Impact of bioactive substances on the gastrointestinal tract and performance of weaned piglets: a review

The EU ban on in-feed antibiotics has stimulated research on weaning diets as a way of reducing post-weaning gut disorders and growth check in pigs. Many bioactive components have been investigated but only few have shown to be effective. Amongst these, organic acids (OA) have been shown to exert a bactericidal action mediated by non-dissociated OA, by lowering gastric pH, increasing gut and pancreas enzyme secretion and improving gut wall morphology. It has been postulated that they may also enhance non-specific immune responses and improve disease resistance. In contrast, relatively little attention has been paid to the impact of OA on the stomach but recent data show they can differently affect gastric histology, acid secretion and gastric emptying. Butyrate and precursors of butyric acid have received special attention and although promising results have been obtained, their effects are dependent upon the dose, treatment duration, initial age of piglets, gastrointestinal site and other factors. The amino acids (AA) like glutamine, tryptophan and arginine are supportive in improving digestion, absorption and retention of nutrients by affecting tissue anabolism, stress and (or) immunity. Glutamine, cysteine and threonine are important for maintaining mucin and permeability of intestinal barrier function. Spray-dried plasma (SDP) positively affects gut morphology, inflammation and reduces acquired specific immune responses via specific and a-specific influences of immunoglobulins and other bioactive components. Effects are more pronounced in early-weaned piglets and under poorer health conditions. Little interaction between plasma protein and antibiotics has been found, suggesting distinct modes of action and additive effects. Bovine colostrum may act more or less similarly to SDP The composition of essential oils is highly variable, depending on environmental and climatic conditions and distillation methods. These oils differ widely in their antimicrobial activity in vitro and some components of weaning diets may decrease their activity Results in young pigs are highly variable depending upon the product and doses used. These studies suggest that relatively high concentrations of essential oils are needed for beneficial effects to be observed and it has been assumed that these plant extracts mimic most of the effects of antibiotics active on gut physiology, microbiology and immunology. Often, bioactive substances protective to the gut also stimulate feed intake and growth performance. New insights on the effects of selected OA and AA, protein sources (especially SDP bovine colostrum) and plant extracts with anti-bacterial activities on the gut are reported in this review

Nutritional management of gut health in pigs around weaning

Early weaning of piglets is often accompanied by a severe growth check and diarrhoea. It is well established that this process is multi-factorial and that post-weaning anorexia and undernutrition are major aetiological factors. Gastrointestinal disturbances include alterations in small intestine architecture and enzyme activities. Recent data indicate transiently-increased mucosal permeability, disturbed absorptive¿secretory electrolyte balance and altered local inflammatory cytokine patterns after weaning. These responses appear to operate according to two distinct temporal patterns, an acute response followed by a long-lasting adaptation response. Pigs coexist with a diverse and dense commensal microbiota in their gastrointestinal tract. Most of these microbes are beneficial, providing necessary nutrients or protection against harmful pathogens for the host. The microbial colonisation of the porcine intestine begins at birth and follows a rapid succession during the neonatal and weaning period. Following the withdrawal of sow's milk the young piglets are highly susceptible to enteric diseases partly as a result of the altered balance between developing beneficial microbiota and the establishment of intestinal bacterial pathogens. The intestinal immune system of the newborn piglet is poorly developed at birth and undergoes a rapid period of expansion and specialisation that is not achieved before early (commercial) weaning. Here, new insights on the interactions between feed components, the commensal microbiota and the physiology and immunology of the host gastrointestinal tract are highlighted, and some novel dietary strategies are outlined that are focused on improving gut health. Prebiotics and probiotics are clear nutritional options, while convincing evidence is still lacking for other bioactive substances of vegetable origin

Digestion des protéines de substitution par le veau de boucherie

National audienc

Effect of diet composition on postweaning colibacillosis in piglets

The weaning of piglets is often associated with digestive disorders, particularly diarrhea—postweaning colibacillosis (PWC)—which is caused by infection with enterotoxigenic strains of Escherichia coli. It has been shown previously that a diet for newly weaned pigs based on cooked white rice and animal protein decreases the occurrence of PWC, whereas the addition of carboxymethylcellulose (CMC) to this diet enhances PWC. The aims of the current work were to 1) determine whether substitution of animal protein with plant proteins in the cooked-white-rice diet influenced its protective effects on PWC and 2) confirm that an increase in viscosity of the digesta by adding CMC to the diet favors the development of PWC—with (Exp. 1) or without (Exp. 2) experimental infection of piglets with E. coli. The diets were 1) cooked white rice and animal protein sources (RAP), 2) RAP + CMC added at 40 g of CMC/kg (air-dry basis) of diet, 3) cooked white rice and plant protein sources (RPP), and 4) wheat and plant protein sources (WPP). Experiments 1 and 2 were conducted using 32 and 24 piglets (eight and six per treatment), respectively. Piglets were weaned at 21 d (d 1), and fed ad libitum until slaughter on d 9. In Exp. 1, piglets were orally infected with enterotoxigenic E. coli on d 4, 5, 6, and 7. On d 8 of Exp. 1, the E. coli scores in feces of pigs fed RAP + CMC were higher than with RAP (P < 0.01). On d 9 after weaning, feces from pigs fed diet RAP were normal or moist, whereas feces from pigs fed RAP + CMC were wet to diarrheic. On d 7 of Exp. 2, pigs fed diets RAP + CMC and WPP had wetter feces than pigs fed diets RAP or RPP (P < 0.05). On d 8, the E. coli scores in feces were higher (P < 0.01) with pigs fed RAP + CMC than with all other diets. The E. coli scores in the digesta were also higher with pigs fed RAP + CMC, and to a lesser extent with diet WPP, than with pigs fed RAP or RPP (P < 0.01). The large intestine was heavier in pigs fed diets RPP and WPP, and the digesta were more acidic (P < 0.05). This study confirmed that diet RAP was protective against PWC, and that substitution of animal proteins with plant protein in a rice-based diet did not diminish its protective effects. The addition of CMC to cooked white rice increased digesta viscosity and enhanced PWC. Consequently, this diet represents a useful model for studying this condition

Evaluation of feed supplementation with SOD on protective effects against stress caused by weaning in piglets

National audienc

Weaning - a challenge to gut physiologists

The aim of this paper is to review the most relevant findings obtained over the last four years on the physiology, microbiology and immunology of the gastrointestinal tract of pigs as influenced by weaning and nutrition in the post-weaning period through the action of feed components or alternative substances to in-feed antibiotics. In recent years, some light has been shed on the physiology of the stomach, including motility, gastric emptying and acid secretion. This organ is important in the control of pathogen entry into the intestines. Recent studies on basic intestinal physiology around weaning have been scarce. Most investigations have been devoted to nutritional approaches on the effects of diet components (e.g. protein, fibre, etc.) and alternative substances (e.g. organic acids, zinc, prebiotics, probiotics, other substances of animal or plant origins) on pig performance and various aspects of gastrointestinal tract physiology, microbiology and immunology. Among these, beneficial effects of some organic acids have been confirmed. Additional data with zinc sources include possible mechanisms of protection. Overall it appears that manipulating carbohydrate (prebiotic) composition of the weaning diet may be the most promising way to improve gut health in weaned piglets. In that respect, consistent results have been obtained with lactose supplementation, and interactions with other feed constituents have been studied. Significant positive results have also been produced with probiotics (bacteria, yeasts) fed to the piglets or to the sows. The major parts of the responses appear to be mediated through changes in gastrointestinal microbiology, including enhanced numbers of favourable bacteria (lactobacilli, bifidobacteria) and/or decreased numbers of potentially pathogenic bacteria (Escherichia coli, Clostridia, etc.) together with more favourable profiles of fermentation products along the intestines. In contrast, measurable effects of these dietary factors on intestinal physiology and mucosal immunology have been limited or difficult to interpret in many cases. Finally, investigations have been conducted with varying diet composition (other than carbohydrates: protein source or level, amino acids, etc) or supplementing with different substances of animal or plant origin. However, positive effects on the gut have often been more variable and sometimes inconsistent

Fermentação ruminal e eficiência microbiana em bezerros holandeses alimentados com dietas contendo diferentes níveis de concentrado Ruminal fermentation and microbial efficiency in Holstein calves fed diets with different concentrate levels

RESUMO - Este trabalho foi realizado para avaliar os efeitos de diferentes níveis de concentrado sobre os parâmetros da fermentação ruminal, as digestibilidades aparente, total, ruminal e intestinal de N, a eficiência microbiana e o balanço de N. Cinco bezerros holandeses, inteiros, fistulados no rúmen e abomaso, com idade média inicial de 5,8±0,7 meses e 107,4±11,0 kg PV médio inicial, foram distribuídos em quadrado latino 5x5 (tratamento x período). Os animais foram alojados em baias individuais e alimentados à vontade com dietas contendo 30,0; 45,0; 60;0; 75,0; e 90,0% de concentrado, com base na MS, em rações contendo como volumoso, o feno de capim coast-cross e no concentrado, o farelo de soja, fubá de milho. Os valores de pH foram influenciados pelos níveis de concentrado das rações, e , 11,3 horas após a alimentação, foram estimandos os valores mínimos de 6,10; 5,89; 5,67; 5,46; e 5,24, para as rações com níveis de 30,0; 45,0; 60,0; 75,0; e 90,0%de concentrado nas rações, respectivamente. A concentração de amônia ruminal reduziu linearmente, em função dos tempos pós-alimentação, apresentando comportamento quadrático, com valores mínimos de 6,84; 7,14; 7,63; 7,82; 8,09; e 8,00 mg/dL, para 86,31; 84,86; 83,41; 81,95; 77,59; e 68,86% de concentrado nas rações. O numero de protozoários ruminais reduziu linearmente com o aumento dos níveis de concentrado nas rações. A eficiência de síntese de compostos nitrogenados microbianos aumentou linearmente com os níveis de concentrado nas rações.<br>ABSTRACT - This work was conducted to evaluate the effects of different concentrate levels on the parameters of at ruminal fermentation, the apparent, total, ruminal and intestinal N digestibilities, the microbial efficiency and the N balance. Five rumen and abomasum fistulated bull Holstein calves, with an initial average age of 5.8±0.7 months and initial average of 107.4±11.0 kg LW were allotted to a 5x5 Latin square design (treatment x period). The animals were housed in individual stalls and full fed diets (DM basis) containing 30.0, 45.0, 60.0, 75,0 and 90.0% of concentrate.The diets were based on coast-cross grass hay as forage and soybean meal and corn ground grain in the concentrate. The pH values were affected by the concentrate levels of the diets, and , 11.3 hours post-feeding, the minimum values of 6.10, 5.89, 5.67, 5.46, and 5.24, respectively, were estimated for the diets with 30.0, 45.0, 60.0, 75.0 e 90.0% of concentrate in the diets, respectively. The ruminal ammonia concentration linearly decreased, in function of post-feeding time and showing quadratic behavior, with a minimum values of 6.84, 7.14, 7,40, 7.63, 7.82, 8.09, and 8.00 mg/dL, for 86.31, 84.86, 83.41, 80,50, 81.95, 77.59, and 68.86% of concentrate in the diets. The number of ruminal protozoa linearly reduced as the dietary concentrate levels increased. The efficiency of microbial nitrogenous compound synthesis linearly increased, as the concentrate levels in the diets increased