SUMMARY Sustainability should be the primary objective of agricultural production even though true sustainability is only likely to be realised in systems unaffected by human activity. Sustainable poultry development is achieved via three pathways: first, the environment – in terms of demand for scarce resources and environmental degradation; second, the ethical and welfare aspects of both the animals being produced and the humans consuming animal products; and third, the economic robustness of the entire supply chain. Often, advances in one aspect of sustainability negatively affect the other elements. All parts of the supply chain need to be considered simultaneously. These include the production of feed ingredients and feed manufacture, poultry production and processing, and the marketing and distribution of products. Continuous improvement in all aspects will be essential as we shift to more sustainable poultry production. All role players, producers and consumers must understand that sustainability is multifactorial. They will require a perspective on the importance of poultry production and products to food security, poverty alleviation and livelihoods. Poultry production is more sustainable than other branches of animal agriculture and many different forms of human endeavour. Policies designed to enhance sustainability should be science-based, but buy-in from all other interested parties is paramount for success. Sustainable production systems are critical in impoverished areas. Rather than focusing on a single aspect, a holistic and pragmatic approach is always required to drive sustainable development pathways in poultry production.

SUMMARY Lighting programmes and schedules are key components of modern broiler production that are used to support growth and welfare. As researchers and industry representatives continue to explore the use of new lighting equipment, technologies, and programmes, it is important to have current summaries of the relevant research literature. This review paper explores the effects of lighting on broiler performance and welfare for the years 2018–2024. It includes the primary topics generally associated with broiler lighting (colour, intensity, duration, and source), but also includes the latest research available on natural lighting and efforts to characterise the lighting environment of commercial broiler houses.

SUMMARY Modern animal farming is increasingly adopting Artificial Intelligence (AI) technologies, with Convolutional Neural Networks (CNN), a critical component of computer vision (CV) and deep learning playing a pivotal role in enhancing productivity, sustainability, and animal welfare. In poultry farming, a cornerstone of global agriculture that contributes significantly to the world’s meat and egg supply, Convolutional Neural Networks have emerged as powerful tools in poultry management and health monitoring due to their proficiency in image and video analysis. Ensuring poultry health is essential for food safety, economic efficiency, and animal welfare. This study provides a comprehensive review of recent advancements and applications of CNN-based models in poultry health monitoring, covering disease detection, behaviour classification, and overall poultry management. We analysed 54 selected articles, categorising them into disease detection and classification, behaviour monitoring, and poultry detection, localisation, and tracking. The results highlight the high accuracy and efficiency of CNN models in early disease detection, identifying specific diseases, and monitoring behavioural changes, key factors for timely intervention and improved poultry welfare. Prominent models such as YOLO, Faster R-CNN, and ResNet are frequently used, showcasing their robustness across various tasks. The analysis indicates a global research effort, with significant contributions from countries like China and the USA. Despite notable progress, challenges remain, including the limited diversity of datasets, the need for non-invasive methods to monitor critical health indicators like body temperature and weight, and the integration of CNN with other AI-driven technologies. Overcoming these challenges through continued research and innovation is vital for advancing poultry health management and ensuring higher standards of productivity, sustainability, and welfare in the industry.

SUMMARY A balanced and nutritious feed is necessary to ensure optimal egg production. Chickens that are raised for sustaining a high level of egg production primarily rely on specific feeds tailored to meet their dietary requirements. The nutritional composition is profoundly influenced by the feed sources, rich in protein (soybean meal), energy (corn) and Ω- enriched sources (flax seed, chia seed, fish oil) provided to laying hens, specifically, the inclusion of various animal and plant oils in the hens’ diets can result in diverse effects on the overall health of the human beings. The Ω-eggs are distinguished by their significant content of essential Ω-3 fatty acids, particularly alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) that enhance the overall nutritional quality, particularly beneficial for consumers who may not regularly consume fish. The addition of tocopherols considerably improves egg quality and they act as antioxidants. The Ω-3 fatty acids, known as healthy fats, play a significant role in enhancing human health, specifically preventing heart diseases by lowering triglyceride (TG) levels. A daily intake of just 200 milligrams of DHA has decreased the likelihood of sudden cardiac arrest by 50%. The Ω-3 fatty acids exhibit anti-inflammatory properties, helping to moderate inflammation in the body, which is imperative for managing conditions like arthritis and autoimmune disorders. The Ω-3s enriched food should be prioritised for dietary inclusion, as obtaining these fatty acids from food sources is generally more beneficial than relying on supplements. This presented review intends to provide a comprehensive overview and information to reader from hen’s feed to end consumer as many egg products including dried, frozen, pre-cooked, and liquid have been tailored in the market to suit the specific needs of food processors, food businesses, commercial food producers and consumers considering factors of cost, transport ease, handling, sensory attributes and shelf life.

SUMMARY Crossbreeding is the mating system aimed at improving the desirable traits through mating of individuals with different genetic backgrounds to produce offsprings which performs better than their parents. Additionally, this mating system represents one of the traditional ways of improving both egg production and quality. However, the best chicken breeds suitable for crossbreeding for improvement of egg production traits in the poultry industry are not fully explored. In this review, the origin of exotic and indigenous chickens used for crossbreeding are documented. Furthermore, the egg production performance and crossbreeding parameters such as heterosis, specific combining ability, general combining ability, reciprocal and maternal heterosis in indigenous, exotic and crossbreds are reported. This review emphasises the significance of crossbreeding exotic and indigenous chickens for improved egg production traits. In addition, it highlights the great potential for genetic improvement of indigenous chickens through crossbreeding.

SUMMARY The rising costs and limited availability of conventional chicken feed ingredients have prompted researchers to seek alternatives. Agricultural waste products are a promising option but are often unsuitable due to their high crude fibre content. Fermentation, a dynamic process, involving bacteria, fungi, and other microbes, breaks down complex materials into simpler, more digestible compounds and enriches waste with probiotics, enzymes, and bioactive compounds. This process not only enhances the nutritional value of waste materials but also improves broiler performance, including growth rate, feed conversion efficiency, and overall gut health, by promoting beneficial microbiota and nutrient absorption. In recent years, fermentation of agricultural waste has gained attention as a means of recycling waste into a valuable resource, offering a cost-effective and sustainable solution for the poultry industry. This review article evaluates the potential of microbial fermented agricultural waste as an alternative to conventional chicken feed, emphasising its role in enhancing broiler productivity and gut health based on insights from recent scientific studies.

SUMMARY Meat chicken (broiler) breeders are exposed to many stressors, and arguably the most severe are feed restrictions during rearing and aggression during production. Chronic stress is a significant animal welfare concern and reduces productive performance in meat chicken breeders, including reduced egg production and hatchability. As such, minimising stress through effective management strategies is essential for the economic viability and sustainability of the chicken meat industry. This review evaluates approaches to reduce stress associated with hunger and aggression, including qualitative feeding programmes, appetite suppressants, and shed design. We highlight knowledge gaps that must be addressed before strategies can be implemented to reduce stress in breeders on commercial farms. Relaxing commercial feed restrictions could reduce hunger, improve welfare and boost productivity, and current feeding practices should be reassessed for modern breeder strains, focusing on behaviour and stress. Although slower-growing strains and certain feed additives can reduce hunger, they remain impractical due to the economic costs and potential welfare concerns, respectively. Qualitative feed restrictions, involving non-nutritive ingredients such as fibre, show promise in alleviating hunger-related stress. However, research is required to determine the optimal concentrations and composition to balance satiety, gut health, and water retention without causing other welfare problems like wet litter and dermatitis. Managing aggression-related stress currently relies on physical mutations, which are also problematic for welfare. Alternative strategies – such as adjusting sex ratios, synchronising sexual maturity and optimising lighting and shed design – offer potential solutions. Insights from rodent research suggest that building stress resilience through environmental complexity could also be effective. However, it is crucial to determine what environmental changes are both beneficial for the birds and feasible to implement in commercial conditions. We recommend a multidisciplinary approach to reducing stress in meat chickens, combining dietary fibre with strategies to enhance stress resilience, enabling birds to better cope with challenging situations.

SUMMARY In poultry production, chickens are exposed to a variety of potential stressors that can compromise their welfare and health by modulating their immune system. A fully functional immune system is crucial not only for maintaining chicken health and welfare, but also for ensuring high productivity and product quality. This review provides a comprehensive overview of current research on the effects of social stressors on the immune system in chickens. These stressors, which arise from interactions with conspecifics, include overcrowding (high stocking densities), social instability (disruptions in social hierarchies), social defeat or subordination (dominance position), and social isolation. It also points out potential mechanisms and interactions underlying these effects.

SUMMARY Broiler chickens have been accompanied with significant genetic modification to provide markets with higher quantities of meat. However, the modifications might negatively deregulate expression of responsible genes in the synthesis of ribonucleotide reductase with role of either DNA production or repairment of genes. Then, this deregulation reduces energy (ATP) production in muscular mitochondria, and enhances cell death. In subsequent, the normal procedures of cellular division, collagen generation, and vascular network development in the woody breast (WB) muscle will be disrupted and, this in turn, increases either fibrosis (tough meat) or fat accumulation in WB, loses its normal physical feature, nutritional value, and desirable taste for consumers. In order to deal with the issue, studies have offered several approaches to overcome the issue, one of the cheapest and practical strategies to address the issue is using nutritional strategies such as Silybum marianum. Silybum marianum contains silybin, fatty acids from omega family, and flavonoid as a kind of polyphenolic compound such as silymarin, which respectively might acclimatise the muscle metabolism, improve the mitochondrial reticulum, and enhance the ATP synthesis with the help of many intrusive factors alongside of the intestine–liver–muscle axis as well as the modulatory activities of immune cells and gut colonisation of beneficial bacteria. To sum up, each of this compounds existing in Silybum marianum and its derivations via different metabolic pathways might modulate either collagen or fat amounts in muscle to finally cope with muscle disorders such as WB myopathy without having other side effects.

SUMMARY In the poultry sector, sex determination of a one-day-old chick is one of the critical activities. Current sexing methods include cloacal examination, feather sexing, genetic testing, etc. However, there are limitations in using these methods, such as operational difficulties, high costs involved, effective for only certain breeds, and the need for highly skilled workers. In recent years, there has been growing interest in using chicken vocalisations for stress detection, health monitoring and welfare study as they are non-invasive, cheaper and also provide valuable information. Sounds produced by male and female birds vary greatly due to anatomical variation in vocal organs and vocalisation mechanisms. Analyzing the sound signals can help determine the sex of birds. Gender determination of birds using vocalisation analysis started with wild monomorphic birds because of the difficulty in capturing and restraining them for wildlife studies or management. Voice-based sexing using separate calls or duet calls can be used for sex identification of adult birds of more than 69 species from 16 orders. In adult birds, distinct differences in the voice of male and female birds because of the fully developed organs, makes it easier to identify. However, the task is tough in one day old chicks where the vocal organs not fully matured. However, recent studies showed the potential of chicken vocalisations for the determination of gender of one day old chick. However, there are still a lot of challenges in collecting the audio signals from chicks, processing the data and analysis and automating the process. Considering that the use of audio signals for sex determination is non-invasive, efficient, less labour-intensive, as research in this domain advances, the technology may represent a feasible alternative to the current gender determination techniques for routine use in commercial hatcheries especially in developing countries.