Effect of Phytase Derived from the E. coli AppA Gene on Weaned Piglet Performance, Apparent Total Tract Digestibility and Bone Mineralization.

The objective of this study was to assess the effect of novel appAT1 and appAT2 phytase inclusion at 250 phytase units (FTU)/kg on weaned piglet performance, the apparent total tract digestibility of P and Ca, and bone mineralization. Piglets (48 males) were randomly divided into four treatment groups: a positive control (PC), with recommended levels of phosphorus (P) and calcium (Ca), a negative control (NC) deficient in P and Ca, and two experimental groups with NC diets supplemented with phytase derived from the appA gene of Escherichia coli. Diets fed in a mashed form were divided into prestarter (0-21 days) and starter (22-42 days) periods. During the whole period of the study, the experimental diets improved (p < 0.05) the body weight gain (BWG) and feed conversion ratio (FCR) compared to the NC diet. The apparent total tract digestibility (ATTD) of the dry matter and crude protein was not significantly different among the diets. Phytase-supplemented diets improved the ATTD of P (p < 0.05) and the ATTD of Ca (p < 0.05). Bone ash content in the third metacarpal and P and Ca content were improved among the phytase supplemented diets compared to the NC diet.

Yeast-secreted, dried and food-admixed monomeric IgA prevents gastrointestinal infection in a piglet model.

Oral antibodies that interfere with gastrointestinal targets and can be manufactured at scale are needed. Here we show that a single-gene-encoded monomeric immunoglobulin A (IgA)-like antibody, composed of camelid variable single domain antibodies (VHH) fused to IgA Fc (mVHH-IgA), prevents infection by enterotoxigenic Escherichia coli (F4-ETEC) in piglets. The mVHH-IgA can be produced in soybean seeds or secreted from the yeast Pichia pastoris, freeze- or spray-dried and orally delivered within food.

Medium-chain glycerides affect gut morphology, immune- and goblet cells in post-weaning piglets: In vitro fatty acid screening with Escherichia coli and in vivo consolidation with LPS challenge.

The influence of medium-chain glycerides on performance and gastrointestinal well-being in weaning piglets was assessed. First, caproic (C6), caprylic (C8) and capric (C10) acid activity against Escherichia coli was screened in vitro. Pig flora of the whole small intestine was used as inoculum. Seven in vitro incubations were done in duplicate at pH = 3 and 5: C10 (15 mM), C8 (12 mM), C6 (15, 12, 10 mM), a non-incubated-negative control and incubated negative control. Culture suspensions were plated on E. coli-selective agar. Controls showed bacterial growth. C6 and C8 showed no growth at both pH-values, where C10 showed growth at pH = 5. Secondly, an in vivo study was done with 80 weaned piglets over 42 days, housed in pens of eight animals (five pens/treatment), fed a basal diet containing broken rice/soya bean meal/fish meal and supplemented with C6 and C8 in medium-chain glyceride form (MCT6/8, 0.175%) or antibiotic growth promoter (AGP, 0.020%) (Kasetsart University, Thailand) serving as control. Feed intake, daily gain and feed-to-gain ratio did not differ between MCT6/8 and AGP. Per replicate, two random selected piglets were challenged intravenously with E. coli-lipopolysaccharide (LPS) or saline solution (S) at Days 21 and 28. All challenged animals were sacrificed; blood and digestive tract samples (jejunum/ileum) were collected at Day 35. LPS challenge consistently reduced villus height and crypt depth for MCT6/8 and AGP. However, LPS-challenged piglets supplemented with MCT6/8 restored villus height, where AGP did not. MCT6/8 piglets had higher serum IgA, more jejunal IgA-positive plasma cells and goblet cells than AGP. At the ileal level, results were similar, though less pronounced. The present study offers new insight in the benefits of MCT6/8 over AGP in the post-weaning period. There is in vitro anti-microbial action of C6 and C8 on E. coli. In vivo, MCT6/8 also has protective effects in the small intestine that may result in growth promotion.