Effects of Zinc Glycinate on Growth Performance, Serum Biochemical Indexes, and Intestinal Morphology of Yellow Feather Broilers

Abstract

The purpose of this study was to investigate the effects of zinc glycinate (Gly-Zn) on growth performance, serum biochemical index, intestinal morphology, and hepatic metallothionein (MT) mRNA expression in the liver of yellow feather broilers. A total of 540 18-day-old yellow feather broilers were randomly divided into three groups: control group (basal diet), ZnSO4 group (basal diet plus 60 mg Zn/kg from ZnSO4), and Gly-Zn group (basal diet plus 60 mg Zn/kg from zinc glycinate). Each treatment group had 6 replicates with 30 birds in each replicate. The experiment lasted for 42 days (18 to 59 days of age). The results showed that Gly-Zn supplementation significantly improved the average daily gain (ADG) and average daily feed intake (ADFI) of broilers during 18 to 39 days of age compared with that in the control group (P < 0.05) but not different from the ZnSO4 group. The Gly-Zn group had higher glutathione peroxidase (GSH-Px) (P < 0.05) and lower malondialdehyde (MDA) concentrations than the broilers in the control and ZnSO4 group. It was also observed that zinc content in the tibia of Gly-Zn group broilers was higher than the control and ZnSO4 group (P < 0.05). The results of intestinal morphology parameters showed that the Gly-Zn group significantly increased the villus height in duodenum and jejunum (P < 0.05) and decreased crypt depth in duodenum and ileum compared to the control group. However, there were no significant differences between the Gly-Zn group and ZnSO4 group in duodenum and ileum regarding intestinal morphology parameters. The Gly-Zn group significantly increased mRNA expression of MT in the liver than both control and ZnSO4 groups (P < 0.05). Collectively, the results indicated that supplementing 60 mg Zn/kg through zinc glycinate improved growth performance and serum indexes as well as intestinal morphology of yellow feather broilers. It also regulates MT gene expression more effectively than the ZnSO4 group at the transcriptional level.

Effects of dietary valine chelated zinc supplementation on growth performance, antioxidant capacity, immunity, and intestine health in weaned piglets

“…This result was partially consistent with Diao et al [7], who observed that 100 mg/kg ZnVal increased villus height and the ratio of villus height to crypt depth of jejunum in piglets. Similarly, Zhu et al [12] found that 60 mg/kg ZnGly signi cantly increased the villus height in duodenum and jejunum and decreased crypt depth in duodenum in broilers and Li et al [39] reported that 80 mg/kg ZnMet increased villus height, villus area, and villus height/crypt depth ratio but reduced crypt depth in jejunum in laying hens. Zinc has been shown to promote cell differentiation through the PI3K/AKT/mTOR signaling pathway and upregulate the expression of tight junction protein zonula occludens-1 (ZO-1), consequently enhancing the barrier function of the intestinal mucosa [40].…”

“…It also exhibits cell growth-promotion functions [18]. As a new e cient green feed additive, dietary supplementation of ZnMet and ZnGly were shown to improve growth performance [9,12]. The improvement in growth performance may be related to the promotion of rapid proliferation of taste bud cells in tongue mucosa by zinc, thus prolonging the residence time of the feed in the digestive tract, improving the secretion of the digestive system and increasing the activity of enzymes in tissue cells [19,20].…”

“…In addition, Li et al [9] showed that 60 mg/kg ZnMet increased the T-AOC, GSH-Px activity in serum and the T-AOC, Cu/Zn-SOD, GSH-Px activity in liver of laying hens. Zhu et al [12] found that the zinc glycinate group had higher GSH-Px and lower MDA concentrations than the broilers in the control and ZnSO 4 groups. Besides, it is indicated that diets supplemented with lower levels of Zn-threonine and Zn-methionine can maintain egg production performance, improve egg quality, enrich eggs, increase bioavailability [13].…”

“…Besides, it is indicated that diets supplemented with lower levels of Zn-threonine and Zn-methionine can maintain egg production performance, improve egg quality, enrich eggs, increase bioavailability [13]. Previous studies have shown that amino acidchelated zinc could improve antioxidant capacity and immunity in hens [9,12]. Therefore, the bene cial effect and optimum supplementation amount in piglets needs to be studied.…”

Recent Developments in Zn-Based Biodegradable Materials for Biomedical Applications

“…Zn performs a significant role in bone metabolism and the growth of an organism. Zn supplementation enhances bone formation, meanwhile, increasing bone strength by stimulating osteoblast and differentiation of osteoclast [ 36 , 37 , 38 ]. Zn deficiency is associated with the weakness and health of bones.…”