During weaning piglets are susceptible to enteric diseases causing diarrhea and reduced growth performance, a problem which is often dealt with by formulating feed with antibiotics and additives like blood plasma. However, public concerns with antibiotic use, and human safety concerns for the use of blood plasma have led to the study of alternative additions for the weaning diets. Pharmaceutical levels of zinc oxide can reduce the occurrence of diarrhea, but have a possible environmental impact from waste. Weaning gastric pH is higher than grow-finish gastric pH as they transition to solid food, so organic acids can lower the pH and reduce intestinal pathogens. Probiotics are microorganisms that are thought to benefit gastointestinal health, although studies showing no benefit exist, that may be due to dose, strain, diet, and facility sanitation. Prebiotics can also aid the microbiota in the intestines, and can be obtained from fermentable carbohydrates like wheat bran or sugar beet pulp, or from treating the feed with enzymes. Antibodies can reduce pathogen-caused diarrhea, but it is the most useful if the pathogen is known rather than just a general treatment. Sow milk is higher in nucleotides than starter diets, so supplementation may be able to help. However, responses vary, probably due to the presence of other active compounds in nucleotide containing products. Finally, reducing the crude protein can help reduce diarrhea in piglets, but amino acid supplementation should be added to meet nutritional requirements. As antibiotics and blood plasma come under scrutiny, it is useful to have alternative feed additives to help piglet intestines adjust to solid feed.