Table 2.

Effects of weaning stress on intestinal development and flora in young ruminants.

Animal	Conclusion	References
Lambs	Weaning stress can cause changes in the immune system of lambs.	(1)
Lambs	Early weaning significantly increases the bacterial diversity in the ileum of lambs. Simultaneously, it increases the expression of TLRs and tight junction protein genes.	(68)
Lambs	Early weaning leads to decreased growth performance and immunity of lambs, impaired intestinal morphology, and disrupted intestinal microecological balance.	(69)
Goats	Early weaning can cause intestinal damage, leading to a series of long-term symptoms such as inflammation, malabsorption and diarrhea.	(70)
Holstein Calves	Weaning stress can reduce the feed intake of calves, destroy the small intestine structure of calves, and affect their production capacity in adulthood.	(71)
Young Goats	Mammalian weaning can lead to intestinal dysfunction and intestinal microbial disorders.	(72)