The effects of partial defeathering on energy metabolism in the laying fowl

1. The effects of a complete removal of feathers from the neck and/or breast on the energy metabolism of laying hens were measured by indirect calorimetry.

2. The daily heat production of fed birds was significantly increased if feathers were removed from the entire neck plus breast region but not if the neck only or breast only were denuded.

3. Removal of feathers from the neck plus breast led to a 10% increase in food consumption.

4. The partially‐defeathered birds laid more eggs.     

Microbial cross-contamination by airborne dispersion and contagion during defeathering of poultry

1. A readily identifiable strain of Escherichia coli K12 was used as a 'marker' organism to determine the sources, routes and patterns of microbial cross-contamination during mechanical defeathering of broiler chicken carcases. 2. Inoculation of scald water with the marker organism led to a relatively even pattern of carcase contamination during subsequent defeathering. Microbial cross-contamination was greater by this route of inoculation than by either surface inoculation of a 'seeder' carcase or oral inoculation of a live bird one day before slaughter. 3. Dispersal of the marker organism was strongly influenced by the mechanical action of the defeathering machines. Forward transmission of the marker occurred by aerosol or large airborne droplets and particulates such as feathers. Moving carcases through the defeathering machines when these were non-operational clearly reduced backward transmission of the marker. 4. Although microbial dispersal was unaffected by increasing the spacing between individual carcases or installing a water curtain at the entry and exit of the defeathering machines, shielding of carcases with aluminium baffles reduced counts of the marker organism from contaminated carcases by > 90%. 5. The results imply that microbial cross-contamination of broiler chicken carcases during defeathering occurs mainly via the airborne route, which could be contained by physical means.     

Effects of defeathering and insulative jackets on production by laying hens at low temperatures

1. Exposure to a temperature of 5 °C compared with 20 °C resulted in a 20.5% increase in food consumption and an 18.8% decrease in efficiency of food utilisation with intermediate values resulting from exposure to 10 °C and 15°C.

2. Removal of feathers from the neck, back and (or) breast resulted in a 5 to 6% increase in food consumption.

3. The effects of feather removal and temperature on food consumption were additive.

4. Cloth jackets effectively insulated the back and breast areas when feathers had been removed but also resulted in increased food intake and lower efficiency.     

Factors affecting piglet mortality in loose farrowing systems on commercial farms

Crating sows in farrowing systems greatly restricts their normal behaviour (e.g. movement, nest-building, leaving the nest site for defecation), which is usually justified by the assumption that piglet mortality is higher with loose-housed sows. Based on experiments showing that this is not the case, farrowing crates were banned in Switzerland in 1997, with a 10-year transitional period. Since then, many farms have introduced loose farrowing systems, enabling an analysis of risk factors for piglet mortality in crateless farrowing systems based on a large sample size. Data from a Swiss sow recording scheme (UFA2000) were analysed using generalised linear mixed-effects models with an underlying Poisson distribution. Average total piglet mortality for the years 2002 and 2003 on 99 farms (N = 12457 litters) with loose farrowing systems amounted to 1.36 liveborn piglets per litter. The number of crushed piglets was 0.64 piglets per litter, whereas the number of piglets that died for other reasons was 0.72 piglets per litter.Herd size, pen size, possibility of confinement of the sow, presence of piglet protection bars and year of data collection did not significantly influence total piglet losses, losses due to crushing and losses due to reasons other than crushing. With greater litter size at birth, significantly more losses occurred due to all reasons (total, crushed, others). Total piglet mortality and losses for reasons other than crushing were significantly higher in older sows. Losses were therefore mainly attributable to sow-related characteristics rather than to the design of the farrowing pen.     

Evaluation of four commercial anaerobic systems for identification of Eubacterium suis

Four commercial anaerobic systems (CASs) were evaluated for usefulness in identification of Eubacterium suis. Twelve strains were evaluated in each system in triplicate, and results were interpreted independently by 5 individuals. Statistically significant differences (P less than 0.01) due to strain variation and reader interpretation accounted for discrepancies encountered. The reactivity, repeatability, and unique profiles generated made both CAS-1 and CAS-2 suitable adjuncts for identification of E. suis when colony morphology and Gram reaction were considered. Limited reactivity in CAS-3 limited its use as an aid in identification. Variability in test observations and the large number of numerical profiles generated precluded use of CAS-4.     

Pharmacodynamics of ibafloxacin in micro-organisms isolated from cats

The pharmacodynamic properties of ibafloxacin were investigated in micro-organisms isolated from cats. Minimal inhibitory concentrations (MIC) of ibafloxacin (racemate, R- and S-enantiomers) and its metabolites (7-hydroxy- and 8-hydroxy-ibafloxacin) and time-kill kinetics were determined against Gram-negative and Gram-positive bacteria isolated from dermal and respiratory and urinary tract infections in cats. Racemic ibafloxacin has a broad spectrum of bactericidal activity against Gram-negative and some Gram-positive bacteria. Escherichia coli and Pasteurella, Klebsiella and Staphylococcus spp. are commonly isolated from feline infections and all are susceptible to ibafloxacin (MIC90 < or = 0.5 microg/mL), whereas Pseudomonas aeruginosa, Proteus mirabilis and Streptococcus spp. are considered intrinsic resistant. Microbiological activity resides primarily in the S-enantiomer of ibafloxacin whereas the R-enantiomer is less active. Killing curves using concentrations of racemic ibafloxacin and 8-hydroxy-ibafloxacin, which are representative of the in vivo situation observed in cats, showed at least 99.9% reduction in viable bacterial isolates from feline clinical samples over 24 h. Bacterial eradication was achieved in cats with Cmax/MIC and AUC/MIC values much lower than the target values previously established in man and laboratory animals. Additional studies in dogs and cats are necessary to define more clearly the surrogate markers of antibacterial activity (i.e. Cmax/MIC, AUC/MIC ratios), which are associated with a good clinical response.     

商品猪生产体系及其主要福利挑战:猪生长周期

商品猪生产由原来的小型家庭式农场生产模式逐渐转变为一位私营农场主雇佣多位或许多雇员的大型工业化养猪场生产模式,人们逐渐意识到消费者、决策者和零售商使用工业化生产方法带来的相关动物福利问题。本文围绕猪生长周期论述不同生产阶段的猪对动物福利要求。     

商品猪生产体系及其主要福利挑战:动物福利的挑战和可能的改进措施

商品猪生产由原来的小型家庭式农场模式逐渐转变为一位私营农场主雇佣多位或许多雇员的大型工业化养猪场生产模式,人们逐渐意识到消费者、决策者和零售商使用工业化生产方法带来的相关动物福利问题。本文就猪的不同生长阶段讨论相应的福利挑战和可能的改进措施。     

商品猪生产体系及其主要福利挑战:饲养系统和欧盟动物福利法

商品猪生产由原来的小型家庭式农场模式逐渐转变为一位私营农场主雇佣多位或许多雇员的大型工业化养猪场生产模式,人们逐渐意识到消费者、决策者和零售商使用工业化生产方法带来的相关动物福利问题。文章按照猪生长周期就饲养体系和欧盟动物福利法展开论述。     

家禽饮水中微生物的净化

水是家禽的重要营养物质,而饮水中的微生物污染(如大肠杆菌、病毒及有机质等)常常威胁着家禽的健康.     

Behaviour of laying hens in two types of aviary systems on 25 commercial farms in Sweden

1. Fifty-one flocks of laying hens in two high-density loose-housing systems were studied on 25 commercial farms in Sweden as part of a government test programme for evaluating new systems for laying hens. Six different hybrids were used in group sizes ranging from 250 to 5 000 birds. Stocking-densities varied from 10.2 to 19.1 birds per m2 floor area. No birds were beak trimmed. 2. The distribution of birds in the system, the frequency and location of aggressive pecks and feather pecks, the dust bathing activity and the birds' fear reaction to the keeper and to a novel object were measured. Direct behaviour observations were carried out twice per flock, at weeks 35 and 55. 3. The proportion of birds at the different locations was relatively constant across the 8-h observation period in the tiered system, but changed over time in the perch system, which may reflect a difference in access to resources between the systems. At night the top perches/tiers were preferred although when stocking-density increased, other sites were also used. 4. Aggression occurred mainly on the litter or in the nest areas. It did not differ between hybrids, but increased with age in the tiered system. Feather pecks occurred mainly on the litter. Brown hybrids feather pecked more than white ones, while white hybrids reacted more both to the keeper and to a novel object than did the brown hybrids. 5. It was concluded that access to nests was insufficient in both systems, as was litter space. Feed space was insufficient in the tiered system if food requirements increased. Design of the top perches, in the perch system, should be improved to allow birds to perch high up in the system without blocking access to feed etc. for others.     

Habitats and Dispersal of Southern African Anura

The data required to make it possible to relate dispersal of southern African Anura to the habitats occupied are considered. Habitat must be defined in terms of breeding populations; data on the breeding seasons of the taxon under consideration are needed, with comparative data on possible competitors in the breeding sites. Possible routes of dispersal under present conditions are considered; the distribution of the habitats of some taxa are considered in relation to presumed past conditions. Possible centres of origin and dispersal of genera and species endemic to southern Africa are discussed.     

Assessment of different surveillance systems for avian influenza in commercial poultry in Catalonia (North-Eastern Spain)

Compulsory surveillance programmes for avian influenza (AI) have been implemented in domestic poultry and wild birds in all the European Member States since 2005. The implementation of these programmes is complex and requires a close evaluation. A good indicator to assess their efficacy is the sensitivity (Se) of the surveillance system. In this study, the sensitivities for different sampling designs proposed by the Spanish authorities for the commercial poultry population of Catalonia were assessed, using the scenario tree model methodology. These samplings were stratified throughout the territory of Spain and took into account the species, the types of production and their specific risks. The probabilities of detecting infection at different prevalences at both individual and holding level were estimated. Furthermore, those subpopulations that contributed more to the Se of the system were identified. The model estimated that all the designs met the requirements of the European Commission. The probability of detecting AI circulating in Catalonian poultry did not change significantly when the within-holding design prevalence varied from 30% to 10%. In contrast, when the among-holding design prevalence decreased from 5% to 1%, the probability of detecting AI was drastically reduced. The sampling of duck and goose holdings, and to a lesser extent the sampling of turkey and game bird holdings, increased the Se substantially. The Se of passive surveillance in chickens for highly pathogenic avian influenza (HPAI) and low pathogenicity avian influenza (LPAI) were also assessed. The probability of the infected birds manifesting apparent clinical signs and the awareness of veterinarians and farmers had great influence on the probability of detecting AI. In order to increase the probability of an early detection of HPAI in chicken, the probability of performing AI specific tests when AI is suspected would need to be increased.     

Production and economic results of commercial flocks with white layers in aviary systems and battery cages

1. In the Netherlands aviary systems are in use on 19 commercial farms. In the present study the results of 19 flocks kept in aviaries, with an average flocksize of 16,000 hens, were analysed and compared with 47 flocks kept in battery cages.

2. The aviary flocks had lower egg weights, lower mortality rates and poorer food conversion. The difference in food intake per hen per day was not significant. The average percentage of floor eggs in aviaries was 4.6, ranging from 0.9 to 11.5.

3. Production costs per kg eggs produced in aviaries were 8.2% greater than in cages. This increase was mainly caused by higher costs for pullets, housing and labour.     

Dispersal of Dictyocaulus viviparus larvae from bovine faeces in Ireland

An involvement of Pilobolus species fungus in the dispersal of Dictyocaulus viviparus third stage larvae from dung to surrounding herbage under Irish conditions was investigated. The presence of Pilobolus kleinii on artificial dung pats containing first stage larvae of D viviparus was associated with a 19-fold increase (P less than 0.05) in numbers of third stage larvae recovered from the surrounding herbage. A subjective examination of natural dung pats showed that the presence of Pilobolus species was significantly correlated with hours of bright sunshine (r = -0.5, P less than 0.01), total rainfall (r = 0.41, P less than 0.05) and the height of herbage surrounding the pats (r = 0.31, P less than 0.001). A multiple regression analysis showed that meteorological parameters and the height of surrounding herbage accounted for 38 per cent of the variation in growth of Pilobolus species on dung pats. The incidence of extensive damage to natural dung pats within five days of deposition, caused by biotic factors, another possible cause of D viviparus third stage larvae dispersal, varied from 0 to 92 per cent of the pats depending on their degree of dryness.     

退化高寒草甸上高原鼠兔的扩散研究

在高寒草甸上高原鼠兔是必不可少的生态关键种,同时由于密度过高又加剧着高寒草甸的退化.应加强对高原鼠兔种群动态的管理,使其保持适当的密度和适当的时空分布,发挥其关键物种的作用,但不对高寒草甸造成破坏.为此有必要掌握高原鼠兔的扩散规律.通过高原鼠兔的扩散试验得到了以下结果:环境容纳量K和植被高度h有如下关系:K={6.2237h 17.2237(h＜4.8717) 47.5438(h=4.8717) -4.0654h 67.3494(h＞4.8717);高原鼠兔月扩散距离为32.16 m;高原鼠兔对原有栖息地留恋的量α为0.3371.