Interpretive Summary: Effect of storage of wet brewer’s grains with incremental levels of salt on apparent total tract nutrient digestibility and purine derivative excretion in dairy heifers
By Anne Zinn
A study recently published in the Journal of Animal Science aimed to evaluate apparent total tract nutrient digestibility and purine derivative excretion in dairy heifers limit-fed diets containing wet brewer’s grains treated with salt. The high moisture content of wet brewer’s grains is associated with high costs of transportation and a short storage shelf-life; while different preservation strategies have been examined to increase the length of storage, most of these conservation techniques have not be evaluated for their effect on nutrient digestibility and utilization when fed to animals. Based on this information and examined results from recent studies, the research team from the University of New Hampshire hypothesized that treating and storing wet brewer’s grains with salt would enhance dietary nutrient digestibility and improve microbial crude protein synthesis.
Results of the present study demonstrated that treating and storing wet brewer’s grains with incremental levels of salt before being included in diets results in a decreased mold growth and a decreased loss in wet brewer’s grains, which suggests that the salt treatment would be efficient for wet brewer’s grains preservation. In addition, feeding wet brewer’s grains treated with intermediate salt levels resulted in increased total purine derivative, which would suggest an improvement in microbial protein synthesis. It is important to note, however, that feeding diets containing wet brewer’s grains treated with high levels of salt resulted in a decreased nutrient digestibility, which could limit the growth performance of animals if maintained on the diets for a long period of time. It was observed that the growth performance of heifers seemed to improve as salt inclusion was increased, observations that would need to be examined in larger feeding studies.
The full paper can be found on the Journal of Animal Science website.