Allium sativum L. for prophylaxis of diarrhea in weaned piglets – how to find the right dosage?

In piglets an infection with enterotoxigenic Escherichia coli strains leads to high economic losses as a result of a constant high morbidity and mortality. The incidence of neonatal diarrhea in piglets depends on concentration of antibodies in sow's colostrum. While piglets are protected by the antibodies in sow's milk, the predisposition for postweaning diarrhea increases with weaning. Additional factors to the immunological gap, including abrupt changes in diet, an increase in stomach pH, and changes in the enzymatic and cellular configuration of the intestine lead to dysbiosis.

Several medicinal plant species are known for their antibacterial properties. Allium sativum L. (AS) exhibits antibacterial, antidiarrheal, anti-inflammatory and immunomodulatory effects, therefore it may be used for prophylaxis and treatment of diarrhea [1]. Based on a systematic review [1], 16 peer-reviewed references, 2 textbooks on veterinary phytotherapy, ESCOP and Commission E monographs were screened regarding scientific proven or recommended daily dosages of dry plant equivalent (DEV). Due to a lack of given data, for only 3 peer-reviewed references (pigs: 1; cattle: 1; poultry: 1) a dosage calculation was possible. To include data from studies with human and different animal species, the amount of used DEV was calculated in g/kg metabolic body weight (MBW) per day (table 1). Daily dosages range from a minimum of 30 mg to a maximum of 1052 mg DEV AS/kg MBW (mean: 520.8 mg; median: 557 mg).

Tab. 1: Dosages of Allium sativum L in dry plant equivalent (DEV) in mg/kg metabolic body weight (MBW; kg ^0,75) and re-converted for a 15 kg piglet

reference	specification of the reference (dr: dosage recommendation)	animal species	daily dosage
			per kg MBW (mgDEV/kg0,75)	per 15 kg piglet (mg DEV)
Kommission E	monograph (dr)	human	30	239
Aichberger et al, 2012	textbook (dr)	livestock	120	900
ESCOP	monograph (lower dr)	human	247	1877
Grela et al, 2007	clinical trial (lower dosage)	swine	526	4000
Reichling et al, 2015	textbook (lower dr)	swine	526	4000
ESCOP	monograph (upper dr)	human	588	4470
Ghosh et al, 2010	clinical trial	cattle	664	5053
Reichling et al, 2015	textbook (upper dr)	swine	789	6000
Hanieh et al, 2010	clinical trial	poultry	973	7400
Grela et al, 2007	clinical trial (upper dosage)	swine	1052	8000

The authors gratefully thank the Swiss retailer Migros for funding this study.

[1] Ayrle, H, Mevissen, M, Kaske, M, Nathues, H, Grützner, N, Melzig, M, Walkenhorst, M, BMC Veterinary Research 2016, 12:89; DOI 10.1186/s12917 – 016 – 0714 – 8