Effects of early weaning on the development of gastrointestinal tract, rumen microbiota and host gene regulation in goat kids

Early weaning (EW) could shorten ewes’ reproductive cycles and promote rumen development in goat kids. During the transition from breastfeeding to a solid diet, significant changes occur in rumen development. However, few studies have focused on goat kids, which are more sensitive to stress than lambs. Here, we assessed the effects of EW on hematological parameters, rumen microbiota, and host gene expression in Chengdu Brown goat kids. The EW kids (weaned at day 42) did not display differences in growth performance and blood biochemical parameters compared to the control group (Control group, CON). However, these younger kids had higher levels of butyric acid than the CON group. EW altered the composition of rumen microbiota and host gene expression, with genes such as RNF183, SCD, SAMD8, MME, and TULP1 being up-regulated, all of which are related to protein generation or binding. Conversely, ADRA1A, GLI1, GRIA4, and CACNA1B were down-regulated, involving neuroactive ligand-receptor interaction, MAPK, and cAMP signaling pathways. Furthermore, Christensenellaceae_R_7_group and Prevotella showed significant correlations with the expressions of differently expressed genes DMGDH and FABP. These results could be beneficial to understanding the interactions among indicators in goat kids around weaning and facilitating management of weaning practices in intensive production systems.