Yeast cell wall extracts from Saccharomyces cerevisiae varying in structure and composition differentially shape the innate immunity and mucosal tissue responses of the intestine of zebrafish (Danio rerio)

With the rising awareness of antimicrobial resistance, the development and use of functional feed additives (FFAs) as an alternative prophylactic approach to improve animal health and performance is increasing. Although the FFAs from yeasts are widely used in animal and human pharma applications already, the success of future candidates resides in linking their structural functional properties to their efficacy in vivo. Herein, this study aimed to characterise the biochemical and molecular properties of four proprietary yeast cell wall extracts from S. cerevisiae in relation to their potential effect on the intestinal immune responses when given orally. Dietary supplementation of the YCW fractions identified that the α-mannan content was a potent driver of mucus cell and intraepithelial lymphocyte hyperplasia within the intestinal mucosal tissue. Furthermore, the differences in α-mannan and β-1,3-glucans chain lengths of each YCW fraction affected their capacity to be recognised by different PRRs. As a result, this affected the downstream signalling and shaping of the innate cytokine milieu to elicit the preferential mobilisation of effector T-helper cell subsets namely Th17, Th1, Tr1 and FoxP3+-Tregs. Together these findings demonstrate the importance of characterising the molecular and biochemical properties of YCW fractions when assessing and concluding their immune potential. Additionally, this study offers novel perspectives in the development specific YCW fractions derived from S. cerievisae for use in precision animal feeds

Dietary tuna hydrolysate modulates growth performance, immune response, intestinal morphology and resistance to Streptococcus iniae in juvenile barramundi, Lates calcarifer

This study investigated the effects of tuna hydrolysate (TH) inclusion in fishmeal (FM) based diets on the growth performance, innate immune response, intestinal health and resistance to Streptococcus iniae infection in juvenile barramundi, Lates calcarifer. Five isonitrogenous and isoenergetic experimental diets were prepared with TH, replacing FM at levels of 0% (control) 5%, 10%, 15% and 20%, and fed fish to apparent satiation three times daily for 8 weeks. The results showed that fish fed diets containing 5% and 10% TH had significantly higher final body weight and specific growth rate than the control. A significant reduction in blood glucose was found in fish fed 10%, 15% and 20% TH compared to those in the control whereas none of the other measured blood and serum indices were influenced by TH inclusion. Histological observation revealed a significant enhancement in goblet cell numbers in distal intestine of fish fed 5 to 10% TH in the diet. Moreover, fish fed 10% TH exhibited the highest resistance against Streptococcus iniae infection during a bacterial challenge trial. These findings therefore demonstrate that the replacement of 5 to 10% FM with TH improves growth, immune response, intestinal health and disease resistance in juvenile barramundi

L'Impératrice Eugénie, à mi-corps, le corps de face, la tête légèrement de tr. q. à dr., le menton et la joue appuyés sur la main dr. ; même costume qu'au n° De Vinck 16703 ; portrait dans un ovale : [photographie]

Référence bibliographique : De Vinck, 16704Appartient à l’ensemble documentaire : Est19Vinc

Dietary cation-anion difference could enhance acid-base status of lactating dairy cows submit to a subacidosis

International audienc

Dietary cation-anion difference could enhance acid-base status of lactating dairy cows submit to a subacidosis

International audienc

L'acidose latente chez la vache laitière

National audienceToday, latent acidosis is a cause of the zootechnical inefficacy of the established food rations and for this reason has become one of the major preoccupations in modern nutrition of high potential ruminants. Dairy cows are required to treat large quantities of rapidly fermentable organic matter, which imperils the control of ruminal acidity and eventually the animal's homeostasis. The risk factors are now well known. The level of ingestion, rapidly digestible carbohydrates and the excessive chopping of corn silage figure amongst these factors. Even though it is not always desirable to reduce the amount of food ingested, the risks can be reduced by limiting the intake levels of rapidly degradable carbohydrates (wheat, barley, pulp) and by surveying the physical presentation of the fodder. Unfortunately, no system yet exists that allows to precisely rationalise the food ration as a function of these factors. The intraoptimal rations can be protected by distributing buffers. More recently, it has appeared that cation enrichment and protein intake level are also factors that protect the rations. The management of the risk of appearance of latent acidosis should be preventive and should include a better overall balance of the ration. In the absence of a reliable system that predicts the zones at risk, it is preferable not to incorporate more than 20% of rapidly degradable carbohydrates in the ration, especially if the electrolytic balance is low, which is the case for wheat, barley and citrus pulp. It is also important to make sure that the forage sent to the feeding trough is not chopped too finely. The rations can also be protected by including buffering substances at a concentration of 1% DM and/or by including cations that give an electrolytic balance close to 200mEq/kg MS as well as maintain a level of protein intake close to 100g PDIE/UFL. These precautions are more efficient in managing the excess of acidity than that of hay in the ration. It is no longer necessary to include degradable proteins in excess, which will just only increase the amount of nitrogen in waste.L’acidose latente constitue aujourd’hui une cause d’inefficacité zootechnique des rations bien établie et est de ce fait l’une des préoccupations majeure pour la nutrition moderne des ruminants à haut potentiel. Les vaches laitières sont amenées à traiter des quantités très importantes de matière organique rapidement fermentescible dans le rumen ce qui met en péril le contrôle de l’acidité ruminale et à terme l’homéostasie de l’animal. Les facteurs à risques sont maintenant bien connus. Au premier rang figurent le niveau d’ingestion, les glucides à dégradation rapide et le hachage excessif des ensilages de maïs. S’il n’est pas toujours souhaitable de réduire le niveau d’ingestion, on peut réduire les risques en limitant les niveaux d’apport de glucides à dégradation très rapide (blé, orge, pulpes) et en veillant à la présentation physique du fourrage. Il n’y a malheureusement pas encore de systèmes permettant de raisonner précisément les rations sur la combinaison de ces facteurs. Les rations infra-optimales peuvent être sécurisées par la distribution de tampons. Plus récemment, il est apparu que l’enrichissement en cations et le niveau d’apport de protéines sont aussi des facteurs de sécurisation des rations. La gestion des risques d’apparition d’acidose latente doit être préventive et passe par un meilleur équilibre global de la ration. En l’absence d’un système fiable de prévision des zones à risques, il est préférable de ne pas incorporer plus de 20 % de glucides rapidement dégradables dans la ration surtout si leur bilan électrolytique est faible, ce qui est le cas du blé, de l’orge et les pulpes de citrus et veiller à ce que le fourrage rendu dans l’auge ne soit pas haché trop finement. Les rations peuvent également être sécurisées par l’apport de substances tampon à raison de 1 % de la MS et /ou par un apport de cations permettant d’atteindre un bilan électrolytique proche de 200 mEq/kg MS ainsi que par le maintien d’un niveau d’apport protéique proche de 100 g PDIE/UFL. Ces précautions apparaissent plus efficaces pour gérer les excès d’acidité que l’incorporation de paille dans la ration. Il n’est pas non plus nécessaire d’apporter des protéines dégradables en excès ce qui n’aura d’autre effet que d’accroître les rejets azotés