Welfare and environmental benefits of integrating commercially viable free-range broiler chickens into newly planted woodland: A UK case study

The commercial, welfare and environmental impacts of rearing small colonies of free-range chickens in newly planted woodland at two sites in the UK, during the first 2 years of the enterprise, were investigated. Newly planted rather than established trees were used so that commercially viable species could be planted in a way that would suit the management of the chicken enterprise, and small colonies were used so that farmers wishing to diversify could buy into the system progressively. It was anticipated that marketing a high specification product would provide an immediate income, whilst waiting for the future investment in trees to grow.     

散养鸡鼠伤寒沙门氏菌的分离?鉴定?耐药性研究

从疑似感染的成年散养鸡蛋壳和发病雏鸡的肝脏、脾脏中分离到2株细菌,通过培养特性、镜检结果、生化鉴定、血清学分型等,2株分离细菌均被鉴定为鼠伤寒沙门氏菌,分别命名为AH-DY01和AH-DY02。药物敏感性检测结果表明,AH-DY01对氟苯尼考、左氧氟沙星和环丙沙星敏感,对其他12种抗生素耐药;AH-DY02对阿米卡星、氟苯尼考、左氧氟沙星、复方新诺明、庆大霉素、链霉素、环丙沙星和大观霉素敏感,对其他7种药物耐药,2株沙门氏菌均表现多重耐药性。动物回归试验结果表明,2株鼠伤寒沙门氏菌均可致死雏鸡。对分离菌的16S r DNA进行测序与遗传进化分析,结果表明AH-DY01与标准菌株ATCC-1592和ATCC13311的同源性最高,而AH-DY02与日本分离株之间的亲缘关系最近。     

The economic viability and potential of a novel poultry agroforestry system

Investigating agroforestry systems that incorporate poultry is warranted in Northern Europe as they may offer benefits including: improved welfare and use of range; reduced feed costs; price premia on products; reduced payback periods for forests; and, greater returns on investment. Free-range egg production accounts for 27% of the United Kingdom egg market and demand for outdoor broilers is increasing. No research has been conducted recently on the economic viability of agroforestry systems with poultry. An economic model was constructed to: assess economic viability of a broiler agroforestry system; and, investigate the sensitivity of economic performance to key factors and interactions, and identify those which warrant attention in research and management. The system modelled is a commercial trial established in Southern England in 2002 where deciduous trees were planted and broilers reared in six- or nine-week periods. The model uses Monte Carlo simulation and financial performance analyses run for a 120-year period. An Internal Rate of Return (IRR) of 15.5% is predicted for the six-week system which remains viable under a ‘worst case’ scenario (IRR of 12.6%). Factors which affect financial performance most (decreasing in magnitude) are prices achieved for broilers, costs of brooding houses, chicks, arks, feed and timber prices. The main anticipated effects of biological interactions on financial performance (increased ranging on feed conversion and excess nutrient supply on tree health) were not supported by analysis. Further research is particularly warranted on the welfare benefits offered by the tree component and its relation to price premia.     

林地宁都黄鸡大棚散养模式探讨

林地大棚散养是宁都黄鸡的主要饲养方式.2010年,宁都黄鸡出栏3 632万只,产值5.6亿元,劳动力转移1万多人,成为宁都县农业增收、农民脱贫致富的农业支柱产业.但是,伴随着宁都黄鸡产业的发展,林地植被的破坏越来越严重,要引起高度重视,做到二者平衡发展.     

不同周龄和饲养方式对岭南黄鸡鸡蛋品质的影响研究

试验比较了20周龄笼养、30周龄笼养和30周龄放养三种饲养方式下的岭南黄鸡鸡蛋品质指标:蛋重、哈夫单位、全蛋胆固醇、蛋黄指数、蛋形指数、蛋壳相对重和蛋壳厚度。试验结果表明,三组蛋形指数无显著差异;笼养条件下岭南黄鸡随着产蛋周龄的增加,蛋重增加、其他指数下降;30周龄放养鸡鸡蛋的蛋重接近20周龄笼养鸡蛋,蛋壳显著增厚,全蛋胆固醇含量高于其他两组。     

Prevalence and distribution of gastrointestinal helminths and their effects on weight gain in free-range chickens in Central Zambia

Examination of helminths from gastrointestinal tracts of 125 free-range chickens in Zambia revealed a 95.2% prevalence rate. The species and their prevalences were: Allodapa suctoria (85.6%), Tetrameres americana (80.8%), Ascaridia galli (28.8%), Gonglonema ingluvicola (50.4%), Raillietina spp. (81.6%) and Heterakis gallinarum (32.8%). No trematodes or Syngamus trachea were found. Mixed infections accounted for 88.2% as compared to 7.2% of single infections. Effects of helminthoses on weight gain were investigated in 100 growing chickens randomly assigned to treatment (levamisole) and untreated control groups. There was a significant mean (±SEM) weight gain (grams) of 812.8 ± 51.4 in the treatment group and 623 ± 57.4 in the control group (p < 0.01). The mean (±SEM) worm burdens from the control group and the treatment group were 96.3 ± 5.61 and 22.05 ± 2.61, respectively. These results confirm the higher risk of helminth infections in free-range systems and may explain the deleterious effects in chickens.     

Molecular study and genotyping of Cryptosporidium baileyi and Cryptosporidium parvum from free-range and commercial broiler chickens in Guilan province,Iran

Cryptosporidiosis acutely impacts the digestive and/or respiratory tract of the birds in many species of various orders. More importantly, it is also well known as a significant zoonotic disease, which can lead to diarrhea in humans and livestock. Regarding increasing demand for free-range products and increasing the number of free-range poultry farms, the present paper evaluated histopathological and molecular detection of Cryptosporidium baileyi and Cryptosporidium parvum in free-range and commercial broiler chickens in the north part of Iran. For this purpose, 100 fecal and tissue samples of the chickens in Guilan province were collected. After microscopic examination using Ziehl-Neelsen staining, molecular analyses of the fecal samples were processed by Nested-PCR targeting the 18S rRNA gene followed by sequencing of the amplicons and phylogenetic analyses. Eventually, the tissue samples were studied for histological lesions. Findings demonstrated the presence of Cryptosporidium baileyi and Cryptosporidium parvum in 6 % and 2 % of fecal samples, respectively. This is the first identification of C.parvum in avian hosts in Iran, and for the first time, C.baileyi and C.parvum are shown in native free-range chickens in Iran. All of the PCR positive birds with clinical symptoms showed gross lesions of respiratory infections. There was no significant difference between infection rate in free-range and commercial broiler chickens; however, the infection rate was significantly higher in chickens <25 days old. To conclude, we present here a notable Cryptosporidium infection rate in the free-range chicks in Iran, which notify the role of this host as a reservoir and should be more noted due to the economic and zoonotic importance.     

Biologic and genetic comparison of Toxoplasma gondii isolates in free-range chickens from the northern Pará state and the southern state Rio Grande do Sul, Brazil revealed highly diverse and distinct parasite populations

The prevalence of Toxoplasma gondii in 84 free-range chickens (34 from the northern Pará state, and 50 from Rio Grande do Sul, the southern state) from Brazil, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 39 (46.4%) of 84 chickens with titers of 1:10 in one, 1:20 in two, 1:40 in four, 1:80 in seven, 1:160 in five, 1:320 in six, 1:640 in eight and > or =1:1280 in six. Hearts and brains of 45 chickens with titers of 1:20 or less were pooled and fed to two T. gondii-free cats. Hearts and brains of 39 chickens with titers of 1:10 or higher were bioassayed in mice. Feces of cats were examined for oocysts. One cat fed tissues from 31 chickens with titers of less than 1:10 from Rio Grande do Sul shed T. gondii oocysts. T. gondii was isolated by bioassay in mice from 33 chickens with MAT titers of 1:20 or higher. All infected mice from 10 isolates died of toxoplasmosis. All 34 isolates (15 from Pará, 19 from Rio Grande do Sul) were genotyped using 11 genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, a new SAG2 and Apico. Eleven genotypes were revealed for Pará isolates and seven genotypes for Rio Grande do Sul. No genotype was shared between the two geographical locations. These data suggest that T. gondii isolates are highly diverse and genetically distinct between the two different regions in Brazil that are 3500 km apart.