Modern piglet feeds without antibiotics require rethinking in many aspects, including the issue of high lactose levels used previously.
The value of lactose in piglet feeds has never been questioned as much as in the past decade when antibiotic-free diets were designed. As it happens, lactose is a mild laxative, and any form of loose fecal material was and is still perceived as a failure of the new feeds. Interestingly, when antibiotics were used routinely, producers and veterinarians were able to discern and discard osmotic diarrhea due to the laxative nature of highly complex starter feeds. Lamentably, such knowledge or toleration is no longer encountered in modern piglet feeding enterprises. As such, lactose, along with several other ingredients with similar laxative activity, have been reduced to the point that some high-quality feeds no longer contain any!