Commercial Broiler Chickens Research Articles

Hypoxia-mediated programmed cell death is involved in the formation of wooden breast in broilers

BackgroundWooden breast (WB) myopathy is a common myopathy found in commercial broiler chickens worldwide. Histological examination has revealed that WB myopathy is accompanied by damage to the pectoralis major (PM) muscle. However, the underlying mechanisms responsible for the formation of WB in broilers have not been fully elucidated. This study aimed to investigate the potential role of hypoxia-mediated programmed cell death (PCD) in the formation of WB myopathy.ResultsHistological examination and biochemical analysis were performed on the PM muscle of the control (CON) and WB groups. A significantly increased thickness of the breast muscle in the top, middle, and bottom portions (P<0.01) was found along with pathological structure damage of myofibers in the WB group. The number of capillaries per fiber in PM muscle, and the levels of pO2 and sO2 in the blood, were significantly decreased (P < 0.01), while the levels of pCO2 and TCO2 in the blood were significantly increased (P < 0.05), suggesting hypoxic conditions in the PM muscle of the WB group. We further evaluated the PCD-related pathways including autophagy, apoptosis, and necroptosis to understand the consequence response to enhanced hypoxic conditions in the PM muscle of birds with WB. The ratio of LC3 II to LC3 I, and the autophagy-related factors HIF-1α, BNIP3, Beclin1, AMPKα, and ULK1 at the mRNA and protein levels, were all significantly upregulated (P < 0.05), showing that autophagy occurred in the PM muscle of the WB group. The apoptotic index, as well as the expressions of Bax, Cytc, caspase 9, and caspase 3, were significantly increased (P < 0.05), whereas Bcl-2 was significantly decreased (P < 0.05) in the WB-affected PM muscle, indicating the occurrence of apoptosis mediated by the mitochondrial pathway. Additionally, the expressions of necroptosis-related factors RIP1, RIP3, and MLKL, as well as NF-κB and the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6, were all significantly enhanced (P < 0.05) in the WB-affected PM muscle.ConclusionsThe WB myopathy reduces blood supply and induces hypoxia in the PM muscle, which is closely related to the occurrence of PCD including apoptosis, autophagy, and necroptosis within myofibers, and finally leads to abnormal muscle damage and the development of WB in broilers.

Weak purifying selection in allelic diversity of the ADSL gene in indigenous and local chicken breeds and red junglefowl in Thailand

High levels of purine and uric acid, which are associated with health issues such as gout and cardiovascular disease, are found in the meat of fast-growing broiler chickens, which raises concerns about the quality of chicken meat and the health of the consumers who consume it. High genetic homogeneity and uniformity, particularly in genes involved in the synthesis of inosine monophosphate (IMP) and subsequent process of purine synthesis, which are associated with the meat quality, are exhibited in commercial broiler chickens owing to intensive inbreeding programs. Adenosine succinate lyase (ADSL) is a key enzyme involved in de novo purine biosynthetic pathway and its genetic polymorphisms affect IMP metabolism and purine content. In this study, we investigated the polymorphism of the ADSL gene in indigenous and local chicken breeds and red junglefowl in Thailand, using metabarcoding and genetic diversity analyses. Five alleles with 73 single nucleotide polymorphisms in exon 2, including missense and silent mutations, which may act on the synthesis efficiency of IMP and purine. Their protein structures revealed changes in amino acid composition that may affect ADSL enzyme activity. Weak purifying selection in these ADSL alleles was observed in the chicken population studied, implying that the variants have minor fitness impacts and a greater probability of fixation of beneficial mutations than strong purifying selection. A potential selective sweep was observed in Mae Hong Son chickens, whose purine content was lower than that in other breeds. This suggests a potential correlation between variations of the ADSL gene and reduced purine content and an impact of ADSL expression on the quality of chicken meat. However, further studies are required to validate its potential availability as a genetic marker for selecting useful traits that are beneficial to human health and well-being.

Impact of Nanoencapsulated Rosemary Essential Oil as a Novel Feed Additive on Growth Performance, Nutrient Utilization, Carcass Traits, Meat Quality and Gene Expression of Broiler Chicken.

This study evaluated the effect of free and nanoencapsulated rosemary essential oil (REO) as an antibiotic alternative in broiler diets on growth performance, nutrient digestibility, carcass traits, meat quality and gene expression. Four hundred twenty day-old commercial broiler chicks (VENCOBB) were randomly allocated to seven dietary treatments, each having four replicates of fifteen chicks. The dietary treatments comprised control (CON) fed a basal diet only, AB (basal diet + 10 mg enramycin/kg), CS (basal diet + 150 mg chitosan nanoparticles/kg), REOF100 and REOF200 (basal diet + 100 mg and 200 mg free REO/kg, respectively), and REON100 and REON200 (basal diet + 100 mg and 200 mg nanoencapsulated REO/kg, respectively). Overall (7-42 d), REON200 showed the highest (p < 0.001) body weight gain (1899 g/bird) and CON had the lowest gain (1742 g/bird), while the CS, REOF100 and REOF200 groups had a similar gain, but lower than that of the AB and REON100 groups. Feed intake was not affected by dietary treatments. Overall, the feed efficiency increased (p = 0.001) by 8.47% in the REON200 group and 6.21% in the AB and REON100 groups compared with the CON. Supplementation of REO improved (p < 0.05) dry matter and crude protein digestibility, with the highest values in REON100 and REON200. Ether extract, crude fiber, calcium and phosphorus digestibility values showed no difference among the groups. The dressing, breast, thigh % increased (p < 0.05) and abdominal fat % decreased (p < 0.001) more in the REON200 group than with other treatments and CON. In breast meat quality, water holding capacity and extract reserve volume increased (p < 0.05) while drip loss and cholesterol content decreased (p < 0.05) in REON100 and REON200. No change was observed in the breast meat color among dietary treatments and CON. The REON100 and REON200 groups had reduced (p < 0.05) meat lipid peroxidation as depicted by the decreased levels of TBARS, free fatty acids and peroxide value compared to other treatments and CON. The expression of the Mucin 2, PepT1 and IL-10 genes was upregulated (p < 0.001) and TNF-α downregulated (p < 0.001) by dietary addition of REO particularly in the nanoencapsulated form compared with the CON. In conclusion, nanoencapsulated REO, especially at 200 mg/kg diet, showed promising results as an antibiotic alternative in improving the performance, nutrient digestibility, carcass traits, meat quality and upregulation of growth and anti-inflammatory genes.

PERFORMANCE AND CARCASS EVALUATION OF BROILER CHICKENS FED DIFFERENT COMMERCIAL DIETS

An experiment was carried out to determine the utilization of five selected commercial broiler chicken diets by broilers. Three hundred day-old chicks were randomly allotted to five diets in replicates of three containing 20 birds each in a Completely Randomized Design. Feed and water were supplied ad libitum and the feeding trial lasted for six weeks. Results for overall performance, indicated that daily feed intake was higher (P&lt;0.05) on diets A (103.00 g), D (101.79 g) E (100.18 g) and B (96.06 g) which were the same and lower on diet C85.21 g) while daily weight gain and feed conversion ratio assumed the same trend as daily feed intake. Carcass evaluation showed a higher (P&lt;0.05) dressing percentage on diet D (76.72 %) and lowest on diet C (67.96 %). It was therefore concluded that diets D and A gave higher dressing percentages, hence recommended for broiler chicken farmers in the study area.

Plasmid-mediated quinolone resistance in Escherichia coli isolates from commercial broiler chickens in Semnan, Iran

Background and Objectives: Antibiotic resistance within the poultry sector presents a considerable health concern due to treatment inefficacy and resistance transmission to humans and the environment. The investigation of plasmid-mediated quinolone resistance (PMQR) in Escherichia coli, acknowledged for its role in advancing resistance, remains inadequately studied in Iranian poultry. This study aimed to evaluate PMQR gene prevalence as well as to determine correlation between resistance phenotype and genotype in E. coli obtained from poultry colibacillosis. Materials and Methods: A collection of 100 E. coli isolates from the viscera of broilers suspected to colibacillosis was assessed. Using the Kirby-Bauer disk diffusion method, antimicrobial susceptibility tests were conducted for ofloxacin, nalidixic acid, levofloxacin, ciprofloxacin, and ampicillin. Additionally, PCR was employed to screen for qnrS, qnrB, and aac(6)Ib-cr genes. Results: Among the analyzed E. coli isolates, 51% demonstrated resistance to at least one of the tested antibiotics, with 17% exhibiting resistance to four different antibiotics. Nalidixic acid displayed the highest resistance rate at 48%, while ampicillin had the lowest at 16%. PMQR genes were detected in 28% of the E. coli isolates, with aac(6′)-Ib-cr being the most prevalent at 14%, followed by qnrB in 13%, and qnrS in 7%. Conclusion: The study underscores the vital need for careful antibiotic usage in poultry to curb the emergence of antibi- otic-resistant bacteria. The results illuminate the prevalence of PMQR genes and their association with resistance trends in Iranian poultry, forming a pivotal basis for forthcoming approaches to combat antibiotic resistance within the poultry sector.

Genetic Sequence and Pathogenicity of Infectious Bursal Disease Virus in Chickens in Egypt During 2017-2021.

The continued circulation of infectious bursal disease virus (IBDV) in Egypt, despite the use of various vaccines, is a serious problem that requires continuous detection of IBDV. In the current study, real-time reverse transcriptase polymerase chain reaction testing of 100 diseased chicken flocks during 2017-2021 revealed the presence of very virulent IBDV (vvIBDV) in 67% of the flocks, non-vvIBDV in 11%, and a mixture of both vvIBDV and non-vvIBDV in 4%. Twenty-nine IBDV isolates were submitted for partial sequencing of the viral protein 2 hypervariable region (VP2-HVR), and 27 isolates were confirmed to be genogroup A3 (vvIBDV) with 96.3%-98.5% similarity to the global A3 (vvIBDV) and 88.9%-97% similarity to genogroup A1 vaccine strains. The remaining two isolates were non-vvIBDV and showed 91.1% and 100% identity with classical genogroup A1 strains, respectively. Furthermore, the sequence and phylogenetic analysis of VP1 (amino acids 33-254) of two selected isolates of A3, 5/2017 and 98/2021, clustered them as B2, vvIBDV-like, strains with high similarity (99.5%) to four Egyptian, 99% to Chinese and European, and 97.7% to Chinese and Polish vvIBDV isolates. Experimental infection of commercial broiler chickens with two vvIBDV-A3B2 isolates (5/2017 and 98/2021) showed no mortality despite typical tissue lesions, clear histopathological changes, and strong ELISA antibody response. Isolate 98/2021 was more pathogenic, as confirmed by histopathology, whereas isolate 5/2017 induced a stronger serological response. In conclusion, vvIBDV (A3B2) strains with two amino acid (aa) substitutions in VP1 as V141I and V234I as well as VP2 as Y220F and G254S are still circulating in Egypt.

Elevated mortality in 3-week-old commercial broiler chickens.

Elevated mortality in 3-week-old commercial broiler chickens.

Appraisal of Three Commercial Inactivated Avian Influenza Vaccines Efficacy Against Challenge with Egyptian Duck-Origin Clade 2.3.4.4b H5N8 in Commercial Broiler Chickens

Appraisal of Three Commercial Inactivated Avian Influenza Vaccines Efficacy Against Challenge with Egyptian Duck-Origin Clade 2.3.4.4b H5N8 in Commercial Broiler Chickens

Effect of Dietary Supplementation of Andrographis paniculata and Curcuma longa Powder on Growth Performance, Immunity and Carcass Characteristics of Commercial broiler Chicken

Effect of Dietary Supplementation of Andrographis paniculata and Curcuma longa Powder on Growth Performance, Immunity and Carcass Characteristics of Commercial broiler Chicken

Effect of modified shelter arrangements on growth performance, stress and water usage of commercial broilers in hot and humid climate

The current research was conducted to study the effect of modified shelter arrangements on commercial broiler’s performance and water usage in hot and humid climatic regions. Ninety six commercial Vencobb broiler chicks of one week of age were segregated into four groups with three replicates having eight chicks per replicate, viz. TA (asbestos roof as control), TAG (asbestos roof with gunny bags screen), TH (modified asbestos with thatched roof), and THG (modified asbestos with thatched roof with gunny bags as the screen). The overall maximum temperature of the asbestos group’s experimental sheds throughout the trial period was substantially greater than that of the thatch group. Significantly, the highest THI was seen in the TAG shed. The cumulative body weight gain was significantly highest in TH shed. The cumulative FCR and performance indices of the thatched group were found to be significantly better than the asbestos group. The net profit/bird and net profit/kg were better in the TH group. According to behavioural studies, the panting rate rose with age in weeks but was much lower in the thatched group. Serum corticosterone levels were considerably lower in the TH and THG groups than in the asbestos roof groups. In hot and humid locations, modified asbestos with a thatched roof may be suitable for commercial broiler poultry.

Effect of baker's yeast fermented moist feed on the growth and bone mineralization in broiler.

The effect of feeding yeast-fermented feed in various forms on broiler growth performance and bone mineralization was studied. Initially, a corn-soy-based diet was formulated and fermented in anaerobic conditions at 28°C in laboratory space for 48 h with yeast (2.0%) and moisture (50%). Afterward, the 150 newly hatched Arbeor Acres commercial broiler chicks were divided into 5 dietary groups (30 chicks, 6 cages, and 5 birds per cage). Each group received one of the following formulated and fermented diets: dry feed (DF), moist feed (MF), yeast-added dry feed (Y-DF), yeast-added moist feed (Y-MF), or yeast-fermented moist feed (YF-MF). Water and feed were supplied ad libitum. Six birds per group were slaughtered at age 37 for the determination of carcass traits and tibia ash. Fermentation improved crude protein from 20.7% to 22.8% but declined crude fiber from 7.9% to 6.3% in the YF-MF group compared to the DF group. High body weight gain was recorded in 771, 830, and 992 gm in the MF, Y-MF, and YF-MF groups, respectively, compared to the DF (762 gm) group (p < 0.01). The feed conversion ratio was better in the Y-MF (1.57) and YF-MF (1.57) groups than in the DF (1.75) group. Feeding a fermented, moist diet resulted in improved carcass yield (69%) in the YF-MF group. Bone mineralization expressed a better tibia ash percentage (35% from 30%) in the YF-MF group compared to the DF group. Therefore, YF-MF enhanced the quality of feed and improved growth, carcass weight, and bone mineralization in broiler.

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.

Antimicrobial resistance of avian pathogenic Escherichia coli isolated from broiler, layer, and breeder chickens.

Antimicrobials are extensively used in poultry production for growth promotion as well as for the treatment and control of diseases, including avian pathogenic Escherichia coli (APEC). Poor selection, overuse, and misuse of antimicrobial agents may promote the emergence and dissemination of antimicrobial resistance (AMR) in APEC. This study aimed to assess antimicrobial susceptibility patterns and detect antibiotic resistance genes (ARGs) in APEC isolated from clinical cases of colibacillosis in commercial broiler, layer, and breeder chickens. A total of 487 APEC were isolated from 539 across 300 poultry farms in various regions of Nepal. Antimicrobial susceptibility patterns was determined using the Kirby-Bauer disk diffusion and broth microdilution methods. The index of AMR, such as multiple antibiotic resistance (MAR) index, resistance score (R-score), and multidrug resistance (MDR) profile, were determined. Polymerase chain reaction was employed to detect multiple ARGs and correlations between phenotypic and genotypic resistance were analyzed. The prevalence of APEC was 91% (487/539). All of these isolates were found resistant to at least one antimicrobial agent, and 41.7% of the isolates were resistant against 8-9 different antimicrobials. The antibiogram of APEC isolates overall showed the highest resistance against ampicillin (99.4%), whereas the highest intermediate resistance was observed in enrofloxacin (92%). The MAR index and R-score showed significant differences between broiler and layers, as well as between broiler breeder and layers. The number of isolates that were resistant to at least one agent in three or more antimicrobial categories tested was 446 (91.6%) and were classified as MDR-positive isolates. The ARGs were identified in 439 (90.1%) APEC isolates, including the most detected mobilized colistin resistance (mcr1) which was detected in the highest (52.6%) isolates. Overall, resistance gene of beta-lactam (blaTEM), mcr1, resistance gene of sulphonamide (sul1) and resistance gene of tetracycline (tetB) (in broiler), were detected in significantly higher than other tested genes (p < 0.001). When examining the pair-wise correlations, a significant phenotype-phenotype correlation (p < 0.001) was observed between levofloxacin and ciprofloxacin, chloramphenicol and tetracycline with doxycycline. Similarly, a significant phenotype-genotype correlation (p < 0.001) was observed between chloramphenicol and the tetB, and colistin with blaTEM and resistance gene of quinolone (qnrA). In this study, the current state of APEC AMR in commercial chickens is revealed for the first time in Nepal. We deciphered the complex nature of AMR in APEC populations. This information of molecular surveillance is useful to combat AMR in APEC and to contribute to manage APEC associated diseases and develop policies and guidelines to enhance the commercial chicken production.

A computer vision approach to monitor activity in commercial broiler chickens using trajectory-based clustering analysis

To monitor changes in broiler behaviour related to animal health and welfare, farmers typically observe their flocks using manual observation. However, due to the labour intensive and continuous aspect of this task, the analysis of broiler behaviour could be automated using camera technology. This paper proposes a proof-of-concept camera surveillance system based on the automated detection and tracking of broilers to monitor activity bouts using unsupervised 2D trajectory clustering. Firstly, a convolutional neural network-based detector was trained and tested on our labelled dataset which resulted in a precision, recall and f score of 0.98, 0.90 and 0.94, respectively. Using a tracking-by-detection approach, the proposed system was able to track chickens across video frames with a multi-object tracking accuracy of 74.7%. A component-based feature saliency Gaussian mixture model (CFSGMM) was subsequently generated and applied to objectively cluster the trajectories based on their spatiotemporal information. Nineteen features were extracted from the trajectories, representing both static and dynamic characteristics of broiler movement, and three activity classes were identified: ‘least active/resting,’ ‘active’ and ‘highly-active.’ The proposed method was validated on one-minute monocular video sequences. CFSGMM was applied to cluster 2D trajectories relating to broiler activity bouts within the commercial rearing environment with an agreement ranging from 6.0 to 99.7% when compared to human observation. We demonstrate the potential of the computer vision system to monitor overt, short-term changes in broiler activity associated with on-farm events and discuss the opportunities of leveraging the technology to monitor longer term changes in welfare state. It is anticipated that further development of the detection and tracking systems will improve the performance of the trajectory clustering method.

Prevalence and Antibiotic Resistance Profile of Salmonella Spp. in Broiler Carcasses from Dominant Poultry Production Areas in Bhutan

Background: Salmonella is an important zoonotic pathogen, and its infections are considered among the most commonly and widely distributed food-borne illness reported worldwide. Poultry products have been identified as important sources of Salmonella infection to humans. While there have been reports of high prevalence of Salmonella and multidrug resistance in imported chicken meat in Bhutan, the safety of nationally produced broiler meat with regards to Salmonella contamination is not known. In the absence of national surveillance of Salmonella in food animals in Bhutan, this study assessed the prevalence of Salmonella and its serotypes in broiler chicken carcass in the dominant poultry production areas of the country and determine its antibiotic susceptibility patterns. Methods: A cross-sectional study was conducted in January to April 2016 in all five major commercial broiler meat producers and suppliers in Bhutan located in the Samphelling and Darla gewogs. Following a systematic random sampling method, 36 broiler carcasses were sampled from each of the five broiler commercial farms producing a total sample size of 180 samples. Salmonella was isolated and identified following the International Organization for Standardization methods (ISO 6579:2002). All Salmonella isolates were subjected to antibiotic susceptibility testing (AST) following the procedures of the Clinical and Laboratory Standards Institute (CLSI) method. Results: The overall prevalence of Salmonella in broiler chicken meat samples was 12.78% (95% CI, 10.98-14.58). The prevalence of Salmonella spp. was higher in farms of the samphelling gewog compared to Darla gewog [14.81% (95% CI, 8.2.7-21.5) vs 9.72% (95% CI, 2.9-16.6) respectively]. Among 23 Salmonella isolates, the most prevalent serovar was Salmonella ser. Typhi (73.9%). The Salmonella isolates showed high sensitivity to gentamicin (73.9% of isolates) followed by streptomycin (56.5%) and ampicillin (47.8%). The highest proportion of resistance was noted to tetracycline (95.6%), trimethoprim (86.9%), amoxicillin (65.2%), and ampicillin (47.8%). Among 23 Salmonella isolates, 60.87% (n=14) were considered multidrug resistant and 7 patterns of multidrug resistance were discovered. Conclusion: The estimates of Salmonella prevalence and multidrug resistance in nationally produced commercial broiler chicken carcasses from the two main broiler meat producing areas in Bhutan, raises significant public health concerns highlighting the need for an integrated national Salmonella surveillance program across the poultry market chain.

The efficacy of simultaneous successive classic and variant infectious bronchitis virus vaccines versus circulating variant II Egyptian field virus.

Being a ubiquitous, highly contagious virus with a continuous mutation and a large number of evolutions worldwide, the infectious bronchitis virus (IBV) continues to wreak problems among Egyptian chickens and generate economic losses. The commonly applied IBV vaccination protocols in broilers include alternatives to classic and/or variant attenuated live virus vaccines. The current study targeted to assess the protective efficacy of concurrent and successive Ma5 and 4/91 vaccine strain regimens against the field variant II IBV strain (IBV-EGY-ZU/Ck-127/2021) in chickens. Commercial broiler chickens were vaccinated with Ma5 and 4/91 strains simultaneously at 1 and 14 days of age. The evaluation parameters included clinical protection and humoral and early innate immunity aspects in the renal tissues of vaccinated and infected birds. The vaccine regimen ameliorated the clinical and histopathological lesions against variant II IBV and enhanced body gain as well as succeeded in preventing tracheal shedding and minimizing cloacal shedding of the field virus. The IL-1β mRNA gene expression was evident as early as 24 hours, with highly significant upregulation at 48 hours post vaccination and 24 hours post challenge (PC) in vaccinated birds. Remarkable upregulation was observed in oligoadenylate synthetases (OAS) expression 48 hours PC in vaccinated and unvaccinated infected birds. The vaccinated birds developed a significant antibody titer of 704.0 ± 111.98 at 28 days of age, with a consistent antibody titer increase after the challenge. Overall, a combination of heterologous protectotype commercial vaccines achieved good protection against the Egyptian variant II IBV strain. This vaccine program could be an effective protocol against the threat posed by IBV viruses circulating in the Egyptian field.

A perspective of the prevalent H9N2 virus with a special focus on molecular and pathological aspects in commercial broiler chicken in Punjab, Pakistan.

Frequent outbreaks of avian influenza H9N2 virus in Pakistan revealed that this subtype has become endemic in the poultry industry and, besides economic losses, poses a threat to public health. The present study describes the molecular characterization and pathological alterations in naturally infected broiler chickens with the current H9N2 field strain and their phylogenomic dynamics. In this study, tissue samples (trachea, lung, kidney and intestine) from 100 commercial chicken flocks were collected from July 2018 to August 2019. Samples were subjected to molecular detection, phylogeny and subsequent pathological examination. The complete length of the HA gene was successfully amplified in five samples. Nucleotide sequencing revealed positive samples placed in a clade belonging to the B2 sub-lineage of the G1 genotype and categorized as LPAIV based on the amino acid sequence of the HA gene at the cleavage site (PAKSSR/G). Genetic analysis of the haemagglutinin (HA) gene revealed nt: 80.5%-99.5%; aa: 83.8%-98.9% homology to H9N2 strains reported previously from Pakistan, neighbouring countries, and (A/Quail/Hong Kong/G1/97). Gross lesions include a slight airsacculitis, mild hemorrhages, diffuse congestion and purulent exudate in tracheal mucosa, fibrinonecrotic cast in the trachea lumen and mild pulmonary congestion. Histopathological alterations include sloughing of epithelial cells and infiltration of inflammatory cells in the trachea, mononuclear cells (MNCs) infiltration, pulmonary congestion and exudate in the lumen of parabronchi, peritubular congestion in the kidneys with degeneration of tubular epithelial cells and degenerative changes in the intestinal villi epithelial cells and goblet cell hyperplasia. Immunohistochemistry analysis confirmed the presence of AIVH9N2 antigen in the trachea, lungs, kidney and intestine. Electron microscopy revealed ultrastructural changes in the trachea, including degenerated cilia, mitochondrial swelling and enlarged endoplasmic reticulum. Based on all essential analysis, the present study revealed the distribution of the H9N2 virus of G1 genotype in Punjab, Pakistan, with mild to moderate pathogenicity.

Protective effectiveness of two vaccination schemes against the prevalent Egyptian strain of Newcastle disease virus genotype VII.

Despite the strict preventive immunization used in Egypt, Newcastle disease remained a prospective risk to the commercial and backyard chicken industries. The severe economic losses caused by the Newcastle disease virus (NDV) highlight the importance of the trials for the improvement and development of vaccines and vaccination programs. In the present study, we evaluated the effectiveness of two vaccination schemes for protection against the velogenic NDV (vNDV) challenge. Four groups (A-D) of commercial broiler chickens were used. Two groups (G-A and G-B) were vaccinated with priming live HB1 GII simultaneously with inactivated GVII vaccines at 5 days of age, then boosted with live LaSota GII vaccine in group A and live recombinant NDV GVII vaccine in group B on day 16. Groups A to C were challenged with NDV/Chicken/Egypt/ALEX/ZU-NM99/2019 strain (106 Embryo infective dose 50/0.1 ml) at 28 days of age. Two vaccination schemes achieved 93.3% clinical protection against NDV with body gain enhancement; whereas, 80% of the unvaccinated-challenged birds died. On day 28, the mean HI antibody titers were 4.3 ± 0.33 and 5.3 ± 0.33 log2 in groups A and B, respectively. As well as both programs remarkably reduced virus shedding. The two vaccination schemes displayed close protection efficacy against the vNDV challenge. Therefore, using the combination of a live attenuated vaccine with an inactivated genetically matched strain vaccine and then boosting it with one of the available live vaccines could be considered one of the most effective programs against current field vNDV infection in Egypt.

Effect of wet feeding on performance, blood plasma indices, intestinal histomorphometry, and economics of broiler chickens under hot climatic conditions.

The study aimed to investigate the impact of wet feeding on broiler chicken performance and intestinal histomorphometry. The research was conducted at the Veterinary College, Udaipur, India, using 144 commercial broiler chicks from day 1 to 6 weeks of age. The chicks were divided randomly into three experimental groups, each with four replicates comprising 48 birds. The control group (G1) was fed dry; while, group 2 (G2) received wet feed supplemented with 1.00 g water per g of feed and group 3 (G3) received wet feed supplemented with 1.20 g water per g of feed. Results revealed that G3 had significantly superior feed conversion ratios, lower feed intake, and increased body weight and weight gain compared to G2 and G1. Among the three treatment groups, there were no variations in blood plasma indicators. In comparison with G1, duodenum and ileum in G2 had higher villus height. The G3 revealed higher net profit margins and 18.89% saving of feed compared to G1, suggesting that it may be a valuable tool for lowering chicken feed costs.

Effects of grain-based pecking blocks on productivity and welfare indicators in commercial broiler chickens.

This experiment was conducted to investigate the effect of grain-based pecking blocks on productivity and welfare status at two commercial broiler welfare-certified farms. Production and welfare indicators were assessed at two farms (designated Farm A and B). Both farms had two windowless houses with forced tunnel-type ventilation and housed broilers at stocking densities of approximately 16.7 birds/m2 (Farm A) and 16.8 birds/m2 (Farm B). Each house was divided into two or three equal sections and was provided with or without pecking blocks. Grain-based pecking blocks, measuring 25 × 25 × 25 cm, were given to broilers in both farms at 1 block per 1,000 birds. Various parameters including productivity (body weight and flock uniformity), corticosterone levels (in fecal droppings and feathers), footpad dermatitis, hock burn, feather dirtiness, gait score, litter quality, body surface temperature, and volatile fatty acids in fecal samples were assessed at 26 days of age, whereas litter quality was analyzed at 13 and 26 days of age. There were no significant effects of providing pecking blocks on productivity (body weight and uniformity), fecal and feather corticosterone, welfare indicators (i.e., footpad dermatitis, hock burn, feather cleanliness, and gait score), and litter quality (i.e., moisture, nitrogen, and pH). No differences in body surface temperature between the control and enrichment treatments were noted in Farm B, but body surface temperatures of the head (p = 0.029) and legs (p = 0.011) in the enrichment vs. control group were elevated in Farm A. Butyrate concentration in the enrichment vs control group was higher in Farm B (p = 0.023), but this effect was not detected in Farm A. It is concluded that grain-based pecking blocks did not affect performance and welfare indicators. Further studies are warranted to elucidate the potential impact of grain-based pecking blocks on gut health indicators.