Abstract Aquaculture presents a sustainable alternative to traditional capture fisheries, offering livelihoods and a valuable protein source while alleviating pressure on natural ecosystems. However, environmental stressors often impede the success of aquaculture, posing risks to aquatic life. Functional feed additives are a promising solution to combat stress in fish culture. These additives are integrated into feed formulations to meet animals’ nutritional requirements and enhance growth, health, and stress resistance. Among these additives, L-carnitine has emerged as a promising candidate in aquaculture. By boosting mitochondrial fatty acid β-oxidation and regulating energy metabolism, L-carnitine can help alleviate stress induced by water temperature fluctuations, enhance immunity and growth, shield cells from ammonia toxicity, and eliminate harmful substances from mitochondria. While numerous studies have explored the benefits of L-carnitine supplementation in aquaculture, few studies, according to our knowledge, have reported its specific role in stress mitigation in fish. This review seeks to consolidate existing research and underscore the potential of L-carnitine in high-fat diets, growth promotion, and stress reduction. In conclusion, further exploration of L-carnitine’s mechanisms in reducing fish stress is essential, as it shows promise as a valuable additive for aquafeed formulations.

Abstract The research aimed to determine whether the yolk sac resorption rate, the maternal antibody levels, as well as the efficiency of the immune system of growing turkeys may be affected by early administration of antibiotics and feeding a diet containing a coccidiostat. The experiment was conducted in a 3 × 2 factorial design, which included 3 groups of birds (CON, ENR, DOX), each of which was fed with or without monensin (+, −). The CON groups did not receive antibiotic supplementation (control groups), while those in the ENR groups received enrofloxacin at a dose of 10 mg/kg body weight (BW) for the first 5 days of life, and those in the DOX groups received doxycycline at a dose of 50 mg/kg BW for the first 5 days of life. The CON−, ENR−, DOX− groups did not receive monensin in their diet, while those in the CON+, ENR+, DOX+ groups received monensin at a dose of 90 mg/kg of feed. Adding monensin to the diet significantly decreased the feed conversion ratio (FCR) (P < 0.01) and body weight in 3-day-old and 7-day-old turkey hens (P < 0.05). Early enrofloxacin administration increased anti-ORT antibody titers in 1-day-old turkeys (P < 0.05), while monensin supplementation decreased several antibody titers such as anti-MPV, anti-NDV, and anti-ORT (P < 0.05). Immunoglobulin levels (IgY and IgM) and T cell percentages (CD4 + , CD8 + ) were also significantly reduced in young turkeys fed monensin (P < 0.01 to P < 0.05). Monensin disturbs passive and specific immunity, especially in young turkeys. Early enrofloxacin or doxycycline administration to young turkeys may lead to undesirable changes in the developing immune system, including impaired humoral immunity in later life. Enrofloxacin administration to turkeys in the first five days of life and feeding them a diet containing the coccidiostat monensin strongly stimulated the immune system, which in consequence caused changes in the immune system, indicating immunosuppression in the period distant from the enrofloxacin administration. The early administration of the antibiotics enrofloxacin or doxycycline with a diet without coccidiostat or containing the coccidiostat monensin did not affect the turkeys’ growth performance.

Abstract A2 milk, produced by cows which are homozygous for the A2 β-casein genotype (A2A2 β-CN), has recently attracted increasing attention for its potential health benefits, especially for individuals with certain conditions. However, from an industrial perspective, it is essential to consider the technological challenges and implications associated with the processing of A2 milk. The aim of the current study was to evaluate the effect of the β-CN genetic variant in milk of Simmental cows on the physicochemical, sensory and microbiological quality of selected types of fermented milks. Probiotic yoghurt (ABT-yoghurt), kefir and cultured milk were produced from A2 β-CN milk and compared with those produced from A1 β-CN milk in terms of chemical composition, acidity, antioxidant capacity (ferric reducing antioxidant power and scavenging activity against DPPH radicals), sensory and microbiological quality, instrumental texture and colour profiles, as well as rheological characteristics. The study found no significant differences in basic chemical composition, acidity, antioxidant properties and microbial quality between A1 and A2 fermented milks. Textural and rheological differences related to the β-CN variant were more pronounced in probiotic yoghurts made from A2 milk, which exhibited higher hardness and viscosity, as well as lower structural resistance to deformation. Colour stability remained high across all variants and storage times, with no visually perceptible differences. The sensory quality of cultured milk was rated higher in the A2 variant compared to the A1 variant, due to its better consistency and appearance. In conclusion, A2 milk is well-suited for the production of various types of fermented milk, maintaining microbiological and sensory quality, providing good consistency and texture, though it may need gentler post-production handling.

Abstract The rise of antibiotic resistance and increasing environmental concerns have accelerated the demand for effective, sustainable alternatives to conventional therapeutics in aquaculture. Medicinal plants have emerged as promising candidates due to their diverse bioactive compounds, which exhibit strong immunomodulatory and antioxidant properties. However, the biological efficacy of plant-based interventions varies greatly depending on the specific plant part utilized. This meta-analysis systematically evaluated the differential effects of ethanol-extracted plant parts—roots, leaves, fruits, flowers, stems, and whole plants—on key immune and antioxidant markers in fish. Thirty peer-reviewed studies were included, with a combined sample size exceeding 8,000 fish. Immune-related outcomes such as white blood cell (WBC) count and lysozyme activity, as well as oxidative stress biomarkers including superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA), were analysed. The results demonstrated that leaf and root extracts were the most effective in enhancing immune responses and antioxidant enzyme activities, significantly upregulating SOD and CAT while reducing MDA levels. Notably, leaf extracts showed superior efficacy in increasing lysozyme activity and WBC counts. Conversely, fruit extracts were associated with increased MDA, indicating potential pro-oxidant effects. Subgroup analyses confirmed significant heterogeneity based on plant part, highlighting the need for selective use. This review confirms that the choice of plant part critically determines the health-promoting effects of medicinal plants in fish. The main conclusion from this review is that leaf and root extracts represent the most reliable plant parts for enhancing immune function and oxidative stability in aquaculture species.

Abstract The European Declaration on Alternatives to Surgical Castration of Pigs stipulated that from 2012, surgical castration could only be performed using anesthetics and/or analgesics, and that it would be completely abandoned by 2018. Many Member States disagreed with the conditions set out in the Declaration. The issue of surgical castration arouses serious controversy among consumers due to their concerns over animal welfare and rearing conditions. According to the Council Directive 2008/120/EC of 18 December 2008 laying down the minimum standards for the protection of pigs, surgical castration can be performed without anesthesia until the seventh day of a piglet’s life. Castration is considered painful and can have many adverse health and production consequences. Alternatives to surgical castration include immunocastration or the fattening of entire male pigs. However, these methods also evoke many emotions in both consumers and pork producers. The most common concerns relate to the presence of boar taint in pork, and the appearance of aggressive and sexual behavior within herds. Despite ample literature sources from recent decades, it is difficult to definitively determine whether it is possible to completely eliminate the surgical castration of male pigs. While the use of anesthesia and/or analgesics appears to meet the welfare requirements for pigs, it also poses practical and economic challenges to producers.

Abstract Continuous and sustainable aquaculture development is essential to provide affordable protein sources for the global population. Nevertheless, the intensification of fish farming at high stocking density led to chronic crowding stress that could impair the growth performance, immune system, and antioxidant capacity of an aquaculture species. Consequently, the prevalence of disease outbreaks increases, resulting in low aquaculture production. Various countries remain highly dependent on antibiotics and chemotherapies to overcome this problem. Recently, researchers have proposed and developed alternative solutions using environmentally-friendly feed additives, such as probiotics, phytobiotics, and synthetic immune stimulants, to mitigate crowding stress. The feed additives reportedly alleviate crowding stress, promote growth performance, enhance gut microbiota, immune system, and antioxidant capacity, and stimulate disease resistance, contributing to the overall improvement of the health status of aquaculture species and boosting aquaculture production. The application of feed additives in aquafeed has been investigated in various aquaculture species to explore their beneficial effects at optimum doses. The study outcomes illustrated that feed additives in aquafeed are promising in mitigating crowding stress among aquaculture species. Herein, this review paper discussed and summarised the impacts of crowding stress on the growth, immune system, and antioxidant capacity of aquatic animals. In addition, this review highlighted the potential of feed additives such as probiotics, phytobiotics, and synthetic immune stimulants in mitigating crowding stress in aquatic animals.

Abstract Microplastics (MPs) are pervasive pollutants impacting ecosystems worldwide, causing physical harm and behavioral changes in wildlife. MP toxicity mainly depends on size, porosity, weathering, and surrounding compounds. MPs disrupt feeding and metabolism, resulting in reproductive, neurological, and behavioral disorders. These impacts significantly alter ecological niches and reduce animal survival. Understanding these impacts is crucial for assessing the broader ecological effects of plastic pollution and developing effective mitigation strategies. This review investigated 110 papers on quantifying the behavioral consequences of MPs while considering their physiological basis, emphasizing the significance of these changes and their potential long-term influence on populations and ecosystems. This study thoroughly investigates model species, including plankton, fish, amphibians, crustaceans, pollinators, and mammals. Fish exhibited the most significant behavioral impact, while crustaceans showed the least. Mice, representing mammals, displayed the most severe physiological damage.

Abstract Utilizing fish byproducts is a strategic focus on reducing waste from fish processing, garnering significant global attention from researchers and fish processors aiming for sustainable practices in line with Sustainable Development Goal 12 by 2030. One highly effective approach involves converting these byproducts into valuable commodities, such as collagen and its hydrolysates. Collagen is an important protein in living organisms that serves as fibrous structural component in the extracellular matrix. Over the last decade, fish collagen has gained interest due to its superior physicochemical properties, biocompatibility, biodegradability, safety, and high absorption by the human body. These attributes make fish collagen a promising area of research, particularly for wound healing applications. This review covers the extraction procedures and characteristics of collagen derived from fish byproducts, providing a comprehensive overview of the methods used to obtain high-quality collagen. Additionally, it highlights recent research progress on the use of collagen as a wound healing agent, evaluated through both in vitro and in vivo studies. The review also addresses the challenges associated with applying collagen for wound healing, such as optimizing extraction methods, ensuring consistent quality, and overcoming potential regulatory hurdles. Furthermore, it presents a future perspective on the potential of fish collagen as an efficient and effective wound healing product, emphasizing its role in advancing biomedical research and applications. By offering new insights and stimulating further development in the utilization of fish collagen, this review aims to contribute to waste reduction in fish processing and enhance the economic value of byproducts. Thus, fish collagen holds significant promise as a sustainable and innovative solution in the biomedical field, aligning with global efforts to achieve sustainability and improve human health.

Abstract Climate change is becoming a global issue, with important implications for dairy cow performance and well-being. It is distinguished by a gradual rise in universal temperature and the risk of extreme weather occurrences. Studies have shown that heat stress (HS) impacts many biological processes that can have significant economic issues. Due to their elevated metabolic rate, cows are mostly liable to HS, which negatively affects immune function, particularly cell-mediated immune response, and subsequent reduced production performance and inferior immunity, which leads to elevated susceptibility to disease, increased incidence of intramammary infections, and an elevated somatic cell count, as well as calf mortality, particularly during the summer season. Furthermore, dry cows subjected to HS had reduced immunoglobulin levels after vaccination, although this impact fades with cooling after parturition. On the other hand, cows subjected to HS while dry demonstrate carryover impacts on the innate arm of the immunity in early lactation, resulting in losses. Heat mitigation technologies are cost-effective and necessary for sustaining milk production and the dairy farm’s profitability. Furthermore, a check of present HS mitigation measures is required to understand better and identify acceptable abatement plans for future stress management.

Abstract Aquaculture has been expanding worldwide due to the emerging global population, which is needed to meet the increasing food demand of mankind. As they emerge rapidly, they create pressure on the environment through intensive resource exploitation and carbon emissions. Therefore, sustainable aquaculture technologies should be explored to resolve this issue. Biofloc technology (BFT) has emerged as a transformative approach to modern aquaculture that addresses critical challenges in productivity, environmental sustainability, and resource efficiency. By leveraging microbial processes, BFT converts nitrogenous waste into protein-rich microbial biomass, thereby enhancing nutrient recycling, water quality, and system productivity. This innovative approach minimizes reliance on conventional feed and water exchange systems, while providing a supplementary food source rich in essential amino acids, lipids, vitamins, and minerals. BFT significantly improves growth performance, feed conversion efficiency, immune responses, and survival rates in intensive aquaculture systems, demonstrating adaptability across diverse aquatic species, such as tilapia, carp, shrimp, and catfish. Despite its numerous advantages, BFT implementation faces several challenges, including the need for precise control of carbon-to-nitrogen (C/N) ratios, aeration, and energy management. Addressing these challenges through advancements in automation, real-time monitoring, and sustainable energy solutions is essential for maximizing their potential. This review examines the principles, applications, and benefits of BFT and highlights its role in enhancing water quality, optimizing stocking densities, and improving the physiological and immunological performance of cultured species. By adopting BFT, the industry can achieve a sustainable and resilient framework, meeting the global demand for aquatic proteins while minimizing the environmental impact.