Is the feed about to expire?

Today, I had nothing to chat with the driver who pulled the goods and found that what I couldn't understand was that a customer had been specializing in producing materials for several days and asked the reason. Once, the feeding effect of the rest of the chicken was better than that of the new material. The formula has not changed, and the raw materials have not changed significantly. Has anyone ever experienced anything like this? It is possible, but it should be very accidental, and it is estimated that it has something to do with the "post-ripening" in the process of storage after feed production. Such a thing is very strange. -- We have had this kind of thing several times, and customers always report that the quality of the previous batch is good, and we can't find any reason: good feed = raw material + formula + process. I think it's due to problems in the processing process, or high moisture. If you use too many materials, it will cause psychological problems, and there will be in-depth investigation.