This study investigates the potential of brewer’s spent grain (BSG) as a cost-effective alternative to soybean meal in the diets of house crickets ( Acheta domesticus ) to enhance sustainable cricket rearing. BSG, a by-product of the brewing industry, was chosen due to its local availability and high protein content (38%). Here, the impacts of varying levels of BSG substitution (0%, 10%, 20% and 30%) on the growth performance, nutrient utilisation, chemical composition, and volatile compound profiles of crickets over a 45-day period was assessed. Crickets were reared under controlled conditions and divided into five groups, each receiving one of the experimental diets. Growth performance parameters, including body weight, average daily gain, and feed conversion ratio, were measured. Chemical analysis of the crickets and their diets was conducted, focusing on protein efficiency ratio, apparent dry matter digestibility (ADMD), and nitrogen retention. Volatile compounds were identified using gas chromatography-mass spectrometry. Crickets fed BSG diets exhibited higher protein deposition and lower fat content compared to those on a commercial diet, suggesting BSG’s potential to improve protein quality while reducing fat accumulation. ADMD was also higher in BSG-fed crickets, likely due to the prebiotic effects of components such as β-glucans and arabinoxylans. Additionally, the inclusion of BSG up to 30% in cricket diets reduced production costs by up to 29% compared to a commercial diet. Volatile compound analysis revealed that crickets fed BSG diets produced different odour profiles, with 2-heptanone, a compound with a fruity aroma, detected only in BSG-fed crickets. These findings suggest that BSG is a viable and sustainable ingredient for cricket feed, offering both economic and nutritional benefits while also influencing the sensory characteristics of crickets. Further research is recommended to optimise BSG inclusion levels and explore its broader applications in insect and animal farming.

Objective: Rearing broilers in high-temperature environments can impair growth performance, affecting the economic efficiency of broiler production. Dietary fiber sources like yam bean pulp (YBP) may mitigate these effects by promoting digestive organ development and gut integrity, enhancing nutrient absorption and growth. This study aimed to evaluate the impact of YBP inclusion on digestive development, gut morphology, nutrient digestibility, serum lipid profiles, and growth performance in broilers raised under high environmental temperatures.Methods: Since YBP has not previously been used in poultry diets, its optimal inclusion level was determined using in vitro digestibility measurements, which identified 4% YBP as the optimal initial inclusion level for further in vivo study. Subsequently, the in vivo study was conducted with 200 one-day-old ROSS broiler chicks, randomly assigned to four dietary treatments (0%, 4%, 8%, and 12% YBP; 5 replicates of 10 birds each), and housed in an open system at an average temperature of 32.1±3.7°C. Digestive traits, nutrient digestibility, serum lipid profiles, and growth performance were assessed over 21 days.Results: Results showed that YBP inclusion (up to 12%) improved gut morphology by increasing villi height and the villi height-to-crypt depth ratio in the duodenum and ileum, alongside dose-dependent improvements in dry matter digestibility. However, crude protein digestibility declined when YBP levels exceeded 8%. Despite these benefits, YBP inclusion did not alleviate heat stress effects on growth performance, digestive organ development, or serum lipid profiles, even at the highest inclusion level.Conclusion: Dietary YBP can enhance gut morphology and nutrient digestibility in broilers from day 1 to 21, with optimal inclusion levels not exceeding 8%. However, its use does not mitigate the negative effects of heat stress on broiler growth in high-temperature environments.

Objective: Rising poultry feed costs and shortages in Southeast Asia, particularly in Thailand, underscore the need for sustainable alternatives. This study evaluated shrimp meal (SM), a protein-rich by-product, and yam bean (YB), an underutilized energy-rich root crop, as promising alternative feed ingredients for laying hens.Methods: An in vitro analysis was conducted to determine the chemical composition and digestibility of diets containing SM and varying levels of YB. An 8-week in vivo trial was conducted using 90 ISA-Brown hens (25-week-old), divided into nine dietary groups: one control and eight treatment groups with 10% or 15% SM combined with 0%, 3%, 6%, and 9% YB. Laying performance, egg quality and composition, and nitrogen (N) retention were assessed.Results: SM was rich in protein while YB contained high N-free extracts and gross energy, supporting their use as alternative protein and energy sources, respectively. The inclusion of SM and YB had no negative effect on in vitro dry matter or protein digestibility. In vivo, combined inclusion of up to 15% SM and 9% YB did not adversely affect laying performance, egg quality, nutrient composition, or N retention compared to the control. A main effect analysis revealed that SM enhanced yolk color, eggshell weight, and eggshell thickness (p<0.05), while reducing egg fat content (p<0.05). Although higher levels of SM were independently associated with reduced hen-day egg production and egg mass, these effects were mitigated when SM was combined with YB, resulting in no differences from the control group at the highest inclusion levels (15% SM and 9% YB).Conclusion: The SM and YB are viable, eco-friendly alternatives to conventional poultry feed ingredients. Their combined inclusion, up to 15% SM and 9% YB, is recommended to maintain laying performance and egg quality while promoting sustainable feeding practices through the utilization of processing by-product and underutilized local crops.