Fecha de publicación: -- Fuente: PubMed "agrofood sustainability" Front Vet Sci. 2026 Aug 14;13:1868627. doi: 10.3389/fvets.2026.1868627. eCollection 2026.ABSTRACTTannins are plant-derived compounds that can improve animal health by modulating gut health, and reducing the incidence of diarrhea, also influencing the emissions of nitrous oxide and ammonia in animal manure. This study evaluated the effects of hydrolysable tannins from sweet chestnut (Castanea sativa Mill.) on growth performance, intestinal health, clinical insights, and ammonia and nitrous oxide emissions from manure in Holstein calves. Twenty-four preweaning female Holstein calves were randomly assigned to two experimental groups according to body weight (BW; 39.37 ± 3.42 kg) and age (3.83 days-of-life) for a 56-day trial, a control group (CTRL) fed with milk replacer, and a treatment group (VITAN) fed milk replacer supplemented with 10 g/day of chestnut tannins. Body weight and rectal temperature were recorded on d 0, 7, 14, 21, 28, 35, 42, 49, 56. Milk intake, hay intake, average daily feed intake of solid feed, average daily gain and fecal and clinical scores were daily recorded. Fecal samples were collected on d0, d28, and d56 to determine total bacterial counts, coliforms and Lactobacillus spp. Blood samples were collected on d0 and d56 for metabolic profile. After the in vivo trial, manure (feces, urine and straw) of CTRL and VITAN were collected from individual pens, and pooled into six dynamic-chambers (3/treatment) to simulate a 49-day manure storage period. Emissions of NH3 and N₂O (mg/g/h) were monitored by Gasmet-GT5000, and chemicals analysis were performed on d0 and d49. VITAN group showed a reduction of solid average daily feed intake (p < 0.01) without compromising growth performance. The VITAN group showed significantly higher frequency of normal fecal consistency (FS0-1; p < 0.01) and improved fecal consistency. Tannin supplementation appeared to influence manure emissions, lower NH₃ emissions were observed on d0 and 1, and lower N₂O emissions on d1, 2, and 5 in VITAN group. Manure temperature was higher in VITAN group. Chemical analysis also showed lower total solids, ash, and total carbon in VITAN manure on d49. These results should be considered preliminary and require confirmation in studies including biological replicates and appropriate statistical evaluation. In conclusion, tannins might represent a promising nutritional strategy with potential effects on health-related parameters and manure gaseous emissions under the conditions evaluated in this study.PMID:42666831 | PMC:PMC13523563 | DOI:10.3389/fvets.2026.1868627