Radiographic, computed tomographic, and histologic characteristics of bone for clinically normal laying hens in a free-range housing system.

Laying hens are increasingly being kept in backyard flocks and considered family pets; however, diagnostic imaging characteristics of bone for clinically normal backyard hens are currently limited. This prospective, descriptive study was to describe radiographic, computed tomographic, and histologic characteristics of bone for a group of clinically normal laying hens housed in conditions comparable to those of backyard flocks. Sixteen 60-week-old Lohmann Brown laying hens were included. Hens were housed in a free-range unit with outdoor access at a university research and teaching farm. Hens were defined as clinically normal by the farm manager and a veterinary researcher in laying hen behavior and welfare. Findings from the horizontal beam, left lateral, sternal radiographs (n = 16), postmortem, and whole-body CT scans (n = 4) were recorded by a veterinary radiologist and a research technician. Histologic findings for sternal, femoral, and tibiotarsal bone samples (n = 5) were recorded by a veterinary pathologist. The most frequent radiographic findings for the sternal carina (keel bone) were smoothly marginated concave deviations of the ventral margin and caudal section fractures. Multiple punctate mineral opacities (PMOs) were present in radiographs and CT images for all hens and were involved in the sternal carina and multiple other bones in the axial and appendicular skeleton. No bone abnormalities were identified in any histologic sections where PMOs were radiographically detected. Authors propose that PMOs are normal radiographic and CT findings in the bones of mature, laying hens and may represent temporary calcium reservoirs formed during osteoclastic activities.

Preparation, Structural Analysis, and Growth-Promoting Effects of Amomum longiligulare Polysaccharide 1-Mg (II) Complex.

In this study, Amomum longiligulare polysaccharide 1 (ALP1) is used to chelate with magnesium (Mg) to synthesize the ALP1-Mg (II) complex (ALP1-Mg). Based on Box-Behnken response surface design, the optimum technological conditions are 22 mg mL-1 trisodium citrate, 2.10 mol L-1 MgCl2, reaction at 70 °C for 2.9 h, resulting in a maximum Mg content of 2.13%. Next, the physicochemical properties and structural characteristics of ALP1 and ALP1-Mg are characterized, and the results show that the morphology, conformation, crystallinity, and thermal stability of ALP1-Mg are changed. In addition, dietary supplementation of 500 mg kg-1 ALP1-Mg significantly reduces the feed conversion ratio during the grower (15-35 d). Meanwhile, the villus height/crypt depth of the duodenum and ileum are significantly increased, and the relative abundance of Lactobacillus is significantly elevated. Taken together, the results suggest that ALP1-Mg is a potential growth-promoting feed additive.

Synergistic Effects of Hydroxychloride and Organic Zinc on Performance, Carcass Characteristics, Liver and Tibia Mineral Profiles of Broiler Chickens.

This study investigated the potential synergism between hydroxychloride and organic zinc (Zn) at different levels on performance and carcass characteristics of broiler chickens. There were seven experimental diets including a negative control diet without any supplemental Zn, and six diets with 80 mg/kg added Zn in the forms of ZnSO4, hydroxychloride Zn (HCZ) and organic Zn (ORZ), and a combination of HCZ and ORZ at 40 mg/kg HCZ + 40 mg/kg ORZ (HCZ40-ORZ40), 55 mg/kg HCZ + 25 mg/kg ORZ (HCZ55-ORZ25), and 70 mg/kg HCZ + 10 mg/kg ORZ (HCZ70-ORZ10). Each diet was replicated eight times with 17 chicks per replicate. On day 35, HCZ70-ORZ10 and HCZ40-ORZ40 diets resulted in the highest body weights (P < 0.05). Throughout the entire production period (1-35 days), all HCZ and ORZ diets significantly improved feed conversion ratio (FCR) compared to PC (P < 0.05), with HCZ40-ORZ40 showing the lowest FCR. Breast meat yield was lower in NC-fed birds, while HCZ80 and HCZ70-ORZ10 groups had the lowest abdominal fat weight (P < 0.05). Liver and gizzard weight, tibia breaking strength, and ash percentage, footpad dermatitis, and hock burns were not affected. Tibia Zn content was higher in HCZ or ORZ-supplemented birds compared to NC (P < 0.05), whereas other minerals in tibia and liver were unaffected. In summary, the absence of supplemental Zn negatively affects growth and carcass characteristics, whereas replacing ZnSO4 with HCZ, ORZ, or their combinations improves bodyweight and FCR. HCZ70-ORZ10 and HCZ40-ORZ40 were identified as optimal combinations for maximizing feed efficiency.

Effects of cassava root meal on the growth performance, apparent nutrient digestibility, organ and intestinal indices, and slaughter performance of yellow-feathered broiler chickens.

With the global population growth and shortage of food, the competition between humans and animal for food will become increasingly fierce. Therefore, the development of unconventional energy feed cassava feed is of great significance. The objective of this study was to investigate the effects of cassava root meal (CRM) on the growth performance, apparent digestibility, and organ and intestinal indices of broiler chickens. A total of 140 one-day-old chicks were randomly assigned to four dietary treatment groups [control diet (CT), 15% CRM (CRM15), 30% CRM (CRM30), and 45% CRM (CRM45)] with five replicates of seven birds per replicate. The results showed that the body weight of broiler chickens fed diets containing CRM were significantly lower than that in the CT group at 21 and 42 days of age, the average daily gain and average daily feed intake in the CRM group were significantly lower than those in the CT group from 1 to 21 days of age. However, from days 22 to 42, there were no significant differences between CRM15 and CT birds regarding average daily gain and average daily feed intake. but there was no difference in feed conversion rate between the CRM15 and CT groups. At 42 days of age, there were no significant differences between CRM15 and CT birds in in body measurements, the slaughter performance and the percentage of semi-eviscerated yield. The addition of CRM reduced the proportion of breast and thigh muscles during the feeding period, although we detected no significant difference between CRM15 and CT regarding the apparent digestibility of nutrients. Collectively, our findings indicate that 15% cassava was the optimal proportion for supplementing diets for broiler chicken production.

Family flock size and age-sex structure of indigenous village chickens.

BACKGROUND: Indigenous village chickens (IVCs) significantly contribute to rural development. There is considerable variation in family flock size and age-sex structure of IVCs. OBJECTIVES: This study reports the family flock size, age-sex group structure, and demographic history of IVCs. METHODS: This work involved a cross-sectional study conducted using face-to-face general informants' individual interviews with 119 smallholder farmers in highland and lowland agroecological zones. RESULTS: The average family flock size of the sampled households was small (mean = 7.28, range: 1-38). Female birds (hens and pullets) represented the largest proportion of the family flocks (50.2%). The proportion of chicks (26.4%) and pullets (14.4%) was lower than that of hens (35.8%), which creates a considerable challenge in producing replacement breeding flocks. Similarly, the proportion of cockerels (9.1%) was lower than that of cocks (14.3%). The average cock-to-hen ratio (one cock to seven hens) was better than the commonly recommended proportion (1 cock to 8-10 hens). As a result, smallholder farmers have not faced the problem of producing infertile eggs. The estimated effective population size (Ne) of 4.02 and the corresponding inbreeding coefficient of 0.12 at the family flock level show that to some extent inbreeding may occur at the family flock level; besides, the estimated Ne represents 55.2% of the census size. However, inbreeding could be offset by the high rate of flock turnover and uncontrolled mating among scavenging birds. CONCLUSIONS: Family flocks contain a few birds, which may lead to consanguineous mating. Inbreeding is, however, considerably reduced by uncontrolled breeding among birds that share a common scavenging ground. The driving factors behind the low proportion of chicks and juvenile birds and the family flock size need to be further investigated to improve the contribution of local chickens to rural livelihoods.

Effects of cinnamon, rosemary and oregano on growth performance, blood biochemistry, liver enzyme activities, excreta microbiota and ileal morphology of Campylobacter jejuni-challenged broiler chickens.

BACKGROUND: Phytogenic additives would be helpful to mitigate the detrimental impact of Campylobacter jejuni on broiler chickens. OBJECTIVE: The experiment aimed to assess the effects of cinnamon, rosemary and oregano powder on physiological responses of broiler chickens challenged with C. jejuni from 0 to 42 days of age. METHODS: A total of 192 one-day-old male broiler chickens were divided into 6 treatment groups. The treatments included: negative control (NC; basal diet without additives and no C. jejuni challenge), positive control (PC; basal diet with C. jejuni challenge), PC with cinnamon, rosemary or oregano powder (3 g/kg each), and PC with Erythromycin (55 mg/kg). Except for the NC group, all chicks were orally challenged with 2 × 108 CFU/mL C. jejuni daily from days 21-25. Feed intake, body weight gain (BWG), feed conversion ratio (FCR), energy efficiency ratio (EER) and protein efficiency ratio (PER) were assessed during the rearing period (0-42 days). On day 42 of age, fresh excreta samples were collected from each pen to determine apparent dry matter digestibility and excreta microbiota. In addition, at the end of the experiment, blood samples were collected to evaluate blood profile and liver enzyme activities. RESULTS: C. jejuni challenge (PC treatment) decreased BWG, EER and PER, while increasing FCR of broiler chickens (p < 0.05), whereas rosemary, oregano and Erythromycin improved these performance parameters akin to NC. PC diet showed negative effect in ileal morphology, alleviated by additives except cinnamon (p < 0.05). Dietary additives successfully reduced Campylobacter levels and increased Lactobacilli counts in the PC. Rosemary and oregano lowered plasma total cholesterol (p < 0.05). Alanine aminotransferase elevation by C. jejuni challenge in the PC group was prevented by rosemary, oregano and Erythromycin (p < 0.05). CONCLUSIONS: Oregano and rosemary alleviate the impact of C. jejuni challenge.

ESBL Producing E. coli in Chickens and Poultry Farms Environment in Selangor, Malaysia: A Cross-Sectional Study on Their Occurrence and Associated Risk Factors With Environment and Public Health Importance.

INTRODUCTION: Extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) are widespread multidrug-resistant zoonotic bacteria that threaten animal production, food safety and antimicrobial therapy worldwide including Malaysia. Poultry has been reported as one of the pathways for human exposure to ESBL-EC. There has been little research on the occurrence of ESBL-EC within the Malaysian poultry food chain. Hence, the objectives of the study were to determine the occurrence of ESBL-EC in chickens and to identify the potential risk factors associated with their occurrence in poultry farms. METHODS: A cross-sectional study was conducted on 400 samples, consisting of 240 cloacal swabs from chickens and 160 from poultry farms environments in eight districts in Selangor, Malaysia using culture and disk combination methods and multiple polymerase chain reaction assays. In the determination of possible factors associated with the presence of ESBL-EC at poultry farms, a questionnaire was used to obtain the information and data. RESULTS: The findings demonstrated the wide distribution of ESBL-EC in all the farms with an overall occurrence of 37.2%. Farms in Gombak, Klang and Hulu Selangor had the highest occurrence rates at 62%, 50% and 50%, respectively, followed by farms in Petaling 38%, Sepang at 34%, Kuala Langat at 26% and Kuala Selangor at 24%, and the lowest was in Hulu Langat 14%. Among the study samples, chickens had the highest occurrence rate at 45.4%, followed by chicken house floors at 40% and flies at 30%, while feed and water samples at 17.5% and 12.5%, respectively. The present study indicated the high occurrence and wide dissemination of ESBL-EC in chickens and poultry farms environment. The ESBL-EC occurrence was associated with several factors including imprudent use of antibiotics, poor husbandry, management and biosecurity practices at the farms. CONCLUSIONS: Our study showed the presence and spread of ESBL EC among chickens in the farms and their environment; this may lead to being spread to outside of farm environment by flies, vermins, flying birds, litter and farm wastes and possibly to humans upon contact with the contaminated environment and by poultry meat. Thus, the findings of the study can assist to serve as a piece of useful information to veterinary authority in designing evidence-based mitigation strategies for the control of ESBL-EC in poultry farms.

Dynamic response of the intestinal microbiome to Eimeria maxima-induced coccidiosis in chickens.

Eimeria maxima is a major cause of coccidiosis in chickens and a key predisposing factor for other economically significant diseases such as necrotic enteritis. However, a detailed understanding of the intestinal microbiome response to E. maxima infection is still lacking. This study aimed to comprehensively investigate the dynamic changes of the intestinal microbiome for 14 days post-infection (dpi) with E. maxima. Bacterial 16S rRNA gene sequencing was performed with the ileal and cecal digesta collected from mock and E. maxima-infected chickens at the prepatent (3 dpi), acute (5 and 7 dpi), and recovery phases (10 and 14 dpi) of infection. Although no notable changes were observed at 3 dpi, significant alterations of the microbiota occurred in both the ileum and cecum at 5 and 7 dpi. By 14 dpi, the intestinal microbiota tended to return to a healthy state. Notably, Lactobacillus was enriched in response to E. maxima infection in both the ileum and cecum, although individual Lactobacillus, Ligilactobacillus, and Limosilactobacillus species varied in the temporal pattern of response. Concurrently, major short-chain fatty acid-producing bacteria, such as Faecalibacterium, were progressively suppressed by E. maxima in the cecum. On the other hand, opportunistic pathogens such as Escherichia, Enterococcus, and Staphylococcus were significantly enriched in the ileum during acute infection. IMPORTANCE: We have observed for the first time the dynamic response of the intestinal microbiota to Eimeria maxima infection, synchronized with its life cycle. Minimal changes occur in both the ileal and cecal microbiota during early infection, while significant alterations coincide with acute infection and disruption of the intestinal mucosal lining. As animals recover from coccidiosis, the intestinal microbiota largely returns to normal. E. maxima-induced intestinal inflammation likely creates an environment conducive to the growth of aerotolerant anaerobes such as Lactobacillus, as well as facultative anaerobes such as Escherichia, Enterococcus, and Staphylococcus, while suppressing the growth of obligate anaerobes such as short-chain fatty acid-producing bacteria. These findings expand our understanding of the temporal dynamics of the microbiota structure during Eimeria infection and offer insights into the pathogenesis of coccidiosis, supporting the rationale for microbiome-based strategies in the control and prevention of this condition.

Polymelia and concurrent intestinal duplication and cloacal atresia in a broiler chick: case report and literature review.

Congenital malformations are a highly diverse group of conditions reported in both humans and animals, characterized by defects in morphogenesis observed at birth. Although most cases are idiopathic, genetic and environmental factors may be involved. The frequency of such conditions varies with species, geographic regions, and the specific malformation involved. In polymelia, supernumerary limbs are attached to different parts of the body. Gastrointestinal duplications are described less frequently and can be associated with polymelia. Cloacal atresia is among the least-reported malformations in avian species, described only once in a kiwi. Here we describe a case with these 3 malformations in a single broiler chick (Gallus gallus domesticus) and provide a literature review about the occurrence of these malformations in birds. The 3-d-old chick also had an unidentified structure projecting from the pygostyle region. We performed clinical, radiographic, and postmortem examinations. The intestinal duplication was identified only during the postmortem evaluation. Detailed descriptions of avian congenital malformations are scarce. Although similar cases have been reported, we retrieved no cases of concurrent polymelia, intestinal duplication, and cloacal atresia in broiler chickens in our literature search, suggesting that the simultaneous occurrence of these conditions has not been reported previously in this species.

Efficacy and Growth Performance between Two Different Ionophore Coccidiostats (Narasin and Salinomycin) in Broiler Chickens after Challenge with Eimeria spp.

The objective of this study was primarily to assess the different performance impacts of two ionophore coccidiostats (narasin and salinomycin) used to manage coccidiosis. While both products may be efficacious in controlling disease challenges, previous literature has suggested that some ionophores are less well tolerated by the broiler chickens. In this study, we were particularly interested to know how the use of different coccidiostat programs translates into broiler health and performance, as measured by zootechnical parameters such as the feed conversion ratio, average daily gain, and final body weight. A total of 352 male Ross 308 one-day-old broilers were randomly divided into two treatment groups (T1 and T2). Treatment 1 included a basal diet (BD) + nicarbazin/narasin (Maxiban®, Elanco) at 100 ppm 0-24 days, narasin at 70 ppm 25-42 days, and (2) Treatment 2 included basal diet + nicarbazin/narasin at 100 ppm 0-24 days, salinomycin (Sacox®, Huvepharma) at 70 ppm 25-42 days. Efficacy and performance parameters, slaughter analysis, dry matter (DM) in litter, and intestinal integrity (I2) were measured for the broilers from both treatment groups. The findings demonstrated more favorable results for broilers reared in the group diet fed with narasin (in the finisher phase), including higher daily body weight gain, higher final body weight, lower feed conversion ratio value (improved feed efficiency), and higher European Production Efficiency Factor value, compared with the salinomycin-supplemented group.

Effects of high-level dietary distillers dried grains with solubles supplemented with multienzymes on growth performance, nutrient utilization, intestinal morphology, and pellet quality in broiler chickens.

Background and Aim: With the increasing cost of bulk raw materials and advancements in the feed enzyme industry, corn distillers dried grains with solubles (DDGS) have shown more opportunities for use in broiler diets. Supplementation with multiple enzymes could mitigate anti-nutritional factors in DDGS, enhance nutrient digestibility, and thereby increase its utilization in broiler diets, leading to reduced feed costs. This study evaluated the effects of multienzyme supplementation on growth performance, nutrient utilization, intestinal morphology, and pellet quality in broiler chickens fed diets containing conventional levels of DDGS (C-DDGS) and higher levels of DDGS (H-DDGS). Materials and Methods: A total of 800 1-day-old Cobb 500 chicks was assigned to four dietary treatments with eight replicates of 25 birds each: C-DDGS (5% DDGS in Starter and 10% in Grower), C-DDGS + Enzyme (C-DDGS diet supplemented with multienzyme), H-DDGS (10% and 20%) + Enzyme (H-DDGS diet supplemented with multienzyme, 10% DDGS in Starter and 20% in Grower), and H-DDGS (15% and 30%) + Enzyme. Results: The C-DDGS + enzyme diet increased (p < 0.05) body weight gain (BWG), reduced the feed conversion ratio, enhanced (p < 0.05) digestibility of dry matter (DM), crude protein, and hemicellulose (HC), and improved (p < 0.05) intestinal villus height and villus: crypt ratio of broilers. The H-DDGS (10% and 20%) + enzyme diet exhibited no difference in (p > 0.05) growth performance, nutrient digestibility (except HC), and intestinal morphological parameters, whereas the H-DDGS (15% and 30%) + enzyme diet decreased (p < 0.05) feed intake and BWG and reduced (p < 0.05) energy and DM digestibility by impact (p < 0.05) intestinal morphology compared with the C-DDGS enzyme-free diet. The H-DDGS diet had lower (p < 0.05) pellet hardness and poorer durability than the C-DDGS diet. Conclusion: Supplementing multienzyme in the C-DDGS (5% and 10%) diet improved growth performance from day 0 to 28 and diminished growth performance in the H-DDGS (15% and 30%) diet by influencing intestinal morphology and feed pellet quality in broiler chickens. In addition, when supplemented with multienzyme, the dietary DDGS level can be safely included at levels of 10% in 0-7 days and 20% in 8-28 days of age.

The Influence of Dietary Supplementation with Dried Olive Pulp on Gut Microbiota, Production Performance, Egg Quality Traits, and Health of Laying Hens.

This study examines the dietary effect of dried olive pulp (OP) on the overall performance, egg quality, health, and gut microbiota of laying hens during a 36-week trial. A total of 180 Isa Brown layers, aged 23 weeks, were assigned to 15-floor pens and divided into three feeding groups (CON, OP4, and OP6) based on the dietary level of OP. Egg quality and biochemical parameters were assessed in 39- and 59-week-old hens. Fecal samples were collected for microbiota analysis. Data were analyzed with an Analysis of Variance. The percentage of broken eggshells was found to be 15-34% lower in the OP groups compared to the CON groups. At 59 weeks of age, a significant reduction in shell thickness was observed in the CON eggs compared to the OP eggs (p < 0.05). At 39 weeks of age, OP6 eggs had the darkest yolk color of all groups (p < 0.05). Fecal microbial diversity was affected only by hens' age. However, an enrichment in bacterial species belonging to the genera Megasphaera and Megamonas was found in the OP groups at 59 weeks of age. Our results demonstrate that OP feeding beneficially affects egg quality and promotes the proliferation of bacteria involved in the degradation of complex plant compounds, potentially contributing to the overall health of the gut microbiota.

The anticoccidial effects of probiotics and prebiotics on the live coccidia vaccine and the subsequent influence on poultry performance post-challenge with mixed Eimeria species.

Live vaccines containing Eimeria oocysts are commercially available to protect against avian coccidiosis. Additionally, probiotics (PRO) and prebiotics (PRE) improve the poultry productivity and health and can be used as anticoccidial substitutes. However, the impact of PRO and PRE on reproductive potential, lesion score, intestinal health, and immunization outcomes of the live coccidia vaccines has not received adequate attention. Five groups of unsexed 1-day-old broiler chicks were used as follows: negative control (NC); challenged control (CC); vaccinated and challenged (VC); vaccinated, PRO-treated, and challenged (V-PRO); and vaccinated, PRE-treated, and challenged (V-PRE). At 21 d post-vaccination (pv), the vaccine increased the count of cecal anaerobes (P ≤ 0.05) and coliforms (P > 0.05) as well as harmed body weight gain (WG) (P ≤ 0.05), cecal lactic acid bacteria (P ≤ 0.05), and plasma carotenoid level (P > 0.05). None of the additives decreased oocyst shedding after vaccination, although they lowered the middle intestine and cecal lesion scores (P > 0.05). Compared to VC (2.68 ± 0.12) and V-PRE (2.66 ± 0.05), the V-PRO group showed an improved carotenoid level pv (2.96 ± 0.05) (P ≤ 0.05). V-PRE exhibited higher WG (822.95 ± 18.25) (P > 0.05) and FI (1153.01 ± 10.02) (P ≤ 0.05) than VC (781.86 ± 25.16 and 1109.85 ± 33.68) and V-PRO pv (787.61 ± 19.92 and 1077.43 ± 15.99). Following the homologous coccidia challenge, coccidia-vaccinated broilers adminstered the PRO or PRE continued to exhibit protection levels comparable to those received the vaccine alone. During 2 weeks post-challenge, VC, V-PRO and V-PRE improved bird performance and reduced oocyst shedding and lesion scores compared to CC. Ultimately, PRO and PRE treatments did not significantly reverse the reduction in growth performance in broiler chickens vaccinated against coccidia during the 1st three weeks of age.

Characterization of the Coding Sequence of the MC1R (Melanocortin 1 Receptor) Gene of Ayam Cemani Black Chickens.

Plumage color is one of the most important traits characterizing chicken breeds. Black-boned chickens constitute a specific group of breeds with a unique phenotype. One of the representatives is the Indonesian Ayam Cemani. The extraordinary black phenotype results from a specific chromosomal rearrangement. We used complete CDS of crucial color-related gene MC1R, which plays a key role in melanin distribution but has not been previously studied in Ayam Cemani. It turned out that Ayam Cemani individuals possess a newly found non-synonymous mutation G355A resulting in amino acid substitution D119N. Together with the presence of G274A (E92K), the new missense variant enabled us to distinguish a new extended black allele at the E locus. All of the investigated birds were heterozygous in terms of the new mutation. Previous studies and our own results indicate a high level of genetic variation within the MC1R gene within and between chicken breeds. Besides the key mutations that make it possible to distinguish particular major alleles, there are also numerous substitutions that give haplotypes more characteristics for individual breeds.

Single nucleus/cell RNA-seq of the chicken hypothalamic-pituitary-ovarian axis offers new insights into the molecular regulatory mechanisms of ovarian development.

The hypothalamic-pituitary-ovarian (HPO) axis represents a central neuroendocrine network essential for reproductive function. Despite its critical role, the intrinsic heterogeneity within the HPO axis across vertebrates and the complex intercellular interactions remain poorly defined. This study provides the first comprehensive, unbiased, cell type-specific molecular profiling of all three components of the HPO axis in adult Lohmann layers and Liangshan Yanying chickens. Within the hypothalamus, pituitary, and ovary, seven, 12, and 13 distinct cell types were identified, respectively. Results indicated that the pituitary adenylate cyclase activating polypeptide (PACAP), follicle-stimulating hormone (FSH), and prolactin (PRL) signaling pathways may modulate the synthesis and secretion of gonadotropin-releasing hormone (GnRH), FSH, and luteinizing hormone (LH) within the hypothalamus and pituitary. In the ovary, interactions between granulosa cells and oocytes involved the KIT, CD99, LIFR, FN1, and ANGPTL signaling pathways, which collectively regulate follicular maturation. The SEMA4 signaling pathway emerged as a critical mediator across all three tissues of the HPO axis. Additionally, gene expression analysis revealed that relaxin 3 (RLN3), gastrin-releasing peptide (GRP), and cocaine- and amphetamine regulated transcripts (CART, also known as CARTPT) may function as novel endocrine hormones, influencing the HPO axis through autocrine, paracrine, and endocrine pathways. Comparative analyses between Lohmann layers and Liangshan Yanying chickens demonstrated higher expression levels of GRP, RLN3, CARTPT, LHCGR, FSHR, and GRPR in the ovaries of Lohmann layers, potentially contributing to their superior reproductive performance. In conclusion, this study provides a detailed molecular characterization of the HPO axis, offering novel insights into the regulatory mechanisms underlying reproductive biology.

Productive, internal organ and intestinal histomorphological characteristics of broiler chickens in response to dietary rapeseed meal: A meta-analysis.

The use of rapeseed as a source of protein in broiler chicken diets has been highlighted. However, there are inconsistent findings on the performance data of broiler chickens fed rapeseed meal (RSM). Therefore, this meta-analysis aimed to resolve the inconsistent findings on the effect of RSM on growth performance, carcass characteristics, internal organs, and intestinal histomorphology of broiler chickens, identify knowledge gaps and create new insights using published data. Fourteen studies on the topic were identified via a systematic search performed on bibliographic databases, and the data generated was analysed using OpenMEE software. A random-effects model was used, and effect sizes were presented as standardised mean difference (SMD) at a 95% confidence interval (CI). Sources of heterogeneity were evaluated using broiler strains, inclusion levels, processing methods, rearing phases and sex as moderators. In comparison with the controls, the results showed that RSM decreased feed intake (SMD = -0.29; 95% Cl: -0.41, -0.18; p < 0.001), average daily gain (SMD = -0.48; 95% Cl: -0.63, -0.32; p < 0.001), and liver weight (SMD = 1.24; 95% Cl: 0.78, 1.71; p < 0.001), but had no effect on feed conversion ratio (SMD = 0.10; 95% Cl: -0.05, 0.23; p = 0.19). Likewise, broiler chickens fed RSM had significantly reduced carcass yield, weights of thigh, abdominal fat and heart when compared with the control. Results indicate that duodenum villus height (DVH) and jejunum villus height (JVH)/crypt depth (CD) ratios were improved in broiler chickens fed RSM. Meta-regression revealed that the analysed moderators are significant predictors of feed intake, average daily gain and feed conversion ratio in broiler chickens. In conclusion, dietary RSM negatively influenced growth performance, liver weight and carcass characteristics in broiler chickens, but improved aspects of intestinal histomorphology traits. Therefore, innovative research on processing methods that will improve the feeding value of rapeseed meal in broiler chickens is recommended.

Impact of different range areas on behavior, welfare, and performance of Naked Neck chickens.

This study aimed to evaluate the effect of different environmental enrichment tools on behavior, welfare, productive performance, and egg quality traits of Naked Neck chickens. A total of 1080 Naked Neck female chickens (30 weeks old) were used in the present study. A completely randomized experimental design, with 3 treatments having 4 replicates of 90 birds each, was applied. Treatments consisted of 3 different range areas A (121.9 m2), B (152.4 m2), and C (190.5 m2). Behavior (walking, feeding/foraging, sitting, aggressiveness wing flapping, perching, dust bathing, and range use), welfare (foot pad dermatitis, lameness, gait score, and feather pecking), productive performance (egg weight, egg production %, egg mass, and feed intake), egg quality traits (morphometry, egg weight, shell, albumen, and yolk characteristics) were evaluated. There was no influence (P > 0.05) of different range area on bird's behavior, and egg quality traits except walking and rang usage. The range area C promoted productive performance including egg weight, egg production %, egg mass and feed intake, but it did not influence welfare traits. It might be concluded that Naked Neck chicken when reared in free range with different range enrichments did not reveal any difference regarding behavioral parameters, egg morphometry, and egg quality traits. The range area within minimum length and effectively used environmental enrichments (perching and dust bathing area) should be used for backyard poultry to obtain ideal performance.

Dietary bile acids supplementation decreases hepatic fat deposition with the involvement of altered gut microbiota and liver bile acids profile in broiler chickens.

BACKGROUND: High-fat diets (HFD) are known to enhance feed conversion ratio in broiler chickens, yet they can also result in hepatic fat accumulation. Bile acids (BAs) and gut microbiota also play key roles in the formation of fatty liver. In this study, our objective was to elucidate the mechanisms through which BA supplementation reduces hepatic fat deposition in broiler chickens, with a focus on the involvement of gut microbiota and liver BA composition. RESULTS: Newly hatched broiler chickens were allocated to either a low-fat diet (LFD) or HFD, supplemented with or without BAs, and subsequently assessed their impacts on gut microbiota, hepatic lipid metabolism, and hepatic BA composition. Our findings showed that BA supplementation significantly reduced plasma and liver tissue triglyceride (TG) levels in 42-day-old broiler chickens (P < 0.05), concurrently with a significant decrease in the expression levels of fatty acid synthase (FAS) in liver tissue (P < 0.05). These results suggest that BA supplementation effectively diminishes hepatic fat deposition. Under the LFD, BAs supplementation increased the BA content and ratio of Non 12-OH BAs/12-OH BAs in the liver and increased the Akkermansia abundance in cecum. Under the HFD, BA supplementation decreased the BAs and increased the relative abundances of chenodeoxycholic acid (CDCA) and cholic acid (CA) in hepatic tissue, while the relative abundances of Bacteroides were dramatically reduced and the Bifidobacterium, Escherichia, and Lactobacillus were increased in cecum. Correlation analyses showed a significant positive correlation between the Akkermansia abundance and Non 12-OH BA content under the LFD, and presented a significant negative correlation between the Bacteroides abundance and CA or CDCA content under the HFD. CONCLUSIONS: The results indicate that supplementation of BAs in both LFD and HFD may ameliorate hepatic fat deposition in broiler chickens with the involvement of differentiated microbiota-bile acid profile pathways.

Evaluation of different heterologous-homologous vaccine regimens against challenge with GI-23 lineage infectious bronchitis virus.

This study assesses different IBV vaccination regimens in broiler chickens using commercially available live attenuated GI-23 (Egyptian-VAR2) and GI-1 (H120) vaccines. Vaccines were administered at 1, 14 days of age, or both. The ciliostasis test, following wild-type VAR2 challenge at 28 days of age, indicated that classic H120+VAR2 at one day old followed by the VAR2 vaccine at 14 days of age provided the highest level of protection (89.58%). Similarly, administering VAR2 at 1 day of age and classic H120 at 14 days of age demonstrated substantial protection (85.42%). Conversely, administering only classic H120 and VAR2 at one day old resulted in the lowest protection level (54.17%). Tracheal virus shedding quantification and assessment of trachea and kidney degenerative changes were significantly lower in vaccinated groups compared to the unvaccinated-challenged group. In conclusion, a carefully planned vaccination regimen based on homologous vaccination offers the most effective clinical protection in broiler chickens.

Clostridium perfringens antigens and challenges for development of vaccines against necrotic enteritis in poultry.

INTRODUCTION: Chickens with Necrotic Enteritis (NE), caused by Clostridium perfringens, exhibit acute and chronic symptoms that are difficult to diagnose, leading to significant economic losses. Vaccination is the best method for controlling and preventing NE. However, only two vaccines based on the CPA and NetB toxins have been commercialized, offering partial protection, highlighting the urgent need for more effective vaccines. OBJECTIVE: This review aimed to identify promising antigens for NE vaccine formulation and discuss factors affecting their effectiveness. METHODS: A systematic review using five scientific databases identified 30 eligible studies through the Rayyan tool, which were included for quality review. RESULTS: We identified 25 promising antigens, including CPA, NetB, FBA, ZMP, CnaA, FimA, and FimB, categorized by their role in disease pathogenesis. This review discusses the biochemical, physiological, and genetic traits of recombinant antigens used in vaccine prototypes, their expression systems, and immunization potential in chickens challenged with virulent C. perfringens strains. Market supply challenges, immunogenic potential, vaccine platforms, adjuvants, and factors related to vaccination schedules-such as administration routes, dosing intervals, and age at immunization-are also addressed. Additionally, the study notes that vaccine formulations tested under mild challenges may not offer adequate field-level protection due to issues replicating aggressive conditions, strain virulence loss, and varied methodologies. CONCLUSIONS: An ideal NE vaccine should incorporate multiple antigens, molecular adjuvants, and delivery systems via in ovo and oral routes. The review underscores the challenges in developing and validating NE vaccines and the urgent need for a standardized protocol to replicate aggressive challenges accurately.