Meat-type Chickens Research Articles

Renal Sugar Metabolites and mRNA Expression of Glucose Transporters in Meat-Type Chickens with Differing Residual Water Intake.

Molecular differences exist between birds with high residual water intake (HRWI) compared to those with low residual water intake (LRWI). Residual water intake (RWI) is defined as the difference between the water intake of a bird and the expected water intake corrected for metabolic body weight, feed intake, and body weight gain. Tissue metabolomic analysis revealed significantly increased kidney glucose, fructose, and arabitol in the LRWI group compared to the HRWI group. mRNA expression analysis of apical sodium glucose cotransporters SGLT1, SGLT4, SGLT5, and SGLT6 showed decreased expression of SGLTs 1, 5, and 6 in LRWI birds (p < 0.05), whereas SGLT4 expression was increased compared with HRWI birds (p < 0.01). An analysis of basal glucose transporters GLUT1, GLUT2, GLUT5, and GLUT9 showed significantly increased GLUT2 expression in LRWI birds compared with HRWI birds (p < 0.01). We postulate that SGLT4 is the main apical transporter in chicken kidneys and that its increased expression reduces these birds' need for water, resulting in less drinking. This is balanced by the increased expression of the basal transporter GLUT2, indicating better glucose retention, which may partly explain the physiological mechanism behind why these birds drink less water. Innately driven broiler water intake could therefore be influenced by the expression of kidney solute transporters.

Garlic Powder Supplementary Diet Prevents Pulmonary Hypertension Syndrome by Reducing Apoptosis in Broiler Chickens

Background: Pulmonary hypertension syndrome (PHS) is a metabolic disorder presenting with cardiopulmonary symptoms. However, garlic powder (GP) is used to treat many diseases, such as heart and lung diseases. Objectives: This study investigated the effects of GP supplementary diet on apoptosis and right ventricle hypertrophy in broiler chickens with PHS. Methods: Ninety meat-type chickens were randomly divided into three groups: Sham, PHS and PHS+GP. The PHS was induced by triiodothyronine (T3) in broiler chickens, and GP was added to the ration after week 1 of rearing (PHS+GP). Then, lung and ventricle tissues were collected at 21 and 49 days of age. PHS was calculated at 21 and 49 days based on the ratio of the right ventricle to the total ventricles (RV/TV) weight index. Gene expression of caspase1 (CASP1) and caspase1 (CASP2) were evaluated by semi-quantitative RT-PCR in the lungs and right heart ventricles. Results: The findings showed that right ventricular hypertrophy increased at day 49 in the PHS group compared to sham (P&lt;0.001), while garlic consumption decreased this ratio to the control level (P&lt;0.05). Also, the expression of CASP1 and CASP2 in the lungs elevated on day 49 (P&lt;0.001), and the GP diet prevented this increase (P&lt;0.05). Moreover, in the right ventricle tissue, PHS affected CASP1 on days 21 and 49, although the expression of CASP2 significantly increased just at day 49 in the PHS group (P&lt;0.001). This increase in both times was weakened by garlic consumption (P&lt;0.05). Conclusion: Consuming garlic as a dietary supplement could prevent PHS by influencing apoptosis in the lung and heart of broilers.

Slaughter Performance, Meat Quality and Organoleptic Indices of Crossbred Progenies from Meat-Type Chicken and Nigerian Indigenous Chicken Breeds

Slaughter Performance, Meat Quality and Organoleptic Indices of Crossbred Progenies from Meat-Type Chicken and Nigerian Indigenous Chicken Breeds

Physical attributes and nutritional composition of meat from dual purpose (Sasso C431 and TR51) broiler breeds in Ntabazinduna, Zimbabwe.

The growing animal welfare concerns regarding poultry production have led to the rearing of slow-growing meat type chickens also known as free-range chickens. In Zimbabwe these slow-growing chickens are gaining popularity as an alternative to the commercial broiler chickens owing to their preferred sensory attributes comparatively. Little is known regarding the quality of the meat versus that of the conventional broilers. We evaluated the physical characteristics and nutritional composition of meat from dual purpose slow-growing hybrids, Sasso C431 and TR51 in comparison with the commercial broiler breed Ross 308, under intensive feeding conditions. Birds were fed the standard commercial chicken feed produced by Hamara, a local chicken and chicken feed producing company. Birds were slaughtered on days 42, 56 and 70 of life where carcass and breast yield were measured. The pH, drip loss and cooking losses were determined for all carcasses. Proximate composition (dry matter, ash, protein, fat, carbohydrate) and mineral composition (iron, zinc and phosphorus) were determined for all the meat samples. The fast-growing broiler breed had a higher breast yield; than the slower-growing breeds, Sasso C431 and TR51 breeds (P&lt;0.05). The highest cooking and drip loss were observed in the faster growing breed Ross 308 and the lowest ones for Sasso C431 and TR51 breeds (P&lt;0.05). Shear texture values were higher in the Sasso C431 and TR51 than the Ross 308 breed (P&lt;0.05). The Sasso C431 and TR51 breeds can produce more meat with a lower fat and a higher protein compared to the Ross breeds.

Microwave cavity antenna for automatic detection of chicken breast muscles affected by wooden breast defect

Over the past years, artificial selection for meat-type (broiler) chickens has resulted in improved production efficiency, but also in an increased incidence of skeletal muscle abnormalities. In particular, wooden breast (WB) abnormality causes abrupt changes in meat quality and enormous economic losses. Thus, the poultry processing industry requires a reliable method to detect the abnormality in production lines in a non-destructive and contactless way. The present research aimed to evaluate the effect of WB on dielectric properties to develop a potential online technique to distinguish unaffected from affected breasts. Sixty-five pectoralis major muscles were picked 3 h post-mortem from the same flock (42-day-old broilers, 2.8 kg average live weight) and classified by visual inspection according to their phenotype as normal (N, not showing not any signs of the WB condition; n = 33) or WB (exhibiting extensive hardened areas and stiffness perceived by manual palpation throughout the entire fillet; n = 32). WB muscles exhibited remarkably higher values of dielectric constant and loss factor in a wide range of the explored frequencies (200 MHz–14 GHz), suggesting higher water mobility and a higher solvate capacity; this makes the electromagnetic technique for classification promising. Based on the above evidence, a rapid microwave electric technique in the range 1.5 GHz–3 GHz was developed for the online detection of WB. Indeed, combining the use of a cavity antenna (vector network analyzer instrumental chain with partial least square – discriminant analysis), this technique correctly classified 100% of the validation test set.

Linear and nonlinear models for assessing carcass composition using dual X-ray absorptiometry in egg- and meat-type chickens

The objective of this study was to develop appropriate correction equations for dual energy X-ray absorptiometry (DXA) for total carcass composition of live meat- and egg-type chickens. Linear (bivariate linear and multivariate linear) and nonlinear (polynomial, multivariate polynomial, broken-line and Gompertz) equations were used to estimate carcass composition of DXA-scanned birds based on chemical proximate analysis. A total of 288 laying females (10-30 wk of age) and 305 broiler breeder females (4-32 wk of age) were used. The same birds scanned by DXA were dissected and utilized for whole-body proximate chemical analysis for body lean, fat, and mineral content (ash). As indicators of carcass fat and lean, abdominal fat pad and breast muscle weights were also recorded. Models were evaluated using root mean square error (RMSE), Bayesian Information Criterion (BIC), coefficient of determination (R2), Durbin Watson test for autocorrelation (DW), and residuals observation (RES). Model estimations were done separately by strain or combined. Estimations of composition responses fit at least 1 of each linear and nonlinear models for the egg- and meat-type chickens on all parameters estimated (P < 0.05). In the egg-type chickens, multivariate linear regression was the best fit for body lean with the lowest RMSE and BIC, and highest R2 whereas body fat, body ash, and breast muscle were best predicted by the multivariate polynomial model. In the meat-type chickens, body lean was best predicted by the multivariate linear model with the lowest RMSE and BIC, and the highest R2 whereas the multivariate polynomial was the most parsimonious model for body fat, body ash, and abdominal fat. Positive autocorrelations were observed in several models tested for body fat, body ash, breast muscle, and abdominal fat pad when both strains were analyzed combined (P < 0.05). In summary, a strain-based correction is recommended to all the parameters, with exception of the BW estimation. Correction equations developed in this study demonstrated that the DXA technique is a reliable alternative to proximate chemical analysis in egg- and meat-type chickens.

Comparative study of gastrointestinal tract size in three parent breeds for the production of dual-purpose organic chickens.

An alternative to culling male hatchlings of layers is breeding dual-purpose chickens. One breeding objective is the ability to digest low-quality feed. Certain measurements of the gastrointestinal tract may be useful indicators of this ability. The present study compared the gastrointestinal tract of adult hens of two layer-type breeds (White Rock (WR), New Hampshire (NH)) and the meat-type ÖTZ (Ökologische Tierzucht gGmbH) Bresse Gauloise (BR), used for the production of dual-purpose organic chickens. Flocks had the same housing and feeding conditions. At slaughter at 19 months, the body weight and gastrointestinal organs of 134 hens (51 WR, 55 NH and 28 BR) were measured. The muscle thickness of the proventriculus and ventriculus and the length and width of the duodenum, jejunoileum, caeca and colorectum were measured and variances between the groups were analysed using a one-factor covariance analysis. Significant differences between the breeds were found in total intestine length and the lengths and/or widths of single gastrointestinal segments. For example NH showed the highest mean total intestinal length and BR showed the lowest mean (NH: 186.73 cm, WR 185.86 cm, BR 157.91 cm; p = 0.001). To our knowledge, this is the first study comparing the gastrointestinal tract size of adult female layer- and meat-type chicken breeds kept under the same feeding and housing conditions. Given the possible relationship between intestinal length parameters and chicken performance, measurement of the gastrointestinal tract may be a simple, quick and inexpensive additional method to help select layer-, meat-type and dual-purpose chickens suitable for organic production when a selection process using genetic markers is not possible.

Unlocking Phytate with Phytase: A Meta-Analytic View of Meat-Type Chicken Muscle Growth and Bone Mineralization Potential.

The inclusion of exogenous phytase in P- and Ca-deficient diets of broilers to address the growing concern about excessive P excretion into the environment over the years has been remarkably documented. However, responses among these studies have been inconsistent because of the several factors affecting P utilization. For this reason, a systematic review with a meta-analysis of results from forty-one studies published from 2000 to February 2024 was evaluated to achieve the following: (1) quantitatively summarize the size of phytase effect on growth performance, bone strength and mineralization in broilers fed diets deficient in P and Ca and (2) estimate and explore the heterogeneity in the effect size of outcomes using subgroup and meta-regression analyses. The quality of the included studies was assessed using the Cochrane Collaboration's SYRCLE risk of bias checklists for animal studies. Applying the random effects models, Hedges' g effect size of supplemented phytase was calculated using the R software (version 4.3.3, Angel Food Cake) to determine the standardized mean difference (SMD) at a 95% confidence interval. Subgroup analysis and meta-regression were used to further explore the effect size heterogeneity (PSMD ≤ 0.05, I2 > 50%, n ≥ 10). The meta-analysis showed that supplemental phytase increases ADFI and BWG and improves FCR at each time point of growth (p < 0.0001). Additionally, phytase supplementation consistently increased tibia ash, P and Ca, and bone strength (p < 0.0001) of broilers fed P- and Ca-deficient diets. The results of the subgroup and meta-regression analyses showed that the age and strain of broiler, dietary P source, and the duration of phytase exposure significantly influence the effect size of phytase on growth and bone parameters. In conclusion, phytase can attenuate the effect of reducing dietary-available phosphorus and calcium and improve ADFI, BWG, and FCR, especially when added to starter diets. It further enhances bone ash, bone mineralization, and the bone-breaking strength of broilers, even though the effects of bone ash and strength can be maximized in the starter phase of growth. However, the effect sizes of phytase were related to the age and strain of the broiler, dietary P source, and the duration of phytase exposure rather than the dosage.

Oxidative stress and plasma ceramides in broiler chickens.

The selection for rapid growth in chickens has rendered meat-type (broiler) chickens susceptible to develop metabolic syndrome and thus inflammation. The sphingolipid ceramide has been linked as a marker of oxidative stress in mammals, however, the relationship between sphingolipid ceramide supply and oxidative stress in broiler chickens has not been investigated. Therefore, we employed a lipidomic approach to investigate the changes in circulating sphingolipid ceramides in context of allopurinol-induced oxidative stress in birds. Day zero hatched chicks (n = 60) were equally divided into six groups; an unsupplemented control, an allopurinol group (25mg/kg body weight), a conjugated linoleic acid (CLA) group where half of the oil used in the control diet was substituted for a CLA oil mixture, a CLA and an allopurinol group utilizing the same dose of CLA and allopurinol, a berberine (BRB) group consisting of berberine supplementation (200mg/kg feed), and a BRB and allopurinol group, utilizing the same dose of BRB and allopurinol. Conjugated linoleic acid and berberine were utilized to potentially enhance antioxidant activity and suppress the oxidative stress induced by allopurinol treatment. Body weight, plasma uric acid, nonesterified fatty acids (NEFA) and sphingolipid ceramides were quantified. Allopurinol induced an inflammatory state as measured by a significant reduction in plasma uric acid - an antioxidant in birds as well as a metabolic waste product. Results showed that both total and saturated sphingolipid ceramides declined (p < 0.05) with age in unsupplemented chicks, although plasma ceramides C16:0 and 18:0 increased in concentration over the study period. Simple total and saturated sphingolipid ceremide's were further decreased (p < 0.05) with allopurinol supplementation, however, this may be an indirect consequence of inducing an inflammatory state. Neither CLA or BRB were able to significantly attenuate the decline. The administration of allopurinol specifically targets the liver which in birds, is the primary organ for fatty acids synthesis. For this reason, sphingolipid ceramide production might have been unwittingly affected by the addition of allopurinol.

Temporal Changes in Splenic Immune Cell Populations following Infection with a Very Virulent plus MDV in Commercial Meat-Type Chickens.

Marek's disease virus (MDV) can cause severe immunosuppression in chickens. Our previous study showed that infection with very virulent plus (vv+) MDV strains of one-day-old commercial meat-type chickens possessing maternal antibodies against MDV resulted in severe depletion of splenocytes at 28-30 days of age. In the present study, we have investigated the effect of vv+MDV strain 686 on splenic immunophenotypes at 6, 20, and 30 days post-infection (dpi). Both live and dead cells were analyzed, and the data were statistically compared to the uninfected control. The results revealed a decrease in the total live cell population starting on day 20, primarily affecting B cells, CD8β+, and gamma delta (γδ) T cells, while the frequencies of both live and dead CD3+ and CD4+ T cells were increased. The MHC-I expression of CD3+ and CD4+ T cells was higher at 20 and 30 dpi, while the expression of MHC-II on these cells was downregulated at 6 dpi but was upregulated at 30 dpi. Collectively, these results suggest that maternal antibodies seem to delay the negative effects of vv+MDV on the splenic lymphoid populations, albeit being non-protective. Our results emphasize the importance of MD vaccination in vv+MDV endemic areas.

C2H2-type zinc-finger protein BCL11B suppresses avian Leukosis virus subgroup J replication by regulating apoptosis

Apoptosis plays a crucial role in host antiviral defense. The avian leukosis virus subgroup J (ALV-J), an avian oncogenic retrovirus, has been shown to suppress apoptosis while promoting its own replication. ALV-J induces myeloid tumors and hemangiomas in chickens resulting in significant economic losses for commercial layer and meat-type chicken production. B-cell lymphoma/leukemia 11B (Bcl11b) encodes a C2H2-type zinc finger protein—BCL11B, that exerts critical functions in cell proliferation, differentiation, and plays an essential role in the immune system. Previous study has been shown that Bcl11b is associated with ALV-J infection. In this study, we further investigated the pathological changes in ALV-J infected cells and examined the role and expression regulation of chicken Bcl11b. Our results demonstrate that Bcl11b, as an interferon-stimulated gene (ISG), encodes C2H2-type zinc finger protein BCL11B that promotes apoptosis to inhibit ALV-J infection. Additionally, gga-miR-1612 and gga-miR-6701-3p regulate apoptosis and are involved in ALV-J infection by targeting Bcl11b, thus revealing immune response strategies between the host and ALV-J. Although the underlying mechanisms require further validation, Bcl11b and its regulatory miRNAs are the first to demonstrate inhibition of ALV-J replication via apoptosis. BCL11B can a valuable target for treating diseases triggered by ALV-J infection.

Impact of Light Wavelength on Growth and Welfare of Broiler Chickens – Overview and Future Perspective

Abstract Lighting in poultry production holds notable importance with the advancement and modernization of the industry, as it plays a significant role in the physiology and growth of broiler chickens. Increasing attention has been paid to the impacts of lighting management on growth performance, immune status, and welfare of meat-type chickens. It is essential to have an appropriate lighting regimen that includes the light source, intensity, duration, and wavelength of light to improve broilers’ growth and behavior. By manipulating various physiological, immunological, and behavioral activities, altering the color of light has been acknowledged as a potent managerial strategy capable of mitigating an array of stressors in broiler chickens. Assessing animal welfare is necessary for animal behavior and product quality perspectives. Birds have a unique visual system, and their behavior is primarily mediated by vision. Different monochromatic light regimes can affect feed conversion ratio, modulating broiler chickens’ systematic immune response and aggressive behavior. With the advancement of lighting technology, new possibilities have emerged to enhance traditional lighting programs in poultry houses. This review integrates recent findings on the use of monochromatic light and its impact on broilers’ welfare, growth, and physiological response.

Profitability and meat quality of fast-, medium- and slow-growing meat-type chicken genotypes as affected by growth and length of rearing

The study aimed to evaluate the profitability, meat quality, and carcass parameters of fast-, medium-, and slow-growing meat-type chicken genotypes of Bangladesh. Nine hundred DOCs were randomly allocated to 6 treatments: T1 = commercial broilers, T2 = CPF-3 (central poultry farm-3), T3 = cockerel, T4 = sonali, T5 = NDD (non-descriptive desi), and T6 = hilly, having 5 replications of 30 chicks each. Birds were reared under complete confinement until their respective market ages (commercial broilers = 35 d; CPF-3 = 45 d; cockerel = 56 d, and hilly = 77 d; sonali = 63 d and NDD = 77 d) and fed commercial broiler diets. Net returns, meat quality, growth, and carcass yield were measured. NDD and hilly showed significantly the highest profitability and superior meat quality. Commercial broilers exhibited the highest final body weight (2355.59 g/b) followed by hilly (1241 g/b) and NDD (1006 g/b), while CPF-3 (860.21 g/b), cockerel (915.49 g/b), and sonali (788.43 g/b) had lower final body weights at their respective market ages. Commercial broilers had the highest carcass weight and dressing yields, followed by hilly and cockerel, and lower in sonali, CPF-3, and NDD. The study concluded that rearing slow- or medium-growing NDD and hilly is superior to fast-growing commercial broilers or CPF-3 regarding profitability, and meat quality. The results of current findings help small-scale farmers in choosing a suitable meat-type chicken that yields better profitability and also for the consumers who wish to pay a fair price for the birds, considering the meat quality specific to each chicken genotype.

Advances on ALV-J in China over the past two decades

Avian leukosis is an important tumorigenic disease caused by the avian leukosis virus (ALV) in poultry. ALVs belong to the retroviral family and are classified into 11 subgroups (ALV-A to ALV-K). Among them, ALV-J was first introduced into China in 1999, spreading widely and evolving from infecting meat-type chickens to layer chickens and Chinese local chickens. ALV-J typically induces myeloid leukosis in infected chickens, but also induces a high proportion of hemangiomas in infected layer chickens, posing a serious threat to poultry breeds in China. As a retrovirus, the genome of ALV-J has undergone significant mutations, which may be related to the expansion of the infection host range and increased pathogenicity of ALV-J. Over the last two decades, the introduction and spread of ALV-J in China have caused substantial losses to the poultry industry. Specialized detection assays have been developed to combat ALV-J infections in China. Additionally, ongoing research aims to employ gene-editing technology as a novel antiviral strategy to control the spread of ALV infections. This review highlights the importance of understanding the impact of ALV-J on the Chinese poultry industry and emphasizes the need for ongoing research and innovation to safeguard poultry health and promote sustainable poultry farming practices in China.

Research Note: Chicken breast muscle satellite cell function: effect of expression of CNN1 and PHRF1

The Wooden Breast myopathy results in the necrosis and fibrosis of breast muscle fibers in fast-growing heavy weight meat-type broiler chickens. Myogenic satellite cells are required to repair and regenerate the damaged muscle fibers. Using Genome Wide Association, candidate genes affected with Wooden Breast have been previously reported. The effect of these genes on satellite cell proliferation, differentiation, and the synthesis of lipids by satellite cells is unknown. Satellite cells isolated from the pectoralis major muscle from commercial Ross 708 broilers and a Randombred chicken (RBch) line were used. Expression of calponin 1 (CNN1) and PHD and ring fingers domains 1 (PHRF1) were knocked down by silent interfering RNA to determine their effect on satellite cell-mediated proliferation, differentiation, and lipid accumulation. CNN1 and PHRF1 affected satellite cell activity and lipid accumulation in both lines. Proliferation was reduced in the Ross 708 and RBch lines by knocking down the expression of both genes, and differentiation was affected with a line and treatment interaction when gene expression was reduced at the beginning of proliferation. During differentiation lipid accumulation was decreased with knocking down the expression of CNN1 and PHRF1. Both CNN1 and PHRF1 have not been reported previously in skeletal muscle and further research is required to determine their effect on satellite cell-mediated growth and regeneration of the pectoralis major (breast) muscle.

Influence of sex hormones on the aggressive behavior during peck order establishment and stabilization in meat and egg type chickens

In the poultry industry, broiler and layer strains are genetically selected for different purposes (e.g., high meat-yield and high egg-production). Genetic selection for productivity can have unintended consequences on the behavioral repertoire of the birds, including aggression. Alongside the increasing societal concern regarding the welfare of animal in agriculture, the number of countries that are advocating the prohibition of using battery cages for laying hens has resulted in the transition and adoption of cage-free or free-range systems. Thus, both broiler and layer chickens are housed in large flocks rather than housed individually in cages. Housing birds in groups increases the opportunity for birds to engage in social behaviors, including aggression, that are used to establish social status. Aggressive interactions are associated with the risk of injury and the potential for a subordinate animal to have unmet needs (e.g., access to feed). The aim of this study was to characterize the relationships among aggressive behavior, neurobiology, and hormones during peck order establishment and social hierarchy stabilization of 2 divergently selected strains (meat- and egg-type chicken). Meat-type strains performed more male on male (P < 0.001), male on female (P < 0.0001), and female on female (P < 0.0001) non-reciprocal aggression behavior (NRA) than egg-type strains. Greater serum testosterone and estradiol concentrations in the weeks after the peck order establishment were observed in meat-type birds compared those in egg-type birds for both males and females (all P < 0.05). Greater (P < 0.05) cellular densities of androgen receptors, but not estrogen receptors, were observed in the hypothalamus of meat-type birds compared to egg-type birds. These findings suggest that greater sex hormone concentrations in the meat-type birds may be a consequence of genetic selection for rapid growth resulting in more sex hormones-induced aggressive behavior.

Comparison of necrotic enteritis effects on growth performance and intestinal health in two different meat-type chicken strains Athens Canadian Random Bred and Cobb 500

Chickens have undergone genetic improvements in the past few decades to maximize growth efficiency. However, necrotic enteritis (NE), an enteric disease primarily caused by C. perfringens, remains a significant problem in poultry production. A study investigated the differences in intestinal health between the nonselected meat-type chicken Athens Canadian Random Bred (ACRB) and the modern meat-type Cobb 500 broilers (Cobb) when challenged with experimental NE. The study utilized a 2 × 3 factorial arrangement, consisting of two main effects of chicken strain and NE challenge model (nonchallenged control, NC; NE challenge with 2,500/12,500 Eimeria maxima oocysts + 1 × 109C. perfringens, NE2.5/NE12.5). A total of 432 fourteen-day-old male ACRB and Cobb were used until 22 d (8 d postinoculation with E. maxima on d 14, dpi), and the chickens were euthanized on 6 and 8 dpi for the analysis. All data were statistically analyzed using a two-way ANOVA, and Student's t-test or Tukey's HSD test was applied when P < 0.05. The NE12.5 group showed significant decreases in growth performance and relative growth performance from d 14 to 20, regardless of chicken strain (P < 0.01). The ACRB group exhibited significant decreases in relative body weight and relative body weight gain compared to the Cobb group from d 14 to 22 (P < 0.01). On 6 and 8 dpi, both NE challenge groups showed significant decreases in intestinal villus height to crypt depth ratio, jejunal goblet cell count, and jejunal MUC2 and LEAP2 expression (P < 0.01). Additionally, the NE12.5 group had significantly higher intestinal NE lesion score, intestinal permeability, fecal E. maxima oocyst count, intestinal C. perfringens count, and jejunal IFNγ and CCL4 expression compared to the NC group (P < 0.05). In conclusion, NE negatively impacts growth performance and intestinal health in broilers, parameters regardless of the strain.

Transportation stress: Impact on behaviour and welfare in meat-type chickens under indian scenario

In order to find standard transport time and its effect on the welfare, 480 marketable commercial broiler chickens (CARIBRO VISHAL; avg. 2.0 kg body weight) were transported for 2, 4, 8h and without transport in crates in three replicates in a completely randomized design. Transport affected welfare as well as behaviour of broiler chickens. Transport stretch impacted the gait score and tonic immobility with maximum aggravation with extended duration. Runaway results shown that 8h group exhibited more run-away time (279.20sec). Number of birds affected by physical injuries increases with the duration. Bodyweight change was significant among transported groups, especially 8h travelled group exhibited more (−8.21%) body weight loss. It is concluded that a transport period of more than 4h in Indian conditions is not recommended as its causing a significant level of stress in the birds leading to stress, production loss and hampering welfare of broilers.

Host transcriptome response to heat stress and Eimeria maxima infection in meat-type chickens.

Eimeria (E.) maxima parasite infects chickens' midgut disrupting the jejunal and ileal mucosa causing high morbidity and mortality. Heat stress (HS) is a seasonal stressor that impacts biological functions leading to poor performance. This study elucidates how HS, E. maxima infection, and their combination affect the ileum transcriptome. Two-hundred and forty 2-week-old males Ross708 chickens were randomly allocated into four treatment groups: thermoneutral-control (TNc), thermoneutral-infected (TNi), heat-stress control (HSc), and heat stress-infected (HSi), with 6 replicates each of 10 birds. Infected groups received 200x103 sporulated E. maxima oocysts/bird, and heat-treated groups were raised at 35°C. At 6-day post-treatment, ileums of five randomly selected chickens per group were sampled, RNA was extracted and sequenced. A total of 413, 3377, 1908, and 2304 DEGs were identified when applying the comparisons: TNc vs HSc, TNc vs TNi, HSi vs HSc, and TNi vs HSi, respectively, at cutoff ≥1.2-fold change (FDR: q<0.05). HSc vs TNc showed upregulation of lipid metabolic pathways and degradation/metabolism of multiple amino acids; and downregulation of most immune-related and protein synthesis pathways. TNc vs TNi displayed upregulation of most of immune-associated pathways and eukaryotic mRNA maturation pathways; and downregulation of fatty acid metabolism and multiple amino acid metabolism pathways including tryptophan. Comparing HSi versus HSc and TNi revealed that combining the two stressors restored the expression of some cellular functions, e.g., oxidative phosphorylation and protein synthesis; and downregulate immune response pathways associated with E. maxima infection. During E. maxima infection under HS the calcium signaling pathway was downregulated, including genes responsible for increasing the cytoplasmic calcium concentration; and tryptophan metabolism was upregulated, including genes that contribute to catabolizing tryptophan through serotonin and indole pathways; which might result in reducing the cytoplasmic pool of nutrients and calcium available for the parasite to scavenge and consequently might affect the parasite's reproductive ability.

Vaccine Immunogenicity versus Gastrointestinal Microbiome Status: Implications for Poultry Production

At the turn of the 21st century, the importance of maintaining a balanced microbiome was brought to the forefront of the microbiology, immunology, and physiology research fields. Exploring the complex interactions between vaccine administration, mucosal microbiome, oral tolerance, and enteric inflammation in health and disease is challenging since environmental factors (such as diet and sanitation) have major influences on gut microbiota composition. High enteric pathogen load has been shown to contribute to dampened cell-mediated and humoral immune responses to vaccines in human case studies, either through elevated enteric inflammation or increased tolerance to environmental microbes. Although antibiotic and probiotic interventions have been evaluated in human health as well as research animal models, effective measures to mediate vaccine hyporesponsiveness are still ill-defined. Research in this field is becoming increasingly important for managing flock health in commercial poultry production, especially as antibiotic-free production is more prevalent and vaccination programs remain extensive during the first weeks of a bird’s life. By understanding the cellular interactions between commensal microbiota, vaccine antigens, and the host immune system (particularly in avian models), advancements in bacterial and viral vaccine immunogenicity could lead to improved flock health in meat-type and egg-type chickens in the future.