Search Results (214)

Laying hens require lighting for proper development and reproduction. There is limited research on the effects that lighting types have on birds’ welfare quality. A novel lighting source, Pulsed Alternating Wavelength System (PAWS), is being evaluated in the industry that claims to improve birds’ growth rate, decrease age at first egg, and decrease aggressive and nervous behaviors. Understanding how PAWS effects hen’s welfare, both physically and physiologically, is critical if this technology is to be adopted by industry. The project evaluated the effects of two PAWS lighting recipes on neurotransmitter turnover and welfare quality of commercial, conventionally caged laying hens. Three flocks of White leghorn hens (control [fluorescent lights] and two PAWS flocks [PAWS1 and PAWS2]) were sampled from 22 to 70 weeks of age, depending on the flock. The physical welfare of 50 hens per flock and neurotransmitter turnover of 10 hens per flock were assessed at each timepoint. The majority of welfare quality parameters were influenced by age as opposed to lighting type. No differences in dopamine turnover were observed. The hens housed under PAWS1 had reduced serotonin turnover, thus increased serotonin activity, and PAWS2 hens had improved keel bone damage scores; both indicative of improved welfare compared to control hens. The novel lighting may be beneficial to layer welfare, which may lead to increased longevity and productivity. Implementation in cage-free housing should be explored to delve into potential behavioral differences that could further influence welfare outcomes. Full article

This study aimed to evaluate the efficacy of oregano essential oil (OEO) in improving the production performance, health, and welfare of late-phase laying hens raised under commercial farm conditions by analyzing its effect on performance metrics and metabolic and endocrine profiles. Daily performance data for approximately 7884 Hy-Line Brown layers divided into two commercial flocks, one consisting of 96-week-old hens (n = 3849) and the other of 79-week-old hens (n = 4035), were recorded before (Pre-OEO Tx), during (OEO Tx-Week) and one week (Post-OEO Tx Week) following the week of water supplementation with commercial oregano essential oil (5%) of Origanum heracleoticum containing carvacrol (79.75%) as the main component (300 mL of product/1000 L of water). The results show a significant improvement in hen-day egg production (HDEP) during treatment (p < 0.05), a significant decrease in daily mortality one week after the cessation of treatment, mainly in the youngest hens (p < 0.05), and a reduction in feed conversion rate (p < 0.05). The general model (GLM) analysis of data from blood samples collected before and after OEO addition showed a significant decrease in plasma levels of procalcitonin (PCT), calcium, albumin (p < 0.05), and aspartate aminotransferase (AST) (p < 0.01). In contrast, a significant increase in estradiol, total protein globulin (p < 0.01), and phosphorus levels (p < 0.05) was recorded. The changes in endocrine profiles were significantly related to a restoration of calcium–phosphorus balance and a decrease in hepatic activity of AST and gamma glutamyl transferase (GGT). These results reveal the investigative value of PCT, in conjunction with metabolic profiling and reproductive hormones, for evaluating the effectiveness of phytogenic additives. Further studies are suggested to determine whether essential oil components can improve health and production performances of laying hens by a potential concurrent modulation of their metabolism, inflammatory response, and reproductive axis function. Full article

Soybean meal has traditionally dominated poultry diets as the protein source. However, its widespread use raises concerns regarding economic costs, environmental impact and social sustainability. As a result, there is growing interest in alternative protein sources, such as canola meal, which may reduce feed costs while sustaining productivity. This review evaluates the potential of canola meal as a sustainable protein source in modern poultry production systems, focusing on nutritional, economic and environmental advantages, as well as the potential implications of canola meal inclusion in reduced-protein diets. Evidence from scientific studies indicates that canola meal’s nutritional profile supports bird growth and production, although higher fiber content and anti-nutritional compounds reduce metabolizable energy, making it more suitable for laying hens than broiler chickens. Processing techniques, enzyme supplementation, fermentation, and modern cultivars have improved both nutritional value and practical utility of canola meal. Performance outcomes differ by species. Broilers exhibit variable growth at high inclusion levels, whereas laying hens are estimated to tolerate up to 20% without affecting laying performance or egg quality; however, data is severely lacking, particularly under the context of modern reduced-protein diets. Economically, canola meal is cost-competitive with soybean meal. From an environmental perspective, substituting imported soybean meal with local canola reduces greenhouse gas emissions, enhances resource efficiency, and supports pollinators. Nevertheless, trade-offs exist, including increased land use, variable digestibility, and potential eutrophication. Incorporating canola meal into reduced-protein diets offers both economic and ecological benefits, though effectiveness depends on the extent of protein reduction and the precision of amino acid formulation. Overall, canola meal offers a sustainable, economically viable, and environmentally responsible protein source for modern poultry production, provided that inclusion levels are adjusted to species-specific requirements and regional conditions. Full article

Eggs from ten Slovenian chicken genotypes—four layer-type purebreds, three meat-type purebreds, and three commercial F₁ crossbreds—were analysed at 50 weeks of age (n = 118). All hens were reared indoors in identical floor-barn systems and fed the same complete layer diet, with feed intake restricted only in meat-type hens. Cholesterol was determined spectrophotometrically, and results included cholesterol per yolk dry matter and fresh yolk, per whole egg and egg content, total cholesterol per egg, and the yolk-to-albumen ratio. Production type significantly affected all traits (p < 0.0001): meat-type hens had the highest cholesterol concentrations and totals, layer-type purebreds were intermediate, and crossbreds the lowest. The yolk-to-albumen ratio showed the same gradient (≈0.44 in crossbreds, ≈0.46 in layer purebreds, ≈0.50 in meat types; p = 0.004), indicating that a larger yolk fraction contributes to higher total cholesterol. Reciprocal crossbreds did not differ in cholesterol levels (p > 0.05), suggesting negligible maternal or sex-linked effects. Under standardised conditions, genotype and production orientation were the main determinants of egg cholesterol and yolk proportion. These results provide reference values for Slovenian breeding and conservation populations and confirm exploitable genetic variability for future selection aimed at improving egg composition. Full article

Spotty liver disease (SLD), primarily caused by Campylobacter hepaticus and (less frequently) by Campylobacter bilis, significantly impacts commercial layer hens by causing liver lesions, reducing egg production, and increasing mortality, meaning it can result in serious economic losses for farmers. This study explored the relationship between infection, liver dysfunction, and reproduction, aiming to identify host genetic markers for tracking SLD progression. Hens were orally inoculated with the C. hepaticus strain NSW44L and monitored over a seven-day period. Pathogen colonisation was quantified using qPCR across the liver, bile, caeca, spleen, and ovarian follicles, while liver lesions were scored and hepatic transcriptomes analysed using RNA-seq. C. hepaticus was detected in the liver, caeca, and spleen from one day post-inoculation (dpi) (1.44–1.68 log₁₀ CFU/mL), appeared in bile by the third dpi (3.64 log₁₀ CFU/mL), and reached the follicles by the fourth dpi (3.25 log₁₀ CFU/mL). The highest bacterial loads were found in bile on days six and seven (up to 7.18 CFU/mL). Liver lesions were first observed on the fourth dpi, reaching their peak at the sixth and seventh dpi. Gene expression analysis in liver tissue revealed a notable downregulation of yolk-precursor and metabolic genes, such as prolactin receptor (PRLR), 7-dehydrocholesterol reductase (DHCR7), and malic enzyme 1 (ME1). In contrast, from days three to seven post-infection, there was significant upregulation of avidin (AVD), a biotin-binding protein, and versican (VCAN), which is linked to tissue remodelling and inflammation. These findings correlate with the disease’s progression from initial liver infection to widespread bacterial presence, suggesting value as host biomarkers for effective SLD monitoring and the development of targeted therapies. Full article

Limited published data are available on the ratio of digestible non-essential amino acid (DNEAA) to digestible lysine (DLys) for layers. The effect of different DNEAA-to-DLys ratios on performance parameters of Hy-Line Silver-Brown layers was studied from 20 to 35 weeks. Experimental design was randomized with ten dietary treatments of increasing concentrations of DNEAA-to-DLys ratio (10.61, 10.84, 11.08, 11.31, 11.54, 11.77, 12.00, 12.23, 12.46, 12.69). Average daily feed intake, total feed intake, laying rate, cumulative egg number, egg weight, hen body weight, feed conversion ratio, egg mass output, albumen weight, eggshell weight, yolk weight, eggshell breaking strength, eggshell thickness, carcass and feather weight, carcass protein, carcass fat, liver weight, and liver fat were recorded. Changing the DNEAA/DLys ratio did not affect production parameters. Yolk and yolk-to-egg weight decreased with an increase in DNEAA/DLys ratio, while albumen-to-yolk and albumen-to-egg weight increased. The DNEAA/DLys ratio did not affect carcass or liver composition, but liver and liver-to-body weight (%) decreased as the DNEAA/DLys ratio increased. Hy-Line Silver-Brown layers during peak production sustained egg production and quality even on the lowest ratio in this study. Low DNEAA/DLys ratios increased liver fat deposition. Full article

The aim of this study was to develop a dynamic factorial model for predicting amino acid requirements in Hy-Line Gray laying hens during critical early growth stages (0–84 days), addressing the need for precision feeding in modern poultry production systems. Methods: Four sequential trials were conducted. In Trial 1, growth curves and protein deposition equations were developed based on fortnightly body composition analyses, with parameters evaluated using the Akaike and Bayesian information criteria (AIC and BIC). In Trial 2, the carcass and feather amino acid profiles were characterized via HPLC. And established the amino acid composition patterns of chicken feather protein and carcass protein (AAF and AAC). In Trial 3, maintenance requirements were quantified through nitrogen balance studies, and in Trial 4, amino acid patterns of feather protein (APD) and apparent protein digestibility (ADD) were established using an endogenous indicator method. These datasets were integrated through factorial modeling to predict age-specific nutrient demands. Results: The developed model revealed the following quantitative requirements (g/day) for 18 amino acids across developmental stages: aspartic acid (0.1–0.863), glutamic acid (0.170–1.503), serine (0.143–0.806), arginine (0.165–0.891), glycine (0.258–1.279), threonine (0.095–0.507), proline (0.253–1.207), alanine (0.131–0.718), valine (0.144–0.737), methionine (0.023–0.124), cysteine (0.102–0.682), isoleucine (0.086–0.458), leucine (0.209–1.067), phenylalanine (0.086–0.464), histidine (0.024–0.133), lysine (0.080–0.462), tyrosine (0.050–0.283), and tryptophan (0.011–0.060). The model demonstrated strong predictive validity throughout the 12-week growth period. Conclusion: This integrative approach yielded the first dynamic requirement model for Hy-Line Gray layers during early development. The factorial framework enables precise adjustment of amino acid provisions to match changing physiological needs and has high potential value in optimizing feed efficiency and supporting sustainable layer production practices. Full article

This study evaluated the effects of replacing inorganic trace minerals with organic glycinate forms at two inclusion levels in layer breeders during the late laying cycle over 6 weeks (66 to 72 weeks of age). For this, a total of 180 layer breeders (162 hens and 18 males; Lohmann LSL Ultralite) were randomly divided into three treatment groups having six replicates of nine hens each and one male for each replicate following a completely randomized design (CRD). The dietary treatments included: (1) Basal diet + inorganic trace minerals at breed recommended levels (ITM100), (2) Basal diet + organic trace minerals at recommended levels (OTM100), (3) Basal diet + organic trace minerals at half dose of recommended levels (OTM50). The trace mineral contents in the samples (feed, bone, and excreta) were determined through inductively coupled plasma optical emission spectroscopy. The results indicated that glycinate minerals supplementation at half dose enhanced (p ≤ 0.05) tibial breaking strength compared to the inorganic minerals (38.97 vs. 29.55 MPa). Similarly, egg quality (egg geometry, yolk index, eggshell properties), and hatching traits (hatchability and fertility) were enhanced (p ≤ 0.05) following the use of glycinate organic minerals as compared to inorganic minerals. Copper deposition was higher (p ≤ 0.05) in the OTM100 as compared to other groups. Excreta levels of zinc (Zn) and manganese (Mn) were higher (p ≤ 0.05) in the ITM100 group compared to OTM100 and OTM50. In conclusion, supplementation of glycinate trace organic minerals to layer breeder hens during the late laying cycle had enhanced the bone and eggshell breaking strength, hatching traits, and absorption of certain trace minerals. Full article

Peanuts and poultry production predominate within the southeast US. Hence, the objective of this study was to determine the dietary effects of unblanched (skin-intact) high-oleic peanuts (HOPNs) and peanut skins (PN skins) on layer performance, egg quality, and fatty acid profile. To meet these objectives, 200 hens were randomly assigned to four treatments, housed in floor pens, and fed ad libitum for 8 weeks a control, HOPN (24%), PN Skin (3%), or 2.5% oleic acid (OA) diet. All empirical data was statistically analyzed for variance at the p < 0.05 level. Hens fed the HOPN and PN Skin diets had heavier body weights relative to the controls at week 8 (p < 0.05). Layers fed the HOPN treatment had poor FCR and smaller egg weights with lower levels of polyunsaturated fatty acids relative to the controls (p < 0.05). Hens fed the PN Skin treatment had similar performance parameters, egg quality, and egg chemistry relative to the controls over the 8-week study. These results imply that PN skins may be an acceptable poultry feed additive without adverse effects on performance, egg quality, or egg lipid chemistry. Also, these results demonstrate the potential value-added utilization of PN skins, a waste by-product of the peanut industry, as a layer feed ingredient. Full article

(1) Background: The goal of the present study was to evaluate whether the supplementation with a multi-species probiotic in the diet of laying hens can change the microbiota and health status of the oviduct. (2) Methods: A total of 60 cages housing lightweight laying hens (36 weeks old) were randomly assigned to the following two different treatments: a control group fed a diet without probiotic, and a treatment group receiving diets supplemented with 50 g/ton of probiotics. The trial lasted for 26 weeks, after which five layers were slaughtered per treatment for oviduct (magnum) assessment, focusing on microbiome composition, oxidant and antioxidant status, and morphological analyses. Additionally, intestinal (jejunum) samples were collected to determine oxidant and antioxidant status. (3) Results: Probiotic supplementation resulted in lower counts of organisms from the RB41 order (p = 0.039) and Burkholderia genus (p = 0.017), and a total reduction in Bacillus and Corynebacterium (p = 0.050) compared to the control treatment. Genera Burkholderia (p = 0.017), Corynebacterium (p = 0.050), and Bacillus (p = 0.050) were also lower with the probiotic supplementation in relation to the control. Genera Epulopiscium (p = 0.089), Flavobacterium (p = 0.100), Ruminococcus (p = 0.089), and Staphylococcus (p = 0.100) tended to be lower in the probiotic group compared to the control. No significant differences were found between treatments for oviduct lesions. Probiotic treatment resulted in a higher protein thiol level in the intestine compared to the control (p < 0.001). However, the use of probiotics tended to reduce glutathione S-transferase levels in the oviduct compared to the control (p = 0.068). (4) Conclusions: These results suggest that dietary supplementation with probiotics can modulate the oviduct microbiota and improve the antioxidant status of laying hens, without causing tissue damage. Further research is warranted to explore the long-term implications of these changes on reproductive performance and egg quality. Full article

This review explores sexual aggression in broiler breeder males, aiming to synthesize existing scientific evidence regarding its causes, behavioral manifestations, and consequences, while addressing the genetic, neuroendocrine, and environmental mechanisms involved. Through an extensive analysis of scientific literature, the paper highlights that intensive genetic selection aimed at enhancing growth and productivity has resulted in unintended behavioral dysfunctions. These include the reduction or absence of courtship behavior, the occurrence of forced copulations, and a notable increase in injury rates among hens. Reproductive challenges observed in meat-type breeder flocks, in contrast to those in layer lines, appear to stem from selection practices that have overlooked traits related to mating behavior. Environmental and managerial conditions, including photoperiod manipulation, stocking density, nutritional imbalances, and the use of mixed-sex rearing systems, are also identified as contributing factors to the expression of sexual aggression. Furthermore, recent genetic findings indicate a potential link between inherited neurobehavioral factors and aggressive behavior, with the SORCS2 gene emerging as a relevant candidate. Based on these insights, the review emphasizes the importance of considering behavioral parameters in breeding programs in order to reconcile productivity objectives with animal welfare standards. Future research may benefit from a more integrative approach that combines behavioral, physiological, and genomic data to better understand and address the multifactorial nature of sexual aggression in poultry systems. Full article

Background: Reliable and non-invasive methods for assessing welfare in poultry are essential for improving evidence-based welfare monitoring and advancing management practices in commercial production systems. The iris-to-pupil (IP) ratio, previously validated by our group in primates and cattle, reflects autonomic nervous system balance and may serve as a physiological indicator of stress in laying hens. This study evaluated the utility of the IP ratio under field conditions across diverse commercial layer housing systems. Materials and Methods: In total, 296 laying hens (Lohmann Brown, n = 269; White Leghorn, n = 27) were studied across four locations in Canada housed under different systems: Guelph (indoor; pen), Spring Island (outdoor and scratch; organic), Ottawa (outdoor, indoor and scratch; free-range), and Toronto (outdoor and hobby; free-range). High-resolution photographs of the eye were taken under ambient lighting. Light intensity was measured using the light meter app. The IP ratio was calculated using NIH ImageJ software (Version 1.54p). Statistical analysis included one-way ANOVA and linear regression using GraphPad Prism (Version 5). Results: Birds housed outdoors had the highest IP ratios, followed by those in scratch systems, while indoor and pen-housed birds had the lowest IP ratios (p < 0.001). Subgroup analyses of birds in Ottawa and Spring Island farms confirmed significantly higher IP ratios in outdoor environments compared to indoor and scratch systems (p < 0.001). The IP ratio correlated weakly with ambient light intensity (r² = 0.25) and age (r² = 0.05), indicating minimal influence of these variables. Although White Leghorn hens showed lower IP ratios than Lohmann Browns, this difference was confounded by housing type; all White Leghorns were housed in pens. Thus, housing system but not breed was the primary driver of IP variation. Conclusions: The IP ratio is a robust, non-invasive physiological marker of welfare assessment in laying hens, sensitive to housing environment but minimally influenced by light or age. Its potential for integration with digital imaging technologies supports its use in scalable welfare assessment protocols. Full article

Rooster behavior and activity are critical for egg fertility and hatchability in broiler and layer breeder houses. Desirable roosters are expected to have good leg health, reach sexual maturity, be productive, and show less aggression toward females during mating. However, not all roosters are desirable, and low-productive roosters should be removed and replaced. The objectives of this study were to apply an object detection model based on deep learning to identify hens and roosters based on phenotypic characteristics, such as comb size and body size, in a cage-free (CF) environment, and to compare the performance metrics among the applied models. Six roosters were mixed with 200 Lohmann LSL Lite hens during the pre-peak phase in a CF research facility and were marked with different identifications. Deep learning methods, such as You Only Look Once (YOLO) models, were innovated and trained (based on a comb size of up to 2500 images) for the identification of male and female chickens based on comb size and body features. The performance matrices of the YOLOv5u and YOLOv11 models, including precision, recall, mean average precision (mAP), and F1 score, were statistically compared for hen and rooster detection using a one-way ANOVA test at a significance level of p < 0.05. For rooster detection based on comb size, YOLOv5lu, and YOLOv11x variants performed the best among the five variants of each model, with YOLOv5lu achieving a precision of 87.7%, recall of 56.3%, and mAP@0.50 of 60.1%, while YOLOv11x achieved a precision of 86.7%, recall of 65.3%, and mAP@0.50 of 61%. For rooster detection based on body size, YOLOv5xu, and YOLOv11m outperformed other variants, with YOLOv5xu achieving a precision of 88.9%, recall of 77.7%, and mAP@0.50 of 82.3%, while YOLOv11m achieved a precision of 89.0%, recall of 78.8%, and mAP@0.50 of 82.6%. This study provides a reference for automatic rooster monitoring based on comb and body size and offers further opportunities for tracking the activities of roosters in a poultry breeder farm for performance evaluation and genetic selection in the future. Full article

Stocking density is one of the major concerns in all production systems, which is why lawmakers, retailers, and consumers are increasingly concerned about this issue and its relation to animal welfare. The aim of this study was to identify if stocking density had an effect on white egg layer production, egg quality, bird health, and welfare parameters. For this study, five stocking densities were evaluated in colony cages: 1342 cm²/hen, 897 cm²/hen, 671 cm²/hen, 535 cm²/hen, and 445 cm²/hen. Egg production and physical egg quality were measured. Hen health and welfare parameters including corticosterone levels, H/L, oxidative stress pathways, jejunum tight junction protein expression, bone health, gut histology, body condition, and cytokine expression were evaluated. The results from this indicated that higher stocking densities resulted in lower production but larger eggs, while feed efficiency remained unaffected. Furthermore, physical egg quality parameters also remained unaffected. When stress and welfare parameters were analyzed, this research identified that decreasing stocking density did not affect jejunum oxidative stress pathways, pro-inflammatory cytokine expression, bone health, or intestinal health. At the final sampling period (69 weeks), the highest stocking density demonstrated higher corticosterone concentrations and IL-10 expression compared to the lowest stocking density. Furthermore, feather scores were found to be poorer as density increased. Finally, the highest density had higher Hansen’s test scores compared to other densities, which indicates a greater fear response. In conclusion, it appears that decreasing stocking density may provide some benefits in production and welfare to commercial egg layers, particularly at the end of the laying cycle. Full article

Limited published data areavailable on the current DLys requirements of Hy-Line Silver-Brown layers. The effects of energy (AMEn) and standardized ileal digestible lysine (DLys) concentration on the performance of Hy-Line Silver-Brown layers were studied from 20 to 35 weeks of age. The experimental design was randomized with twenty-four dietary treatments arranged as a 2 × 12 factorial with two AMEn concentrations (2750 and 2900 kcal/kg feed) and twelve levels of DLys (4.2, 4.5, 4.8, 5.1, 5.4, 5.7, 6.0, 6.6, 6.3, 6.9, 7.2, and 7.5 g/kg). Total egg weight (TEW), average egg weight, total egg number (TEN), laying rate, total feed intake, average daily feed intake (ADFI), mortality, hen body weight, hen body weight gain, eggshell thickness, eggshell breaking strength, yolk weight, albumen weight, and eggshell weight were recorded. An increase in energy content from 2750 to 2900 kcal AMEn/kg reduced ADFI (p < 0.001), egg mass output (p = 0.042), and feed conversion ratio (p = 0.018, g/g; p = 0.001, g/dozen) and increased the fat percentage in the liver (p = 0.028). An increased DLys intake from 529 to 882 mg/hen/day increased the TEN (p = 0.001), TEW (p < 0.001), and egg mass output (p < 0.001); improved the feed conversion ratio (p < 0.001); and reduced carcass (p = 0.001) and liver fat percentage (p = 0.05). Hy-Line Silver-Brown hens require no more than 780 mg (optimized egg production) and 880 mg (maximized egg weight) DLys/hen/day during pre-peak and peak production phases. Full article