Zinc AA supplementation alters yearling ram rumen bacterial communities but zinc sulfate supplementation does not1

Abstract

Despite the body of research into Zn for human and animal health and productivity, very little work has been done to discern whether this benefit is exerted solely on the host organism, or whether there is some effect of dietary Zn upon the gastrointestinal microbiota, particularly in ruminants. We hypothesized that (i) supplementation with Zn would alter the rumen bacterial community in yearling rams, but that (ii) supplementation with either inorganically sourced ZnSO 4 , or a chelated Zn AA complex, which was more bioavailable, would affect the rumen bacterial community differently. Sixteen purebred Targhee yearling rams were utilized in an 84-d completely randomized design, and allocated to one of three pelleted dietary treatments: control diet without fortified Zn (~1 × NRC), a diet fortified with a Zn AA complex (~2 × NRC), and a diet fortified with ZnSO 4 (~2 × NRC). Rumen bacterial community was assessed using Illumina MiSeq of the V4 to V6 region of the 16S rRNA gene. One hundred and eleven OTUs were found with > 1% abundance across all samples. The genera Prevotella, Solobacterium, Ruminococcus, Butyrivibrio, Olsenella, Atopobium, and the candidate genus Saccharimonas were abundant in all samples. Total rumen bacterial evenness and diversity in rams were reduced by supplementation with a Zn AA complex, but not in rams supplemented with an equal concentration of ZnSO 4 , likely due to differences in bioavailability between organic and inorganically sourced supplement formulations. A number of bacterial genera were altered by Zn supplementation, but only the phylum Tenericutes was significantly reduced by ZnSO 4 supplementation, suggesting that either Zn supplementation formulation could be utilized without causing a high-level shift in the rumen bacterial community which could have negative consequences for digestion and animal health.

Dietary zinc source impacts intestinal morphology and oxidative stress in young broilers

“…To our knowledge, no literature is available about the effect of supplementation of different zinc sources on the microbiota composition in broilers. A study conducted by Ishaq et al ( 2019 ) in yearling rams revealed that supplementation of ZnAA supplementation alters bacterial communities compared to the supplementation of ZnS. In the present study, the microbial composition in the ileum did not differ in bacterial diversity or richness but does show a trend towards a changing microbial composition.…”

Impact of Zinc and/or Herbal Mixture on Ruminal Fermentation, Microbiota, and Histopathology in Lambs

“…The Zn, Herbs and Zn+Herbs diets did not significantly affect the parameters of fermentation or the protozoal populations in the lambs. This finding probably indicates relatively low contents of antimethanogenic phytochemical substances or the adaptation of the microbiota to both herbal ( 43 , 44 ) and/or zinc ( 45 ) diets. Herbal diets can influence the ruminal microbiome, the kinetics of fermentation and the response and adaptation to antimethanogenic compounds and diets that sometimes lead to the inconsistent efficacies of phytochemical substances ( 46 ).…”

The Effect of Zinc and/or Herbal Nutraceuticals on Rumen Fermentation, Microbiota and Histopathology in Lambs

“…The relative abundance of the cellulolytic bacteria R. albus, amylolytic S. bovis and polysaccharide-degrading B. proteoclasticus increased and the abundance of cellulolytic R. avefaciens decreased in the Zn group compared to the other diet groups. Certain bacterial species were probably enriched by Zn supplementation in the diet at the expense of total bacterial abundance [44]. These changes in total bacteria and relative abundance of some bacteria in the Zn groups were not accompanied by changes in VFAs in rumen fermentation in vivo.…”

“…No dietary effects (i.e., Zn, Herbs, and Zn+Herbs) were found in the present study on either fermentation parameters or protozoal populations in lambs. This probably points to the relatively low content of the anti-methanogenic phytochemical substances or the adaptation of microbiota to both herbal [42,43] and/or zinc diets [44]. Herbal diets can in uence the rumen microbiome, the kinetics of fermentation and the response and adaptation to anti-methanogenic compounds and diets that lead sometimes to the inconsistent e cacy of phytochemical substances [45].…”

“…However, the decrease in relative abundance of cellulolytic bacteria (i.e., F. succinogenes and R. avefaciens) in the Zn or Zn+Herbs groups, respectively, probably also lowered the substrate digestibility in vitro in these groups (Table 4). It seems that the rumen microbiota has its requirements for zinc supplementation which does not cause a major shift in the rumen bacterial community and is without negative consequences for digestion and animal health [44]. Additionally, bacterial phylotypes are known to contribute to differences in feed e ciency and host productivity and can or needn't depend on diets [53].…”