Effect of intravenously injected zinc on tissue zinc and metallothionein gene expression of broilers

Abstract

1. The effect of intravenously injected zinc (Zn) on tissue Zn concentrations and pancreas metallothionein (MT) gene expression in broilers was investigated to detect differences in the tissue utilisation of Zn from different Zn sources. 2. A total of 432 male chickens were randomly allotted on d 22 post-hatch to one of nine treatments in a completely randomised design. Chickens were injected with either a 0.9% (w/v) NaCl solution (control) or a saline solution supplemented with Zn sulphate or one of three organic Zn chelates with weak (Zn-AA W), moderate (Zn-Pro M) or strong (Zn-Pro S) chelation strengths at two injected Zn dosages calculated according to two Zn absorbability levels (6 and 12%). 3. Bone and pancreas Zn concentrations, pancreas MT mRNA levels and MT concentrations increased on d 6 and 12 after Zn injections as the injected Zn dosages increased. Chickens injected with the Zn-Pro S had lower bone Zn concentration than those injected with the Zn-Pro M or Zn-AA W on d 6 after injections. However, no differences among Zn sources were observed in bone Zn concentration on d 12 after injections, pancreas Zn concentrations, pancreas MT mRNA levels and MT concentrations on both d 6 and d 12 after injections. 4. It was concluded that the injected Zn-Pro S was the least favourable for bone Zn utilisation of broilers. The pancreas Zn concentration and pancreas MT gene expressions might not be sensitive enough to detect differences in the tissue utilisation of injected Zn in broilers between organic and inorganic Zn sources or among organic Zn sources.

Effect of dietary zinc pectin oligosaccharides chelate on growth performance, enzyme activities, Zn accumulation, metallothionein concentration, and gene expression of Zn transporters in broiler chickens1

“…This result indicated that replacement of ZnSO 4 with Zn-POS would stimulate Zn absorption. Similar results were reported in pancreas of chicks fed with diets supplemented with ZnSO 4 (Huang et al, 2007(Huang et al, , 2009Shen et al, 2013), demonstrating that Zn-POS stimulates Zn absorption. Like the transporter MT, ZnT-1, and ZnT-2 mRNA levels in pancreas were also linearly and quadratically increased in the broilers fed diets with 600 or 800 mg Zn-POS supplementation.…”

“…The present data showed that replacing partial of ZnSO 4 with Zn-POS (800 mg/kg) in the equal Zn level in the diet linearly and quadratically enriched gene expression of MT in pancreas of broilers. Because increasing Zn concentration induced the gene expression of MT in pancreas that has been observed in chicks fed with diets supplemented with ZnSO 4 (Huang et al, 2007(Huang et al, , 2009Shen et al, 2013), the increased enrichment of MT expression in pancreases could be due to the increased availability of Zn in pancreas of broilers fed diets with Zn-POS. This result indicated that replacement of ZnSO 4 with Zn-POS would stimulate Zn absorption.…”

Effect of pectin oligosaccharides and zinc chelate on growth performance, zinc status, antioxidant ability, intestinal morphology and short‐chain fatty acids in broilers

“…Furthermore, our results indicated that the metabolic utilization of Zn from Zn-POS is different from ZnSO 4 according to MT concentrations in the pancreas of broiler chickens, which was similar to the findings of Sandoval et al, (1998) who reported that supplementation of broilers with Zn acetate improved MT concentrations in the pancreas compared with the chicks fed with Zn oxide. Although following researches conducted by Huang et al (2007) and Shen et al (2013) demonstrated that there were no differences of MT concentrations in the pancreas of broilers among Zn sources, they reported that the pancreatic MT concentrations linearly increased the response to higher dietary Zn supplemental level. Therefore, we can hypothesize that addition of POS or Zn-POS in the diets lowered Zn accumulation in the pancreas but increased the utilization of Zn resulting in higher MT concentrations in the pancreas of broilers.…”

Effect of in ovo zinc injection on the embryonic development, tissue zinc contents, antioxidation, and related gene expressions of broiler breeder eggs

“…It plays a protective role in antioxidant responses by scavenging free radicals, particularly the hydroxyl radical (Ruttkay-Nedecky et al 2013). It was found that tissue MT was positively related to dietary Zn intake in chicks (Huang et al 2007(Huang et al , 2009(Huang et al , 2013Liu et al 2011Liu et al , 2013Liu et al , 2015Liao et al 2013;Shen et al 2013;Suo et al 2015).…”

“…Zinc plays an essential role in a wide variety of biochemical processes (Vallee and Auld 1990), and it acts as an antioxidant supplement for protecting poultry against oxidative damage. Dietary Zn supplementation or intravenous Zn injection could enhance expression levels of metallothionein (MT) and copper-and Zn-containing superoxide dismutase (CuZnSOD) as free radical scavengers in tissues of broilers (Huang et al 2007(Huang et al , 2009(Huang et al , 2013Liu et al 2011Liu et al , 2013Liu et al , 2015Liao et al 2013;Shen et al 2013;Suo et al 2015). Zinc deficiency in maternal purified or semi-purified diets of laying breeder hens resulted in a decreased hatchability, abnormal embryonic development, and poor growth performance of offspring birds, whereas maternal dietary Zn supplementation could eliminate these negative effects (Kienholz 1961;Zhu 2016;Zhu et al 2017).…”