In recent years, a supplementation of livestock animals, including poultry, with β-Hydroxy-β-methylbutyrate (HMB) has gained attention for its effects on protein and fat metabolism. This study investigates the effects of HMB in the laying hen diet on egg quality, focusing on amino acid and fatty acid composition. Laying hens were supplemented with 0.02% HMB, with performance parameters and egg components analyzed. HMB supplementation led to increased albumen weight, influencing egg weight while also reducing feed intake per egg without affecting laying rate, yolk indices, fat, or cholesterol content. Notably, the study revealed significant changes in egg amino acid and fatty acid profiles due to HMB supplementation. Various amino acids, including glycine, serine, and isoleucine, were altered in the yolk, impacting nutritional value and potential health benefits. Regarding fatty acids, the study observed changes in both saturated as well as n-6 and n-3 fatty acids, affecting the overall lipid profile of egg yolks. However, the shifts in fatty acid composition could have implications for cardiovascular health due to altered ratios of n-6/n-3 fatty acids. Further research is required to comprehensively understand the implications of these findings for consumer-oriented egg quality and health benefits.

Quality feed is essential for correct bone development and proper functioning of animals. Post-weaned piglets experience a radical change in eating behaviour that can influence their feed intake. For this reason, functional feed additives and ingredients that can be used in post-weaning feeds are needed. The objective of this study was to evaluate the effects of partially replacing wheat with rapeseed meal fermented using Bacillus subtilis strain 87Y on overall bone quality and bone metabolism in weaner piglets. From the 28th day of life, barrows were fed either a standard wheat-based diet or a diet containing 8% fermented rapeseed meal (FRSM) with or without a feed additive containing enzymes, antioxidants, probiotics, and prebiotics. The experimental period lasted 60 days, after which femur quality indices were assessed. Differences in bone length and weight were observed, but there were no changes in bone mineralization or bone mid-diaphysis morphometrical traits between treatments. FRSM inclusion reduced bone mid-diaphysis biomechanical properties, but these changes were dependent on feed-additive supplementation. Analysis of the levels of serum bone turnover markers suggests the intensification of bone resorption in FRSM-fed groups as deoxypyridinoline levels increase. The results obtained warrant further research on what the disturbances in bone mechanical properties and metabolism observed in FRSM-fed weaners means for the subsequent fattening period.

Ducks exhibit substantial ecological and dietary diversity, which drives morphological and functional adaptations in their digestive systems. This study analyzed the small intestine and cecum of three wild duck species: Mallard (Anas platyrhynchos), Tufted Duck (Aythya fuligula), and Green-Winged Teal (Anas crecca) collected post-mortem. Histomorphometric analysis and immunohistochemistry (IHC) with the pan-neuronal marker HuC/D were performed. The Tufted Duck showed the thickest intestinal muscle layers, particularly in the duodenum and ileum, and the largest enteric ganglia, indicating adaptation to a fibrous and protein-rich diet. The Mallard displayed the longest villi and deepest crypts, consistent with its omnivorous diet rich in plant material. The Green-Winged Teal, which consumes highly digestible insect-rich food, had the shortest villi and thinnest muscle layers. Differences in enteric ganglion size and organization among species suggest varying neuroregulatory demands in different gut segments. These findings confirm that intestinal morphology and enteric nervous system (ENS) structure are tightly linked to dietary specialization and ecological strategies. The results highlight the high adaptive plasticity of the avian digestive system in response to feeding behavior.

In the expansive domain of neuropeptide investigation, spexin (SPX) has emerged as a captivating subject, exerting a significant impact on diverse physiological processes. Initially identified in mice, SPX’s distribution transcends various organs, suggesting its potential regulatory roles. Despite extensive research in smaller species, a notable gap exists in our comprehension of SPX in larger mammals, particularly ruminants. Our study meticulously explores the immunolocalization of SPX within the gastrointestinal organs of bovines, with a specific focus on the abomasum, jejunum, and colon. Tissue samples from Holstein–Friesian cattle underwent careful processing, and gene mRNA expression levels, particularly GALR2 and SPX, were assessed. Intriguingly, our findings revealed that GALR2 expression was highest in the jejunum, signifying a potentially critical role in this digestive segment. Immunohistochemistry further unveiled distinct patterns of SPX immunoreactivity in each examined region—abomasum, jejunum, and colon—highlighting nuanced, region-specific responses. Notably, the abomasum and jejunum predominantly exhibited positive immunoreactivity in the submucosal plexus, while the colon, in contrast, demonstrated a higher degree of immunoreactivity in myenteric plexus neurons. Our investigation, grounded in the hypothesis of ubiquitous SPX distribution in ruminants, delves deeper into the intricate role of SPX within the enteric nervous system. This study meticulously explores the spatial distribution of SPX within the myenteric and submucosal plexuses, integral components of the enteric nervous system. These findings significantly enhance our understanding of SPX’s potential roles in gastrointestinal regulation in bovines, providing a unique perspective on larger mammals and enriching our comprehension of this intriguing neuropeptide’s significance in various physiological processes.

Introduction: This study explored the effects of prenatal exposure to fumonisins B (FB) on bone innervation in newborn Wistar rats. Material and Methods: Pregnant dams (n = 6 per group) were assigned to either the control or one of two FB-exposed groups (60 mg or 90 mg/kg body weight) from the 7 ^th day of gestation until parturition. On the day of parturition, one male pup from each litter (n = 6 per group) was randomly selected and euthanised, and their femurs were dissected for analysis. Bone innervation was quantified by examining the morphology patterns of sympathetic, parasympathetic, sensory and cocaine- and amphetamine-regulated transcript (CART)-positive fibres. Prepared bone sections were analysed using immunohistochemistry staining for protein gene product 9.5, tyrosine hydroxylase, choline acetyltransferase, vasoactive intestinal peptide (VIP), substance P and CART-positive neurons. Results: The group that received a higher dose of FB demonstrated an increase in both the size and complexity of the complete bone neuronal network together with heightened sympathetic and sensory innervation, and displayed a decrease in neuron density and sympathetic innervation. Fumonisin B exposure led to a decrease in galanin-positive and VIP-positive bone neuronal networks in both groups exposed to FB, while in the lower-dose group, there was also a decrease in CART-positive innervation. Conclusion: Prenatal FB exposure significantly influences the neuronal bone network of rats, which is essential for maintaining bone homeostasis. These findings emphasise the necessity for further research to understand the lasting effects and underlying mechanisms of alterations induced by FB.

Within the complex regulatory network of the gastrointestinal tract, enteroendocrine cells play a fundamental role in coordinating digestive processes and maintaining metabolic balance. These cells produce a wide range of hormones that influence secretion, motility, and nutrient utilization, constituting an essential component of gastrointestinal physiology in ruminants. Despite the growing interest in the role of endocrine regulation in digestive system function, comprehensive studies evaluating enteroendocrine cell populations across different segments of the gastrointestinal tract in cattle remain limited. In particular, the organization of these cell populations in key digestive segments such as the abomasum and small intestine requires further investigation to better understand their functional significance. The aim of the present study was to provide a comparative characterization of selected enteroendocrine cell populations in the abomasum and small intestine of young and adult Holstein–Friesian bulls. Tissue samples collected from the abomasum, duodenum, jejunum, and ileum were subjected to histological and immunohistochemical analyses. Chromogranin A (CgA) was used as a general marker of enteroendocrine cells, and the number of cells immunoreactive to CgA as well as to gastrin, secretin, somatostatin (SOM), glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-1 (GLP-1) was quantified in the examined segments of the gastrointestinal tract. All types of immunoreactive cells were counted using a standardized quantitative method based on the assessment of positively stained cells in randomly selected microscopic fields of histological sections. The results revealed clear differences in the number of enteroendocrine cells between the analyzed segments of the gastrointestinal tract as well as between the studied age groups. These findings indicate regional and age-related variation in enteroendocrine cell populations within the gastrointestinal tract and highlight their association with the functional organization of individual segments of the digestive system.