Broiler chicken health, welfare and fluctuating asymmetry in organic versus conventional production systems

The potential of pumice as a litter material and its influence on growth performance, carcass parameters, litter quality traits, behavior, and welfare in broiler chickens

This study evaluated the possibilities of pumice (light stones) as litter material in broiler production. Experimental treatments included wood shavings (WS), acidic pumice (AP), and basic pumice (BP) alone, and in combination; wood shaving + acidic pumice (WSAP) and wood shaving + basic pumice (WSBP) in a ratio of 1:1. Two trials were performed, one in summer, and the other in winter. Each trial involved 750 mixed-sex Ross (308) broilers. Also, there were 15 replicate pens with 50 broilers and a stocking density of 12.5 birds/m2 for each pen at the beginning of each trial. Performance, litter quality, carcass parameters, body and leg abnormalities, body temperature, fear and stress responses, proportional asymmetry, and some behavior expressions were investigated. The litter treatment influenced the final live body weight, litter moisture, ammonia concentration, footpad dermatitis, hock burn, breast blister, hot carcass yield, heart, liver, spleen, abdominal fat, wing and neck ratio, breast and back cleanliness, and the expression of dust bathing and foraging behaviors (P < 0.01; P < 0.05). Furthermore, there was a seasonal effect on live body weight, feed conversion ratio, livability, litter pH, 42-day litter moisture, hot carcass yield, back cleanliness, footpad dermatitis, hock burn, footpad temperature, heterophil-to-lymphocyte ratio, and expression of pecking behavior (P < 0.01; P < 0.05). It is suggested that acidic pumice stone alone or in a mixture with wood shavings could be used as a reliable litter material, alternative to wood shavings.

The Link between the Perception of Animal Welfare and the Emotional Response to Pictures of Farm Animals Kept in Intensive and Extensive Husbandry Systems: An Italian Survey

As livestock production grows to satisfy the global demand for animal products, understanding public attitudes towards different husbandry systems becomes essential for both animal welfare and socio-economic reasons. This study aimed to investigate people's emotional responses toward pictures of farm animals kept in intensive and extensive husbandry systems, their perception of animal welfare, and their choices as animal product consumers. A questionnaire that included demographic questions and photos of cows, pigs, chickens, and rabbits in both intensive and extensive systems was distributed electronically and physically and completed by 835 respondents. Photos of animals in intensive systems elicited more negative emotions, especially for pigs and rabbits (p < 0.05), as opposed to extensive systems, which elicited more positive emotions, especially for chickens (p < 0.001). Higher welfare levels were perceived for extensively farmed animals (p < 0.001) and for cattle compared to all other species, regardless of the husbandry system (p < 0.001). The quality of the emotional response was positively associated with welfare perception (p < 0.001) and negatively associated with the importance given to welfare when purchasing animal products (p < 0.001). Finally, the emotional response was found to be affected by gender, education, household composition, living area, pet ownership, and eating habits. The implications and limitations of these findings are discussed.

Water pollution from pharmaceutical use in livestock farming: Assessing differences between livestock types and production systems

Livestock production is a major source of pharmaceutical emissions to the environment. The current scientific discourse focuses on measuring and modeling emissions as well as assessing their risks. Although several studies corroborate the severity of pharmaceutical pollution resulting from livestock farming, differences in pollution between livestock types and production systems are largely unknown. In fact, there is no comprehensive analysis of factors influencing pharmaceutical use-the emission's source-in the diverse production systems. To address these knowledge gaps, we developed a framework to investigate pharmaceutical pollution from different livestock production systems and applied it in a first pilot assessment to compare pollution from organic and conventional cattle, pig, and chicken production systems on selected indicator substances, covering antibiotics, antiparasitics, hormones, and nonsteroidal anti-inflammatory drugs (NSAIDs). Given the lack of statistics, for this article we retrieved novel qualitative information about influential factors for pharmaceutical use and pollution from expert interviews and combined this with quantitative data on, among other factors, the environmental behavior of specific substances from the literature. Our analysis reveals that factors across a pharmaceutical's entire life cycle influence pollution. However, not all factors are livestock type or production-system dependent. The pilot assessment furthermore reveals that differences in pollution potential between conventional and organic production exist, but for antibiotics, NSAIDs, and partially for antiparasitics, some factors lead to greater pollution potential in conventional systems, and others in organic systems. For hormones, we identified a comparatively greater pollution potential from conventional systems. Among the indicator substances, the assessment over the entire pharmaceutical life cycle illustrates that flubendazole in broiler production has the greatest per unit impact. The framework and its application in the pilot assessment generated insights useful to identifying which substances, livestock types, production systems, or the combination thereof have great or little pollution potential, informing more sustainable agricultural management practices. Integr Environ Assess Manag 2023;19:1495-1509. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Welfare of broiler chickens in Brazilian free-range versus intensive indoor production systems

We compared broiler chicken welfare in free-range (FR) and intensive indoor (IN) systems using the Welfare Quality® Protocol. Ten FR and 11 IN farms in Brazil were assessed. Results are shown as either scores ranging from 0 to 100, where higher scores indicate better welfare, or prevalence, where lower prevalence indicates better welfare. In FR, the median prevalence was lower than in IN for mortality (2.0% vs. 4.7%, p = 0.0262), culling (0.0% vs. 0.6%, p = 0.0168), ascites (0.0% vs. 0.17%, p = 0.0431). Median welfare scores on FR farms were better for plumage cleanliness (100 vs. 59, p = 0.0001), panting or huddling (100 vs. 29, p = 0.0001), lameness (81 vs. 19, p = 0.0001), hock burn (93 vs. 37, p = 0.0001), footpad dermatitis (35 vs. 26, p = 0.0018). However, FR scores were worse for litter quality (34 vs. 100, p = 0.0003), dust (53 vs. 78, p = 0.0002), breast blisters (90 vs. 100, p = 0.0077), touch test (70 vs. 99, p = 0.0082). Better emotional states were observed in FR (p < 0.001). Even though there is room for welfare improvement in both systems, the number of welfare indicators with better results was superior in FR than in IN farms.

Effect of different pasture species on welfare and behavior of slow-growing broiler chickens in free-range production system

This study investigated the effect of various pasture species on the welfare and behavior of slow-growing broiler chickens in the free-range production system. After 21 days completely indoors, the birds were permitted access to outdoor pens cultivated with one of the following pasture treatments: Medicago sativa (A), Trifolium repens (WC), Lolium perenne (PR), and a mixture (Mix, A + WC + PR). The range availability was restricted between 08:30 and 16:30 daily. It was found that pasture type had a significant effect on the fluctuating asymmetry of the face and radius length (P < 0.01). Duration of tonic immobility and blood parameters did not differ among the pasture species and between sexes at 11 weeks of broiler age (P > 0.05). Pasture treatment had no significant effect on broiler behaviors (P > 0.05). However, the age of broilers had a significant effect on pecking, dustbathing, and scratching (P < 0.01). Pecking behavior was affected by the time of the day; morning and afternoon (P < 0.01). Location had a significant effect on pecking and stretching behaviors (P < 0.01). In the study, dustbathing behavior was significantly affected by the interaction between location and age (P < 0.01), age and time of the day (P < 0.01), and location, age, and time of the day (P < 0.05). Scratching behavior was significantly affected by the interaction between location and time of the day (P < 0.05) and location, age and time of the day (P < 0.01). Stretching behavior was significantly affected by the interaction between location and age (P < 0.05) and location, age and time of the day (P < 0.05). It was concluded that access to the studied pasture species does not affect the evaluated welfare traits and observed behaviors. Therefore, it is suggested that other pasture species should be investigated to identify their effect on slow-growing strains in the free-range production system.

Effect of silvopasture system on fearfulness and leg health in fast-growing broiler chickens

A silvopasture system intentionally integrates trees, forages, and livestock, allowing dual land use. These systems can provide high-quality habitat for broiler chickens; however, such systems have not been widely adopted by the broiler industry in the United States. The objective of this study was to examine the effect of silvopasture versus open pasture access on fearfulness and leg health in fast-growing broiler chickens. A total of 886 mixed-sex Ross 708 chicks in Experiment 1 (Exp 1) and 648 chicks in Experiment 2 (Exp 2) were housed in coops and had access to 16 (Exp 1) or 12 (Exp 2) 125m2 silvopasture plots (x̄ = 32% canopy cover) or open pasture plots (no canopy cover) from day 24 of age. Fearfulness was measured using a tonic immobility test (tonic immobility duration), and leg health was assessed by quantifying footpad dermatitis, hock burns, gait, and performing a latency-to-lie test on days 37-39 of age. Birds in the silvopasture treatment were less fearful than birds in the open pasture treatment. Overall, birds in both silvopasture and open pasture systems had excellent leg health. Silvopasture birds had lower footpad dermatitis scores than open pasture birds. Silvopasture birds tended to have worse gait than open pasture birds in Exp 1, but not in Exp 2. Hock burn scores and latency-to-lie did not differ between treatments in Exp 1 or Exp 2. Raising birds in silvopasture reduced fear and improved footpad health compared to birds raised in open pastures, which indicates that silvopasture systems provide some benefits for affective state and leg health in fast-growing broilers.

Avian Inflammatory Markers

Inflammation represents a fundamental response to diverse diseases ranging from trauma and infection to immune-mediated disease and neoplasia. As such, inflammation can be a nonspecific finding but is valuable as an indicator of pathology that can itself lead to disease if left unchecked. This article focuses on inflammatory biomarkers that are available and clinically useful in avian species. Inflammatory biomarkers are identified via evaluation of whole blood and plasma and can be divided into acute and chronic, with varying degrees of specificity and sensitivity. Evaluation of multiple biomarkers may be necessary to identify subclinical disease.

Smart Feeding Unit for Measuring the Pecking Force in Farmed Broilers

Simple Summary

We present a novel method for assessing broiler pecking force data during feeding. The prototype consisted of a power supply unit with a data acquisition module, management software connected to a computer for data storage, and a video camera to verify the pecking force during signal processing. The acquisition, processing, and classification of the pecking force signal information were valuable during broilers’ feeding. The smart feeding unit (SFU) prototype was useful in the continuous generation of information that could be applied to evaluate the amount of pecking force and performance during the broilers’ growth.

Abstract

Feeding is one of the most critical processes in the broiler production cycle. A feeder can collect data of force signals and continuously transform it into information about birds’ feed intake and quickly permit more agile and more precise decision-making concerning the broiler farm’s production process. A smart feeding unit (SFU) prototype was developed to evaluate the broiler pecking force and average feed intake per pecking (g/min). The prototype consisted of a power supply unit with a data acquisition module, management software connected to a computer for data storage, and a video camera to verify the pecking force during signal processing. In the present study, seven male Cobb-500 broilers were raised in an experimental chamber to test and commission the prototype. The prototype consisted of a feeding unit (feeder) with a data acquisition module (amplifier), with real-time integration for testing and intuitive operation with Catman Easy software connected to a computer to obtain and store data from signals. The sampling of average feed intake per pecking per broiler (g) was conducted during the first minute of feeding, subtracting the amount of feed provided per the amount of feed consumed, including the count of pecking in the first minute of feeding. An equation was used for estimating the average feed intake per pecking per broiler (g). The results showed that the average broiler pecking force was 1.39 N, with a minimum value of 0.04 N and a maximum value of 7.29 N. The average feed intake per pecking (FIP) was 0.13 g, with an average of 173 peckings per minute. The acquisition, processing, and classification of signals in the pecking force information were valuable during broilers’ feeding. The smart feeding unit prototype for broilers was efficient in the continuous assessment of feed intake and can generate information for estimating broiler performance.

Health and welfare in organic livestock production systems—a systematic mapping of current knowledge

This review aimed to systematically map and summarize the status of animal health and welfare in organic production. The prevalence of diseases and behavioural effects in organic dairy cow, beef cattle, sheep, pig, laying hen and broiler chicken were discussed in the context of the organic values and current knowledge on animal health and welfare. In total 166 peer-reviewed scientific publications between 2008 and 2020 were included. No strong evidence for neither inferior nor distinctly higher animal welfare in organic compared with conventional production could be supported. The welfare status of organic livestock is in general good in relation to the OIE definition of animal health and welfare. However, organic systems are still facing several challenges related to animal health and the arising of goal conflicts due to management and practical implications. Greater possibilities to perform species-specific behaviours in organic production systems, however, indicate that the organic standards offer a good framework for high animal welfare management. For organic dairy farmers, the main health problems are similar to those of non-organic farms; especially mastitis and lameness need improvement. Parasites, together with mastitis and lamb mortality, are important welfare issues in organic sheep production. Piglet mortality, leg problems, parasite load and increasing respiratory problems are of major relevance in organic pig production. For organic laying hens, major health challenges relate to feather pecking and cannibalism, parasites and possibilities to express species-specific behaviours. For organic broilers, dermatitis of footpads, hocks and breast are reported as main health issues.

Characteristics of the fecal microbiota of high- and low-yield hens and effects of fecal microbiota transplantation on egg production performance

The microbiota that resides in the digestive tract plays pivotal role in maintaining intestinal environmental stability by promoting nutrition digestion and intestinal mucosal immunity. However, whether the intestinal microbiota in laying hens affects egg laying- performance is not known. In this study, 16S rDNA gene sequencing and fecal microbiota transplantation were used to determine the structure of the intestinal microbiota and the effect of the intestinal microbiota on egg production. The results revealed that Firmicutes were dominant in both the H (high egg laying rates) and L (low egg laying rates) groups, while Bacteroides, Actinobacteria and Proteobacteria were significantly enriched in the L group compared to the H group. The laying rates were weakly affected in H hens transplanted with the fecal microbiota from L hens, except for temporary fluctuation, while the egg laying rates were significantly increased in L hens transplanted with the fecal microbiota from H hens. Therefore, we concluded that the population structure of the intestinal microbiota varied between the H and L groups, and the intestinal microbiota of high-yield laying hens had significant effects on low-yield laying hens performance.

Husbandry Practices, Health, and Welfare Status of Organic Broilers in France

Simple Summary

Organic poultry production has grown rapidly in Europe for the past several years in the context of sustainable development within farming. The authors carried out a field study in France between 2014 and 2015 concerning 85 organic broiler flocks that showed a wide diversity of farming management systems from independent farmers set up for direct sales of poultry to farmers under contract with a company for product sales. Health and welfare characteristics did not significantly differ between these two farming systems, except slightly dirtier feathers and more footpad dermatitis on the independent farms, related to the poultry housing conditions in mobile houses. A mortality rate of 2.8% was found, with digestive problems mainly being observed. Better knowledge of husbandry practices, health, and the welfare status of organic poultry is of primary importance to improve the management of organic production and to help in characterizing farming sustainability.

Abstract

Organic poultry production has increased sharply with growing consumer demand in the context of sustainable development. A study was conducted in 85 organic broiler flocks between 2014 and 2015 to describe the husbandry practices and the health and welfare status of organic broilers in France, and to study farming diversity by comparing independent farms (Ind farms, n = 15) with direct sales to farms working with companies (Comp farms, n = 70). Each flock was visited at 3 and 11 weeks of age to collect data on farming conditions, health disorders, and mortality. Welfare notation of 30 broilers per flock and parasitic examination of 5 broilers per flock was also performed. Findings showed significantly different farming management between Ind farms and Comp farms, with smaller flocks on the Ind farms (476 broilers/house vs. 3062 broilers/house, p < 0.01) more frequently in mobile houses. The mean mortality rate was 2.8%, mainly involving digestive disorders. Helminths were detected in 58.8% of the flocks. On average, 21.9% and 5.8% of broilers in a flock had footpad dermatitis and dirty feathers, respectively. The health and welfare characteristics of organic broilers on Ind farms vs. Comp farms were not significantly different, except dirtier feathers and more footpad dermatitis on Ind farms (19.1% vs. 2.9%, p = 0.03 and 39.6% vs. 18.1%, p = 0.02, respectively), associated with poultry housing conditions in mobile houses (p < 0.01). This study provides greater insight into farming sustainability aspects related to the husbandry practices, and the health and welfare of organic broilers in France.

Transcriptome changes provide genetic insights into the effects of rearing systems on chicken welfare and product quality

Farm animals raised under free-range (FR) systems are assumed to have improved welfare and higher-quality products that are better to eat than intensively reared animals. However, the modulations are limited in scientific investigations. In this study, we compared 2 rearing systems (FR and cage) and their effects on chickens, including production performance, product quality, body condition, physiological indicators, and gene expression. By using a match-mismatch design in which each treatment was transferred to the other treatment during the last period of the experiment, we aimed to understand the influence of current and former rearing conditions and the ability of individuals to adapt to the current environment. The results indicated that the FR system led to better chicken welfare (e.g., gait score, feather condition, and physiological indicators, P < 0.05) and contributed to higher product quality (P < 0.05), although it resulted in poorer production performance (P < 0.05) and foot pad condition (P < 0.05) than that of the cage rearing system. Additionally, the FR system triggered a series of inner changes and genetic responses in chickens, such as the upregulation of calcium and GnRH signaling, actin and cytoskeleton regulations, immune functions, and developmental processes, and the downregulation of pathological regulations (q-value < 0.05 for all gene ontology terms and P < 0.05 for all Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways). In conclusion, rearing systems alter chicken gene expression patterns, which provide a genetic basis for the adaptability to rearing environments and ultimately affects chicken welfare and products.

Salmonella control in poultry flocks and its public health impact

An increase in confirmed human salmonellosis cases in the EU after 2014 triggered investigation of contributory factors and control options in poultry production. Reconsideration of the five current target serovars for breeding hens showed that there is justification for retaining Salmonella Enteritidis, Salmonella Typhimurium (including monophasic variants) and Salmonella Infantis, while Salmonella Virchow and Salmonella Hadar could be replaced by Salmonella Kentucky and either Salmonella Heidelberg, Salmonella Thompson or a variable serovar in national prevalence targets. However, a target that incorporates all serovars is expected to be more effective as the most relevant serovars in breeding flocks vary between Member State (MS) and over time. Achievement of a 1% target for the current target serovars in laying hen flocks is estimated to be reduced by 254,400 CrI95[98,540; 602,700] compared to the situation in 2016. This translates to a reduction of 53.4% CrI95[39.1; 65.7] considering the layer-associated human salmonellosis true cases and 6.2% considering the overall human salmonellosis true cases in the 23 MSs included in attribution modelling. A review of risk factors for Salmonella in laying hens revealed that overall evidence points to a lower occurrence in non-cage compared to cage systems. A conclusion on the effect of outdoor access or impact of the shift from conventional to enriched cages could not be reached. A similar review for broiler chickens concluded that the evidence that outdoor access affects the occurrence of Salmonella is inconclusive. There is conclusive evidence that an increased stocking density, larger farms and stress result in increased occurrence, persistence and spread of Salmonella in laying hen flocks. Based on scientific evidence, an impact of Salmonella control programmes, apart from general hygiene procedures, on the prevalence of Campylobacter in broiler flocks at the holding and on broiler meat at the end of the slaughter process is not expected.

Effect of Zinc Sulfate and Zinc Glycine Chelate on Concentrations of Acute Phase Proteins in Chicken Serum and Liver Tissue

The aim of the study was to determine how inorganic and organic forms of zinc affect the concentrations of C-reactive protein (CRP), serum amyloid A (SAA), alpha-1-acid glycoprotein (α-1-AGP), haptoglobin (Hp), and transferrin (TRF) in the blood and liver tissue of 450 1-day-old Ross 308 chicken. Four experimental groups received one the following: inorganic zinc (ZnSO4), a zinc phytase enzyme supplement (ZnSO4-F), organic zinc in combination with glycine (Zn-Gly), or organic zinc supplemented with phytase (Zn-Gly-F). The chicken serum and liver homogenates were assayed using an ELISA kit. The results of the study showed statistically significantly higher serum and liver concentration of SAA in the group of birds that received zinc sulfate in comparison to the group of birds receiving zinc in organic form. A statistically significantly higher serum concentration of CRP and α-1-AGP was also noted in the group receiving zinc sulfate as compared to the Zn-Gly group. Comparison of the serum concentration of TRF between the supplemented groups showed a statistically significant increase in this parameter in the Zn-Gly-F group as compared to the ZSO4-F group. The increase in the serum concentration of Hp in all groups in comparison to the control may indicate stimulation of local immune mechanisms. The results of this study showed an increase in the concentrations of APPs such as AGP and TRF following the administration of zinc glycine chelates, which may demonstrate their effect on metabolic processes in the liver and on immunocompetent cells that regulate the intensity of the immune response.

A comparative study of acute-phase protein concentrations in historical and modern broiler breeding lines

Acute-phase proteins (APP) are secreted from the liver as a result of inflammation or infection and are measurable in serum and plasma. To determine whether the constitutive APP serum amyloid A (SAA), alpha-1-acid glycoprotein (AGP), ceruloplasmin (Cp), and ovotransferrin (Ovt) have changed as a result of selection for improved production and growth characteristics over the last 40 yr two historical broilers lines were compared to a modern line of the same lineage. Serum was harvested from blood samples taken from the 3 broiler lines on days 10, 17, and 20, and the APP concentrations were determined using immunoassay methods. Most of the significant changes observed were age related, with SAA and Cp having significantly lower concentrations at day 20 than days 10 and 17 in all lines. The only significant difference between lines was observed at day 20 on which both Cp (P = 0.01) and AGP (P = 0.03) were significantly higher in the modern line than the 90s line, though no significant differences were noted between the modern and 70s line. When evaluating the difference in APP concentrations between males (Cx) and females (Px) across all 3 lines, females had a higher SAA at day 17 and lower SAA at day 20, P = 0.0078 and 0.0327 respectively, and males had a significantly higher Ovt on days 17 and 20 (P = 0.0002 and P = 0.003 respectively). These results reveal that APP concentrations fluctuate over this early period of growth and that the changes in APP serum concentration appear uniform between 3 lines with very contrasting selection history, suggesting the improvements made in meat production efficiency since the 1970s have not affected the circulating concentrations of these constitutively expressed APP.

Review of environmental enrichment for broiler chickens

Welfare problems are commonly found in both conventional and organic production of broiler chickens. In order to reduce the extent of welfare problems, it has been suggested to provide stimulating, enriched environments. The aim of the present paper is to provide a review of the effect on behavior and welfare of the different kinds of environmental enrichments in the production of broilers that have been described in the scientific literature. Environmental enrichment is defined as an improvement of the environment of captive animals, which increases the behavioral opportunities of the animal and leads to improvements of the biological function. This definition has been broadened to include practical and economic aspects, as any enrichment strategy that adversely affects the health of animals or that has too many economic or practical constraints will never be implemented on commercial farms and thus never benefit animals. Environmental enrichment for broilers often has the purpose of satisfying behavioral needs and/or stimulating the broilers to an increased level of activity, which among others will reduce the occurrence of leg problems. Potentially successful environmental enrichments for broiler chickens are elevated resting-places, panels, barriers, and bales of straw ("point-source enrichment"), as well as covered verandas and outdoor ranges ("complex enriched environments"). Many of the ideas for environmental enrichment for broilers need to be further developed and studied, preferably in commercial trials, with respect to the use, the effect on behavior and on other welfare aspects such as leg health, and the interaction with genotype, production system, stocking density, light, and flock size. In addition, information on the practical application and the economics of the production system is often lacking, although it is important for application in practice.

Comparison of the loads and antibiotic-resistance profiles of Enterococcus species from conventional and organic chicken carcasses in South Korea

Antibiotic-resistant bacteria in poultry meat are a threat to public health. In this study, we compared the Enterococcus spp. loads and antibiotic-resistance profiles between carcasses of conventionally and organically raised chickens. A total of 144 chicken carcasses (72 conventional and 72 organic) was collected from local retail markets in Seoul, South Korea. Overall, 77.7% (112 of 144; 75% conventional and 80% organic) of chicken carcasses were positive for Enterococcus. The mean loads of Enterococcus spp. were greater in conventional chicken carcasses, at 2.9 ± 0.4 log CFU/mL, than those in organic chicken carcasses, at 1.78 ± 0.3 log CFU/mL (p < 0.05). A total of 104 isolates (52 from conventional and 52 from organic chicken carcasses) was randomly selected for further analysis. The predominant species was Enterococcus faecalis in both conventional and organic chicken carcasses (57.7 and 76.9%, respectively; P > 0.05). Rates of resistance to ciprofloxacin and erythromycin, which are used in veterinary medicine in South Korea, were significantly higher in conventional chicken carcasses than in organic chicken carcasses. However, we found no difference between the rates of resistance to antibiotics such as vancomycin and tigecycline, which were not registered for use in veterinary medicine in South Korea, of Enterococcus isolates from conventional and organic chicken carcasses. In addition, although multidrug resistant isolates were obtained from both types of chicken samples, the prevalence of samples positive for Enterococcus was significantly higher in conventional chicken carcasses than in organic chicken carcasses (P < 0.05). The most common multidrug resistance pattern was erythromycin-tetracycline-rifampicin in conventional chicken carcasses and quinupristin-dalfopristin-tetracycline-rifampicin in organic chicken carcasses. A high level of gentamicin resistance was observed in isolates from not only conventional (5.8%) but also organic chicken (1.9%) carcasses, with no significant difference in rates between them (P > 0.05). Despite this, our results suggest that organic food certification is effective in reducing fecal contamination and the burden of antibiotic-resistant Enterococcus spp. in chicken carcasses.

Animal Board Invited Review: Comparing conventional and organic livestock production systems on different aspects of sustainability

To sustainably contribute to food security of a growing and richer world population, livestock production systems are challenged to increase production levels while reducing environmental impact, being economically viable, and socially responsible. Knowledge about the sustainability performance of current livestock production systems may help to formulate strategies for future systems. Our study provides a systematic overview of differences between conventional and organic livestock production systems on a broad range of sustainability aspects and animal species available in peer-reviewed literature. Systems were compared on economy, productivity, environmental impact, animal welfare and public health. The review was limited to dairy cattle, beef cattle, pigs, broilers and laying hens, and to Europe, North America and New Zealand. Results per indicators are presented as in the articles without performing additional calculations. Out of 4171 initial search hits, 179 articles were analysed. Studies varied widely in indicators, research design, sample size and location and context. Quite some studies used small samples. No study analysed all aspects of sustainability simultaneously. Conventional systems had lower labour requirements per unit product, lower income risk per animal, higher production per animal per time unit, higher reproduction numbers, lower feed conversion ratio, lower land use, generally lower acidification and eutrophication potential per unit product, equal or better udder health for cows and equal or lower microbiological contamination. Organic systems had higher income per animal or full time employee, lower impact on biodiversity, lower eutrophication and acidification potential per unit land, equal or lower likelihood of antibiotic resistance in bacteria and higher beneficial fatty acid levels in cow milk. For most sustainability aspects, sometimes conventional and sometimes organic systems performed better, except for productivity, which was consistently higher in conventional systems. For many aspects and animal species, more data are needed to conclude on a difference between organic and conventional livestock production systems.

Prevalence, genotyping and risk factors of thermophilic Campylobacter spreading in organic turkey farms in Germany

BACKGROUND

The need for organic food of animal origin has increased rapidly in recent years. However, effects of organic animal husbandry on food safety have not been rigorously tested especially in meat turkey flocks. This study provides for the first time an overview on the prevalence and genetic diversity of Campylobacter species (spp.) in five organic meat turkey farms located in different regions in Germany, as well as on potential risk factors of bacterial spreading. Thirty cloacal swabs as well as water samples and darkling beetles were collected from each flock and examined for the presence of Campylobacter by conventional and molecular biological methods. The isolates were genotyped by flaA-RFLP.

RESULTS

Campylobacter spp. were detected in cloacal swabs in all 5 turkey flocks with prevalence ranged from 90.0 to 100 %. 13 cloacal swabs collected from birds in farm III and IV were harboured mixed population of thermophilic campylobacters. In total, from 158 Campylobacter isolated from turkeys 89 (56.33 %) were identified as C. coli and 69 (43.76 %) as C. jejuni. Three Campylobacter (2 C. jejuni and 1 C. coli) were detected in drinkers of two farms and 3 C. coli were isolated from darkling beetles of one farm. No Campylobacter were isolated from main water tanks. flaA-RFLP assay showed that turkey farms can harbour more than one genotype. In a single turkey two different genotypes could be detected. The genotypes of campylobacters isolated from water samples or beetles were identical with those isolated from turkeys. No effect was found of some environmental parameters [ammonia concentration (NH3), carbon dioxide concentration (CO2), relative humidity (RH) and air temperature)] on Campylobacter prevalence in organic turkey farms. Additionally, drinking water and darkling beetles might be considered as risk factors for the spreading of Campylobacter in turkey flocks.

CONCLUSIONS

This study highlights the high prevalence and genotypic diversity of Campylobacter spp. isolated from organic turkey flocks. Further research is needed to assess other potential risk factors responsible for bacteria spreading in order to mitigate the spread of Campylobacter in organic turkey flocks by improving biosecurity control measures.

Belgian citizens' and broiler producers' perceptions of broiler chicken welfare in Belgium versus Brazil

New EU regulations require more stringent country-of-origin labeling, while imports of broiler meat from non-EU countries are increasing. In light of these trends, we have studied citizens' and producers' perceptions of broiler meat originating from Belgium versus Brazil and their perception of broiler production in Belgium versus Brazil. A particular focus was the association between country of origin and perceived level of animal welfare. We also investigated the perception of scaling-up and outdoor access in terms of perceived level of animal welfare. Cross-sectional survey data was collected among Flemish citizens (n = 541) and broiler producers (n = 114). In accordance with literature on general farm animal welfare, both stakeholder types claimed to allocate great importance to broiler welfare and generally agreed with the Welfare Quality model of broiler welfare. Citizens disagreed with the producers that 1) consumers are not willing to pay more for higher welfare products, 2) that broilers suffer little, 3) that broiler welfare in current Belgian production units is generally non-problematic, 4) that scaling-up production units would not have a positive impact on profitability nor a profoundly negative impact on broiler welfare, and 5) that the impact of providing broilers with outdoor access is negative for consumers, farmers, and broilers. Country of origin had a strong influence on the perception of both broiler production and broiler meat. Belgian citizens, and producers (much more than citizens) considered nearly all aspects related to broiler production and broiler meat to be significantly superior for chicken produced in Belgium compared to Brazil. Further research should focus on how these perceptions influence purchase intentions and production decisions. Future avenues for research are to quantify market opportunities for country-of-origin labeling and to investigate to which extent stakeholders' perceptions correspond with reality.

The effect of transport stress on turkey (Meleagris gallopavo) liver acute phase proteins gene expression

The aim of this study was to investigate the effects of transport-related stress on the liver gene expression of four acute phase proteins (APP), namely α1-acid glycoprotein (AGP), C-Reactive Protein (CRP), Serum Amyloid A (SAA) and PIT54, in turkeys (Meleagris gallopavo). A group of seven BUT BIG 6 commercial hens was subjected to a two-hour long road transportation and the quantitative gene expression of APP in the liver was compared to that of a non transported control group. The expression of AGP and CRP mRNA was found to be increased in animals slaughtered after road transport. The presence of AGP protein was also confirmed by immunohistochemistry and Western blotting. The results of this study showed that road-transport may induce the mRNA expression of immune related proteins. The finding that AGP and CRP can be upregulated during transport could suggest their use as for the assessment of turkey welfare during transport.

Genetic analysis of leg problems and growth in a random mating broiler population

Improvement in growth has been widely reported as the cause of increased incidence of leg problems in broiler chickens. We report herein the genetic relationship between growth and leg problems in a random mating broiler control population. The traits studied were valgus (VL), varus (VR), and tibial dyschondroplasia (TD), which were expressed on a binary scale of 0 (normal) and 1 (abnormal); growth rates from 0 to 4 wk (BWG 0-4) and from 0 to 6 wk of age (BWG 0-6); and residual feed intake from 5 to 6 wk of age (RFI 5-6). A threshold-linear mixed model was employed for the joint analysis of the categorical and linear traits. Incidences of VL, VR, and TD were 26, 4, and 2%, respectively. Heritability of leg problems ranged from 0.11 to 0.13. Phenotypic correlations alluded to an unfavorable relationship between growth and leg problems; however, the genetic relationship between growth and leg problems was extremely weak, ranging from 0.01 to 0.08. There is, therefore, a basis for genetic improvement in leg problems. However, improved management practices would also be important to reduce incidence of leg problems in broiler chickens.

Effects of dietary tryptophan and stocking density on the performance, meat quality, and metabolic status of broilers

Background

Highly automated cage-rearing systems are becoming increasingly popular in China. However, a high stocking density can cause oxidative stress and decrease broiler performance. The tryptophan (TRP) derivative 5-hydroxytryptophan (5-HT) has been shown to preserve membrane fluidity in birds suffering from oxidative stress. Therefore, this experiment was conducted to determine the effects of dietary TRP supplementation on performance, breast meat quality and oxidative stress in broilers reared in cages with a high or low stocking density.

Methods

Female Arbor Acres broilers (25-d-old, n = 144) were randomly allocated to 1 of 4 treatments. The birds were fed a diet based on corn, soybean meal, cottonseed meal and corn gluten meal containing either 0.18 or 0.27% TRP and were housed with stocking densities of 11 or 15.4 birds/m² in a 2 × 2 factorial experiment. Broiler performance was evaluated from d 25 to 42. Eight birds from each treatment were slaughtered on d 42 and plasma and breast muscle samples were collected to measure biochemical indices.

Results

A higher stocking density tended to be associated with reduced weight gain (P < 0.10), and significantly increased plasma glutamic-pyruvic transaminase (GPT) activity (P < 0.001). Increased dietary TRP significantly reduced the activities of lactic dehydrogenase and GPT while increasing total cholesterol in the plasma (P < 0.01), reducing drip loss of breast muscle (P < 0.10) and improving feed efficiency (P < 0.10).

Conclusions

An increase in dietary TRP, 1.5-fold higher than the standard supplementation level, can alleviate oxidative stress as well as improve welfare and feed efficiency in broilers reared in cages with a high stocking density.

The impact of broiler production system practices on consumer perceptions of animal welfare

This research explores the extent to which different farm management practices influence the perceived animal friendliness of broiler production systems, and how this differs between individuals. Using a conjoint design with paired comparisons, respondents evaluated broiler production systems that were described on the basis of 7 animal welfare-related practices. It was found that practices in the area of outdoor access, stocking density, and day-night rhythm were overall perceived to have a larger impact on perceptions of animal friendliness than other practices, such as transport duration or the type of breed used. However, individuals differed regarding the extent to which they believed the different farm management practices influenced the animal friendliness of the production system. Differences between individuals regarding their knowledge about and familiarity with livestock farming, degree of anthropomorphism, and their moral beliefs regarding animal welfare partly explained the relative importance individuals attached to farm management practices. The obtained insight into which welfare-related farm management practices, in consumers' minds, most strongly contribute to animal welfare, and the existence of differences between consumers, can be helpful in the development of animal welfare-based certification schemes that are appealing to consumers, as well as the positioning of welfare concepts in the market.

Animal Health and Welfare Issues Facing Organic Production Systems

Simple Summary

The demand for organically grown, animal derived produce is increasing due to a growing desire for consumer products that have minimal chemical inputs and high animal welfare standards. Evaluation of the scientific literature suggests that a major challenge facing organic animal production systems is the management and treatment of health-related issues. However, implementation of effective management practices can help organic animal producers achieve and maintain high standards of health and welfare, which is necessary to assure consumers that organic animal-based food and fibre has not only been produced with minimal or no chemical input, but under high standards of animal welfare.

Abstract

The demand for organically-grown produce is increasing worldwide, with one of the drivers being an expectation among consumers that animals have been farmed to a high standard of animal welfare. This review evaluates whether this expectation is in fact being met, by describing the current level of science-based knowledge of animal health and welfare in organic systems. The primary welfare risk in organic production systems appears to be related to animal health. Organic farms use a combination of management practices, alternative and complementary remedies and convenional medicines to manage the health of their animals and in many cases these are at least as effective as management practices employed by non-organic producers. However, in contrast to non-organic systems, there is still a lack of scientifically evaluated, organically acceptable therapeutic treatments that organic animal producers can use when current management practices are not sufficient to maintain the health of their animals. The development of such treatments are necessary to assure consumers that organic animal-based food and fibre has not only been produced with minimal or no chemical input, but under high standards of animal welfare.

The influence of stocking density on broiler chicken bone quality and fluctuating asymmetry

Because broiler chickens are juvenile animals undergoing physical development, stocking density during rearing may influence this development. Some of these physical changes may cause welfare problems, for example, decreased bone quality, which may lead to fracture during catching and transport. Others do not influence welfare directly but can be used as indicators of the animal's ability to cope with its environment (e.g., fluctuating asymmetry). The present study evaluates the effect of stocking density on bone quality and fluctuating asymmetry. Birds were stocked at densities of 2.4, 5.8, 8.8, 12.1, 13.6, 15.5, 18.5, and 21.8 birds/m(2) from 1 until 39 d of age. Increased stocking density had a negative effect on some aspects of bone quality (tibia curvature and shear strength). Tibias were shorter at high density, possibly due to increased curvature. Several other bone quality aspects (tibia weight, torsion, and dyschondroplasia, and femur curvature and epiphysis shape) remained unaffected. Middle-toe length was the only character that showed a significant increase with increasing density when each character was analyzed separately. Nevertheless, a composite index of fluctuating asymmetry, which combined data on all 11 measured characters, tended to increase with stocking density. Such increased fluctuating asymmetry may indicate decreased welfare. However, one of the assumptions of fluctuating asymmetry is that the animal is subjected to the same environmental influences on both sides. This assumption may not be fulfilled when leg deformations occur, as these may lead to asymmetric changes in bone growth by altering the division of force over the 2 legs. In addition, leg deformations decrease the accuracy of bone length measurements made in a straight line. This raises some concerns on the applicability of fluctuating asymmetry measurements on broiler chicken legs, especially because stocking density did not effect the asymmetry of the head.

Effect of copper on antioxidant ability and nutrient metabolism in broiler chickens stimulated by lipopolysaccharides

The aim of the experiment was to investigate the interaction between Cu intake, inflammatory challenge and oxidative stress in broiler chickens. Furthermore, it was tested whether plasma ceruloplasmin (Cp) could be a sensible parameter for dietary Cu. One hundred forty-four day old chickens were raised on a basal control diet without added copper (Group Cu-6.5, basal Cu content 6.5 mg/kg diet) or a diet supplemented with Cu at 8 or 50 mg/kg (Groups Cu-14.5 and Cu-56.5, respectively) with four replicates of 12 animals for each treatment. Starting on day 21, chickens were injected intraperitoneally with lipopolysaccharides (LPS) once a day for 3 days. Before this challenge, Group Cu-14.5 had the lowest gain and the feed to gain ratio was the highest. After injection of LPS, however, chickens of Group Cu-14.5 had the best zoo-technical performance. For chickens of Group Cu-6.5, LPS injection resulted in elevated rectal temperature, and lower erythrocyte superoxide dismutase (CuZn-SOD) activity, compared with the other groups. LPS injection increased plasma uric acid in Group Cu-6.5 significantly, but was without influence in Group Cu-56.5. At all Cu-levels, LPS injection increased erythrocyte CuZn-SOD activity and decreased thiobarbituric acid reacting substances. No significant difference in plasma Cp was found in chickens fed different dietary Cu. LPS injection significantly increased plasma Cp in Group Cu-56.5. The results suggest that varying dietary Cu levels seem to modulate the parameters involved in immunological responses and oxidant stress and that plasma Cp is not a reliable parameter for dietary Cu.

Stocking density effects on broiler welfare: identifying sensitive ranges for different indicators

Although stocking density is perceived as a topic of major importance, no consensus has been reached on what density would allow for good welfare. In the present study, the welfare of 4 replicates of birds stocked at 8, 19, 29, 40, 45, 51, 61, and 72 broilers per pen (or 6, 15, 23, 33, 35, 41, 47, and 56 kg actually achieved BW/m(2)) was studied using 6 welfare indicators. Density did not affect bursa weight, mortality, or concentrations of corticosterone metabolites in droppings but did influence leg health (P = 0.015) and footpad and hock dermatitis (P < 0.001) and tended to influence fearfulness (P = 0.078). However, not every increase in density or group size, or both, led to poorer welfare for the affected indicators: leg health and fearfulness showed unexpected peaks at intermediate densities. Furthermore, the indicators were influenced at different densities: leg strength showed a steep decrease from 6 to 23 kg/m(2), hock dermatitis rose from 35 to 56 kg/m(2), and footpad dermatitis and fearfulness were only significantly higher at the highest density of 56 kg/m(2). No threshold stocking density above which all aspects of welfare were suddenly altered was found in this study. Instead, different aspects of welfare were influenced at different densities or group sizes, or both. Thus, evaluating the effects of stocking density on welfare as a whole would require either identification of acceptable levels for each separate indicator or a weighting of the indicators in an integrated welfare score. A tentative attempt to such an integration, made using equal weights for all parameters, showed a decrease in welfare as density increased (P < 0.001). The lowest 2 densities (6 and 15 kg/m(2)) scored better than most middle densities (23, 33, 35, and 47 kg/m(2)), whereas all densities scored better than the highest density (56 kg/m(2)).

Comparison of the prevalence of bacterial enteropathogens, potentially zoonotic bacteria and bacterial resistance to antimicrobials in organic and conventional poultry, swine and beef production: a systematic review and meta-analysis

The prevalences of zoonotic and potentially zoonotic bacteria or bacteria resistant to antimicrobials in organic and conventional poultry, swine and beef production were compared using systematic review and meta-analysis methodology. Thirty-eight articles were included in the review. The prevalence of Campylobacter was higher in organic broiler chickens at slaughter, but no difference in prevalence was observed in retail chicken. Campylobacter isolates from conventional retail chicken were more likely to be ciprofloxacin-resistant (odds ratio 9·62, 95% confidence interval 5·67–16·35). Bacteria isolated from conventional animal production exhibited a higher prevalence of resistance to antimicrobials; however, the recovery of some resistant strains was also identified in organic animal production, where there is an apparent reduced antimicrobial selection pressure. Limited or inconsistent research was identified in studies examining the prevalence of zoonotic and potentially zoonotic bacteria in other food-animal species. There is a need for further research of sufficient quality in this area.