Effect of oral zinc supplementation on hematology, serum biochemistry, performance, and health in neonatal dairy calves

Replacing Inorganic Source of Zinc with Zinc Hydroxy Chloride: Effects on Health Status, Hemato-biochemical Attributes, Antioxidant Status, and Immune Responses in Pre-ruminant Crossbred Calves

The current research aimed to assess the feasibility of using Zn hydroxy chloride (ZnOHCl) as an alternative to ZnSO4 in pre-ruminant crossbred calves. Twenty-four male crossbred calves (Tharparkar × Holstein Friesian) were categorized into four groups according to body weight and age (body weight 31 kg; age 10 days). Experimental calves were kept on a similar feeding regimen except that different groups were supplemented with either 0 mg Zn/kg DMI (Zn-0), 80 mg Zn/kg DMI as ZnSO4 (ZnS-80), 40 mg Zn/kg DMI as ZnOHCl (ZnH-40), or 80 mg Zn/kg DMI as ZnOHCl (ZnH-80). All the calves were fed for 90 days as per ICAR (2013) feeding standard to fulfill their nutrient requirements for growth rate of 500 g/day. The study observed the influence of different sources and varying levels of Zn supplementation over a 90-day experimental period on health status, hemato-biochemical attributes, antioxidant status, immune responses, and plasma minerals and erythrocyte Zn concentrations. The data was examined using a randomized complete block design (RCBD) with fixed effects of treatment, period, and their interaction. The results indicated that irrespective of the sources and levels of Zn, supplementation did not lead to significant changes in health status as assessed by fecal score, nasal score, ear score, and eye score. Hematological parameters remained unchanged following supplementation with different sources and levels of Zn. Zn-supplemented groups showed higher levels of total protein, globulin, and alkaline phosphates (ALP) compared to the non-supplemented group. However, no significant variations were detected within the Zn-supplemented groups. Zinc supplementation significantly increased total antioxidant capacity (TAC), antioxidant enzyme activity, total immunoglobulin (Ig), immunoglobulin G (IgG), cell-mediated immunity (CMI), and humoral immunity (HI); however, no significant variations were detected among Zn-supplemented groups. Zn supplementation enhanced plasma and RBC Zn concentration without affecting the plasma concentration of other minerals. However, among the Zn-supplemented groups, 80 mg Zn/kg DMI as ZnOHCl resulted in the highest RBC Zn concentration. The study results demonstrate that Zn supplementation enhanced biomarkers of zinc status, antioxidant levels, and immune responses in pre-ruminant crossbred calves. Nevertheless, no significant variations were observed between the different Zn sources (ZnSO4 and ZnOHCl) utilized in this study. Research suggests that ZnOHCl could be a feasible alternative to ZnSO4 in the diet of pre-ruminant crossbred calves.

Clinical, hematological, and biochemical studies on hypozincemia in neonatal calves in Egypt

Background and Aim

Zinc has a wide spectrum of biological activities and its deficiency has been related to various dysfunctions. This study aimed to clarify the clinical, hematological, and biochemical changes in Holstein dairy calves with naturally occurring hypozincemia before and after treatment.

Materials and Methods

This study was carried out on 25 Holstein dairy calves <1 month of age in the El-Salhya Dairy Farm, Al-Sharqiya Province, Egypt. Calves were born from apparent healthy dams without any clinical signs of zinc deficiency. They were divided into two groups. The first group (G1) included five clinically healthy calves that were used as controls. The second group (G2) included 20 calves suffering from alopecia and skin lesions. The diseased calves were then treated by oral administration of zinc oxide at the rate of 80 mg/day for 10 successive days and then 20 mg/week for 2 weeks (G3). A total of 90 samples, whole blood and serum samples were collected during the study across all groups. Whole blood was evaluated for complete blood count and serum was used to estimate total protein, albumin, globulin, zinc, calcium, magnesium, phosphorus, and the activity of alkaline phosphatase (ALP) and aspartate aminotransferase.

Results

The diseased calves had macrocytic normochromic anemia. Total leukocytes, neutrophils, and lymphocytes were significantly reduced in the diseased calves than in the control and treated groups. Biochemical analysis of serum revealed a highly significant decrease in the globulin, zinc, and calcium concentrations in the diseased calves than in the control and treated groups. ALP activity was significantly lower in the diseased and treated calves than in control. There were no differences in any other parameters between the groups.

Conclusion

Zinc deficiency naturally occurring in calves caused clinical, hematological, and biochemical alterations such as alopecia, skin abnormalities, and macrocytic normochromic anemia. In addition, zinc deficiency altered the cell-mediated immunity as indicated by leukopenia and lymphopenia. These alterations were improved by oral administration of zinc oxide.

Zinc: The Metal of Life

The importance of zinc was 1st reported for Aspergillus niger. It took over 75 y to realize that zinc is also an essential trace element for rats, and an additional 30 y went by before it was recognized that this was also true for humans. The adult body contains about 2 to 3 g of zinc. Zinc is found in organs, tissues, bones, fluids, and cells. It is essential for many physiological functions and plays a significant role in a number of enzyme actions in the living systems. Bioinformatics estimates report that 10% of the human proteome contains zinc-binding sites. Based on its role in such a plethora of cellular components, zinc has diverse biological functions from enzymatic catalysis to playing a crucial role in cellular neuronal systems. Thus, based on the various published studies and reports, it is pertinent to state that zinc is one of the most important essential trace metals in human nutrition and lifestyle. Its deficiency may severely affect the homeostasis of a biological system. This review compiles the role of zinc in prophylaxis/therapeutics and provides current information about its effect on living beings.