Organic acids for performance enhancement in pig diets

Abstract

Organic acids and their salts appear to be potential alternatives to prophylactic in-feed antibiotics and growth promoters in order to improve the performance of weaned piglets, fattening pigs and reproductive sows, although their growth-promoting effects are generally less than that of antibiotics. Based on an analysis of published data, the growth-promoting effect of formates, fumarates and citrates did not differ in weaned piglets. In fattening pigs, formates were the most effective followed by fumarates, whereas propionates did not improve growth performance. These acids improved the feed : gain ratio of both weaned piglets and fattening pigs. In weaned piglets, the growth-promoting effects of dietary organic acids appear to depend greatly on their in¯uence on feed intake. In sows, organic acids may have anti-agalactia properties. Successful application of organic acids in the diets for pigs requires an understanding of their modes of action. It is generally considered that dietary organic acids or their salts lower gastric pH, resulting in increased activity of proteolytic enzymes and gastric retention time, and thus improved protein digestion. Reduced gastric pH and increased retention time have been dif®cult to demonstrate, whereas improved apparent ileal digestibilities of protein and amino acids have been observed with growing pigs, but not in weaned piglets. Organic acids may in¯uence mucosal morphology, as well as stimulate pancreatic secretions, and they also serve as substrates in intermediary metabolism. These may further contribute to improved digestion, absorption and retention of many dietary nutrients. Organic acid supplementation reduces dietary buffering capacity, which is expected to slow down the proliferation andaor colonization of undesirable microbes, e.g. Escherichia coli, in the gastro-ileal region. However, reduced scouring has been observed in only a few studies. As performance responses to dietary organic acids in pigs often varies, more speci®c studies are necessary to elucidate an explanation.

Divergent modulation of swine ileal microbiota by formic acid and methionine hydroxy analogue-free acid

“…Differences in the diet composition, buffering capacity and farming practices make it difficult to compare results from different studies. However, in general, significant effects on performance and intestinal microbiota were observed in trials with higher than 0.5% inclusion level of FA (Bolduan et al, 1988;Partanen and Mroz, 1999;Canibe et al, 2005;Franco et al, 2005), whereas studies using less than 0.5% FA did not report significant effects (Gabert et al, 1995;Knarreborg et al, 2002). This, together with the observations made in the present investigation, strongly suggest that it is the inhibitory, rather than stimulatory, effect of FA that improves the animal performance.…”

“…It is beyond the scope of this paper to evaluate in detail which microbiota-modulating mode of FA is beneficial for the performance and health, the stimulation of lactic acid fermentation, or general inhibition of bacterial activities in the small intestine of swine. Whichever mode is better for performance, the existence of two opposite outcomes of FA inclusion in feed explains why the results of animal trials testing the effects of FA on animal performance, have been inconclusive (Partanen and Mroz, 1999;Close, 2000;Doyle, 2001;Mroz, 2005). Differences in the diet composition, buffering capacity and farming practices make it difficult to compare results from different studies.…”

“…Organic acids (OA) have been used as the first alternative to in-feed antibiotics by many feed companies, especially in diets for piglets (Kim et al, 2005;Mroz, 2005). Meta-analysis confirms that OA improve performance of weaned piglets, but the significance and magnitude of the effect appears to depend on the type and level of the OA used, as well as differences in feed composition and buffering (Partanen and Mroz, 1999;Partanen, 2001). Formic acid (FA, 90%) is one of the most commonly used OA, which have been shown to exert positive effects on animal performance and gastrointestinal health (Bolduan et al, 1988;Kirchgessner et al, 1992;Canibe et al, 2005;Franco et al, 2005;Partanen et al, 2007).…”

Effects of a dietary organic acid mixture and of dietary fibre levels on ileal and faecal nutrient apparent digestibility, bacterial nitrogen flow, microbial metabolite concentrations and rate of passage in the digestive tract of pigs

“…Dietary acidification with organic acids has been shown to improve the growth and feed-to-gain ratio of weaned piglets and growing-finishing pigs, but the mechanisms whereby dietary organic acids enhance pig performance are still poorly understood (Ravindran and Kornegay, 1993;Partanen and Mroz, 1999). Several studies have demonstrated that dietary organic acids improve the ileal apparent digestibility of protein and amino acids in growing-finishing pigs Kemme et al, 1999;Mroz et al, 2000;Partanen et al, 2001).…”

Digestibilidade de nutrientes e balanço de Ca e P em suínos recebendo dietas com ácido butírico, fitase e diferentes níveis de cálcio

“…Por sua vez, a adição de ácidos objetiva reduzir o efeito alcalinizante da dieta no estômago, tornando mais efetiva a barreira gástrica que impede/ou dificulta a entrada de microorganismos patogênicos no intestino delgado (TSILOYIANNIS et al, 2001). Tem-se observado que o uso de ácidos orgânicos melhora o desempenho animal e aumenta a digestibilidade ileal de aminoácidos e minerais e o aproveitamento da energia (PARTANEN & MROZ, 1999). Em experimentação in vitro, a utilização de ácidos orgânicos em tecidos da mucosa do cólon de ratos aumentou a absorção de cálcio através do mecanismo de transporte paracelular intestinal (MINEO et al, 2001).…”