Work

Effect of pre-weaning solid-feed intake level on growth performance and intestinal development in yak calves

Year: 2026

Type: article

Abstract: Early-life nutrient supply plays an important role in regulating growth and gastrointestinal development in young ruminants. However, the effects of restricted solid-feed intake on intestinal morphology and the associated gut microbial and metabolic responses in yak calves remain unclear. This study aimed to investigate the effects of different levels of solid-feed intake on growth performance, intestinal development, gut microbiota, and metabolic profiles in yak calves. Twenty-one male yak calves aged 60 ± 3 d were randomly assigned to three groups according to their solid-feed intake levels: ad libitum feeding (AL), 70% of the solid-feed intake of the AL group (IR70), and 40% of the solid-feed intake of the AL group (IR40). All calves received milk replacer, and the solid feed consisted of alfalfa hay and starter concentrate at a 70:30 forage-to-concentrate ratio. The experiment consisted of a 20-d adaptation period followed by a 90-d feeding period. Growth performance and body measurements were recorded throughout the experiment. At the end of the feeding period, five calves from each group were slaughtered for intestinal sampling. Intestinal morphology was evaluated by histological examination, while intestinal microbial communities and metabolic profiles were characterized using 16S rRNA gene sequencing and liquid chromatography–mass spectrometry (LC–MS)-based metabolomics, respectively. The AL group exhibited the greatest final body weight and body size measurements, whereas restricted solid-feed intake reduced growth performance ( P < 0.05). Intestinal weights were generally comparable among groups, although duodenal weight tended to differ ( P = 0.061). Solid-feed restriction markedly altered intestinal morphology in a segment-specific manner. Jejunal villus height was greater in the AL and IR70 groups than in the IR40 group, whereas ileal villus height was greater in AL than in IR70 and IR40. The villus height-to-crypt depth ratio was highest in AL in the ileum, while the duodenum and jejunum exhibited distinct responses to solid-feed restriction. Microbial analysis showed that restriction had relatively limited effects on the jejunal microbiota but markedly altered microbial composition in the ileum and large intestine. In particular, IR40 increased the relative abundance of Actinobacteriota and Corynebacterium in the ileum. Metabolomic analysis further revealed distinct metabolic alterations associated with solid-feed restriction, with differential enrichment of carbohydrate- and amino acid-related metabolic pathways in the ileum and colon. Restricted solid-feed intake during early life reduced growth performance and altered intestinal morphology, microbial composition, and metabolic profiles in yak calves, with effects varying among intestinal segments. These findings indicate that adequate solid-feed supply is important for maintaining coordinated growth and gastrointestinal development during the early-life period of yak calves.

Source: BMC Microbiology

DOI: 10.1186/s12866-026-05572-w