Prophylaxis of post-weaning diarrhoea in piglets by zinc oxide and sodium humate

Abstract

ABSTRACT:The high prophylactic doses of ZnO commonly used to control post-weaning diarrhoea (PWD) in piglets have become an environmental problem. The possibility of partial replacement of ZnO by sodium humate (HNa) in PWD treatment was investigated in this study. Weaned piglets (32) were challenged with two enterotoxigenic E. coli strains (ETEC/O149/F4/LT and ETEC/O147/F18/LT) and allocated into four treatments maintained for three weeks: C (no supplementation); ZnO2.5 (2.5 g ZnO/kg diet); HNa + ZnO1.0; HNa + ZnO1.5; HNa + ZnO1.7 (20 g HNa and 1.0, 1.5 and 1.7 g ZnO/kg diet, respectively). The effects on incidence, severity and duration of diarrhoea, faecal shedding of total E. coli and both ETEC strains, growth rate and selected blood parameters were investigated. In contrast with ZnO2.5 and HNa + ZnO1.7, high daily diarrhoea scores, incidence and duration and mortality due to severe dehydration were seen in C, HNa + ZnO1.0 and HNa + ZnO1.5 groups. The administration of ZnO and HNa did not affect the faecal shedding of the challenged ETEC strains for eght days, even in clinically healthy piglets in ZnO2.5 and HNa + ZnO1.7 groups. Signs of growth depression were found in C; HNa + ZnO1.0 and HNa + ZnO1.5 groups during the first week. No difference in growth performance was observed in ZnO2.5 and HNa + ZnO1.7 piglets. Most of the selected biochemical and haematological parameters did not differ significantly among the treatments. However, a significantly higher serum Zn as a result of high dietary ZnO intake in the ZnO2.5 group compared to the control and HNa groups was detected. Significantly lower serum P in ZnO2.5; HNa + ZnO1.7 and HNa + ZnO1.0 groups compared to the control group was most likely induced by the increased Zn in serum. The results indicate the possibility of reducing the high pharmacological levels of ZnO in the prophylaxis of PWD through partial replacement with HNa. Such a treatment maintains the favourable prophylactic effect while lowering the Zn content in faeces.Keywords: humic; enterotoxigenic E. coli; faecal shedding; growth performance; blood chemistry List of abbreviations: ALP = alkaline phosphatase, ALT = alanine transaminase, ANOVA = analyses of variance, AST = aspartate aminotransferase, BWG = body weight gains, CFU = colony forming units, DDS = daily diarrhoea score, ETEC = enterotoxigenic Escherichia coli, FCR = feed conversion ratio, FI = feed intake, HNa = sodium humate, HS = humic substances, PWD = post-weaning diarrhoea

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

“…The high FCR in the ETEC-infected control group reflected the poor health status and growth depression of piglets in comparison with the lower FCR in groups supplemented with ZnO and HNa + ZnO. These results are in accordance with those in our previous experiments in which we confirmed the possibility of reducing the high pharmacological dose of ZnO in PWD treatment through partial replacement with HNa (Trckova et al 2015). To the best of our knowledge, there are no data on the use of HS in the prophylaxis of ETEC-induced diarrhoea in piglets.…”

“…HS in pig diet was also shown to improve growth performance, meat quality, increase the nutrient digestibility and reduce ammonia emission from manure (Ji et al 2006;Wang et al 2008;Pisarikova et al 2010). Our previous studies showed that sodium humate (HNa) was insufficient for the treatment of diarrhoea in piglets challenged by pathogenic strains of Escherichia coli and that in the case of severe diarrhoeal infections supplementation of HNa to piglets can be effective only in combination with a specific dose of ZnO (1700 mg/kg; Trckova et al 2015). However, to what extent the prophylactic effect of HNa and ZnO was due to the maintenance of intestinal health and stabilisation of microbiota after treatment was not determined.…”

Effects of sodium humate and zinc oxide used in prophylaxis of post-weaning diarrhoea on the health, oxidative stress status and fatty acid profile in weaned piglets

“…There are ongoing efforts aimed at finding effective alternatives, that could protect piglets from post-weaning diarrhoea and growth depression after weaning. In our previous studies (Trckova et al 2015;Kaevska et al 2016) we verified the possibility of the substitution of a pharmacological dose of ZnO (2.5 g/kg diet) by humic substances (HS). HS are natural bioactive agents primarily decomposed from organic matter by bacteria in the soil.…”

“…EMEA (1999) has recommended humic acid (HA) and its sodium salt for the treatment of diarrhoea, dyspepsia and acute intoxications in animals. However, our previous results showed that in cases of severe post-weaning diarrhoeal infections caused by enterotoxigenic Escherichia coli strains (ETEC), supplementation of HS to piglets can be adequately effective only in combination with a specific dose of ZnO (1.7 g/kg; Trckova et al 2015). Moreover, there is still a lack of data about other potential effects of this partial substitution of ZnO by HS on the young and vulnerable organism of weaning piglets.…”

Dietary bacteriophages as an alternative for zinc oxide or organic acids to control diarrhoea and improve the performance of weanling piglets

“…This suggests that ZnO protects the small intestine from weaning-associated damage, which could be the reason behind the decreased diarrhoea incidence. Supplementation of piglet diets with a high ZnO dose (2.5 g/kg diet) or a lower ZnO dose (1.7 g/kg diet) supplemented with sodium humate (20.0 g/kg diet) was in both cases shown to be effective in the prophylaxis of post-weaning diarrhoea (Trckova et al 2015). Supplementing a pea protein-based diet with 2880 mg of Zn/kg not only reduced the incidence of diarrhoea, but also expedited the recovery of piglets in this treatment group to within four days of E. coli administration; by contrast, piglets fed a diet without ZnO continued to shed E. coli K88 and had severe diarrhoea (Owusu-Asiedu et al 2003).…”