Rapeseed is the second largest plant protein resource in the world with an ideal profile of essential amino acids. Rapeseed meal (RSM) is one of the by-products of rapeseed oil extraction. Due to the anti-nutritional components (glucosinolates and fiber) and poor palatability, RSM is limited in livestock diets. Recently, how to decrease the anti-nutritional factors and improve the nutritional value of RSM has become a hot topic. Therefore, the major components of RSM have been reviewed with emphasis on the methods to improve the nutritional value of RSM as well as the application of RSM in pig diets.

The current study aimed to investigate the evolution of gut microbiota and its influencing factors for NXP in youth. The results showed that Shannon index increased from d 21 to d 28 whereas the ACE index increased from d 21 until d 60. Firmicutes, mainly Lactobacillus dominated on d 21. The Bacteroides and Spirochetes showed highest relative abundance on d 28. Fiber-degrading bacteria, mainly Prevotellaceae, Lachnospiraceae, Ruminococcaceae, Muribaculaceae, and Oscillospiraceae_UCG−002, dominated the microbial communities at d 28 and d 35. The microbial communities at d 60 and d 75 contained more Clostridium_sensu_stricto_1, Terrisporobacter and Oscillospiraceae_UCG−005 than other ages, which had significantly positive correlations with acetate and total SCFAs concentration. In conclusion, the evolution of gut microbiota was mainly adapted to the change of dietary factors during NXP growth. The response of fiber-degrading bacteria at different stages may help NXP better adapt to plant-derived feeds.