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

Abstract

Zinc is an essential nutritional trace element for all forms of life as it plays an important role in numerous biological processes. In poultry, zinc is provided by in-feed supplementation, mainly as zinc oxide or zinc sulfate. Alternatively zinc can be supplemented as organic sources, which are characterized by using an organic ligand that may be an amino acid, peptide, or protein to bind zinc and have a higher bioavailability than inorganic zinc sources. There are limited number of studies directly comparing the effects of inorganic vs. organic zinc sources on performance and intestinal health in broilers. Therefore, a digestibility and a performance study were conducted to evaluate and compare the effect of an amino acid-complexed zinc source vs. an inorganic zinc source on intestinal health. The experiment consisted of 2 treatments: either a zinc amino acid complex or zinc sulfate was added to a wheat–rye based diet at 60 ppm Zn, with 10 replicates (34 broilers per pen) per treatment. Effects on performance, intestinal morphology, microbiota composition, and oxidative stress were measured. Supplementing zinc amino acid complexes improved the zinc digestibility coefficient as compared to supplementation with zinc sulfate. Broilers supplemented with zinc amino acid complexes had a significantly lower feed conversion ratio in the starter phase compared to birds supplemented with zinc sulfate . A significantly higher villus length was observed in broilers supplemented with zinc amino acid complexes at days 10 and 28. Supplementation with zinc amino acid complexes resulted in a decreased abundance of several genera belonging to the phylum of Proteobacteria. Plasma malondialdehyde levels and glutathione peroxidase activity showed an improved oxidative status in broilers supplemented with zinc amino acid complexes. In conclusion, zinc supplied in feed as amino acid complex is more readily absorbed, potentially conferring a protective effect on villus epithelial cells in the starter phase.

Effects of Zinc Source and Enzyme Addition on the Fecal Microbiota of Dogs

“…The phylum Proteobacteria and its genus Parasutterella (class Gammaproteobacteria) were identified as markers of inorganic zinc supplementation. This agrees with a study in broilers, in which inorganic zinc (zinc oxide) promoted an increase of several genera belonging to the phylum Proteobacteria compared with organic zinc (amino acid chelate; De Grande et al, 2020 ). Although Proteobacteria are the third or fourth most abundant phylum in the gut of healthy dogs ( Suchodolski, 2016 ; Jha et al, 2020 ), a significant increase of this phylum was associated with dysbiosis by either infectious ( Park et al, 2019 ) or idiopathic inflammatory diseases ( Guard and Suchodolski, 2016 ).…”

“…Also, it is possible that for being more bioavailable, the absorption of zinc proteinate may be higher in the small bowel, hindering it from reaching the colon to be used by bacteria. Indeed, this idea is supported by a study by De Grande et al (2020) , which reported a lower excretion of zinc in broilers fed a diet supplemented with organic zinc (amino acid chelate) in comparison with zinc sulfate.…”

Recent Advances in Understanding the Influence of Zinc, Copper, and Manganese on the Gastrointestinal Environment of Pigs and Poultry

“…As Zn is an essential mineral for many bacteria, the lower diversity and expansion of specific taxonomic groups indicates that those bacteria that can successfully compete for limited Zn or survive under Zn-limiting conditions are supported, but a reduction in diversity and expansion of the identified taxonomic groups have been associated with poorer gut health [ 34 ]. In a recent study, a Zn amino acid complex added to a wheat–rye based diet (at 60 mg/kg Zn) of broiler chickens increased Zn digestibility and villus length:crypt depth ratio, reduced abundance of some genera within the Proteobacteria phylum and oxidative stress, and improved starter phase feed conversion ratio compared to an equivalent amount of dietary Zn from Zn sulphate [ 35 ]. Additionally, in a necrotic enteritis broiler chicken challenge model, dietary Zn supplementation (90 mg/kg Zn) reduced NE lesions and mortality, as well as jejunal toll-like receptor 2 and ZnT5 expression [ 36 ].…”

Bioavailability of Methionine-Coated Zinc Nanoparticles as a Dietary Supplement Leads to Improved Performance and Bone Strength in Broiler Chicken Production

“…Amino acid chelated forms of zinc are commonly reported to enhance the bioavailability of zinc as these provide considerable protection from formation of indigestible complexes with phytic acid [17]. Recent research has suggested there is also potential for these forms of zinc in terms of gut health and development [18]. Zinc oxide nanoparticles are typically formed via one of two synthetic routes: a vapour phase reaction between zinc metal vapour and oxygen or a co-precipitation reaction between a zinc metal salt and base [19].…”