Lysozyme is often used as a feed additive to act as an antibacterial protein that boosts the immune system of livestock and poultry while protecting against pathogens. To investigate the effects of recombinant human lysozyme (rhLYZ) from Pichia pastoris and chlortetracycline on broiler chicken's production performance, antioxidant characteristics, and intestinal microbiota, a total of 200, 1-d-old male Arbor Acres broiler chickens (46.53 +/- 0.42 g) were selected for a 42-d experiment. Dietary treatments included a basal diet of corn-soybean meal supplemented with either 0 mg/kg (CON), 50 mg/kg aureomycin (ANT), 20 mg/kg rhLYZ (LOW), 60 mg/kg rhLYZ (MEDIUM), or 180 mg/kg rhLYZ (HIGH). Compared with CON, MEDIUM diet increased (P < 0.05) average daily gain (67.40 g) of broilers from day 22 to 42. In the early (1.29) and overall phases (1.69), MEDIUM led to a reduction (P < 0.05) in the feed conversion ratio of broiler chickens. Furthermore, in comparison to the CON and ANT, MEDIUM exhibited reduced (P < 0.05) levels of INF-gamma and tumor necrosis factor-alpha in the serum. In the cecum, the abundance of Monoglobus and Family_XIII_AD3011_group was lower (P < 0.05) in the MEDIUM treatment compared to CON. Overall, supplementation of 60 mg/kg of rhLYZ improved growth performance, nutrient utilization efficiency, and serum immune function, while also influencing the composition of intestinal microbiota. This suggests lysozyme's potential to replace antibiotic additives in feed.

Frozen storage is an important strategy to maintain meat quality for long-term storage and transportation. Lipid oxidation is one of the predominant causes of the deterioration of meat quality during frozen storage. Untargeted lipidomic and targeted metabolomics were employed to comprehensively evaluate the effect of frozen duration on pork lipid profiles and lipid oxidative products including free fatty acids and fatty aldehydes. A total of 688 lipids, 40 fatty acids and 14 aldehydes were successfully screened in a pork sample. We found that ether-linked glycerophospholipids, the predominant type of lipids, gradually decreased during frozen storage. Of these ether-linked glycerophospholipids, ether-linked phosphatidylethanolamine and phosphatidylcholine containing more than one unsaturated bond were greatly influenced by frozen storage, resulting in an increase in free polyunsaturated fatty acids and fatty aldehydes. Among these lipid oxidative products, decanal, cis-11,14-eicosenoic acid and cis-5,8,11,14,17-dicosapentaenoic acid can be considered as potential indicators to calculate the freezing time of unknown frozen pork samples. Moreover, over the three-month frozen storage, the first month was a rapid oxidation stage while the other two months were a slow oxidation stage.

随着饲料端全面禁抗,养殖端进入减抗、限抗时代,微生物饲料添加剂行业迎来了新的机遇.然而,如果在生产过程中控制不严,会造成产品的微生物污染,因此,需要对产品中的菌群结构进行分析,以保证产品质量.本文以4年采集的113个市售微生物饲料添加剂产品为研究对象,利用宏基因组测序、物种注释和统计学分析,研究微生物饲料添加剂产品的菌群结构和分布规律.结果表明:64.60％的微生物饲料添加剂样品存在非标识菌污染,主要表现在副地衣芽孢杆菌被误用为地衣芽孢杆菌、含有具有抑菌作用的贝莱斯芽孢杆菌和解淀粉芽孢杆菌;污染菌中非致病菌主要是贝莱斯芽孢芽孢杆菌、苏云金芽孢杆菌、副地衣芽孢杆菌、大肠杆菌、解淀粉芽孢杆菌、卷曲乳杆菌;致病菌主要是肺炎克雷伯菌,检出比例为5.98％;其次是蜡样芽孢杆菌,检出比例为12.82％.综上,宏基因测序技术可有效监测微生物饲料添加剂产品的菌群结构,非靶向检测产品中的污染菌.目前,产品存在检测菌种与标识不符、标识菌含量偏低、部分产品存在杂菌甚至致病菌的问题.本研究使用的非靶向研究方法和统计学得到的高频污染菌信息对微生物饲料添加剂产品的质量控制和行业监管具有重要参考意义.

Volatile compounds play vital roles in food sensory attributes and food quality. An analysis of volatile compounds could illustrate the sensory attributes at the microscale level. Here, untargeted profiling approaches for volatiles in five most-consumed meat species were established using headspace SPME-GC/high resolution Orbitrap MS. An extended high-resolution database of meat volatile compounds was established to enhance the qualification accuracy. Using sulfur-containing compounds, aldehydes, and ketones as the research model, the parameters including fiber coating types, extraction temperature, extraction time, and desorbing time were optimized. Principle component analysis, volcano analysis and partial least squares discriminant analysis were applied to run the classification and the selection of discriminant markers between meat varieties, respectively. Different varieties could be largely distinguished according to the volatiles' profiles. 1-Octen-3-ol, 1-octen-3-one, 2-pentyl furan and some other furans degraded from n-6 fatty acids would contribute to distinguishing duck meat from other categories, while methyl esters mainly from oleic acid as well as dimethyl sulfoxide and carbon disulfide possibly produced from the sulfur-containing amino acids contributed to the discrimination of beef. Therefore, volatiles' profiling not only could interpret the aroma style in meat but also could be another promising method for meat differentiation and authentication.

短链脂肪酸又称挥发性脂肪酸,其检测方法常用于动物肠道菌群健康及饲料营养研究.本文综述了近几年在不同类型动物样本中短链脂肪酸检测的方法,讨论了各方法的优势及存在的问题,为今后动物样本中短链脂肪酸检测提供方法参考.随着高分辨质谱技术的崛起,未来应该开发出更快捷方便且灵敏度高的检测技术.

霉菌毒素严重威胁人类和动物的健康,为加强日常饲料质量安全监管,饲料中霉菌毒素的检测工作尤为重要,因此本文综述了霉菌毒素的限量标准、检测标准及近年来主流色谱质谱的检测技术,为日后的霉菌毒素检测提供技术参考.

How parvovirus manipulates host lipid metabolism to facilitate its propagation, pathogenicity and consequences for disease, is poorly characterized. Here, we addressed this question using porcine parvovirus (PPV) to understand the complex interactions of parvovirus with lipid metabolism networks contributing to the identification of novel and practical antiviral candidates. PPV significantly alters host lipid composition, characteristic of subclasses of phospholipids and sphingolipids, and induces lipid droplets (LDs) formation via regulating calcium-independent PLA2β (iPLA2β), phospholipase Cγ2 (PLCγ2), diacylglycerol kinase α (DKGα), phosphoinositide 3-kinase (PI3K), lysophosphatidic acid acyltransferase θ (LPAATθ), and sphingosine kinases (SphK1 and SphK2). PPV utilizes and exploits these enzymes as well as their metabolites and host factors including MAPKs (p38 and ERK1/2), protein kinase C (PKC) and Ca2+ to induce S phase arrest, apoptosis and incomplete autophagy, all benefit to PPV propagation. PPV also suppresses prostaglandin E2 (PGE2) synthesis via downregulating cyclooxygenase-1 (COX-1), indicating PPV hijacks COX-1-PGE2 axis to evade immune surveillance. Our data support a model where PPV to establishes an optimal environment for its propagation and pathogenicity via co-opting host lipid metabolism, being positioned as a source of potential targets.

围绕贯彻落实2019年农业农村部第194号公告中关于"禁止除中药外所有促生长类药物在商品饲料中的使用"的规定,2020年11月笔者赴湖南、四川两省调研,实地走访了7家企业,向省市县管理部门和行业协会等相关部门了解禁抗对饲料企业及养殖业的影响.现将了解到的有关情况和不成熟的观点整理汇总,以飨读者.

现代的现场快速检测仪器具有便携性、精确性的特点,并向着高集成度的方向发展,在农业生产过程中发挥了重要作用.分别从植物生长检测仪器、土壤检测仪器、植物保护与病虫害检测仪器和环境检测仪器4个方面详细概述了各类仪器的研究现状及其在农业中的应用,并对我国未来农业快速检测仪器的研究方向进行了展望.

Zearalenone-14-glucoside (ZEN-14G), a key modified mycotoxin, has attracted a great deal of attention due to the possible conversion to its free form of zearalenone (ZEN) exerting toxicity. In this study, the toxicokinetics of ZEN-14G were investigated in rats after oral and intravenous administration. The plasma concentrations of ZEN-14G and its major five metabolites were quantified using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The data were analyzed via non-compartmental analysis using software WinNonlin 6.3. The results indicated that ZEN-14G was rapidly hydrolyzed into ZEN in vivo. In addition, the major parameters of ZEN-14G following intravenous administration were: area under the plasma concentration–time curve (AUC), 1.80 h·ng/mL; the apparent volume of distribution (VZ), 7.25 L/kg; and total body clearance (CL), 5.02 mL/h/kg, respectively. After oral administration, the typical parameters were: AUC, 0.16 h·ng/mL; VZ, 6.24 mL/kg; and CL, 4.50 mL/h/kg, respectively. The absolute oral bioavailability of ZEN-14G in rats was about 9%, since low levels of ZEN-14G were detected in plasma, which might be attributed to its extensive metabolism. Therefore, liquid chromatography high-resolution mass spectrometry (LC-HRMS) was adopted to clarify the metabolic profile of ZEN-14G in rats’ plasma. As a result, eight metabolites were identified in which ZEN-14-glucuronic acid (ZEN-14GlcA) had a large yield from the first time-point and continued accumulating after oral administration, indicating that ZEN-14-glucuronic acid could serve a potential biomarker of ZEN-14G. The obtained outcomes would prompt the accurate safety evaluation of ZEN-14G.

Enzymatic probe sonication (EPS) was investigated as a novel and alternative technology for the extraction of five Se species SeCys2, MeSeCys, Se (IV), SeMet and Se (VI) from animal feeds. The critical parameters of EPS such as enzyme types, ultrasonic power, sample/enzyme ratio, extraction time and temperature were carefully optimized. Under current conditions, one sample can be extracted in 60s, in contrast to several hours required by the conventional enzymatic methods Moreover, the extraction is performed in pure water, no further temperature control or pH adjustment is needed, and therefore the risk of species interconvertion is drastically reduced or inhibited. The Se species were separated and quantitatively determined by high-performance liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS), which allows the separation of organic and inorganic Se species in a single chromatographic run. The newly developed method was successfully applied to the determination of Se species in 18 feed samples collected from markets and local farms. Concerning the feed samples studied, the results of this work suggest that stricter measures should be taken to control the Se-enriched feed supplements in terms of Se species.

Subcritical water extraction was investigated as a novel and alternative technology for the separation of trace amounts of chloramphenicol, thiamphenicol, florfenicol and its major metabolite florfenicol amine from poultry tissues and its results were compared with those of conventional shaking extraction, ultrasonic extraction, and pressurized liquid extraction. Decreasing the polarity of water by successively increasing the extraction temperature from 50 degrees C to 200 degrees C at the moderate pressure enabled selective, highly effective extractions to be performed. Rapid quantification of the target compounds was carried out by ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). The critical parameters of subcritical water extraction such as solvent modifier, temperature, pressure, extraction time, and static cycles were varied with control. The optimized extraction procedures using subcritical water as extraction solvent, were carried out on a pressurized liquid extractor operated at 150 degrees C and 100 bar, applying two static cycles for 3 min. Average recoveries of the four analytes from fortified samples ranged between 86.8% and 101.5%, with relative standard deviations (RSDs) lower than 7.7%. The limits of detection (LODs) and quantification (LOQs) for the target compounds were in the ranges of 0.03-0.5 mu g kg(-1) and 0.1-2.0 mu g kg(-1), respectively. The proposed method is fast, sensitive, water-based thus more environmental acceptable, making it a suitable replacement for conventional organic solvent extraction in veterinary drug residue analysis. (C) 2015 Elsevier B.V. All rights reserved.

本文对142份血粉、肉骨粉、鱼粉、乳制品和植物性原料样品进行沙门氏菌检测,其中检出率最高的是肉骨粉(50.0％),其次是血粉(18.9％)和鱼粉(15.8％).动物性饲料中沙门氏菌的检出率(25.7％)远高于植物性原料(13.8％).分别将10种沙门氏菌标准菌株在肉骨粉中培养后,以CMCC50115鼠伤寒沙门氏菌的菌数最高(3.8×108cfu/mL);其次是CMCC50774鸭沙门氏菌(4.7×107 cfu/mL).

饲料样品经乙腈-水(8+2)提取,提取液用磷酸盐缓冲溶液稀释,经免疫亲和柱净化后,净化提取液用反相高效液相色谱荧光检测器测定,可以准确检测饲料中玉米赤霉烯酮含量。IAC-HPLC荧光检测法可以有效地将玉米赤霉烯酮与其类似物区别开。利用配合饲料、预混料、鱼粉、豆粕、浓缩饲料、玉米进行玉米赤霉烯酮准确性实验,回收率为90.1%～118%。利用鱼粉、预混料、鸡配合饲料、玉米进行方法精密度试验,相对标准偏差均在5%以内。因此,本方法中建立的免疫亲和柱净化、高效液相色谱荧光检测法具有良好的准确性、稳定性和特异性。

玉米赤霉烯酮是一种具强烈致畸作用的生殖系统毒素,在饲料及饲料原料中污染普遍,给畜牧业带来较大危害。文中介绍了针对玉米赤霉烯酮的吸附法和生物降解法的研究进展,指出吸附法在实用性、有效性和安全性方面还存在较大的问题,生物降解由于高效率、对饲料和环境没有污染、能够避免毒素的重新产生并适于大规模操作而具有广阔的应用前景。

Many methods are used in animal feed quality testing,the microscopic method is widely used for the determination of microorganism,plant protein feed,animal protein feed and other compositions with microstructure characteristics because of its advantage of rapid,easy and cheap.Application of microscope for detecting animal feed quality was reviewed in this article.

利用免疫亲和柱荧光光度法和高效液相色谱法测定饲料中黄曲霉毒素。免疫亲和柱—荧光光度法测定饲料中的黄曲霉毒素的测定范围0～50μg/kg;线性相关系数0.99;检测灵敏度1μg/kg;变异系数<18%;回收率82%～120%;分析时间20min,不需要剧毒的黄曲霉毒素标准品。免疫亲和柱-高效液相色谱法测定可以分别定量地检测饲料中黄曲霉毒素B1,B2,G1,G2,在黄曲霉毒素B1为0～50μg/kg测定范围内其线性相关系数0.91;检测灵敏度1μg/kg;变异系数<10%;回收率81%～110%。

为确保畜禽的健康以及畜禽产品不对人造成危害,有必要对饲料中微生物进行检测.文章主要对细菌总数、大肠菌群、霉菌、沙门氏菌做了简单的介绍,并提出检测方法及应注意的问题.

研究了用免疫亲和柱净化—高效液相色谱法测定饲料样品中T-2毒素的方法。样品用甲醇-水（体积比80∶20）提取,提取液用免疫亲和柱净化,CloversilC18色谱柱分离,紫外检测器检测,外标法定量。对添加不同浓度的T-2毒素进行了多次重复实验,平均回收率为75.9%～90.3%,变异系数为13.06%,检测限为0.1mg/kg。

试验是利用β-萘酚辛酸酯试纸法检测沙门氏菌的准确性、特异性和实用性,并研究了β-萘酚辛酸酯的合成路线.结果表明,此方法有快速、简单、直观和经济等优点,灵敏性和特异性高,适合实验室内进行饲料中沙门氏菌快速检测.