Effects of a 3 strain -based direct-fed microbial and dietary fiber concentration on growth performance and expression of genes related to absorption and metabolism of volatile fatty acids in weanling pigs

Effects of a -based direct-fed microbial (DFM) on growth performance, plasma tumor necrosis factor ɑ (TNFɑ), relative gene expression, and intestinal VFA concentrations in weanling pigs fed low- or high-fiber diets were evaluated. Two hundred pigs (initial BW: 6.31 ± 0.73 kg) were allotted to 1 of 4 dietary treatments (5 pigs per pen and 10 pens per treatment). Treatments were arranged in a 2 × 2 factorial design with 2 diet types [low-fiber (LF) or high-fiber (HF)] and 2 concentrations of DFM (0 or 60 g DFM/t of feed). The DFM contained 1.5 × 10 cfu/g and was obtained from Danisco Animal Nutrition-DuPont Industrial Biosciences, Marlborough, UK. Phase 1 diets were fed for 2 wk post-weaning and phase 2 diets were fed over the following 29 d. Low fiber diets contained corn and soybean meal as main ingredients and HF diets contained corn, soybean meal, corn distillers dried grains with solubles (7.5 and 15.0% in phase 1 and 2, respectively), and wheat middlings (10.0%). Pigs and feed were weighed at the start and at the end of each phase, and ADG, ADFI, and G:F were calculated. At the conclusion of phase 2, blood was collected from 1 pig per pen and 1 pig per pen was sacrificed. Cecum and rectum contents were analyzed for VFA, and tissue samples were collected from the ileum, cecum, rectum, and liver to determine expression of genes related to absorption and metabolism of VFA using quantitative reverse transcription-PCR. Results indicated that feeding HF diets reduced ( ≤ 0.05) ADFI and ADG of pigs compared with feeding LF diets. Pigs fed DFM diets had improved ( ≤ 0.05) G:F compared with pigs fed non-DFM diets. Pigs fed LF diets had greater ( ≤ 0.05) BW at the end of phase 2 compared with pigs fed HF diets. The concentration of VFA in rectum contents was greater ( ≤ 0.05) in pigs fed LF diets than in pigs fed HF diets. The expression of in the rectum of pigs fed HF diets was greater ( ≤ 0.05) than for pigs fed LF diets, and pigs fed DFM-containing diets had an increased ( ≤ 0.05) expression of in the liver. Pigs fed HF diets had greater ( ≤ 0.05) concentrations of urea N in plasma compared with pigs fed LF diets, but dietary fiber and DFM had no effect on plasma concentration of TNF-ɑ. In conclusion, the -based DFM improved overall G:F of weanling pigs, but pigs fed LF diets had greater final BW than pigs fed HF diets.

The efficacy of a new 6-phytase obtained from Buttiauxella spp. expressed in Trichoderma reesei on digestibility of amino acids, energy, and nutrients in pigs fed a diet based on corn, soybean meal, wheat middlings, and corn distillers' dried grains with solubles

Sixteen cannulated pigs were used to evaluate the effect of a new 6-phytase derived from Buttiauxella spp. and expressed in Trichoderma reesei on apparent ileal digestibility (AID) of AA and apparent total tract digestibility (ATTD) of DM, N, Ca, P, Na, Mg, K, Cl, and energy. Pigs were fed 4 diets for 2 periods in a crossover design. Within each period, there were 4 blocks of 4 pigs per block with each diet represented within each block. The average initial BW in periods 1 and 2 were 22 and 30 kg, respectively. Each period lasted 9 d with fecal collection on d 5 and 6 and a 12-h ileal digesta collection on d 7, 8, and 9. Pigs received a daily feed allowance of approximately 4.5% of their BW. The experimental diets were based on corn, soybean meal, wheat middlings, and corn distillers dried grain with solubles. Phytase was added at 0; 500; 1,000; or 2,000 phytase units/kg of diet to a basal diet that contained 205, 15, 5.4, and 10 g of CP, Lys, total P (1.6 g of nonphytate P), and Ca/kg diet, respectively. The addition of phytase improved (P < 0.05) AID of DM, N, Ca, and P. Increasing phytase supplementation linearly and quadratically increased (P < 0.05) AID of P and Ca, respectively, with AID of Ca showing a tendency for a linear increase (P = 0.053). Phytase supplementation of the basal diet improved (P < 0.05) AID of P from 46 to 62%. Phytase supplementation increased (P < 0.05) ATTD of DM, N, Ca, P, Mg, K, and energy. Contrasts showed that phytase supplementation of the basal diet increased (P < 0.05) AID for 8 indispensable AA (Arg, His, Ile, Leu, Lys, Phe, Thr, and Val), 6 dispensable AA (Ala, Asp, Cys, Glu, Ser, and Tyr), as well as for total AA. Furthermore, phytase supplementation to the basal diet showed a tendency (P < 0.10) to increase ileal digestibility of Gly. Ileal digestibility of Met, Trp, and Pro were not affected by phytase supplementation. Increasing the level of phytase supplementation resulted in linear increases (P < 0.05) in AID of 6 indispensable AA (Arg, Ile, Leu, Lys, Phe, and Val) and 1 dispensable AA (Asp) with 4 AA (His, Cys, Glu, and Tyr) showing a tendency for linear increase (P < 0.10) in AID of AA. The results from this study showed that in addition to increasing P and Ca utilization, the new Buttiauxella 6-phytase expressed in Trichoderma reesei enhanced ileal digestibility of N and several AA in growing pigs in a dose-dependent manner.

Digestibility marker and ileal amino acid digestibility in phytase-supplemented soybean or canola meals for growing pigs

Two experiments using soybean meal (SBM) or canola meal (CM) were conducted to investigate whether the choice of digestibility marker influenced the apparent ileal digestibility (AID) or standardized ileal digestibility (SID) of N and AA in diets supplemented with phytase. In each experiment, 18 barrows fitted with T-cannulas at the ileocecal junction were assigned to 3 diets consisting of a N-free diet to determine endogenous losses of N and AA, a semipurified diet (SBM in Exp. 1 or CM in Exp. 2), and the semipurified diet supplemented with phytase at 1,000 phytase units/kg. Three digestibility markers including acid-insoluble ash (AIA), chromic oxide (Cr2O3), and titanium dioxide (TiO2) were added to each diet at 3 g/kg. Each diet was fed for 7 d, consisting of a 5-d adjustment and a 2-d collection of ileal digesta. In both studies, basal ileal endogenous losses determined with Cr2O3 as a digestibility marker were lower (P<0.01) than with those determined with AIA or TiO2 digestibility markers. Using SBM as the protein source in Exp. 1, there was no interaction between phytase and digestibility marker on AID or SID of AA. The AID of N and AA in SBM using AIA as a digestibility marker tended to be lower (P<0.1) compared with Cr2O3 or TiO2 digestibility markers. Phytase supplementation increased (P<0.001) the AID of Ca and P. The use of AIA or Cr2O3 digestibility marker tended to be associated with lower (P<0.1) SID values compared with TiO2. Phytase did not affect the SID of N or any AA in SBM except for Met, for which there was an increase (P<0.05) with phytase supplementation. Using CM as the protein source in Exp. 2, there were significant interactions between digestibility marker and phytase. Phytase supplementation had effects (P<0.01) on AID or SID when Cr2O3 or TiO2 was used as the digestibility marker. With Cr2O3 or TiO2 as the digestibility marker in the CM diets, phytase supplementation increased (P<0.05) the SID of N and all AA (except Trp). There was no SID of N or AA response to phytase supplementation of CM when AIA was used as a digestibility marker. In contrast, there were no clear improvements in AA digestibility from phytase supplementation for SBM. Phytase effects on AID or SID of AA were dependent on the digestibility marker used in diets when CM was used as the protein source but not when SBM was used as the protein source. Therefore, AA digestibility response to phytase supplementation may depend on the protein being evaluated as well as the choice of digestibility marker.

Growth performance and nutrient digestibilities in nursery pigs receiving varying doses of xylanase and β-glucanase blend in pelleted wheat- and barley-based diets

In 2 experiments, dose response efficacy of a xylanase and β-glucanase blend (XB) on growth performance and ileal nutrient digestibility was investigated in nursery pigs fed pelleted wheat (Triticum aestivum)- and barley (Hordeum vulgare)-based diets. A basal diet (meeting NRC [1998] specifications for 6 to 30 kg BW, except for 5% lower DE) was supplemented with XB to give 4 diets (0, 50, 100, and 200 g/t). The xylanase and β-glucanase blend was formulated to contain guaranteed activity of 12,200 and 1520 units/g, respectively. In Exp.1, 192 nursery pigs (initial BW of 6.5 kg) were randomly assigned to 4 diets to give 12 pens (4 pigs/pen) per diet to study growth performance for 42 d. In Exp. 2, apparent ileal digestibility (AID) of energy and AA was evaluated in 4 individually housed ileal-cannulated barrows (21 kg BW) according to a 4 × 4 Latin square design. In Exp. 1, XB linearly and quadratically increased (P < 0.05) G:F compared with control. Adding 200 g/t increased overall G:F by 20% compared with control. In Exp. 2, XB linearly increased (P < 0.05) AID of DM, CP, energy, and AA. In conclusion, supplemental xylanase and β-glucanase in nursery pelleted wheat- and barley-based diets deficient in DE increased energy and nutrient use, resulting in better G:F. In conclusion, an enzyme product containing a combination of xylanase and β-glucanase allowed young pigs to derive more nutrients and energy in a wheat- and barley-based diet deficient in energy.

Degradation and fermentation characteristics of wheat coproducts from flour milling in the pig intestine studied in vitro

Use of wheat (Triticum aestivum) flour milling coproducts (WFM) in pig diets may ameliorate high feed cost. However, digestibility of WFM is lower than feed grains, and limited information exists about their fermentation characteristics. In vitro degradation and fermentation characteristics of 6 WFM samples (2 Shorts, 2 Millrun, middlings, and bran) with varying fiber and protein contents were studied. After a pepsin-pancreatin hydrolysis, WFM were incubated in a buffer solution with minerals and fresh pig feces as inoculum. Accumulated gas production was measured for 72 h and modeled. The VFA concentration was measured in the fermented solutions. The DM degradability during fermentation ranged from 31 to 52% and correlated negatively with ADF (r = -0.65; P < 0.01) and positively with CP (r = 0.50; P < 0.01) content of WFM. Total gas production ranged from 101 to 148 mL/g DM incubated and was negatively correlated with ADF and crude fiber (r = -0.70 and -0.59, respectively; P < 0.01). The VFA production ranged from 2.0 to 3.0 mmol/g and the fractional rate of degradation ranged from 0.08 to 0.11/h. In conclusion, fiber components were associated with degradability and fermentability of WFM. Therefore, treatments targeted to reduce the impact of fiber and protein may increase the digestibility and fermentability of wheat coproducts from flour milling.

Growth performance, diet nutrient digestibility, and bone mineralization in weaned pigs fed pelleted diets containing thermostable phytase

Traditional supplemental dietary phytase loses activity during steam pelleting. The thermal tolerance and bioefficacy of a phytase product with a thermoprotective coating [coated phytase (C-phytase)] was compared in mash and pelleted diets to a traditional, uncoated phytase (U-phytase) added to a negative control (NC) diet, formulated with reduced dietary Ca and P, and compared with a corn-soybean meal based positive control (POC) diet. Growth performance, nutrient digestibility, and third metacarpal bone characteristics were response variables. Weaned pigs (n = 56; 8.20 ± 0.5 kg initial BW; 28 d of age) were individually housed and randomly allotted to 1 of 7 diets for 21 d. The diets were 1) POC mash, 2) NC mash, 3) NC pelleted at 90°C, 4) NC mash + 500 U/kg U-phytase, 5) NC mash + 500 U/kg C-phytase, 6) NC + 500 U/kg C-phytase pelleted at 80°C, and 7) NC + 500 U/kg C-phytase pelleted at 90°C. The POC and NC diets were formulated to be isoenergetic and isolysinic. The content of Ca and available P was 1.01 and 0.40% and 0.83 and 0.22% in the POC and NC diets, respectively. Pig BW and feed intake were measured on d 7, 14, and 21, and feces were collected for 2 d. On d 21, pigs were killed and ileal digesta and the third metacarpal bone collected. Pigs fed POC had greater (P < 0.05) ADG, G:F, P digestibility, and bone mineralization but lower (P < 0.01) energy digestibility than pigs fed NC. Pelleting the NC diet did not improve performance, nutrient digestibility, or P use. Adding the U-phytase to NC mash diet increased (P < 0.05) ADG, G:F, apparent ileal digestibility (AID) of CP and Ile, Leu, Phe, Thr, Val, and Ser, and apparent total tract digestibility (ATTD) of P compared with pigs fed NC. Pigs fed C-phytase in NC mash diets had increased (P < 0.05) G:F and an AID of CP and AA and ATTD of P compared with pigs fed NC but not different than pigs fed U-phytase NC mash diets. Pigs fed pelleted NC diet with C-phytase had a greater (P < 0.05) ATTD of P and energy than pigs fed mash NC diet with C-phytase but had similar growth performance, AID of CP and AA, and bone mineralization to pigs fed U-phytase. In conclusion, release and bioefficacy of phytase after pelleting was not affected by the thermal protective coating.

Thermo-stable Escherichia coli phytase improves growth performance and nutrient utilization in broilers fed mash and pelleted corn-soybean-meal-based diets

The bio-efficacy of Escherichia coli-derived phytase produced by thermo-protective coating technology (coated phytase) was evaluated in mash or pelleted broiler diets. Three hundred and twenty-four broilers were divided into 54 groups of six birds and fed nine corn-based diets (six replicates per diet) from 1 to 22 d of age. The nine diets were a positive control (PC) (calcium, 0.9% and non-phytate phosphorus, 0.45%) fed as mash plus 2 × 4 factorial of a negative control (calcium, 0.78% and non-phytate phosphorus, 0.26%) fed as mash (NC-M) or pellet (NC-P) and with coated phytase at 0, 500, 600 or 700 FTU kg-1. The diets were pelleted at 80°C, and pressure load of 40 psi. Body weight gain (BWG) for the PC diet was higher (P < 0.001) than that for the NC-M or NC-P diet. The BWG and tibia ash were linearly increased (P < 0.001) by increased level of the phytase in NC-M or NC-P diet. The BWG for NC-M or NC-P diet reached that of the PC diet when phytase was supplemented at 600 or 700 FTU kg-1. In conclusion, the coated phytase improved nutrient utilization in broilers, and its bio-efficacy was unaffected by the pelleting process.

Effects of guar gum and cellulose on digesta passage rate, ileal microbial populations, energy and protein digestibility, and performance of grower pigs1,2

Dietary guar gum and cellulose were studied as purified soluble and insoluble nonstarch polysaccharide (NSP) sources, respectively. A control diet containing 14% cornstarch was formulated. A 7% guar gum, a 7% cellulose, and a 7% guar gum + 7% cellulose diet were formulated by adding the NSP to the control diet at the expense of cornstarch (wt/wt), forming a 2 x 2 factorial arrangement. The objectives were to determine whether guar gum and cellulose altered 1) the passage rate of digesta through the small intestine and total tract; 2) the digestibility of energy and CP, characteristics of the digesta, and microbial populations in the ileum; 3) plasma glucose and ghrelin concentrations; and 4) short-term voluntary feed intake and growth performance of grower pigs. In Exp. 1, 12 pigs (27.0 +/- 1.5 kg of BW) were fitted with an ileal T-cannula and were used in a 2-period change-over design, providing 6 observations per diet. Each period included 18 d: a 12-d acclimation period followed by 2-d feces, 3-d digesta, and 1-d venous blood collection periods. In Exp. 1, guar gum and cellulose slowed the passage rate of digesta through the small intestine by 26 and 18%, respectively (P < 0.05). Guar gum increased total tract retention time of the digesta by 14% (P < 0.05). Guar gum and cellulose increased the viscosity of ileal digesta by 72 and 76%, respectively (P < 0.05). Cellulose reduced ileal energy and CP digestibility (P < 0.05), but guar gum only tended to decrease ileal energy digestibility (P < 0.10). Guar gum and cellulose reduced total tract energy and CP digestibility (P < 0.05). At 60 min after feeding, guar gum decreased plasma glucose by 10% (P < 0.10). Guar gum interacted with cellulose to reduce plasma ghrelin before and after feeding (P < 0.05). Guar gum and cellulose interacted to increase ileal bifidobacteria and enterobacteria (P < 0.05); however, guar gum, but not cellulose, increased ileal clostridia (P < 0.05). In Exp. 2, 20 individually housed grower pigs (5 pigs per diet) had free access to the 4 diets used in Exp. 1 for 14 d. Guar gum and cellulose decreased ADG and reduced ADFI on d 0 to 14 (P < 0.05). In summary, increasing purified NSP in the diet reduced the passage rate of digesta, energy and protein digestibility, and feed intake, but increased ileal bifidobacteria and enterobacteria populations. The effects of cellulose were similar to those of guar gum. In conclusion, monitoring of dietary NSP is a critical factor to achieve predictable digestible nutrient intake and intestinal bacterial populations.

Effect of carbohydrase supplementation of wheat- and canola-meal-based diets on growth performance and nutrient digestibility in group-housed weaned pigs

Fibrous components in canola meal and wheat limit their effective use in diets for weaned pigs. Effects of supplementing a carbohydrase (845 and 327 Units g-1 xylanase and β-glucanase) to a wheat-canola meal diet on growth performance, small intestine nutrient digestibility and digesta viscosity were investigated. Ninety-six weaned pigs (7.2 ± 1.2 kg) had free access to control diet [65% wheat, 25% canola meal; 3.15 Mcal digestible energy (DE) kg-1, 10.6 g digestible lysine kg-1] or control diet supplemented with carbohydrase at three inclusion rates (1, 2, or 4 g kg-1) for 28 d. Four pigs were housed per pen for six pens per diet. On days 19 to 21, six pigs per diet were euthanised to collect small intestine digesta. Carbohydrase increased average daily feed intake (ADFI) and average daily gain (ADG) quadratically (P < 0.01) for days 1 to 28, resulting in 16% higher ADFI and 13% higher ADG for 2 g kg-1 carbohydrase compared to control. Carbohydrase did not affect feed efficiency (P > 0.10). The ADG was positively correlated to ADFI (r = 0.94; P < 0.01), but not to feed efficiency (P > 0.10). Carbohydrase did not affect digestibility of dry matter (DM) and energy (P > 0.10). Carbohydrase at 4 g kg-1 only reduced digesta viscosity 30% in the distal small intestine compared to control (P < 0.05). Carbohydrase supplementation increased ADFI and thereby ADG, but not feed efficiency and nutrient digestibility, suggesting that reduction of dietary fibrous components using carbohydrase may stimulate voluntary feed intake of pigs fed diets limiting in DE. Key words: Carbohydrase, canola meal, wheat, pig, feed intake, digestibility

Response of early-weaned pigs to an enterotoxigenic Escherichia coli (K88) challenge when fed diets containing spray-dried porcine plasma or pea protein isolate plus egg yolk antibody

Enterotoxigenic E. coli (ETEC) infection and resulting scours is a major problem for young pigs, especially when purified plant proteins are fed rather than spray-dried porcine plasma (SDPP). The effect of supplementing a pea protein isolate (PPI)-based diet with egg yolk antibodies (EYA) from laying hens immunized with ETEC K88 antigen on piglet performance, incidence of scours, and gut histology was studied in a 14-d trial. Ninety-six 10-d-old weaned pigs were assigned to five dietary treatments in a completely randomized design to give six replicate pens per treatment. The treatments were PPI without EYA (PPI-EYA), PPI with EYA (PPI+EYA), SDPP without EYA (SDPP-EYA), SDPP with EYA (SDPP+EYA), or a combination of PPI and SDPP (PPI+SDPP). Diets were formulated to similar nutrient levels and provided for ad libitum intake. Blood from all pigs was taken on d 0, 7, and 14 for determining plasma urea N (PUN). On d 7, pigs were orally challenged with 6 mL of 10(10) cfu/ mL ETEC K88. Piglets were weighed on d 7 and 14. On d 7, 8, and 14, four pigs per treatment were sacrificed to study the histology of the small intestine. Weekly feed intake, BW changes, and gain:feed were determined. Fecal swabs from 10 pigs per treatment were taken for a PCR test to detect K88 E. coli. Feed efficiency over the 14-d period was not affected (P > 0.78) by dietary treatment. Mean ADFI on an as-fed basis was lower (P < 0.002) in piglets fed PPI-EYA (64.3 g/d) compared with PPI+EYA (94.8 g/d) or SDPP (102 g/d) during wk 1. Piglets fed PPI-EYA tend to have a lower (P < 0.026) overall ADG (84 g/d) than those fed PPI+EYA (123 g/d) or SDPP (127 g/d) (P < 0.006)-based diets. Although scours was evident in all groups of pigs 6 h after the challenge, most of the piglets fed EYA- or SDPP-containing diets recovered 10 to 72 h postchallenge, whereas those fed PPI-EYA continued to have severe diarrhea, resulting in 33% mortality. The PCR results showed that a greater (P < 0.01) percentage of piglets fed PPI-EYA compared with those fed SDPP- or EYA-containing diets continued to shed ETEC K88 at the end of the 14-d study. Piglets fed PPI-EYA had shorter villi (P < 0.01), higher intestinal pH (P < 0.013), and higher PUN (P < 0.05) than those fed the SDPP- or EYA-containing diets during the entire 14-d study. It was concluded that specific EYA and SDPP could provide passive control of ETEC infection and potentially improve feed intake and weight gain in young pigs fed PPI.

Response of early-weaned pigs to an enterotoxigenic Escherichia coli (K88) challenge when fed diets containing spray-dried porcine plasma or pea protein isolate plus egg yolk antibody, zinc oxide, fumaric acid, or antibiotic

The effect of feeding diets containing either spray-dried porcine plasma (SDPP) or pea protein-isolate (PPI) supplemented with either egg yolk antibodies (EYA) from hens immunized with enterotoxigenic Escherichia coli (ETEC) (K88 and F18) antigens, ZnO, fumaric acid (FA), or carbadox (AB) on pig performance, incidence of scours, and gut morphology was studied in a 14-d experiment. Ninety 10-d-old weaned pigs were assigned to six dietary treatments in a completely randomized design to give five pens per treatment with three pigs per pen. The diets were SDPP without EYA (SDPP - EYA), PPI without EYA (PPI - EYA), PPI with EYA (PPI + EYA), PPI with ZnO (PPI + ZnO), PPI with FA (PPI + FA), or PPI with AB (PPI + AB). Diets were formulated to similar nutrient levels, with AB, EYA, FA, and ZnO at 0.25, 0.5, 2.0, and 0.4% of the diet, respectively. Pigs were weighed and bled on d 0, 7, and 14 to determine plasma urea N (PUN). Pigs were orally challenged with a 6-mL dose of 10(10) cfu/mL ETEC (K88) on d 7. On d 14, three pigs per treatment were killed to obtain sections of the small intestine for histological measurements. Weekly feed intake, BW changes, and gain:feed were determined. Incidence of scours and scour scores were monitored and fecal swabs were taken before and after ETEC challenge for PCR test to detect ETEC (K88). Feeding SDPP or supplementing PPI-based diets with EYA, ZnO, FA, or AB did not affect (P > 0.05) ADG, ADFI (as-fed basis), or gain:feed throughout the study. However, pigs fed PPI - EYA tended to have lower (P = 0.08) ADFI during wk 2 (137.9 g/d) and lower (P < 0.10) ADG from d 0 to 14 (100.1 g/d) than those fed the SDPP - EYA (156.6 g/d), PPI + EYA (151.2 g/d), PPI + ZnO (158.9 g/ d), PPI + FA (155.4 g/d), and PPI + AB (152.6 g/d) diets. Although scours was evident in all pigs 8 h after the ETEC challenge, it lasted only 3 to 5 d in pigs fed SDPP or PPI supplemented with EYA, ZnO, FA, or AB. Pigs fed PPI - EYA continued to have severe diarrhea, resulting in 40% mortality vs. 13% or less in the other groups. The PCR results showed that 81% of PPI-fed pigs continued to shed ETEC K88 7 d after ETEC challenge. Pigs fed PPI-EYA had shorter villi (P < 0.05), reduced villi:crypt ratio (P < 0.003), and higher intestinal pH (P < 0.001) and PUN (P < 0.001) than those fed SDPP or PPI supplemented with EYA, ZnO, FA, and AB. In conclusion, SDPP, EYA, ZnO, FA, and AB may have provided passive control to ETEC (K88) infection and potentially enabled young pigs to efficiently utilize a PPI-based diet.

Response of early-weaned pigs to spray-dried porcine or animal plasma-based diets supplemented with egg-yolk antibodies against enterotoxigenic Escherichia colil

Two experiments involving 168 10-d-old weaned pigs were conducted to compare growth-promoting properties of dietary spray-dried animal plasma (SDAP), spray-dried porcine plasma (SDPP), and chicken egg-yolk antibodies (EYA) or egg-yolk powder (EYP, contains no specific antibodies) from d 0 to 14 postweaning. In Exp. 1, 96 pigs (3.2 +/- 0.2 kg BW) were used to test the hypothesis that the superior performance of piglets fed SDPP-based diets was partly due to the presence of specific antibodies against enterotoxigenic Escherichia coli (ETEC), which could be replaced with EYA. Four experimental diets in a completely randomized design and arranged in a 2 x 2 factorial (SDPP without or with autoclaving [AuSDPP] and without [EYP] or with supplementation of EYA) were used. Autoclaving SDPP at 121degrees C for 15 min completely destroyed anti-K88/F18 antibodies. Overall feed intake and gain:feed ratio were similar (P > 0.05) among treatments and averaged 122.7 g/d and 0.688, respectively. However, pigs fed AuSDPP+EYP diets had poorer (P < 0.001) ADG compared with those fed SDPP+EYP or SDPP+EYA from 0 to 14 d. Scours were four times higher (P < 0.05) for treatment AuSDPP+EYP compared with all other treatments. Plasma urea nitrogen concentration was higher (P < 0.05) in AuSDPP+EYP- and AuSDPP+EYA-fed pigs. Also twice the number of piglets fed AuSDPP+EYP appeared unhealthy compared with piglets on treatment AuSDPP+EYA. In Exp. 2, 72 10-d-old weaned pigs (3.5 kg BW) were used to compare the effect of EYA supplementation and oral challenge of ETEC strain F18 on performance and visceral organ weights. The experimental diets consisted of SDAP+EYP, SDAP+EYA, SDPP+EYP, and SDPP+EYA. From d 0 to 7, and the entire experimental period, dietary treatment did not influence (P > 0.05) growth rate and feed consumption. Plasma urea N concentration was higher (P < 0.05) in piglets fed the SDAP+EYP diet before and after the oral challenge. Gain:feed ratio, organ weights, villi heights, and crypt depths were not affected (P > 0.05) by dietary treatments. The results indicate that SDPP contains specific anti-ETEC antibodies, which is one of the factors responsible for its superior growth-enhancing effects. Spray-dried animal plasma, SDPP and EYA have similar growth promoting effect in early-weaned pigs.

Effect of heat processing on nutrient digestibility in pea and supplementing amylase and xylanase to raw, extruded or micronized pea-based diets on performance of early-weaned pigs

Two experiments were conducted to investigate the effect of heat processing on nutrient digestibility and of both processing and exogenous feed enzymes on growth performance of 16-d-old weaned piglets fed pea-based diets. In exp. 1, 12 Cotswold pigs [4.5 ± 0.5 kg initial body weight (BW)] fitted with simple-T cannulae were used to determine apparent and standardized ileal amino acid (AA) digestibilities in raw, extruded, and micronized peas supplemented with amylase and xylanase. In exp. 2, 70 16-d-old weaned pigs were randomly assigned to a soybean-meal- (SBM)-based control and six pea-based diets during two consecutive periods (Phase 1, 4.5–10.0, Phase 2, 10.0–20.0 kg BW). The pea- (raw, extruded and micronized) based diets were fed with or without enzyme supplementation. Pigs were weighed weekly and feed intake was monitored daily. Blood samples were obtained from 10 pigs per treatment on days 0, 7 and 14 for plasma urea nitrogen (PUN) analysis. Heat processing improved (P < 0.05) apparent ileal digestibilities (AID) of most AAs, including lysine, methionine, threonine, and valine in extruded and micronized peas, but not raw peas. The AID was higher (P < 0.05) in enzyme-supplemented extruded and micronized peas than in raw peas. Micronization improved (P < 0.05) AID of lysine from 82 to 91%. The standardized ileal digestibilities (SID) of arginine, lysine, methionine and threonine were higher (P < 0.05) in extruded and micronized pea-based diets than in raw pea-based diets. Mean AID of indispensable AA was numerically improved (P < 0.08) from 79 to 88.0% following micronization. Feed efficiency was improved (P < 0.05) from 1.4 to 1.20 by supplementing raw pea-based diet with amylase and xylanase in phase 1. Supplementing raw pea-based diet with enzyme resulted in reduced (P < 0.05) PUN levels from 9.01 to 5.73 mg dL-1. The results demonstrate that compared to raw peas, extrusion and micronization improved AA digestibilities of amylase and xylanase supplemented pea-based diets and efficiency of feed utilization from 4.5 to 10.0 kg BW. However, feed intake and growth performance were not affected. Key words: Amylase, xylanase, early-weaned pig, amino acids, micronization, extrusion, digestibilities