Poultry is a major nutritional source providing food for large human populations. Infectious diseases threaten the productivity of poultry flocks and diminish animal welfare. Recent advances in genome editing have significantly contributed to our understanding of various physiological aspects and have helped elucidate the interaction between the chicken host and pathogens. Several chicken lines were generated, including those with Type Ⅰ and Type Ⅲ interferon receptor knockouts, those lacking specific T cell populations, and those missing contributing factors to V(D)J recombination, such as the recombination-activating gene 1 (RAG1). In addition, researchers achieved resistance to the avian influenza virus (AIV) by targeting acidic nuclear phosphoproteins. Finally, reinstating retinoic acid-inducible gene I (RIG-I) and RING finger protein 135 (RNF135) in the chicken revealed new insights into their evolutionary role, particularly during host-pathogen interactions with AIV. This review provides an update about recent achievements in genome editing of chickens, particularly in immunology and disease resistance.

Starch serves as the primary energy source for high-producing dairy ruminants, which include both dairy cows and dairy goats. Optimizing starch digestion is crucial for ensuring high milk production and maintaining animal health. This narrative review summarizes and discusses recent findings concerning the degradability of starch in these species. Dietary starch is classified into three distinct types based on the basis of its degradation characteristics: rumen degradable starch (RDS), which ferments in the rumen; rumen escape starch (RES), which is subsequently digested in the small intestine; and resistant starch (RS), which resists complete digestion and enters the large intestine. This review systematically links feed processing methods, which directly influence starch structure, to their subsequent effects on the gut microbiota composition and host metabolic regulation. Three key insights emerge from this synthesis of literature. First, processing techniques such as steam-flaking critically alter the ratio among the three starch types, thereby shifting the effective site of digestion. Second, the optimal application of RDS differs significantly between dairy cows and dairy goats, primarily because these species exhibit distinct digestive physiologies. Nutritionists must carefully account for these species-specific differences to effectively prevent metabolic disorders. Third, the primary site of starch digestion significantly reshaped the gut microbiota profile. While a proper balance supports beneficial bacteria, excessive RS reduces energy efficiency, whereas an overload of RDS can readily lead to severe rumen acidosis. Therefore, balancing the proportions of RDS, RES, and RS is vital for helping animals effectively manage the elevated energy demands experienced during peak lactation. Future research must focus on developing precise starch management strategies tailored to the specific needs of various ruminant species.

The systematic exploration of novel bioactive compounds with superior functional properties is critical for driving innovations in agriculture, healthcare, and related fields, thereby becoming essential for advancing sustainable biotechnological solutions. Nonprotein amino acids (NPAAs), functional amino acids not incorporated into proteins, exhibit unique physiological activities and provide distinctive advantages in nutritional enhancement, functional product formulation, and food/feed processing. These attributes challenge the conventional perception of proteins as mere nutritional carriers, positioning NPAAs as promising bioproducts for biosynthesis and functional applications in agriculture, food, and medicine. This review summarizes the classification of the available NPAAs based on their synthetic substrates for the first time and then outlines their diverse functional roles. A comprehensive analysis of recent advances in biosynthetic pathways, engineering strategies, and production level demonstrates their primary research progress in the laboratory phase. The further sustainable biomanufacturing of NPAAs is hampered by several challenges, including poorly elucidated biosynthetic mechanisms, limited robustness and low productivity of microbial strains, and difficulties in scaling up production for industrial applications. Addressing these bottlenecks will require innovative strategies and technologies to facilitate the translation of NPAA production from bench to industry. This review offers valuable insights into the potential of NPAAs in the development of next-generation bioproducts of nutrition, immune regulation, antioxidant defense, and intestinal homeostasis maintenance, suggesting a promising direction for microbial production of high-performance bioactive molecules in agricultural synthetic biomanufacturing.

As global demand for milk and meat increases, young ruminants need rapid gut development and sufficient mucosal immunity immediately after birth. However, their growing intestines face oxidative and microbial challenges that can harm long-term performance. This review systematically summarizes recent advances in how host genetics, early nutrition, and emerging microbiota interact to influence intestinal development and mucosal immunity under standard rearing conditions. We explore how the host regulates the gut microbiota, the microbiota's role in maintaining gut integrity, barrier function, development, intestinal cell health, mucosal immunity, and how diet modulates gut microbiota composition in young ruminants. Microbial signals promote increased villus length and better epithelial functions. Conversely, dysbiosis delays gut closure, weakens barrier integrity, and skews immunity toward proinflammatory responses. Feeding strategies such as colostrum timing, milk replacers, and the addition of starter fiber and probiotics can alter microbial communities within days. Nonetheless, challenges remain in standardizing neonatal feeding practices, identifying microbe metabolite indicators of gut health, and integrating precision feeding technologies. By mapping the three-way interaction among host, microbiota, and diet, this review offers a blueprint for neonatal ruminant feeding that enhances both animal welfare and the productivity of future ruminant systems. This review also provides a novel mechanistic integration of host genetics, gut microbiota succession, and dietary interventions in young ruminants, filling the gap of fragmented multi-omics analyses in existing literature and offering targeted insights for optimizing gastrointestinal development and production efficiency.

Circadian rhythms are endogenous oscillations with a period of approximately 24 h. They enable organisms to anticipate and adapt to daily environmental changes, such as light and temperature. As the largest metabolic and motor organ in the body, skeletal muscle plays a decisive role in determining meat production efficiency in ruminants. Skeletal muscle development is largely governed by the proliferation and myogenic differentiation capacity of skeletal muscle satellite cells (SMSCs). More than 2,300 genes in skeletal muscle exhibit circadian oscillatory expression and are extensively involved in myogenesis, transcriptional regulation, and metabolic processes. The rhythmic expression of these genes is modulated by external factors including the photoperiod, feeding behavior, gut microbiota, and physical activity. Disruption of the endogenous circadian timing system can inhibit SMSC proliferation and myogenic differentiation, thereby impairing normal muscle development. Therefore, this review focuses on key management aspects of ruminant production—such as environmental control, nutritional regulation, and exercise management— and systematically elaborates on how these husbandry strategies may influence SMSC fate by modulating the circadian clock, along with the underlying molecular mechanisms.