Body weight and range usage affect net energy utilisation in commercial free-range laying hens when evaluated in net energy chambers

Within a given free-range flock, some hens prefer to spend the majority of their time in the shed (stayers), while others frequently access the range (rangers). Laying performance has been associated not only with the development of these sub-populations but also with different body weights (BW). The purpose of this study was to determine if range usage, BW or a combination of both is associated with energy metabolism and as such contribute to improved hen performance. Forty-eight Lohmann Brown hens at 74 wk of age were selected from a commercial free-range farm based on their BW and range usage over a 56-week period. Using a 2 × 2 factorial arrangement, hens were either classified as heavy (mean ± SEM; 2.01 ± 0.02 kg, n = 24) or light (1.68 ± 0.01 kg, n = 24), and also classified as rangers (accessed the range for 84.1% of available days, 242 ± 3.75 d; n = 24) or stayers (accessed the range for 7.17% of available days; 23.4 ± 6.08 d, n = 24). Stayers had significantly higher metabolizable energy (ME) intake per metabolic BW per d (0.852 vs. 0.798 MJ/kg BW^0.75 per d; P = 0.025), higher heat production (0.637 vs. 0.607 MJ/kg BW^0.75 per d; P = 0.005), higher heat increment (0.267 vs. 0.237 MJ/kg BW^0.75 per d; P = 0.005) and retained more nitrogen (1.59 vs. 1.46 g/hen per d; P = 0.023) compared to the rangers. Light hens had significantly higher metabolic energy intake per metabolic BW (0.854 vs. 0.796 MJ/kg BW^0.75 per d; P = 0.018), net energy (NE) intake (0.595 vs. 0.551 MJ/kg BW^0.75 per d; P = 0.032), and retained energy (0.225 vs. 0.181 MJ/kg BW^0.75 per d; P = 0.032), as well as lower heat production (0.936 vs. 1.003 MJ/hen per d; P = 0.002) compared to heavier hens. An interaction was observed across levels of analysis i.e. between light stayers and light rangers. The light rangers had significantly higher NE intake compared to the light stayers (9.77 vs. 9.27 MJ/kg BW^0.75 per d; P = 0.024). In conclusion, light hens were more energy efficient compared to heavy hens. Moreover, light rangers had a more efficient feed utilisation compared to the light stayers.     

Drug resistance and virulence traits of Acinetobacter baumannii from Turkey and chicken raw meat

Acinetobacter baumannii (A. baumannii) is a miscellaneous bacterium with ability of extensive antibiotic resistance. A. baumannii strains have also been isolated from animal origins. The objective of our atudy was characterization of A. baumannii antibiotic resistance and virulence traits from turkey and chicken raw meat. Of 576 turkey and 424 chicken specimens during 2017–2019, 200 (120 from turkey and 80 from chicken) isolates were identified as A. baumannii. Virulence factors and antibiotic resistance patterns of A. baumannii were determined using polymerase chain reaction (PCR) technique and Kirby-Bauer test. All the isolates were resistant to tetracycline and cefoxitin and 81 % and 56 % of them produced ESBLs and carbapenemases. Also 74 % of them (34 % from chicken and 40 % from turkey) were multidrug-resistant (MDR) A. baumannii. Colistin and fosfomycin non-susceptibility was detected among 12 % and 10 % of them, respectively. The existence of tetA, dfrA, tetB, bla_oxa-51-like, bla_oxa-23-like, sul1, bla_oxa-24-like, bla_oxa-58-like, fosA3 and mcr-1 genes accounted for 80 %, 71 %, 70.5 %, 66 %, 62 %, 43 %, 34 %, 22 %, 11 % and 13 % of them, repectively. Additionally, predominant virulence factors included the fimH, afa/draBC, sfa/foc DE, cnfI and cnf2 genes. The rate of antibiotic resistance genes and virulence factors was not significantly different between turkey and chicken (p > 0.05). High rate of antibiotic non-susceptibility even against last-line resorts in poultry products is a concern and suggest that animals play a potential role as reservoirs of transmission of MDR A. baumannii.     

家禽肌肉组织中硝基咪唑类药物残留高效液相色谱检测法研究

 建立了检测家禽肌肉组织中甲硝唑、洛硝哒唑、二甲硝咪唑残留的高效液相色谱法。样品经乙酸乙酯振荡提取 ,浓缩 ,盐酸溶解残渣 ,己烷萃取除去脂肪。氢氧化钠调节溶液到pH 4 .8～ 5 .2 ,过C18小柱 ,甲醇洗脱 ,SpherisorbC18柱分离 ,32 0nm处检测。流动相为醋酸缓冲液 乙腈 (85∶15 ,v/v)。甲硝唑、洛硝哒唑和二甲硝咪唑检测限分别为 0 .5、1.0和 1.0ng·g-1。肉鸡肌肉组织中添加 6 .0ng·g-1水平回收率分别为 :甲硝唑 89.8% ,洛硝哒唑81.7% ,二甲硝咪唑 86 .6 %。此方法具有定性合理 ,检测限低 ,分析快速 ,准确等特点。     

Effects of Two Organic Wastes in Combination with Phosphorus on Growth and Chemical Composition of Spinach and Soil Properties

Abstract

Most agricultural soils in Iran are usually low in organic matter (OM). Therefore, increasing OM in these soils is of great concern. Environmental pollution caused by chemical fertilizers has created an interest in the integrated use of organic wastes with inorganic fertilizers. The main purpose of this greenhouse study was to evaluate the impact of two organic wastes and phosphorus (P) on the growth, and elemental composition of spinach (Spinacia oleracea L.) and soil chemical properties. Treatments consisted of four levels of municipal waste compost, MWC (0, 1, 2, and 4%), five rates of poultry manure, PM (0, 1, 2, 3, and 4%), and three P levels (0, 25, and 50 mg kg^?1 as KH₂PO₄). Application of P and MWC alone or in combination significantly increased the top dry weight of spinach. However, spinach growth was markedly increased up to 3% PM and suppressed with the higher rate, probably due to an excess of soluble salts in the soil. Moreover, the enhancing influence of P on spinach seedling growth was more pronounced at lower levels of MWC and PM. Plant P concentration tended to increase with increasing P, MWC, and PM application rates, whereas nitrogen (N) concentration was only affected by the two organic wastes treatment. Manganese (Mn) concentrations decreased, and copper (Cu), lead (Pb), and cadmium (Cd) increased by soil P application. However, P addition significantly decreased zinc (Zn) concentration only in MWC-treated spinach. Spinach plants enriched with either of the two biosolids accumulated more Mn, Zn, Pb, Cd, chloride (Cl), and sodium (Na) than control plants. Furthermore, spinach grown on MWC-amended soil contained higher Mn, Zn, Cu, and Pb and lower N, Cl, and Na than those raised on PM-treated soil. Postharvest soil sampling indicated that application of the two biosolids significantly increased concentration of soluble salts, (EC_e), OM, TN, NaHCO₃-extractable P, and DTPA-extractable iron (Fe), Mn, Zn, Cu, Pb, and Cd.     

禽流感对中国经济产生的影响及启示

071003 保定市河北农业大学经济贸易学院     

青海东部农区猪鸡寄生虫病调查和防治技术研究

在青海省东部农区进行了猪、鸡寄生虫病原分类、感染情况、季节动态和防治方法及效益的研究。结果证实:农区猪、鸡寄生虫病感染严重,查明猪寄生虫有19种。其中优势虫种4种,鸡寄生虫有13种,其中优势虫种3种;并证明丙硫咪唑8mg/kg,左旋咪唑10mg/kg 或害获灭0.3mg/kg 用于猪,左旋咪唑15—20mg/kg 用于鸡均安全高效。同时,了解了主要气象因素及年龄变化与优势虫种感染的相关性,提出幼年猪在3—6月龄投药,间隔2—3个月第2次投药和鸡在4—8月份投药的防治方案。两次投药可使育肥猪增重提高4.24—14.40kg。一次投药可使群养鸡的产蛋率在高峰期提高2个百分点,每只鸡产蛋期产蛋量增加200g。此项研究已在海东、西宁地区推广使用,效果明显。     

Risk factors of Salmonella infection in laying hens in Menoua Division,Western region of Cameroon (Central Africa)

Salmonella infections in poultry farms are overlooked in many African countries; yet these infections are mostly zoonotic with impact on both poultry industry and public health. Considering the impact of Salmonella in laying hens, and the role of laying hens as a source of Salmonella outbreak in human, knowledge of the status of Salmonella on laying hen farms as well as the factors influencing the presence of Salmonella is important. In a cross sectional study, cloacal swabs were collected from 270 commercial laying hens on 27 farms located in Menoua Division. These samples were cultured on standard media. A questionnaire was used to collect information on animals, farms and farmer’s characteristics. The prevalence of Salmonella was 93.34%; three zoonotic isolates namely S. Enteritidis (75.90%), S. Paratyphi (11.90%), and S. Typhimurium (5.60%) were identified. The location of farms was significantly associated with presence of Salmonella, and the risk of infection was 10-fold higher in Nkong-ni than Santchou (p < 0.05). Other potential risk factors such as flock size, age of the farm (infrastructure), or water source were not associated with Salmonella infection. The prophylactic measures against avian diseases in the country must include measures against Salmonella to protect poultry industry and public health.     

Control of Fusarium wilt of carnation using organic amendments combined with soil solarization,and report of associated Fusarium species in southern Spain

Fusarium wilt is a disease that restricts carnation (Dianthus caryophyllus L.) yield worldwide. Efficacies in reducing the Fusarium wilt of carnation (FWC), of various types of organic amendments (fresh or pelletized poultry manure, pelletized Brassica carinata and olive residue compost) combined with soil solarization, were compared in two biennial field trials conducted in a greenhouse with a history of carnation monoculture over 8 years. Soil treatments combining organic amendments and soil solarization significantly reduced disease incidence (86–99%) and increased the number of commercial carnation stems by 5–9 times compared to non-treated plots. Twenty-one Fusarium spp. isolates, with different colony morphologies were recovered from soil samples taken in the greenhouse, before the application of treatments in June 2013. Nineteen of them were morphological and molecularly characterized. Additionally, two pathogenicity tests with 17 isolates recovered from greenhouse soils and two isolates recovered from organic amendments were performed. Fusarium species associated with carnation cultivation were identified as Fusarium oxysporum (43%), Fusarium proliferatum (24%), and Fusarium solani (33%). The phylogenetic analysis of the translation elongation factor 1 alpha (EF-1α) region distinguished highly aggressive isolates of F. oxysporum f. sp. dianthi, from low aggressive isolates. The pathogenicity tests showed that FWC has a complex etiology, with several Fusarium spp. identified as causal agents. F. proliferatum and F. solani are associated with carnation wilt for the first time in Spain.     

Evaluation of immunogenicity and protective efficacy of adjuvanted Salmonella Typhimurium ghost vaccine against salmonellosis in chickens

Background: Salmonella Typhimurium, a non-host-adapted Gram-negative intracellular pathogen, is capable of infecting a variety of animal hosts and humans.

Objective: This study utilized the prime-booster immunization strategy using Salmonella Typhimurium–LTB (S. Typhimurium–LTB) ghost with the aim of inducing a robust immune response for the prevention of avian salmonellosis. In addition, the effect of Montanide^TM ISA 70VG adjuvant on S. Typhimurium–LTB ghost vaccination was investigated.

Animals and methods: A total of 75 chickens were divided into three groups (n=25) for intramuscular immunization: group A (non-immunized control injected with sterile PBS), group B (immunized with S. Typhimurium–LTB ghost), and group C (immunized with S. Typhimurium–LTB ghost plus Montanide^TM ISA70VG adjuvant).

Results: Compared with group A, the immunized chickens (groups B and C) exhibited increased titers of antigen specific plasma IgG and intestinal secretory IgA antibodies. In addition, group C showed enhanced induction of the humoral immune response compared to group B. The populations of splenic CD3+CD4+ and CD3+CD8+ T-cells increased significantly in both immunized groups. In addition, increased mRNA expression of the Th1 cytokines, IFN-γ, and IL-2 were observed in S. Typhimurium antigen-stimulated peripheral blood mononuclear cells from groups B and C chickens. Chickens from both vaccinated groups showed significant protection against virulent S. Typhimurium oral challenge compared to non-vaccinated chickens and a lower challenge strain count was recovered from the internal organs of group C.

Conclusions: Injection of S. Typhimurium-LTB ghost with or without Montanide^TM ISA70VG adjuvant is capable of inducing protective immunity against the virulent S. Typhimurium infection in chickens.     

饲粮纤维对家禽的营养调控研究进展

纤维曾被视为家禽饲粮所含的一种抗营养因子,但适量的饲粮纤维可有效改善家禽的营养与健康。饲粮纤维成分复杂,不同纤维源的营养功能与作用机制不尽相同。本文介绍饲粮纤维的概念与性质,探讨其对家禽消化生理、肠道健康及生产的影响,阐释其调控家禽营养的机制,为其在家禽生产中高效利用提供科学依据。