This study explored the effects of high-density rearing of pregnant ewes on the intestinal microbiota of their offspring. A total of 40 small-tailed Han sheep were distributed into two groups randomly including the high-density group (1 sheep/m²) and the control/ low-density group (1 sheep/2m²). Fecal samples from ewes and offspring were collected for high-throughput sequencing and multiple-significance analysis. We uncovered the response of gut microbiota in ewes and offspring to different rearing densities. The number of potentially harmful bacteria (Ralstonia pickettii, Ruegeria, Rhodobacteraceae, etc.) was increased in high-density groups, while the abundance of several probiotics (Oscillibacter, Akkermansia, Ruminococcaceae-UCG-010, etc.) was found significantly lesser than that of the control group (P<0.05). In addition, gut microbiota in the high-density groups exhibited more variability with age, indicating that an increase in the housing density has a significant correlation. Taken together, improper increase in the rearing density of pregnant sheep can harm themselves and their offspring, which not only fails to improve economic benefits but also produces harmful effects. This study may provide new ideas for healthy and sustainable sheep reproduction and farming.

To Cite This Article: Wei M, Han Z, Lu S, Gao Q, Liu J, Yang Y, Yang J, Almutairi MH, Almutairi BO, Lv S and Yang S, 2025. Effect of high-density rearing of pregnant ewes on the intestinal microbiota of their offsprings. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.007