Table 5.

Summarized results of the monocyte/macrophage search.

Type of study (N, # groups)	Basal diet Zn	Zn supplement & formulation [Zn dose]	Route	Duration of supplementation	Animals	Outcomes*	Findings	Reference
RCT (N=24, 4)	Not reported	A. 0 mg/kg BW Zn edetate & 0 mg/kg Diphenyl diselenide B. 1 mg/kg BW Zn edetate [0.15 mg/kg Zn] C. 0.3 mg/kg BW Diphenyl diselenide [0 mg/kg Zn] D. 1 mg/kg BW Zn edetate & 0.3 mg/kg BW Diphenyl diselenide [0.15 mg/kg Zn]	s.c.	The study lasted 300 days. Supplementation occurred twice on study day 1 and 20.	50 day old male Holstein calves	Circulating numbers on study days 1, 20, and 40.	B, C & D < A, day 40	(15)
RCT (N=32, 3)	Not reported	A. 100 mg/kg DM Zn sulfate [40.5 mg/kg Zn] B. 200 mg/kg DM Zn sulfate [81 mg/kg Zn] C. 80 mg/kg DM Zn Met & 20 mg/kg DM Zn sulfate [24.9 mg/kg Zn]	PO	30 days	255 ± 15 kg beef heifers	Circulating numbers after challenge with BRD pathogens	C < A & B	(16)

RCT, randomized controlled trial; Zn, zinc; mg, milligram; kg, kilogram; Met, methionine; s.c., subcutaneous; PO, per oral; BW, body weight; DM, dry matter; BRD, bovine respiratory pathogens. *Only stimulations and outcomes relevant to the assessment of monocytes/macrophages are listed.