Calves fed milk replacer supplemented with Mannan-Oligosaccharides (MOS) or Fructo-Oligosaccharides (FOS) gained about the same amount of weight as non-supplemented calves, according to research published in the October 2008 issue of The Professional Animal Scientist.

The study summarizes the results of three trials conducted with calves less than two months old.

In the first two trials, researchers fed 0 grams, 4 grams or 8 grams of FOS per day. They added FOS to a 20-percent crude protein, 20-percent fat milk replacer. In the third trial, calves received a 26-percent protein, 17-percent fat milk replacer supplemented with either 0 grams or 6 grams of MOS per day.

The dietary additives did not improve calf weight gain, feed intake or feed efficiency in any of the trials. The addition of FOS or MOS also did not reduce the number of days of calf scours.