This study investigates the impact of melatonin (MT) treatment at varying concentrations (0, 25, 50, 75, 100 µmol L⁻¹) on the post-harvest quality and shelf life of long green pepper fruits stored under low temperature for 28 days. Every 4 days, pepper fruits were examined for the chilling injury (CI) index, weight loss (WL), respiration rates, firmness, electrolyte leakage (EL), reactive oxygen species (ROS), malondialdehyde (MDA) levels, non-enzymatic antioxidant (NEA) content, antioxidant (AO) enzyme activity (superoxide dismutase (SOD), catalase (CAT), and peroxidases (PODs)), and cellular degrading enzymes (polygalacturonase (PG), pectin methylesterase (PME), phospholipase D (PLD), and lipoxygenase (LOX)). MT-treated samples exhibited delayed and reduced CI stress compared to controls, with higher exogenous MT concentrations (>50 µmol L⁻¹) offering significant (p < 0.05) CI reductions. During storage, WL was notably mitigated by MT treatment in the tested samples compared to control samples. This study also demonstrated that MT-treated pepper fruits effectively decelerated respiration rates and consequently preserved pepper firmness. A higher concentration of MT-treated pepper fruits demonstrated a significantly (p < 0.05) lowered level of ROS and MDA while maintaining membrane stability, as evidenced by reduced EL. MT treatment with increasing concentration increased the levels of glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AsA), dehydroascorbate (DHA), and total phenolic content (TPC) in the pepper fruits compared to control and thus significantly (p < 0.05) suppressed the ROS production (superoxide anion (O₂^•−) and hydrogen peroxide (H₂O₂) radicals) in the pepper fruits. Furthermore, AO enzymes such as SOD, CAT, and POD were also high in the pepper fruits that were treated with higher concentrations of MT (>50 µmol L⁻¹). Additionally, the activities of cellular degrading enzymes (PG, PME, PLD, and LOX), which are linked to senescence and stress-induced physiological disorders, were also effectively regulated by MT-treated (>75 µmol L⁻¹) pepper fruits. Overall, the application of MT at higher concentrations (>75 µmol L⁻¹) demonstrated substantial benefits in preserving the quality and extending the shelf life of pepper fruits during cold storage.

This study examined the supplementation level effects of bamboo charcoal powder including vinegar (BCV) on performance, eggshell quality, alterations of intestinal villi and intestinal pathogenic bacteria populations, in aged laying hens. A total of 200 laying hens (60 weeks of age) were randomly allotted into four treatment groups, with five replicates per treatment and 10 hens per replicate. Hens were fed a basal diet, supplemented with BCV at 0, 0.5, 1.0 or 1.5% level, ad libitum for 12 weeks. Egg production, egg weight, egg mass, feed intake and feed efficiency were not affected by the dietary treatment (p > .05). Damaged egg rate decreased in the hens fed the 1.0 and 1.5% BCV diets during the late feeding stage (69 to 72 weeks of age), and eggshell thickness increased in the 1.5% BCV group (p < .05). In the ileal content, population of Escherichia coli decreased with BCV in the diet, while colony counts of Salmonella spp. were comparatively low with 1.0 and 1.5% BCV (p < .01). Villus height and villus area of duodenum were higher in hens fed with 1.0 and 1.5% diets (p < .01), while villus size of jejunum was higher in hens fed with BCV diets (p < .05). The results of this study demonstrate that a level of 1.0% BCV in a layer’s diet is sufficient for decreasing pathogenic bacteria and stimulating intestinal functions; and that dietary supplementation of BCV at 1.5% can improve eggshell thickness in aged laying hens.

Production Performance, Egg Quality, and Fecal Bacterial Population of Laying Ducks Fed Ration Supplemented by Bamboo Vinegar

This experiment aimed to determine the effects of bamboo charcoal (BC), bamboo vinegar (BV) and their combinations in laying hen diet on performance, egg quality, intestinal bacterial populations and alteration of intestinal villi. A total of 450 Hy-Line Brown hens aged 40 weeks were divided into 9 treatment groups, with 5 replicates per treatment and 10 hens per replicate. They were fed diets with 0% BC and BV (control), 0.5% BC, 1% BC, 0.3% BV, 0.6% BV, 0.5% BC + 0.3% BV (BCV53), 0.5% BC + 0.6% BV (BCV56), 1% BC + 0.3% BV (BCV13) or 1% BC + 0.6% BV (BCV16) from 40 to 56 weeks of age. The overall feed conversion ratio was better in all supplemented groups than in the control (p < .05). Eggshell strength and shell thickness at week 56 were higher in the 0.3% BV, 0.6% BV, BCV56 and BCV16 groups when compared to the control group (p < .05). In the ileal digesta, population of Salmonella spp. decreased in the 0.3% BV, 0.6% BV, BCV56 and BCV16 groups (p < .05) and the population of Lactobacillus spp. increased in the 0.3% BV, 0.6% BV and BCV56 groups (p < .05). Villus height and areas of the duodenum were higher in the groups receiving BV (p < .05), and villus height and areas of jejunum were higher in all groups receiving BV at 0.6% level (p < .05). The present results indicate that feeding of BV alone at 0.3% level was sufficient to improve feed efficiency, eggshell quality, growth of Lactobacillus spp. and function of duodenal villi in laying hens. Supplementation with BV at 0.6% level, either alone or in combination with BC in the diet, had an additional positive effect in stimulating jejunal villi.