女贞子改善家禽肝脏损伤的作用机制

肝脏是动物机体脂质代谢的中心器官和重要的免疫组织,肝脏健康是保证家禽正常生产的前提。女贞子提取物具有抗氧化、抗炎、抗菌等功能,特别是其护肝作用显著。齐墩果酸是女贞子的主要活性成分,临床上被用于护肝、抗炎、治疗急性肝炎等。本文主要探讨肝脏损伤在家禽生产中的危害及女贞子改善肝损伤的作用机制,为女贞子在家禽生产中的推广应用提供理论依据。     

Screening for probiotic characters in lactobacilli isolated from chickens revealed the intra-species diversity of Lactobacillus brevis

Considering the importance of the poultry industry and the increasing interest in alternative growth promoters, probiotics are considered as a potential candidate for use in the poultry industry. In this study, Lactobacillus species were isolated from 21 rectal swabs of 11 healthy 6-day-old and 10 healthy 21-day-old chickens and their fecal and feed samples. The isolates were characterized and their probiotic characteristics, including resistance to gastric acid and bile salts, biofilm formation and adherence to epithelium or mucus, amylase and protease activity and production of inhibitory compounds, were assessed. From 31 acid and bile resistant lactobacilli, only 2 Lactobacillus brevis and 1 Lactobacillus reuteri strains showed significant probiotic properties. These isolates indicated detectable attachment to Caco-2 cells and significant antibacterial activities against Gram-positive and Gram-negative pathogens. Additionally, phenotypic and genotypic diversity of lactobacilli isolates were studied by Phene Plate (PhP) system (PhP-LB) and random amplified polymorphic DNA (RAPD)-PCR, respectively. PhP-LB results of 24 L. brevis isolates showed a high phenotypic variation among the isolates. In comparison, results of RAPD-PCR highlighted a low diversity. Therefore, it seems that combination of the 2 techniques (PhP and RAPD-PCR) could result in a significant discriminatory power than each of them used alone.     

改善我国家禽福利状况的探讨

阐述了实施家禽福利的现实意义,指出了我国推行家禽福利所面临的问题,并提出了相关改善措施。     

鸡场龙头企业信息系统的实现与数据库升迁

在“九五”“蛋鸡系统”研究基础上,进一步集成和扩充,实现鸡场龙头企业信息系统以及系统后台数据库的升迁,介绍实现系统平稳升级的编程和数据库设计技巧,构建一个适用于我国国情的企业生产经营管理辅助决策系统。系统采用Client/Server与Browser/Server相结合的方式运行,以不同的接入方式输入和获取企业生产经营管理决策信息,系统的实现将为集约高效养殖企业提供更全面、准确与及时的生产及经营信息,提高生产、管理、决策和经营水平。     

农用墙排风风机性能参数的分析与选用

介绍了目前国内外常用的几种农用墙排风风机的性能数据，并用通风机相似理论进行了分析和计算，指出了厂家提供的数据中存在的问题，对畜禽舍怎样选择风机，厂家怎样高质量保证风机的特性提出了建议。     

Effects of animal manure application and crop plants upon size and activity of soil microbial biomass under organically grown spring barley

Temporal behaviour of microbial biomass C, N and respiration was measured under barley crops in two experiments on successive years in a recently converted organic production system in Scotland. Soils were fertilised with farmyard manure or poultry manure. Control soils received no manure at the start of the growing season. The effects of plants was also investigated by maintaining fallow subplots. C-flush values approximately doubled over the growing season in both years of the trial, showing a decline to pre-sowing values between the two seasons. This occurred in all soils, whether manured or not, or planted or fallow. Manure tended to increase the C-flush in the 2nd year only. N-flush in the 2nd year showed no increase in planted control plots but did increase in fallow soils. Manures significantly increased the N-flush. Respiration rates were stimulated by the presence of plants. Respiration rates were measured from soils taken from the field at post-sowing, mid-season and post-harvest occasions and incubated under constant conditions for up to 1 year. Here there was evidence that the effects of sampling and adjusting the moisture status could be as great upon microbial activity as the addition of the manures. C-flush also showed a consistent and persistent increase in these incubated soils. This suggests that the fundamental C-supplying characteristics of these soils was such that the biomass was moving towards a new equilibrium value fuelled by the relatively recent introduction of the organic farming regime. Received: 27 February 1996     

Predicting soil erosion in conservation tillage cotton production systems using the revised universal soil loss equation (RUSLE)

Despite being one of the most profitable crops for the southeastern USA, cotton (Gossypium hirsutum L.) is considered to create a greater soil erosion hazard than other annual crops such as corn (Zea mays L.) and soybeans (Glycine max (L.) Merr.). Reduced tillage systems and cover cropping can reduce soil erosion and leaching of nutrients into ground water. The objectives of this study, which was conducted in north Alabama from 1996 to 1998, were to assess the impact of no-till and mulch-till systems with a winter rye (Secale cereale L.) cover crop and poultry litter on soil erosion estimates in cotton plots using the revised universal soil loss equation (RUSLE). Soil erosion estimates in conventional till plots with or without a winter rye cover crop and ammonium nitrate fertilizer were double the 11 t ha⁻¹ yr⁻¹ tolerance level for the Decatur series soils. However, using poultry litter as the N source (100 kg N ha⁻¹) gave soil erosion estimates about 50% below the tolerance level under conventional till. Doubling the N rate through poultry litter to 200 kg N ha⁻¹ under no-till system gave the lowest soil erosion estimate level. No-till and mulch-till gave erosion estimates which were about 50% of the tolerance level with or without cover cropping or N fertilization. This study shows that no-till and mulch-till systems with cover cropping and poultry litter can reduce soil erosion in addition to increasing cotton growth and lint yields, and thus improve sustainability of cotton soils in the southeastern USA.     

云南家禽十项生理常值的测定

 我们进行了云南武定鸡、火鸡、云南鸭、番鸭(瘤头鸭)、云南鸽和鹌鹑等七种家禽的体温、心率、呼吸频率、红细胞沉降速度(血沉)、血红蛋白、红细胞计数、白细胞计数、嗜酸性白细胞计数、血小板计数、白细胞分类计数等十项生理常值的测定。结果表明:云南武定鸡的呼吸频率(28.84次/min)和血红蛋白(102.4g/L)比广东三黄鸡的(19.4次/min)和(74.09g/L)快(高):火鸡的血红蛋白(136.6g/L)比文献报道的值(88～134g/L)高;云南鹅的心率(109.47次/min)和白细胞分类计数中的假嗜酸性白细胞(异嗜性粒细胞)的比例(36.23%)比文献报道的值(300次/min)和(50%)低:云南鸭的心率(102.34次/min)呼吸频率(19.59次/min)和血红蛋白(110.3g/L)比文献报道的值(178次/min)、(42次/min)和(127g/L)低,云南鸽的呼吸频率(56.64次/min)比文献报道的值(30次/min)高,而白细胞数(38.9×10⁹/L)比文献报道的值(13.0×10⁹/L)高。     

Sequence Comparison of MHC Class Ⅱβ (Exon 2) and Phylogenetic Relationship Between Poultry and Mammalian

A fragment spanning over exon 2 and intron 2 of major histocompatibility complex B-LB Ⅱ genes was amplified using PCR,cloned and sequenced in 13 individuals from eight Chinese indigenous chicken breeds and one introduced breed. Another 41 sequences of MHC class Ⅱβ from ten vertebrate species were cited from the NCBI GenBank. Thirteen new B-LB Ⅱ alleles were found in the chicken breeds sampled. Alignment of the exon 2 sequences revealed 91.1-97.8% similarity to each other within the chickens sampled, and the chickens shared 84.1-87.0% homology to Phasianus colchicus, 78.5-81.5% similarity to Coturnixjaponica. The sequences in poultry showed 62.6-68.1% identity to HLA-DRBl, 50-61.5% similarity to DQB (HLA-, SLA- and H2-BB), 53.7-60% to HLA-DPB and 53.3-57.8% similarity to HLA-DOB. The frequency of nonsynonymous substitutions of nucleotide was higher than that of synonymous substitutions, and the frequencies of nonsynonymous and synonymous substitutions in poultry B-LB Ⅱ genes were lower than those observed in mammalian DRB1 and DQB1 genes. The deduced amino acid sequences of MHC class Ⅱβ1 domain exhibited extreme difference in conversed region and variable region patterns among the various species, but the two conserved cysteines forming disulfide-bond were shown consistent in poultry with that in mammalian species; and the carbohydrate attachment site was found more conserved in chicken, Homo sapiens, Bos taurus, Ovis aries and Capra hircus than in Sus scrofa and rodent animals. Compared with exon 2 of DQB1 genes of Homo sapiens, ruminant species and Sus scrofa, the differentia that the deletion of six nucleotides at position195 to 200 of exon 2 of DQB1 genes, and insertion of three nucleotides at position 247 to 249 of the exon 2 existed in rodent species were found, which led to the absence of three AA residues at position 65, 66,and 67 within β1 domain of DQB1 chain, and the insertion of one AA residue at position 85. The difference of the deletion of six nucleotides at position 72 to 77 of exon 2 of DPB1 genes was observed with Homo sapiens DQB1, which caused absence of three AA residues at position 24, 25, and 26 of β1 domain of DPBl chain. The phylogenetic tree revealed that the B-LB Ⅱ sequences from poultry are not orthologous to the class Ⅱ MHC β-chain genes of mammalian species. The tree indicated that genetic evolutionary relationship of chickens with Phasianus colchicus was much closer than with Coturnixjaponica, and the DQB and DPB clusters are more tightly related to each other than to the remaining clusters.     

Trends in feed evaluation for poultry with emphasis on in vitro techniques

Accurate knowledge of the actual nutritional value of individual feed ingredients and complete diets is critical for efficient and sustainable animal production. For this reason, feed evaluation has always been in the forefront of nutritional research. Feed evaluation for poultry involves several approaches that include chemical analysis, table values, prediction equations, near-infrared reflectance spectroscopy, in vivo data and in vitro digestion techniques. Among these, the use of animals (in vivo) is the most valuable to gain information on nutrient utilization and is more predictive of bird performance. However, in vivo methods are expensive, laborious and time-consuming. It is therefore important to establish in vitro methods that are reliable, rapid and practical to assess the nutritional quality of feed ingredients or complete diets. Accuracy of the technique is crucial, as poor prediction will have a negative impact on bird performance and, increase feed cost and environmental issues. In this review, the relevance and importance of feed evaluation in poultry nutrition will be highlighted and the various approaches to evaluate the feed value of feed ingredients or complete diets will be discussed. Trends in and practical limitations encountered in feed evaluation science, with emphasis on in vitro digestion techniques, will be discussed.