AUTHOR=Diao Hui , Yan Jiayou , Li Shuwei , Kuang Shengyao , Wei Xiaolan , Zhou Mengjia , Zhang Jinxiu , Huang Chongbo , He Peng , Tang Wenjie 

TITLE=Effects of Dietary Zinc Sources on Growth Performance and Gut Health of Weaned Piglets

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.771617

DOI=10.3389/fmicb.2021.771617

ISSN=1664-302X

ABSTRACT=The present study aimed to investigate the effects of dietary zinc sources on the growth performance and gut health of weaned piglets. In total, 96 Duroc × Landrance × Yorkshire (DLY) weaned piglets with an initial average body weight of 8.81 ± 0.42 kg were divided into four groups, with six replicates per treatment and four pigs per replicate. The dietary treatment groups were as follows: 1) control group, basal diet; 2) zinc sulphate (ZnSO4) group, basal diet + 100 mg/kg ZnSO4; 3) glycine zinc (Gly-Zn) group, basal diet + 100 mg/kg Gly-Zn and 4) zinc lactate group, basal diet + 100 mg/kg zinc lactate. The whole trial lasted for 28 days. Decreased F/G was noted in the Gly-Zn and zinc lactate groups (P < 0.05). The zinc lactate group had a lower diarrhoea rate than the control group (P < 0.05). Moreover, the ZnSO4, Gly-Zn and zinc lactate groups had significantly higher apparent total tract digestibility of dry matter (DM), crude protein (CP), ether extract (EE), crude ash and zinc than the control group (P < 0.05). The Gly-Zn and zinc lactate groups had higher jejunal villus height and a higher villus height:crypt depth ratio than the control group (P < 0.05). In addition, the ZnSO4, Gly-Zn and zinc lactate groups had a significantly lower mRNA expression level of jejunal ZRT/IRT-like protein 4 (ZIP4) and higher mRNA expression level of jejunal interleukin-1β (IL-1β) than the control group (P < 0.05). The mRNA expression level of jejunal zinc transporter 2 (ZNT2) was higher and that of jejunal Bcl-2 associated X protein (Bax) was lower in the Gly-Zn and zinc lactate groups than in the control group (P < 0.05). Moreover, the zinc lactate group had a higher count of Lactobacillus spp. in the caecal digesta and higher mRNA expression levels of jejunal occludin and mucin 2 (MUC2) than the control group (P < 0.05). In conclusion, dietary supplementation with 100 mg/kg ZnSO4, Gly-Zn or zinc lactate could improve the growth performance and gut barrier function of weaned piglets. Dietary supplementation with organic zinc, particularly zinc lactate, had the best effect.