The effect of zinc oxide supplementation on the stability of the intestinal flora with special reference to composition of coliforms in weaned pigs

Abstract

M. KATOULI, L.MELIN, M. JENSEN-WAERN, P. WALLGREN AND R. MÖ L LB Y. 1999. The effect of a dietary supplementation of zinc oxide (ZnO) on the stability of the intestinal flora and on the composition of coliforms in weaned pigs was investigated. Faecal floras were characterized by their metabolic activities and fermentative capacity (FC) using the Phene Plate generalized microplate. Coliforms were characterized by conventional enumeration and by the Phene Plate-RS plates. The latter measured FC, phenotypic diversity, persistence of each coliform strain in piglets, and similarity among the coliform populations within groups. From weaning onwards, the control pigs (n 5) were fed a basal diet ad libitum, while experimental pigs (n 5) were given the same food supplemented with 2500 ppm ZnO. Metabolic fingerprinting of faecal floras indicated marked differences between the composition of floras of treated and control pigs during the first 2 weeks post-weaning. The FC of faecal flora in both groups decreased as pigs aged, but it was significantly (P ¾ 0·0001) lower in control pigs during the first 2 weeks post-weaning. Neither the number of coliforms, nor their FC-values, differed between the groups. However, during the first 2 weeks post-weaning, there was a significant increase in both variety (P 0·019) and diversity (P ¾ 0·001) of coliforms in control pigs compared with the ZnO treated group. Homogeneity between coliform populations of piglets was high during the suckling period, indicating the presence of many identical strains among piglets. This, however, decreased in control pigs during the first 2 weeks post-weaning. Several coliform strains that colonized the gut at the early stage of the pigs' life were found to be resident in animals of both groups. It is concluded that supplementation of ZnO to weaned pigs helped to maintain the stability of the intestinal microflora and the diversity of coliforms during the first 2 weeks post-weaning, but not later, and that ZnO supplementation to creep feed should be restricted to the first 2 weeks post-weaning in veterinary practice.

Effect of sodium humate and zinc oxide used in prophylaxis of post-weaning diarrhoea on faecal microbiota composition in weaned piglets

“…The reduction of PWD prevalence after pharmacological levels of ZnO may not only be related to direct reduction of pathogenic E. coli in the intestine but can also be associated with the increase of diversity and maintenance of the stability of intestinal flora (Katouli et al 1999;Vahjen et al 2011;Pieper et al 2012;Starke et al 2013). Unlike previous studies, which found an increase in the enterobacterial group including Escherichia coli in the ileum in piglets supplemented with high dietary ZnO (Vahjen et al 2011;Pieper et al 2012), in our ETEC infection model, we did not observe this trend in faecal samples after three weeks of supplementation (Day 21, Table 2) with neither 2500 mg/kg nor 1700 mg/kg ZnO.…”

“…The mechanism of action of zinc is still not fully understood. However, it was found that high dietary ZnO has a positive impact on the stability and diversity of the intestinal flora which contributes to a high colonisation resistance against pathogens and thereby to resistance to diarrhoeal infections and to better growth performance (Katouli et al 1999;Vahjen et al 2011;Pieper et al 2012). Although ZnO has traditionally been included in diets for weaning piglets, its excretion in high amounts represents a hazard to the environment (Heo et al 2013;Sales 2013).…”

Efecto del consumo de zinc orgánico en la respuesta productiva de la cerda y su camada

“…Los niveles más bajos de IgA en el calostro de las cerdas que consumieron alimento adicionado con Met-Zn, se pudo deber al efecto farmacológico del Zn sobre la flora patógena intestinal, disminuyendo o estabilizando su población en el intestino; así como al mantenimiento de la integridad intestinal, lo que evita que ésta sea permeable a las endotoxinas bacterianas. Se ha informado al respecto que la suplementación con ZnO se ha asociado con una disminución en el traslado de bacterias desde el intestino delgado a los nódulos linfáticos mesentérico (Huang et al, 1999) y con un incremento en la estabilidad y homogeneidad en la población de coliformes (Kautouli et al, 1999); así como protegiendo la integridad de la mucosa intestinal (Pearce et al, 2015).…”

Alternatives to in-feed antibiotics in pigs: Evaluation of probiotics, zinc or organic acids as protective agents for the intestinal mucosa. A comparison of in vitro and in vivo results

“…Zinc supplementation has been shown to prevent or alleviate diarrhoea in piglets [30,31,56], to maintain stable levels of the intestinal flora and diverse coliforms that may compete with diarrhoegenic strains for colonisation sites [35] and to reduce translocation of pathogenic bacteria from the small intestine to the mesenteric lymph nodes [30]. However, Li et al [41] did not observe any effect on the microflora collected from the digesta and faeces of piglets after 11 days of high dose ZnO supplementation.…”

“…However, these studies did not investigate whether the effect of zinc supplementation is dependent on the physiological conditions of the cells and on the presence of inflammation induced by bacteria, and whether this effect is associated with a decrease of bacterial infection. Indeed, some authors did not find a reduced number of E. coli in the faeces of pigs treated with ZnO [31,35].…”