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Abstract
Zinc is involved in many biochemical functions essential for the birds’ health and growth. The relative bioavailability values were 107%, 76%, and 127% for zinc hydroxychloride (ZH), zinc-glycinate (ZG), and zinc-lysine-glutamate (ZL) sources, respectively, relative to zinc sulfate (ZS). There were no Zn sources or levels effects on the growth performance of the broiler. However, there was a significant effect of Zn sources on in vitro nitric oxide production (P < 0.05), wherein ZL increases its production compared to ZH diets. Birds receiving ZS diets had lower (P < 0.01) P digestibility than those fed ZH, ZG, and ZL-supplemented diets, and birds fed the ZL diet had higher Cu digestibility (P < 0.05). An interaction was observed for GPX3, in which the expression was upregulated by increasing the Zn level from 25 to 100 mg/kg in ZS, ZH, and ZL-fed diets and downregulated in ZG-fed diet. In our last study, Eimeria challenge significantly (P < 0.05) impaired all performance traits assessed in different ages. Zn source affected weight gain at the end of the grower phase and showed an increase in ZL diet compared to the birds fed ZS diets (P < 0.05). Tibia weight, ash weight, and tibia Zn concentration were significantly (P < 0.05) decreased in challenged birds at 6 days post inoculation (6-dpi) than in non-challenge. Eimeria inoculation decreased the expression of ZnT1 in duodenum, jejunum, and kidney, while upward expression of ZnT5 in duodenum, jejunum and ileum. mRNA expression of JAM2 and CLDN1 in jejunum and CLDN1 in ileum upregulated during Coccidiosis. Metallothionines (MTs) was upregulated by Eimeria challenge in both kidney and pancreas (P < 0.05). Birds displayed lower expressions of ALP1 and GPX1 in the kidney and ALP1 in the liver at 6-dpi. Our studies showed that organic trace minerals of ZL can be beneficial to physiological responses like growth, bone, immunology, and nutrient utilization in broiler chickens. Also, ZS increases VH in the ileum, SCFA, mcC of Cu, CAT1, and GLUT1 mRNA expression. More research needs to be done to justify the higher cost of organic mineral supplementation compared to inorganic one in poultry feed.