Piglet mortality and morbidity in the farrowing and nursery stages have shown little, if any, improvement in the past 10 years. Losses can be contributed to poor feed conversion, cost of treatments, and early weaning. Evidence shows that piglets can grow 70% faster on a liquid diet, which implies that sow milk production is not enough to sustain piglets at an older age. All milk-replacer contraptions must be cleaned and sanitized at regular intervals to minimize bacterial growth. This is why many milk replacements have been acidified; it helps to reduce bacterial growth.

Studies have shown that 18 day old pigs grow 2.3 times faster on milk replacement than pigs weaned straight to the nursery or left to suckle. These pigs gained more body fat, 10% more protein, and have a more developed small intestine. The difference is also significant in hotter temperatures.

Energy is the most difficult aspect of milk replacement. Much of the energy in sow milk comes from fat calories. Feed conversion is better in piglets fed high fat milk replacements than low fat replacements. A negative aspect of high fat replacement is an increase of amino acid oxidation (ultimately they excrete more). This results in less muscle deposition than piglets fed low fat replacement (most likely due to the low-fat feed piglets consuming more feed). Corn syrup solids (CSS) fed as a carbohydrate replacement to piglets had no effect on growth performance, feed conversion, or average daily feed intake. It can be a quality alternative to lactose (the main milk protein) in liquid milk replacement diets.