Meta-analytical study of productive and nutritional interactions of mycotoxins in growing pigs

Abstract

A meta-analysis was carried out in order to study the association of mycotoxins with performance and organ weights in growing pigs. A total of 85 articles published between 1968 and 2010 were used, totaling 1012 treatments and 13 196 animals. The metaanalysis followed three sequential analyses: graphical, correlation and variance-covariance. The presence of mycotoxins in diets was seen to reduce the feed intake by 18% and the weight gain in 21% compared with the control group. Deoxynivalenol and aflatoxins were the mycotoxins with the greatest impact on the feed intake and growth of pigs, reducing by 26% and 16% in the feed intake and by 26% and 22% in the weight gain. The mycotoxin concentration in diets and the animal age at challenge were the variables that more improved the coefficient of determination in equations for estimating the effect of mycotoxins on weight gain. The mycotoxin effect on growth proved to be greater in younger animals. In addition, the residual analysis showed that the greater part of the variation in weight gain was explained by the variation in feed intake (87%). The protein and methionine levels in diets could influence the feed intake and the weight gain in challenged animals. The weight gain in challenged pigs showed a positive correlation with the methionine level in diets (0.68). The mycotoxin effect on growth was greater in males compared with the effect on females. The reduction in weight gain was of 15% in the female group and 19% in the male group. Mycotoxin presence in pig diets has interfered in the relative weight of the liver, the kidneys and the heart. Mycotoxins have an influence on performance and organ weight in pigs. However, the magnitude of the effects varies with the type and concentration of mycotoxin, sex and the animal age, as well as nutritional factors.Keywords: aflatoxins, deoxynivalenol, nutrition, swine, trichothecenes ImplicationsThe mycotoxin effect on animal performance is recognized. However, this effect may be modified by several factors, which are noticeable in the large variability observed in previous results. This study is innovative, because it seeks to understand and quantify the interactions among mycotoxins and other factors such as nutrition, sex or growth phase of the pigs. The meta-analysis used the complementarities among previous studies in order to highlight gaps in mycotoxicology, which is hardly studied in traditional experimental designs. Furthermore, it aimed to assist in understanding the mycotoxin effects that this approach can support in the determination of dynamic growth standards for challenged animals.

Meta-analysis of individual and combined effects of mycotoxins on growing pigs

“…In the present study, most of the mycotoxin effect on weight gain was explained by changes in feed efficiency. Thus, the effects of mycotoxins on pig growth may be strongly associated with primary modes of action, such as reduced feed intake (Andretta et al, 2012). In this context, it is possible to infer that some feeding and nutritional practices could be evaluated as alternatives for alleviating the effects of mycotoxin on pig growth.…”

“…Many of these fungi are producers of mycotoxins, which are a chemically diverse group of secondary metabolites with a wide range of toxic effects (Bryden, 2012). The contamination of grain by mycotoxins represents a major concern worldwide in the pig production chain, since the effect of these toxins is to reduce animal performance (Andretta et al, 2012).…”

“…Lower performance responses are expected for pigs challenged by combined mycotoxins compared with individual contamination, but few studies have quantified this effect and evaluated possible interference in maintenance requirements. This study aimed to evaluate and quantify, through meta-analysis, both the individual and combined effects of mycotoxins on the performance of growing pigs, and is a complementary approach to a previously published meta-analysis in which the challenge characteristic (individual/combined) was not assessed (Andretta et al, 2012).…”

Achieving a nutrition revolution for Africa: The road to healthier diets and optimal nutrition

“…Two meta-analysis papers have analyzed the experimental effects of mycotoxins on pig growth (Dersjant-Li, Verstegen, and Gerrits 2003; Andretta et al 2012); both showed that aflatoxins were among the mycotoxins that affected feed intake the most. Feed conversion ratios and weight gain were also negatively affected due to reduced feed intake.…”

“…Feed conversion ratios and weight gain were also negatively affected due to reduced feed intake. However, the effects of mycotoxins could be compensated by intake of more nutritious feed-for example, increased protein (such as methionine) intake increased weight in exposed pigs (Andretta et al 2012). …”