This study evaluated the effects of dietary yeast culture (YC) supplementation on rumen microbiota and lactation performance in dairy goats. Twenty mid-lactation dairy goats were selected and divided into two groups: the control (CON) group was fed a basal diet; the YC group was supplemented with 10 g of YC in 1 kg of basal diet. The administration of YC was associated with a significant increase in dry matter intake, milk yield, milk protein yield, and milk lactose yield in dairy goats (P < 0.05). Additionally, serum total protein, albumin, creatinine, glucose, superoxide dismutase, and catalase levels were increased (P < 0.05). Furthermore, there was an increase in rumen pH and NH3-N levels (P < 0.05), while volatile fatty acid levels were observed to decrease (P < 0.05). The study found no significant difference in the α-diversity of bacteria and fungi between the YC and CON groups (P > 0.05). However, 15 bacterial genera and 13 fungal genera were upregulated (P < 0.05), while 4 bacterial genera and 11 fungal genera were downregulated (P < 0.05) in the YC group. The relative abundance of pathogenic fungi Dipodascus and Gibberella decreased (P < 0.05). Correlation analysis revealed that the bacterial genera were not significantly correlated with lactation performance (P > 0.05), whereas fungal genera Dipodascus and Gibberella were significantly (P < 0.05) correlated with lactation performance. In conclusion, the study demonstrated that YC can influence the rumen microbial composition, reduce the abundance of harmful fungi in the rumen, and improve lactation performance in dairy goats, suggesting that the addition of YC to dairy goat diets has good application prospects.

Intra-uterine growth-retarded (IUGR) neonates have shown an impairment of postnatal intestinal development and function. We hypothesised that the immune function of IUGR neonates might be affected by increased nutrient intake (NI) during the suckling period. Therefore, we investigated the effects of high NI (HNI) on the growth performance, intestinal morphology and immunological response of IUGR and normal-birth weight (NBW) piglets. A total of twelve pairs of IUGR and NBW piglets (7 d old) were randomly assigned to two different nutrient-level formula milk groups. After 21 d of rearing, growth performance, the composition of peripheral leucocytes, serum cytokines and intestinal innate immune-related genes involved in the Toll-like receptor (TLR)-4–myeloid differentiation factor 88–NF-κB pathway were determined. The results indicated that IUGR decreased the average daily DM intake (ADMI) and the average daily growth (ADG). However, the ADMI and ADG were increased by HNI, irrespective of body weight. Likewise, serum cytokines (TNF-α and IL-1β) and ileal gene expressions (TLR-4, TLR-9, TRAF-6 and IL-1β) were lower in IUGR piglets, whereas HNI significantly increased blood lymphocyte percentage and serum IL-10 concentrations, but decreased neutrophil percentage, serum IL-1β concentrations and ileal gene expressions (NF-κB and IL-1β). Furthermore, IUGR piglets with HNI exhibited lower serum concentrations of TNF-α and IL-1β than NBW piglets, and these alterations in the immune traits of IUGR piglets receiving HNI were accompanied by decreasing ileal gene expressions of TLR-4, TLR-9, NF-κB and IL-1β that are related to innate immunity. In conclusion, the present findings suggest that increased NI during the suckling period impaired the immune function of neonatal piglets with IUGR.