May 19, 2019

Interpretive Summary: Zinc AA and zinc sulfate supplementation on rumen bacterial communities

Interpretive Summary: Zinc AA supplementation alters yearling ram rumen bacterial communities, but zinc sulfate supplementation does not.

By: Anne Wallace

Zinc (Zn) is an essential mineral that is important to animal health and wellbeing. In this paper published in the February 2019 Journal of Animal Science, researchers investigated how two forms of zinc affected the health of rams’ rumen microbiota. They hypothesized that rumen microorganisms would be affected by zinc supplementation, and that more bioavailable forms of zinc (chelated Zn AA complex) would have different effects than less bioavailable forms, e.g. zinc sulfate (ZnSO4).

A total of 44 yearling Targhee rams were fed one of three diets for 84 days: (1) control diet with adequate dietary zinc but without zinc supplementation, (2) Zn AA supplemented diet, or (3) ZnSO4 supplemented diet. Rumen samples were collected at the end of the feeding period for 16S sequencing of microbial rRNA.

Significant differences in rumen microbiota were identified. The rumen microbiota of rams fed Zn AA had reduced Shannon diversity and evenness, compared to the control and ZnSO4 diets. The authors suspect these changes were due to bioavailabity differences between the two forms of zinc. Microbial species richness however was unaffected by diet, with microbial phyla representation largely unchanged and dominated by the phyla Bacteroidetes, Firmicutes and Actinobacteria. Tenericutes were the only phyla found to be significantly reduced in Zn AA fed rams, when compared to ZnSO4 and control.

This study’s results suggest that feed supplementation with bioavailable zinc (Zn AA) may alter the diversity and evenness of rumen microbiota in rams, and potentially decrease Tenericutes, although the significance of these findings is unknown. Larger studies to better elucidate the effects of reduced rumen microbial diversity and evenness and to determine the importance of Tenericutes in rumen microbiota health may be justified.

To view the article, visit the Journal of Animal Science.