Crossbreeding indigenous goats with exotic meat breeds is a common strategy to improve production performance, but its combined effects on growth and reproductive traits and the potential contribution of the gut microbiota have not been systematically evaluated in Chinese goat populations. This study used high-prolific Jining Grey (JJ) does mated with Nubian (N) bucks to establish three genetic groups: purebred Jining Grey (JJ), F1 Nubian × Jining Grey (NJ), and backcross offspring (Nubian × (Nubian × Jining Grey); NJJ). Body weight from birth to 12 months and average daily gain were recorded, reproductive traits (lambing rate, litter size, and kid survival) of primiparous and multiparous does were analyzed, and litter total birth weight and weaning weight per lambing were calculated. Fecal samples from JJ and NJJ goats were subjected to 16S rRNA gene sequencing to characterize gut bacterial communities. Body weight differed significantly among the three genetic groups at all ages (p 0.05), whereas litter total birth weight and weaning weight were higher in crossbred than in purebred does (p 0.05), but community structure was significantly distinct (PERMANOVA, p = 0.001), characterized by an increased Firmicutes-to-Bacteroidota ratio and shifts in several energy metabolism-related genera (p < 0.05). In conclusion, introgression of Nubian genetics into Jining Grey goats improves growth performance and litter weight while maintaining high prolificacy; these improvements are accompanied by a restructured gut microbiota that is associated with these growth patterns.
Cao et al. (Tue,) studied this question.