我国天然低硒饲料对畜禽生产、健康与疾病的影响

 应用我国天然缺硒饲料，在实验室条件下进行了猪、鸡和鸭的缺硒模型试验研究。结果表明：饲料缺硒可导致生产中畜禽发生一系列表现在不同部位、不同程度的病理变化和临床症状。用缺硒饲料喂仔猪8周、雏鸡2周后，血液及组织中含硒量与GSH-Px活性显著降到较低值，并趋于稳定，这与动物开始出现缺硒症状的结果一致。鸡试验证明，缺硒日粮中补加100mg/kg维生素E或补加0.05ppm以上的硒，可防止鸡发生渗出性素质病。但仅补维生素E不能防止鸡胰脏的缺硒病变，还需同时补硒。对鸡胰脏中Cu、Zn、Mn等含量的测定结果表明，缺硒使胰脏变性，导致Cu、 Zn、Mn代谢障碍及含量下降（P＜0.05）。试验还证明，增加日粮中蛋白质水平可加剧缺硒状况对畜禽的危害程度，说明对饲料条件较好，生长较快的畜禽品种，特别是幼畜、幼禽，应适当提高硒的需要量。     

The isolation and characterization of Campylobacter jejuni bacteriophages from free range and indoor poultry

Six hundred and sixty one samples – primarily fresh chicken faeces – were processed to isolate wild type Campylobacter jejuni bacteriophages, via overlay agar methods using C. jejuni NCTC 12662. The aims of this study were to isolate and purify bacteriophages and then test for their ability to lyse field strains of C. jejuni in vitro. Of all samples processed, 130 were positive for bacteriophages. A distinct difference was observed between samples from different poultry enterprises. No bacteriophages could be isolated from indoor broilers. The majority of bacteriophages were isolated from free range poultry – both broilers and egg layers. Bacteriophages were purified and then selected for characterization based on their ability to produce clear lysis on plaque assay, as opposed to turbid plaques. Two hundred and forty one C. jejuni field isolates were tested for sensitivity to the bacteriophages. Lysis was graded subjectively and any minimal lysis was excluded. Using this system, 59.0% of the C. jejuni isolates showed significant sensitivity to at least one bacteriophage. The sensitivity to individual bacteriophages ranged from 10.0% to 32.5% of the C. jejuni isolates. Five bacteriophages were examined by electron microscopy and determined to belong to the Myoviridae family. The physical size, predicted genetic composition and genome size of the bacteriophages correlated well with other reported Campylobacter bacteriophages. The reasons for the observed difference between indoor broilers and free range poultry is unknown, but are postulated to be due to differences in the Campylobacter population in birds under different rearing conditions.     

关于推进肉鸡产业持续健康发展的调查和思考

为了进一步加快肉鸡产业发展步伐,更好地发挥肉鸡产业在畜牧业中的重要作用,对丹东市肉鸡产业发展情况进行了专题调研,深入了解和发现影响制约产业快速发展的原因,探寻促进肉鸡产业发展的途径和措施,推动肉鸡产业又好又快发展。     

Heritability and genetic correlation estimates for performance,meat quality and quantitative skeletal muscle fiber traits in broiler

Broiler feed efficiency and meat quality are the primary factors considered by the poultry industry. This study was conducted to estimate heritability and genetic correlation coefficients for skeletal muscle fiber number, area and diameter and performance and meat quality traits of Pectoralis major in a single male broiler line. (Co) variance components were estimated by restricted maximum likelihood method, using the software MTDFREML. The numerator relationship matrix was composed by 77,474 individuals. Heritability coefficient estimates ranged from moderate to high for juvenile BW, breast weight, ultrasound record of pectoral muscle, lightness and thawing meat loss. Genetic correlation estimates for performance and skeletal muscle fiber traits indicated that selection for higher breast weight and juvenile BW could reduce muscle fiber number and increase muscle fiber diameter and area, which could prejudice the meat quality of this line. Selection for muscle fiber number and against muscle fiber diameter and area might improve meat water retention ability and tenderness in this broiler line, and selection programs could consider those traits as selection criteria, although this may be costly. We recommend the evaluation of the indirect selection caused by the use of the performance traits as selection criteria especially for juvenile BW and breast weight. Direct, intense selection for both traits might be unfavorable for most of the meat quality traits analyzed, which could lead to losses to both the chicken meat processing industry and consumers.     

日全食家禽动物行为观察

对日全食时家禽动物行为进行观察,为家禽养殖及其动物行为学提供基础资料。观察日全食时放养鸡、鹅、番鸭、骡鸭及水鸭等家禽的动物行为学变化。结果:日全食时,家禽敏感程度为,鸡最敏感,番鸭次之,鹅第三,骡鸭和水鸭最不敏感。     

PBL教学法在禽病学教学中的尝试

通过分析传统禽病学教学法的不足及PBL教学法的优势,论述了PBL教学法在禽病学教学中实施情况,讨论了实施PBL教学法过程中存在的问题及对策。     

Preliminary in vivo study on the potential application of a novel method of e-tracking to facilitate traceability in the poultry food chain

The feasibility of using GS1 DataMatrix (GS1 DM) barcodes laser printed onto the beaks of poultry as a possible method of identification and, therefore, traceability of the individual were examined in this study, including a preliminary live trial on layer hens. The optimal laser type and settings for this particular application had been selected during previous in vitro and in vivo trials. GS1 DM barcodes were printed on both sides of the beaks of mature layer hens and read using a high specification camera based 1-Dimensional/2-Dimensional (1-D/2-D) DataMan 7500 barcode reader. The reading procedure was repeated on a number of occasions over a 5 week period to examine the effects of time in a commercial environment on the clarity and readability of the GS1 DM barcode, and the ability of the printed GS1 DM barcodes to resist the physical and chemical challenges of such a setting. The results show a very short timeframe during which all barcodes, both right and left combined, remain readable. Thereafter the readability deteriorates rapidly, due to the growth and healing of the beaks of the layer hens. Results also show that there was no significant difference in the readability between GS1 DM barcodes printed on the right or left side of the beak. The proportion of identification (ι) (i.e. number of layers identifiable by either one or two readable GS1 DM barcodes) was also calculated. All layer hens were fully identifiable for a seven day period by either one or two readable GS1 DM barcodes. Further analysis showed that the proportion of identification (ι) was significantly higher for layer hens when identified with two GS1 DM barcodes as opposed to just one. Secure movement control of live mature poultry at vulnerable points in the food chain, such as transfer of ownership, could well be facilitated by the use of this technology, thereby preventing fraud or substitution at these points.     

试论时下畜禽疾病防治中农村兽医的错误做法及对策

就农村兽医在畜禽疾病防治中存在的误区进行了综述,并提出了相应的对策,旨在为农村畜禽养殖的疾病防治提供借鉴。     

Measuring the costs of biosecurity on poultry farms: a case study in broiler production in Finland

Background

Farm-level biosecurity provides the foundation for biosecurity along the entire production chain. Many risk management practices are constantly in place, regardless of whether there is a disease outbreak or not. Nonetheless, the farm-level costs of preventive biosecurity have rarely been assessed. We examined the costs incurred by preventive biosecurity for Finnish poultry farms.

Methods

We used a semi-structured phone interview and obtained results from 17 broiler producers and from 5 hatching egg producers, corresponding to about 10% of all producers in Finland.

Results

Our results indicate that the average cost of biosecurity is some 3.55 eurocent per bird for broiler producers (0.10 eurocent per bird per rearing day) and 75.7 eurocent per bird for hatching egg producers (0.27 eurocent per bird per rearing day). For a batch of 75,000 broilers, the total cost would be €2,700. The total costs per bird are dependent on the annual number of birds: the higher the number of birds, the lower the cost per bird. This impact is primarily due to decreasing labour costs rather than direct monetary costs. Larger farms seem to utilise less labour per bird for biosecurity actions. There are also differences relating to the processor with which the producer is associated, as well as to the gender of the producer, with female producers investing more in biosecurity. Bird density was found to be positively related to the labour costs of biosecurity. This suggests that when the bird density is higher, greater labour resources need to be invested in their health and welfare and hence disease prevention. The use of coccidiostats as a preventive measure to control coccidiosis was found to have the largest cost variance between the producers, contributing to the direct costs.

Conclusions

The redesign of cost-sharing in animal diseases is currently ongoing in the European Union. Before we can assert how the risk should be shared or resort to the ''polluter pays'' principle, we need to understand how the costs are currently distributed. The ongoing study contributes towards understanding these issues. The next challenge is to link the costs of preventive biosecurity to the benefits thus acquired.     

我国家禽工厂化养殖技术发展现状与趋势

我国的家禽养殖正在向精准养殖、自动化养殖、绿色养殖等方向逐步迈进。工厂化家禽养殖技术和信息化技术的协同研发和应用是促进家禽养殖行业健康可持续发展的关键,对提升家禽养殖规模化、标准化和智能化水平,提高整体产量与经济效益,促进现代化家禽养殖业的转型升级具有重要意义。本文重点围绕家禽养殖智能装备、智能算法和管控平台3个技术领域,分析了智能养殖舍、环境监测调控、智能饲喂、防疫、巡检以及无害化粪污处理等装备,家禽行为检测、盘点技术、体质量预估和健康状态评估算法,工厂化家禽养殖管控平台的最新研究应用进展以及存在的问题;指出了家禽养殖技术的薄弱环节与发展趋势,并对工厂化家禽养殖的发展和改进提出了建议,为我国现代家禽养殖业绿色高质量转型升级与健康可持续发展提供参考。