酸的含量(P<0.01)。实验结果还可以看出,虫草饲料添加剂对肉鸡肌肉中水分、灰分和微量无机元素的含量没有显著性影响(P>0.05),但是可以显著降低胸肌和腿肌中粗脂肪的含量(P<0.05)。     

壳聚糖对肉仔鸡矿物质微量元素代谢、肠道菌群及微绒毛形态密度的影响

选择健康雏鸡(Avian)120只,分为对照组和壳聚糖组,每组60只,5个重复,每个重复12只,雌、雄各半.研究了日粮添加0.1%壳聚糖对肉仔鸡矿物质微量元素代谢、盲肠内容物大肠杆菌、乳酸杆菌、双歧杆菌的数量、免疫器官相对重、微绒毛形态密度及生产性能的影响.结果表明壳聚糖组能显著降低排泄物(粪尿混合物)中重要生命元素Ca、P、Mg、Zn、Cu、Mn的含量(P＜0.05),使其利用率提高,增加了Pb、Al元素的排出量(P＜0.05);对盲肠内容物中大肠杆菌、乳酸杆菌和双歧杆菌均有不同程度的抑制作用;回肠微绒毛密度增加;显著提高胸腺、法氏囊和脾脏的相对重量(P＜0.05).     

不同测定方法及复合酶制剂对玉米有效能值的影响

本试验选用4个不同来源玉米样品为试验材料,采用全收粪法、指示剂法、回肠末端食糜法等3种生物学方法测定玉米表观代谢能、氮校正代谢能和回肠消化能,并评估添加复合酶制剂对玉米有效能值的影响。选取720只21日龄爱拔益加肉仔鸡供试,随机分配到15个处理组,每组设8个重复,每个重复6只鸡。分别接受基础饲粮和由50%基础饲粮分别添加50%待测4个玉米样品组成的试验饲粮,以及在上述5个处理组饲粮中分别添加500 mg/kg复合酶制剂A或100 mg/kg复合酶制剂B共组成15个处理饲粮组。结果表明:不同来源玉米样品的理化成分存在较大变异;全收粪法测得玉米代谢能值高于指示剂法,但无显著差异(P0.05);添加复合酶制剂B提高了玉米4的回肠消化能(P0.05)。     

Steroid hormones in biosolids and poultry litter: a comparison of potential environmental inputs

Steroid hormones can act as potent endocrine disruptors when released into the environment. The main sources of these chemicals are thought to be wastewater treatment plant discharges and waste from animal feeding operations. While these compounds have frequently been found in wastewater effluents, few studies have investigated biosolids or manure, which are routinely land applied, as potential sources. This study assessed the potential environmental contribution of steroid hormones from biosolids and chicken litter. Hormone concentrations in samples of limed biosolids collected at a waste treatment plant over a four year period ranged from < 2.5 to 21.7 ng/g dry weight for estrone (E1) and < 2.5 to 470 ng/g dry weight for progesterone. Chicken litter from 12 mid-Atlantic farms had averages of 41.4 ng/g dry weight E1, 63.4 ng/g dry weight progesterone, and 19.2 ng/g dry weight E1-sulfate (E1-S). Other analytes studied were 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2), testosterone, E2-3-sulfate (E2-3-S), and E2-17-sulfate (E2-17-3).