Mix it-cograzing with cattle reduces broiler losses and increases broiler range use

Pasture access allows broilers to perform a wide range of behaviors and is a prerequisite in organic poultry production, but exposes broilers to various potential hazards including predators. Co-grazing broilers with cattle can reduce land use and could offer protection from avian predation. Thus, we aimed to assess the effects of co-grazing on broiler losses, range use, performance, contact dermatitis and broilers' manipulation of cow pats. To this end, across 5 replicates we compared each a treatment group of 54 to 61 broilers co-grazing with 10 young cattle and a similar sized control group of broilers on a pasture which had been grazed by cattle 2 weeks prior. Broilers had pasture access during civil daylight and were locked in the coop overnight. Continuous video recordings of the pastures were used to identify the cause when broilers were missing or found dead. On 2 days per week in 4 replicates, broiler distribution in the pasture and maintenance behaviour (i.e. foraging, standing, lying, locomotion) were observed directly using instantaneous scan sampling. Based on the broilers' distance to the coop we calculated a group Ranging Distance Index (RDI). Cow pats were assessed weekly and contact dermatitis was scored before slaughter. Broilers in the treatment groups ranged further (p = 0.003) and higher percentages of birds tended to be outside (p = 0.09) compared to the control groups. Broiler losses due to predatory birds were consistently lower in treatment (median, range: 1, 0 to 3) than in control groups (3, 2 to 5, p = 0.025). Live weight before slaughter was slightly higher (p = 0.035) in treatment groups than in control groups. Feed conversion ratio (p = 0.174), maintenance behaviors and prevalence of contact dermatitis were not affected. No manipulation of cow pats by broilers was found or observed. Overall, co-grazing with cattle positively affected broiler range use, losses due to avian predation and weight gain.

Unraveling the flavor profiles of chicken meat: Classes, biosynthesis, influencing factors in flavor development, and sensory evaluation

Chicken is renowned as the most affordable meat option, prized by consumers worldwide for its unique flavor, and universally recognized for its essential savory flavor. Current research endeavors are increasingly dedicated to exploring the flavor profile of chicken meat. However, there is a noticeable gap in comprehensive reviews dedicated specifically to the flavor quality of chicken meat, although existing reviews cover meat flavor profiles of various animal species. This review aims to fill this gap by synthesizing knowledge from published literature to describe the compounds, chemistry reaction, influencing factors, and sensory evaluation associated with chicken meat flavor. The flavor compounds in chicken meat mainly included water-soluble low-molecular-weight substances and lipids, as well as volatile compounds such as aldehydes, ketones, alcohols, acids, esters, hydrocarbons, furans, nitrogen, and sulfur-containing compounds. The significant synthesis pathways of flavor components were Maillard reaction, Strecker degradation, lipid oxidation, lipid-Maillard interaction, and thiamine degradation. Preslaughter factors, including age, breed/strain, rearing management, muscle type, and sex of chicken, as well as postmortem conditions such as aging, cooking conditions, and low-temperature storage, were closely linked to flavor development and accounted for the significant differences observed in flavor components. Moreover, the sensory methods used to evaluate the chicken meat flavor were elaborated. This review contributes to a more comprehensive understanding of the flavor profile of chicken meat. It can serve as a guide for enhancing chicken meat flavor quality and provide a foundation for developing customized chicken products.

Integrating proteomics and metabolomics to elucidate the molecular network regulating of inosine monophosphate-specific deposition in Jingyuan chicken

Inosine monophosphate (IMP) plays a significant role in meat taste, yet the molecular mechanisms controlling IMP deposition in muscle tissues still require elucidation. The present study systematically and comprehensively explores the molecular network governing IMP deposition in different regions of Jingyuan chicken muscle. Two muscle groups, the breast and leg, were examined as test materials. Using nontargeted metabolomic sequencing, we screened and identified 20 metabolites that regulate IMP-specific deposition. We maintained regular author and institution formatting, used clear, objective, and value-neutral language, and avoided biased or emotional language. We followed a consistent footnote style and formatting features and used precise word choice with technical terms where appropriate. Out of these, 5 were identified as significant contributors to the regulation of IMP deposition. We explained technical term abbreviations when first used and ensured a logical flow of information with causal connections between statements. The results indicate that PGM1, a key enzyme involved in synthesis, is higher in the breast muscle compared to the leg muscle, which may provide an explanation for the increased deposition of IMP in the breast muscle. We aimed for a clear structure with logical progression, avoided filler words, and ensured grammatical correctness. The activity of key enzymes (PKM2, AK1, AMPD1) involved in this process was higher in the breast muscle than in the leg muscle. In the case of IMP degradation metabolism, the activity of its participating enzyme (PurH) was lower in the breast muscle than in the leg muscle. These findings suggest that the increased deposition of IMP in Jingyuan chickens' breast muscle may result from elevated metabolism and reduced catabolism of key metabolites. In summary, a metaomic strategy was utilized to assess the molecular network regulation mechanism of IMP-specific deposition in various segments of Jingyuan chicken. These findings provide insight into genetic improvement and molecular breeding of meat quality traits for top-notch broilers.

Carcass Yields and Meat Composition of Roosters of the Portuguese Autochthonous Poultry Breeds: "Branca", "Amarela", "Pedrês Portuguesa", and "Preta Lusitânica"

Poultry meat is an important part of the human diet, and the valorisation of autochthonous breeds is a determinant for the sustainability of the rural areas. The increasing demand for niche products demands for better knowledge of the carcass characteristics and meat quality of these local populations. The present study aims to characterise the roosters' meat from the "Branca" (BR), "Amarela" (AM), "Pedrês Portuguesa" (PP), and "Preta Lusitânica" (PL) breeds. A total of 80 birds (n = 20 per breed) between 38 and 42 weeks old were slaughtered. The physicochemical and nutritional composition were determined in the breast and drumstick meat. The meat of the PL breed had a higher (p ≤ 0.05) pH value, the AM meat revealed a water-holding capacity (WHC) of superior value and moisture content (p ≤ 0.05), while the BR breed had the highest (p ≤ 0.05) ash content. On the other hand, it was observed that the PP meat had a higher (p ≤ 0.05) yellowness index (b*). The breast meat exhibited, in all breeds, a lower pH value, WHC, redness (a*), and lipid content and greater (p ≤ 0.05) lightness (L*), b*, moisture, and ash and protein contents compared to the drumstick. Furthermore, it presented higher (p ≤ 0.05) K, P, and Mg contents and a superior proportion of total and sensorial relevant amino acids. Regarding the fatty acid profile, the breed differences were more significant in the drumstick, with the AM breed lipids presenting a higher (p ≤ 0.05) percentage of MUFAs in the fat, a lower atherogenic index, and a higher (p ≤ 0.05) value for the hypocholesterolemic/hypercholesterolemic fatty acids ratio, while the BR breed lipids presented a higher (p ≤ 0.05) percentage of PUFAs and PUFAs/SFAs ratio and a lower n-6/n-3 ratio. Considering the results obtained, it can be concluded that the meat from these breeds is a wholesome dietary option, distinguished by a favourable overall nutritional composition marked by elevated protein content, reduced lipid amounts, and amino and fatty acid profiles with desirable nutritional indices.

Cadmium and lead bioavailability to poultry fed with contaminated soil-spiked feed

Geophagy is common for free-range chickens, however, the relative bioavailability (RBA) of heavy metals in contaminated soils consumed by chickens has not fully investigated. In this work, chickens were fed diets increasingly spiked with a contaminated soil (Cd = 105, Pb = 4840 mg kg^-1; 3, 5, 10, 20 and 30 % of overall feed by weight), or Cd/Pb reagent spikes (from CdCl₂ or Pb(Ac)₂), for 23 d. After the study period, chicken liver, kidney, femur and gizzard samples were analyzed for Cd and Pb concentrations, and organ/tissue metal concentrations were used to calculate Cd and Pb RBA. Linear dose response curves (DRCs) were established for both Cd/Pb reagents-spiked and soil-spiked treatments. Femur Cd concentrations of soil-spiked treatments were two times of Cd-spiked treatments with similar feed Cd levels, while feed spiked with Cd or Pb also resulted in elevated Pb or Cd concentrations in some organ/tissues. Metal RBA was calculated using three different methods. Most Cd and Pb RBA values were in the range 50-70 %, with the chicken gizzard as a potential endpoint for bioaccessible Cd and Pb. Cadmium and Pb bioavailability values can help with more precise estimation of Cd and Pb accumulation in chicken following heavy metal-contaminated soil ingestion, with overall results helping to protect human health.

Effect of different pasture species on growth performance, carcass traits, internal organ weights, and meat quality of slower growing broilers in free-range production system

This study examined the effect of Medicago sativa (A), Trifolium repens (WC), Lolium perenne (PR), and their mixture (Mix) on growth performance, carcass characteristics, internal organ weights, and meat quality of slower-growing broiler chickens in a free-range production system. The animal materials comprised of mixed-sex Hubbard ISA Red JA, which were reared in the deep litter system for the first 3 weeks, and thereafter, the pop hole in each of the indoor pens was opened to allow birds access to the range containing one of the above pasture treatments. The range availability was ensured from 08:30 a.m. to 4:30 p.m. The results indicated no significant difference in broiler live body weight, feed conversion ratio, and livability between 28 and 77 days among the pasture treatments (P > 0.05). No significant variations were observed in the carcass and internal organ weights among pasture types (P > 0.05). Additionally, while the dry matter content (P < 0.01), TBA value (P < 0.05), and fatty acid profiles differed (P < 0.01), the protein, ash, water holding capacity, and oxidation stability of broiler breast meat did not differ among pasture groups (P > 0.05). Moreover, while the values of breast meat lightness (L*) and brightness (b*) differed (P < 0.05), redness and pH did not differ between the sexes (P > 0.05). Furthermore, sex significantly affected ash, protein content (P < 0.05), and TBA value (P < 0.01) of breast meat but did not affect dry matter, water holding capacity, and peroxide value of breast meat. Also, there was a significant difference in the weight of the neck, breast, thigh, live weight, hot carcass yield, heart, liver, abdominal fat, and digestive system between sexes (P < 0.05). However, breast meat fat content and fatty acid profiles were not influenced by the sex of the broilers (P > 0.05). It was concluded that access to the studied pasture species has no effect on the growth performance traits but results in notable variations in the fatty acid profiles in broiler breast meat.

Linking key husbandry factors to the intrinsic quality of broiler meat

Broiler farming is the fastest-growing animal production sector and broiler meat is the second most-consumed meat in the world. The intensification of broiler production often has a negative impact on the meat quality and carcass characteristics. Consumers, however, expect a quality product from animals reared extensively on farms providing good animal welfare, often intuitively associated with extensive farming practices. Therefore, this literature review investigates how the critical factors contributing to the degree of extensiveness of broiler production affect the quality of meat. We used the data from scientific articles published in the years 2012-2021 to analyze the effect of diet (n = 409), genetics (n = 86), enrichment (n = 25), and stocking density (n = 20) on meat quality and carcass characteristics. Minerals and microelements supplementation in the diet improved all the meat quality aspects: sensory, physical, and chemical in most studies. Minerals and enzymes in the diet had beneficial effects on carcass characteristics, unlike feed restriction and ingredient substitutions. The impact of outdoor access on meat quality and carcass characteristics was most frequently examined, in contrast to the use of perches or effects of litter quality. Overall, enrichment did not affect the meat's sensory or physical parameters, but outdoor access improved its lipid composition. Lower stocking density deteriorated intramuscular fat content, decreased tenderness and juiciness, yet lowered cooking and drip loss, and increased carcass and breast muscle yields. When it comes to genetics, in general, slow growing broiler strains have better meat quality parameters, especially regarding yellowness (b*), redness (a*), cooking and drip loss. Our review shows that the factors which contribute to extensiveness of broiler production systems and birds' welfare also affect meat quality and the carcass characteristics.

Carcass and Meat Quality Traits of Males and Females of the "Branca" Portuguese Autochthonous Chicken Breed

Simple Summary

Local breeds play a crucial role in the rural economies of many countries, as a considerable valuable genetic resource and, well adapted to the environment, their production can reduce the negative impact of intensive production systems. Portuguese chicken breeds are almost extinct, with the “Branca” population presenting the most worrying situation. Bred as a dual-purpose breed, the characterization of meat quality is fundamental to the conservation and promotion of this population., by increasing the value on these small-scale farms production. The carcass characteristics and meat quality of the “Branca” breed were evaluated, showing an interesting physicochemical profile, with good proportion of minerals, essential fatty acids (EFA) and n-3-PUFAs (docosapentanoic (C22:5n-3, DPA), and docosahexaenoic (C22:6n-3, DHA) acids), ensuring that consumers receive a highly nutritional and differentiated product.

Abstract

The “Branca” breed is a dual-purpose Portuguese autochthonous chicken breed, produced in extensive systems and in small flocks, especially in the Entre Douro and Minho regions. A total of 40 birds (n = 20/sex) were slaughtered between 38 and 42 weeks (males) and 110 and 120 weeks (females), and carcass and meat quality parameters were evaluated. The results showed significantly higher weights and differences for males between sexes and pieces (p ≤ 0.05) in the meat physicochemical composition. Water holding capacity (WRC), moisture and ash contents were influenced by sex. They were higher in males in the breast and drumstick and lightness (L*) and lipid content were higher in females (p ≤ 0.05). The breast meat presented greater lightness, moisture, ash and protein contents, while the drumstick showed a higher pH value, redness (a*) and lipid content, in both sexes (p ≤ 0.05). Regarding the nutritional properties, “Branca” meat revealed a good proportion of minerals and the female meat showed, in both pieces (p ≤ 0.05), significantly lower values for total saturated fatty acids (SFAs) and higher values for monounsaturated fatty acids (MUFAs). Breast meat was richer in n-3-PUFAs (C22:5n-3 and C22:6n-3) in both sexes (p ≤ 0.05). Considering the results obtained, it can be concluded that “Branca” breed meat is a healthy food characterized by a good general nutritional profile.

Scientometric Evaluation of 100-year history of Poultry Science (1921-2020)

To have a better contribution to the poultry production community, the Poultry Science Association founded journals including Poultry Science (PS) at 1921. Now, after 100 yr of publishing, PS ranks between the top 10 journals in the category of “agriculture, dairy, and animal science”. One hundred years after publishing the first paper in PS, the poultry industry has been completely revolutionized. Hence, it will be interesting to establish scientometrics study of the PS development during the last century. Therefore, based on findings of the current study, among countries/authors’ collaborations, future research fronts, and possibility of hot topics in the coming years may be predictable. Accordingly, a total of 22,451 articles were retrieved. For content analyses, according to the PS categorization for subject areas, 14 different subject areas were developed, including “behavior, breeding and quantitative genetics, education and extension, health and welfare, immunology, management and environment, metabolism and nutrition, microbiology and virology, modeling, molecular biology, physiology and anatomy, production, products, processing and marketing, and reproduction”. Considering the 100-yr of PS, the most frequent subject area was “nutrition and metabolism” (14,109 articles), and “modeling” (1,114 articles) attracted less scholarly attention. However, considering the last decade (2011–2020), the most important subject area was “molecular biology” (1,420 of 2,466 articles; 57.58%), followed by “modeling” (544 of 1,144 articles; 48.88%). Moreover, the most frequent poultry species/strains were broilers (retrieved in 6,156 articles), followed by laying hens, turkeys, and quail. Considering collaboration of countries and researchers, it can be said that a total number of 108 countries contributed to PS, with the most prolific country being United States (with 9,421 articles; 43.16%), followed by China, Canada, the Netherlands, and Japan. Among the authors, Harms RH (287 articles), and Siegel PB (208) were the most prolific authors, and Siegel PB and Dunnington EA (71 articles) had more collaborations. To study keyword trends, including 3 time periods broilers was the central co-occurrent keyword, while the importance of chickens and turkeys declined during the time. Salmonella spp. was a constant representative of poultry microbiology during 100 yr. While “nutrition and metabolism” was the most important subject area, nutrition-related keywords (major items) were not concentrated and co-occurred with a variety of keywords from different subject areas. While “molecular biology” ranked first over the past decade, the importance of “nutrition and metabolism” should not be ignored. In fact, in recent years, molecular basis of the nutrition has been studied. In big-data era and due to developing the molecular biology technologies, it seems that using mathematical modeling and computational methodologies will increase and probably remains as one of the most attractive research areas for scientists at least in the upcoming future decades.

Health-Based Welfare Indicators and Fear Reaction of Slower Growing Broiler Compared to Faster Growing Broiler Housed in Free Range and Conventional Deep Litter Housing Systems

This study investigated the welfare of a slow-growing broiler with a commercially available fast-growing breed housed in a free-range and conventional deep litter housing system. There were four main groups (2 genotypes x 2 housing systems), and each main group consisted of 5 replicates. Ante-mortem and postmortem health-based welfare indicators wıth fear reactıons and distribution of severity of them in 200 male chicks (100 slow growing, 100 fast growing) were investigated. All welfare parameters investigated were found to be significantly different between both broiler genotypes. No significant differences were detected for all broiler welfare parameters between the two housing systems. There were significant genotype x housing system interactions for breast dirtiness and feather cover of the birds (P < 0.001). In conclusion, it can be said that slow-growing broilers express more health-based indicators of positive welfare, and they might be more suitable for free-range broiler meat production. Planning further studies especially in commercial conditions that take into account economic efficiency as well as animal welfare and growth performance would be very beneficial.

An Outdoor Access Period Improves Chicken Cecal Microbiota and Potentially Increases Micronutrient Biosynthesis

Characterizing the gut microbiota of free-range and alternative poultry production systems provides information, which can be used to improve poultry welfare, performance, and environmental sustainability. Gut microbiota influence not only the health and metabolism of the host but also the presence of zoonotic agents contaminating food of animal origin. In this study, the composition and diversity of the cecal microbiota community of free-range grown chickens were characterized by 16S rDNA high-throughput Illumina sequencing. Significant differences were observed in the composition of chicken cecal microbiota at the time points of 28 days of age (Indoor group) and 56 days of age (Outdoor group), i.e., before and after the outdoor access period of chicken groups. The Outdoor group showed a richer and more complex microbial community, characterized by the onset of new phyla such as Deferribacterota and Synergistota, while the Indoor group showed an increase in Campylobacterota. At the species level, it is noteworthy that the occurrence of Mucispirillum schaedleri in Outdoor group is known to potentially stimulate mucus layer formation in the distal intestinal tract, thus being associated with a healthy gut. We also report a significant decrease in the Outdoor group of Helicobacter pullorum, highlighting that the lower abundance at the age of slaughter reduced the possibility to contaminate chickens' carcasses and, consequently, its zoonotic potential. As revealed by a mutual exclusion study in network analysis, H. pullorum was present only if Bacteroides barnesiae, an uncultured organism of the genus Synergistes, and Bacteroides gallinaceum were absent. Finally, microbiome predictive analysis revealed an increase of vitamins and micronutrient biosyntheses such as queuosine (Q) and its precursor pre Q0, in the Outdoor group, suggesting that the outdoor evolved microbiota of chickens do contribute to the vitamin pool of the gut and the biosynthesis of micronutrients involved in vital cell processes.

Chemical Composition of the “Galo de Barcelos” (Barcelos Rooster Raw Meat)

Simple Summary

The assessment of traditional products is important for the sustainability of agricultural systems and the preservation of a unique gastronomic heritage. The present study aims to determine the chemical composition of “Galo de “Barcelos”” (“Barcelos” Rooster) raw meat, used in the preparation of the typical Portuguese dish “Roasted Rooster from “Barcelos””, in order to evaluate and protect this gastronomic and cultural tradition. The influence of the genotype on the final product was verified, concerning total protein, and fat contents, and a favorable ratio of n-6/n-3 fatty acids of the Sasso line was compared to the “Amarela” breed, contributing to the promotion of its gastronomic potential.

Abstract

Ten roosters produced according to “Barcelos Confraria” rules and ten roosters of autochthonous “Amarela” breed, reared on a similar traditional production system, were analyzed, and the chemical profile of two of the most significant meat portions, breast and drumstick, was determined. The results demonstrated that the “Barcelos” rooster raw meat is rich in proteins (22.3%) and fat (4.31%), particularly in monounsaturated fatty acids (39.1%). Significant differences (p ≤ 0.01) were observed, with the breast having a higher protein content (25.1 vs. 19.7%) and less fat (1.9% vs. 6.7%), compared to the drumstick. The fatty acid profile revealed (SFA 30.0%, MUFA 39.1%, and PUFA 24.6%) a similar composition to the roosters reared in the traditional or organic production systems, such as the “Amarela” autochthonous rooster. The “Barcelos” rooster can be regarded as a highly nutritional meat, with an interesting chemical profile ensuring a high-quality traditional product to consumers.

Quality Assessment of Day-Old Chickens on the Broiler Farms of Hong Kong

Simple Summary

Assessing the quality and determining maternal antibodies against regional pathogens in day-old chickens is important to optimize the production performance and management of flocks. So far, such information in Hong Kong is lacking. The present study was conducted to assess abnormalities in appearance, navel, crop filling, dehydration, body weight, and length uniformity in day-old chicks. In addition, the maternally derived antibody levels against relevant infectious diseases were measured. This study was the first in Hong Kong to provide a baseline for the quality of day-old chicks, and results in evidence-based management advice tailored to the farms. We advise the establishment of a well-managed broiler breeder farm and hatchery, in order to improve the health and productivity of the local broiler chicken industry.

Abstract

The present study aimed to investigate the quality of newly hatched broiler chicks delivered to Hong Kong (imported or local), and to develop tailored recommendations to improve their management. During 2019–2021, 70 batches (34 imported from mainland China and 36 local) of one/three day old chicks on 11 broiler farms were studied. From each batch, 23 or 24 chicks (1647 in total) were assessed for abnormalities in appearance, navel, crop filling, dehydration, body weight, and length uniformity. Chicks were sacrificed, and yolk sac residues in three day old chicks were measured. Maternally derived antibody levels against Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), and avian reovirus (ARV) were measured in all chicks using an enzyme-linked immunosorbent assay (ELISA). The proportion of abnormal navel in most batches is high (median: 59%), ranging between 0 and 100%. The average length of chicks within batches ranges between 16.3 and 20.7 cm, and their average weights are 31–38.5 g upon delivery to the farms. On average, imported batches have a higher body weight and length than their local counterparts. The average yolk-free weight varies between 45 and 55 g, which is significantly lower in local batches (33–43 g). The mean antibody titers against NDV and ARV are higher in imported batches than in the local ones. In contrast, the mean antibody titer against IBDV is significantly lower in the imported batches. Concerning the overall lower quality of local chicks compared to the imported batches, establishing a well-managed broiler breeder farm and a hatchery in Hong Kong is highly recommended to enhance the health and productivity of the local broiler chicken industry.

Analysis of the molecular mechanism of inosine monophosphate deposition in Jingyuan chicken muscles using a proteomic approach

Inosine monophosphate (IMP) is an indicator of meat taste, and the molecular mechanism underlying IMP deposition in muscle tissues is important to developing superior poultry breeds. The aim of this study was to identify the key proteins regulating IMP deposition in different muscle groups of 180-day-old Jingyuan chickens (Hen) using a proteomics-based approach. We identified 1,300 proteins in the muscle tissues of Jingyuan chickens, of which 322 were differentially expressed between the breast and leg muscles (129 proteins were highly expressed in breast muscles and 193 proteins were highly expressed in leg muscles). PGM1, PKM2, AK1, AMPD1, and PurH/ATIC were among the differentially expressed proteins (DEPs) involved in the purine metabolism pathway, of which purH was highly expressed in leg muscles, while the others were highly expressed in breast muscles. The proteomics screening results were verified by PRM, qPCR, and western blotting, showing consistency with the proteomics results. Our findings are not only significant in terms of protecting the Jingyuan chicken germplasm resources, but also provide the molecular basis for generating high-quality broiler chicken breeds.

Morphometric measurements and carcass characteristics of Black Australorp, Naked Neck, and Rhode Island Red crossbreds under alternative production systems

The present trial explained the effect of alternative production systems on growth, morphometric and carcass traits of four different chicken genotypes. The second generation of two genotypes RNN (Rhode Island Red × Naked Neck) and BNN (Black Australorp × Naked Neck) obtained by two self-crosses (RNN × RNN = RR and BNN × BNN = BB) and two reciprocal crosses (RNN × BNN = RB and BNN × RNN = BR) were evaluated in three alternative production systems (conventional cages, enriched cages, and aviary). At the 6th week of age after sexing, a total of 600 birds, comprising 150 from each crossbred with a total of 300 pullets and 300 cockerels were divided into conventional cages, enriched cages, and aviary systems having 200 birds in each.Birds were organized into 3×4 factorial arrangements under Completely Randomized Design (3 production systems × 4 genotypes × 2 sexes × 25 birds = 600 birds). Regarding genotypes, RB and BR males showed higher (p < 0.01) carcass yield, drumstick weight, breast weight, and thigh weight than BB and RR genotypes. Females of BR genotype showed higher (p < 0.01) breast weight, thigh weight and drumstick weight. As far as production systems are concerned, higher (p < 0.01) liver weight, heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight were observed in the males reared in enriched cages compared with conventional cages and aviary system. Females reared in enriched cages showed higher (p < 0.01) heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight when compared with those reared in conventional cages and aviary. It is concluded that chickens (both sexes) of BR and RB genotypes had better morphological measurements and carcass traits than those of RR and BB genotype chickens. Among alternative production systems, chickens reared in enriched cages had better traits than those of reared in conventional cages and aviary during the growing phase.

The Benefit of Hedgerow Access on the Health and Growth Rate of Pasture Raised Broiler Chickens

Pasture rearing is an increasingly common option for small farms to produce humanely raised poultry products for an expanding market, however profit margins tend to be much lower for pastured poultry producers than for those that opt for conventional indoor rearing. Research into simple methods to optimize the growth and health of pasture-raised poultry can help small farmers maximize meat yields and decrease the morbidity and mortality of their flock, ultimately leading to higher profit margins and improved animal welfare. The objective of this study was to measure how the inclusion of mature, native foliage into pastures can impact the production performance and overall health status of two different popular breeds of commercial broiler chickens; fast-growing Cornish cross and slower growing Red rangers. During the finisher phase (30–78 days old), pastured chickens were separated by breed into either a treatment population with access to a mature bordering hedgerow, or a control population without access to a hedgerow. Weekly weight gain, daily feed intake and basic hematologic values were used to evaluate differences in the production performance and health status between each population. We found that hedge access led to a significant improvement in the rate of gain of the Cornish cross without an associated increase in feed intake, suggesting that the addition of hedges can increase meat yields in fast-growing broilers without increasing feed costs. Red rangers with hedge access demonstrated an improved ability to neutralize bacterial pathogens in whole blood and a lesser degree of hemodilution compared to control populations, suggesting improved immune function and a lower degree of heat stress in these populations. We conclude that the addition of natural environmental enrichment such as mature foliage to grass pastures can lead to improved production performance in fast-growing broilers and improvements in the health and immune function of slower growing broiler chickens.

Effects of season, genotype and rearing system on some meat quality traits for broilers raised in semi-intensive systems

We compared fast-growing and slow-growing broilers raised in extensive indoor, free-range, and traditional free-range systems in terms of meat quality in spring and summer. Five different semi-intensive broiler production applications (fast- in extensive indoor, slow- in extensive indoor, fast- in free-range, slow- in free-range and slow- in traditional free-range) were used according to EU standards. Extensive indoor and free-range birds were slaughtered at 57 days of age and traditional free-range chickens at 82 days. The higher (P < 0.05) skin yellowness (b*) values found in spring compared to summer may have been due to better pasture conditions in spring. The pH₂₄ value of breast meat during the summer period was higher (P < 0.05) than that in spring, but lightness (L*) was similar. Thawing and cooking losses were higher (P < 0.05) in breast meat samples from the summer experiment. The season affected (P < 0.05) all sensory attributes of breast meat; spring samples were appreciated more in terms of all the features discussed. Regarding the skin b* value, the highest average value was detected for slow chickens in the slow- in free-range and traditional free-range groups, most likely because slow chickens spent more time grazing. Fast- showed higher pH₂₄ values than slow- (P < 0.05) in extensive indoor and free-range groups. We did not observe differences in pH₂₄ due to grazing in fast-, but grazing slow- showed lower pH₂₄ values than their indoor counterparts. Further, in the extensive indoor system, both genotypes were similar in terms of breast meat L* and b*, whereas slow- in the free-range system showed higher (P < 0.05) averages than fast-. Based on our results, the traditional grazing system has a positive impact on meat sensory features.

Effects of season, genotype, and rearing system on broiler chickens raised in different semi-intensive systems: performance, mortality, and slaughter results

This study aimed to determine the effects of chicken genotype (fast-growing and slow-growing), various semi-intensive production systems (extensive indoor, free-range, and traditional free-range), and season (spring and summer) on animal performance, mortality, growth curve, and slaughter results under semi-environmentally controlled conditions in a subtropical region. Production systems were applied in conformity with the EU standards. While the summer experiment improved performance during brooding (1st-28th days), hot conditions led to a decline in performance during the growing period. In addition, negative effects were determined for all parameters of Gompertz growth curve in summer (P < 0.05, for all). In spring, fast-growing showed 36% higher final live weights than slow-growing, and this difference decreased in summer (16% for extensive indoor and 25% for free-range) (P < 0.05, for all). Fast-growing in extensive indoor and free-range displayed similar weight gains in the growing period, whereas grazing ones consumed less feed (P < 0.05) and thus showed better (P < 0.05) feed conversion. The same situation was true for slow-growing in spring. The mortality was approximately 1% in all groups in spring, while it was 17.36 and 18.06% for fast-growing in extensive indoor and free-range and 1.39, 2.78, and 4.29 for slow-growing in extensive indoor, free-range, and traditional free-range in summer. It is advantageous to choose fast-growing if short-term (56 days) fattening especially under optimum conditions is to be preferred. If the growing period coincides with summer, slow-growing should definitely be preferred and the fattening period should be extended to 82 days. Grazing improved feed conversion (P < 0.05) by reducing cereal-based diet consumption in both genotypes but did not affect carcass yield. However, grazing had a positive effect on fleshing.

Physical quality characteristics of breast and leg meat of slow- and fast-growing broilers raised in different housing systems

This study was made to determine the effects of genotype and housing system on physical quality characteristics of breast and leg meat of broilers under experimental conditions. The 150 slow-growing and 150 fast-growing 1 d old chicks were divided into three sub-groups with indoor raised slatted plastic floor, indoor concrete floor with rice hull litter, and free-range housing systems (2 genotype groups  ×  3 housing systems). All birds were offered the same diet and were housed in similar conditions until they were 56 d old. At slaughter, 10 birds from each main group were selected randomly to determine the quality characteristics of the meat. In total, 60 breast meat pieces (pectoralis major muscle) and 60 legs of the chickens were used for meat quality analysis including pH, shear force, and colour characteristics such as lightness ( L ∗ ), redness ( a ∗ ), yellowness ( b ∗ ), saturation ( C ∗ ), and hue angle ( h ∗ ). The pH of breast meat was significantly affected by genotype and housing system ( P < 0.001 and P < 0.001 ). There were significant genotype  ×  housing system interactions for pH ( P < 0.015 and P < 0.001 ) and shear force values ( P < 0.007 and P < 0.012 ) of leg and breast meat. There were no significant effects of genotype and housing system on leg and breast meat colour properties except for effects of genotype on redness ( a ∗ ) of breast meat ( p < 0.005 ) and effects of housing on redness of leg meat colour ( p < 0.031 ). Slow-growing chickens and chickens housed in deep litter had a higher redness (darker) value of breast and leg meat colour compared to fast-growing birds and free range and slatted floor. In conclusion, it can be said that fast-growing broilers may be more appropriate for slatted plastic floor housing and slow-growing broilers may be more suitable for a free-range housing system, but further research on factors affecting meat quality would be very beneficial, especially in slow-growing broilers.

Influence of free-range days on growth performance, carcass traits, meat quality, lymphoid organ indices, and blood biochemistry of Wannan Yellow chickens

This study investigated the effects of free-range days on growth performance, carcass traits, meat quality, lymphoid organ indices, and blood biochemical parameters of Wannan Yellow chickens. A total of 1,000 one-day-old male Wannan Yellow chickens were reared to 56 D. At 56 D of age, 960 birds with similar body weight (BW) were randomly allocated to free-range treatment at 56, 70, 84, and 98 D of age (assigned to free-range treatment for 42, 28, 14, and 0 D, respectively); 6 replicates with 40 chickens per treatment. In the free-range system, chickens were reared in indoor floor pens with an outdoor free-range paddock measuring 4 × 7 m (28 m2, 1.5 birds/m2). Results showed that BW of birds decreased significantly in the first 2 wk after birds were assigned to free-range treatment compared with those in the conventional treatment (P < 0.05). Average daily gain (ADG) and average daily feed intake (ADFI) decreased significantly (P < 0.05) for chickens assigned to free-range treatment from 56 to 70 D of age, while feed conversion ratio increased significantly (P < 0.05). Breast yield increased linearly with increasing free-range days (P < 0.05), whereas leg and foot yields decreased linearly (P < 0.05). Drip loss and L* value of thigh muscle decreased linearly with increasing free-range days (P < 0.05), while shear force improved linearly (P < 0.05). Additionally, the absolute thymus weight and thymus to BW ratio showed significant increasing and then decreasing quadratic responses to increasing free-range days (P < 0.05). Furthermore, serum glucose, total protein, cholesterol, and triglyceride content declined linearly, while high-density lipoprotein cholesterol (HDL-C) content increased linearly with increasing free-range days (P < 0.05). In conclusion, increasing free-range days had positive effects on breast yield, shear force, thymus weight, and HDL-C content, but negatively affected leg yield, foot yield, drip loss, L* value of thigh muscle, glucose, total protein, cholesterol, and triglyceride levels of Wannan Yellow chickens.

Comparison of the quality characteristics of chicken breast meat from conventional and animal welfare farms under refrigerated storage

In this study, we aimed to investigate the meat quality characteristics, bioactive compound content, and antioxidant activity during refrigerated storage of breast meat of Arbor Acres broilers (carcass weight: 1.1 kg, raised for 35 D) obtained from a conventional farm (BCF, n = 30) and an animal welfare farm (BAF, n = 30) in Korea. The BCF and BAF did not differ in their proximate composition, color, water-holding capacity, creatine, creatinine, and carnosine contents. However, the shear force value was significantly higher in BAF than in BCF (P < 0.05). The 2-thiobarbituric acid reactive substance (TBARS) levels in BCF on days 7 and 9 were significantly higher than those in BAF (P < 0.001). During storage, the total volatile basic nitrogen (VBN) content of BAF was significantly lower, except on day 1. The fatty acid composition of samples was not affected by the storage period, however, saturated fatty acid and unsaturated fatty acid contents did differ among the types of farm systems (P < 0.05). Although the creatine, creatinine, and carnosine contents in BAF and BCF did not differ significantly, the carnosine and creatinine contents decreased with the increase in storage period (P < 0.05). The anserine content of BAF was significantly higher than that of BCF throughout storage. Superoxide dismutase activity was not affected by the type of farm system but was affected by storage period. Overall, BAF showed lower pH, microorganism, TBARS, and VBN values, and higher anserine contents than BCF. These findings can serve as reference data for the evaluation of chicken meat quality of broilers raised in animal welfare farm and conventional farm.

Visceral composition, carcass yield and meat quality parameters of free-range broilers with diets containing different levels of crushed sugarcane

ABSTRACT The aim of this study was to evaluate the visceral composition, cuts, and meat quality of two strains of free-range chickens fed diets containing crushed sugar cane. 448 chickens were distributed at 35 days of age, in two randomized blocks design, in 4x2 factorial, with four levels of replacement in the feed (0; 15; 30 and 45%) by sugarcane and two strains (Pesadão and Label Rouge), in two repetitions per block of fourteen birds per experimental unit. In 30 minutes after slaughter, the parameter a* was higher for animals of the Pesadão strain relation to the Label Rouge lineage. A quadratic effect was observed with increasing levels of sugarcane on the L* parameter of breast meat; and linear effect on parameter b* of the breast skin. Within 24 hours after slaughter, a quadratic effect of sugarcane levels was observed on the b* parameter of the breast meat. The increase in sugarcane levels linearly reduced the weight of heart, liver, chest, thigh plus drumstick, wing, carcass yield and relative heart weight of the animals. A quadratic effect was observed with increase in sugarcane levels over the relative weight of abdominal fat, the lowest fat content was observed in animals that consumed up to 30% of sugarcane in the feed. The use of sugarcane as an alternative feedstuff in up to 45% in the diet maintains the quality of meat and reduces the abdominal fat content, however, decreases the carcass yield.

Performance, behavior, and health of male broilers and laying hens of 2 dual-purpose chicken genotypes

Dual-purpose chicken where both sexes are reared together, before males are separated for final fattening, while females are kept for an entire laying period, may provide an economic alternative under certain production and marketing conditions. Two genotypes, purebred Bresse-Gauloise (PURE, n = 300) and crossbred Bresse-Gauloise × New Hampshire (CROSS, n = 300), were compared. One-day-old mixed-sex chicken were raised for 12 wk under floor husbandry conditions on a broiler diet. Thereafter, males were transferred to a mobile chicken house with free-range access. Males were slaughtered at weekly intervals from 12th to 19th wk of age. Hens were kept for 1 laying period in a mobile house. Growth performance, feed consumption, carcass, meat quality, health and welfare traits were measured in both sexes. In females layers’ performance, egg quality and behavior were recorded, too. At 12 wk, males of PURE reached a live weight of 2,075 g and CROSS of 1,865 g (P < 0.05), while at 16 wk both weighed more than 2,500 g (P > 0.05). Dressing percentage increased with slaughter age and was above 68% in both genotypes when slaughtered at 18 to 19 wk of age. Proportion of legs, breast, and wings was 34.3, 16.0, and 11.0% in PURE and 34.7, 15.5, and 12.1% in CROSS (P > 0.05). Laying performance was 54.5% in PURE and 54.2% in CROSS (P > 0.05). Egg breaking strength decreased during the laying period, but remained above 30 N. Feed conversion was 3.4 kg feed/kg egg. On average, 25% of the animals stayed outdoors during daytime (P > 0.05). Keel bone deformations were observed in 10% and breast blisters in 20% of the hens. Under the specific conditions of marketing products with added value, performances resulted in an overall economic benefit, which was higher for PURE than CROSS. The use of dual-purpose chicken to avoid the killing of 1-d-old chicken and mobile housing may substantiate premium prices in such a system.

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.

Risk perceptions of public health and food safety hazards in poultry husbandry by citizens, poultry farmers and poultry veterinarians

Differences in risk perceptions of public health and food safety hazards in various poultry husbandry systems by various stakeholder groups, may affect the acceptability of those husbandry systems. Therefore, the objective was to gain insight into risk perceptions of citizens, poultry farmers, and poultry veterinarians regarding food safety and public health hazards in poultry husbandry systems, and into factors explaining these risk perceptions. We surveyed risk perceptions of Campylobacter contamination of broiler meat, avian influenza introduction in laying hens, and altered dioxin levels in eggs for the most commonly used broiler and laying hen husbandry systems in Dutch citizens (n = 2,259), poultry farmers (n = 100), and poultry veterinarians (n = 41). Citizens perceived the risks of the three hazards in the indoor systems higher and in the outdoor systems lower than did the professionals. Citizens reported higher concerns regarding aspects reflecting underlying psychological factors of risk perception compared to professionals. Professionals indicated a relatively low level of personal control, which might imply risk denial. Of the socio-demographic characteristics, gender and childhood residence were associated with risk perceptions. The influence of other factors of risks perception are discussed. It is suggested that risk perceptions of all stakeholder groups are influenced by affect, stigma, and underlying values. To adapt current or new husbandry systems that can count on societal support, views of key stakeholders and multiple aspects such as animal welfare, public health, food safety, and underlying values should be considered integrally. When trade-offs, such as between animal welfare and public health have to be made, insight into underlying values might help to find consensus among stakeholders.