[Show abstract][Hide abstract] ABSTRACT: Thermal treatments of feed and organic acids are known to affect the gastrointestinal microbiota in chickens. The present study evaluated the effect of different thermal processes including pelleting (P), long-term conditioning at 85°C for 3 min (L), expanding at 110°C (E110), and 130°C for 3 to 5 s (E130) as well as organic acid (63.75% formic acid, 25.00% propionic acid, and 11.25% water) inclusion levels (0, 0.75, and 1.5%) on gastrointestinal microbiota in broilers. In total, 960 one-day-old chicks were randomly assigned to 8 replicates using a 3 × 4 factorial arrangement. At d 35, bacterial cell numbers in the crop, ileum, and cecum, and bacterial metabolites in the crop, gizzard, ileum, and cecum were determined. The inclusion of 1.5% organic acids increased cell numbers of all clostridial clusters in the crop. The organic acid supplementation increased the propionic acid concentration in the crop and gizzard and there was a decrease in lactic acid concentration. In the ileum, the 0% organic acid group had the highest numbers of Lactobacillus spp. and enterobacteria. Inclusion of 1.5% organic acids increased ileal acetate concentration. Increasing the feed processing temperature led to an increase of lactobacilli in the crop and ileum, whereas clostridia and enterobacteria seemed unaffected. Similarly, lactate concentrations increased in the ileum, but short-chain fatty acids remained identical. In the crop, an increase for acetate was found for the E130 group compared with all other thermal treatments. In conclusion, our study demonstrated that thermal treatments and organic acid supplementation to broiler diets more markedly influenced the bacterial status of the crop compared with the downstream segments and their effects decreased along the length of gastrointestinal tract. Whereas organic acids markedly modified bacterial composition and activity in the crop, expansion increased lactobacilli and lactate in the crop and ileum.
[Show abstract][Hide abstract] ABSTRACT: Minerals play an important role for growth and bone stability in broilers. Thermal treatment and inclusion of organic acids in feed may affect the mineral absorption and tibial quality in broilers. The study was conducted to investigate the effect of thermal processing of feed including pelleting (P), long-term conditioning at 85°C (L), and expanding at 130°C (E) without and with 1.5% of an acid mixture containing 64% formic and 25% propionic acid on the apparent ileal absorption (AIA) of calcium, phosphorus, magnesium, potassium, sodium, iron, copper, manganese, and zinc, their concentrations in liver and tibia, as well as various tibial quality parameters in broilers. In total, 480 one-day-old Cobb broiler chicks were assigned using a completely randomized design with a 3 × 2 factorial arrangement. The ileal digesta, liver, and tibia were collected at d 35. The AIA of calcium and sodium was improved in group E compared with L (P ≤ 0.02 and P ≤ 0.01). Group P and E showed higher AIA for potassium than L (P ≤ 0.01). Bone ash content was increased in group E compared with L (P ≤ 0.04). The BW to bone weight ratio was lower and tibial zinc content was higher in group P compared with E (P ≤ 0.05). Tibial iron content was higher in group L than E (P ≤ 0.03). Acid addition did not affect AIA, mineral content in tibia, or tibial quality parameters. Thermal and acid treatment did not affect mineral concentrations in the liver, except an inconsistent interaction effect for DM content and sodium (P ≤ 0.03 and P ≤ 0.04, respectively). In conclusion, long-term thermal treatment reduced AIA of some minerals compared with short-term thermal treatments, but had no impact on tibia composition. Acid inclusion had no effect on AIA of minerals and tibia quality. Thermal treatment and the use of organic acids can therefore be considered as safe with regard to their impact on bone development in broilers.
[Show abstract][Hide abstract] ABSTRACT: Poultry feed is a potential vector for pathogens. Heat processing and organic acid treatments may decontaminate feed and can affect bird performance as well as feed digestibility. The present study was performed to investigate the effect of different thermal treatments including pelleting (P), long-term conditioning at 85°C for 3 min (L), or expanding at 110°C (E110) and 130°C for 3 to 5 s (E130) without or with 0.75 and 1.5% organic acid supplementation (63.75% formic acid, 25.00% propionic acid, and 11.25% water) on performance, nutrient digestibility, and organ weights of broilers. In total, 960 one-day-old broiler chicks were randomly assigned to 8 replicates using a 3 × 4 factorial arrangement. Performance variables were determined, and the relative organ weights and ileal and total amino acid (AA) digestibilities were measured at d 35. The organic acid inclusion linearly improved feed efficiency in the first week (P ≤ 0.05). The acid inclusion levels and thermal treatments had no significant effect on the performance variables at later intervals of the growing period of the birds. The L group showed the lowest ileal AA and CP digestibility. The inclusion of organic acids had a quadratic effect on total and ileal digestibility of isoleucine (P ≤ 0.05), whereas it had no significant effect on the ileal digestibility of other AA and nutrients. The relative weights of the jejunum and small intestine were significantly higher in the E130 group compared with P and L (P ≤ 0.05). In conclusion, our study demonstrated that long-term heat conditioning can decrease ileal nutrient digestibility, whereas pelleting and expansion, independently of organic acid addition, seemed to have no negative impact on broiler performance and nutrient digestibilities. Moreover, adding a blend of organic acids to broiler diets had neither positive nor negative effects on nutrient digestibility and final broiler performance. This indicates the feasibility of short-term thermal treatment and acid supplementation for hygienization of broiler feed without negatively influencing performance.
[Show abstract][Hide abstract] ABSTRACT: Dimethylglycine (DMG) is a naturally occurring glycine derivative, which is useful as additive to broiler diets as it improves nutrient digestibility and reduces the development of broiler ascites syndrome. This study evaluated the efficacy of dietary DMG to enhance performance of broiler chickens. Three trials were conducted to evaluate the effect of dietary supplementation with 1 g Na DMG/kg on growth performance and carcass characteristics. In Trial 1, the effect of sex was also assessed in a 2×2 factorial arrangement of treatments. In Trials 1 (Germany), 2 (Austria), and 3 (Italy), each treatment consisted of 6, 12, and 11 replicate pens with 20, 15, and 16 one-day-old broiler chickens per pen, respectively. Dietary DMG supplementation resulted in improved feed conversion ratio (FCR) in the starter phase by 8.8 (P=0.004), 6.4 (P=0.001), and 4.8% (P=0.006) compared with the control diet in Trials 1, 2, and 3, respectively. The overall FCR improved in broiler chickens fed the diets supplemented with DMG by 3.8 and 4.1% in Trials 1 (P=0.007) and 3 (P=0.006), respectively. In addition, final body weight increased by 5.5% (P=0.001) in Trial 2 and production value improved by 6.8% (P=0.015) in Trial 1 by dietary DMG supplementation. Mortality in all trials was similar between dietary treatments. In all 3 trials, cold carcass weight and total meat yield were as well similar between broiler chickens fed the control and DMG diets. In Trial 1, dietary DMG had no effect on breast meat yield in male broiler chickens, but it increased breast meat yield in female broiler chickens (diet x sex, P=0.004). Organoleptic quality of roasted breast meat assessed only in Trial 2 was not affected by dietary treatments. In conclusion, dietary supplementation of DMG at 1 g Na DMG/kg can considerably improve s production performance in broiler chickens.
[Show abstract][Hide abstract] ABSTRACT: Dietary inulin can affect the composition and metabolic activity of the gastrointestinal microbiota in piglets. To investigate whether the chain length of inulin may influence its stability in the gut and the bacterial community, 18 weaned piglets were housed 2 per cage, with 1 female and 1 castrated male animal each. The piglets received a control diet without or with 4% inulin, defined by an average degree of polymerisation (DP) of 31 (short-chain, I31) or 57 (long-chain, I57), with 6 piglets/diet. After a short feeding period of 6 d, fructan concentrations, selected bacterial groups, lactic acid, short-chain fatty acid concentrations, and the pH were determined in the digesta of different segments of the gastrointestinal tract. The results indicated that differences in the microbial degradation of inulin were depending on the DP. Compared to the short-chain inulin, the concentrations of the long-chain inulin were numerically greater in the small intestine and caecum, and greater in the digesta of the ascending colon. Differences were also observed in the bacterial composition of the digesta, showing greater cell numbers of enterococci (P=0.029), bifidobacteria (P=0.029), and Lactobacillus mucosae (P=0.028) in the ileum in group I57 compared to group I31. However, most bacteria tended to be numerically reduced in the ileum in group I31 compared to both control and I57 groups. Minor effects were observed in the ascending colon: L. reuteri and L. amylovorus were decreased in group I57 compared to the control group (P=0.031 and 0.034, respectively), and L. mucosae was decreased in group I31 compared to the control animals (P=0.029). The concentrations of bacterial metabolites were distinctively changed in the large intestine of the piglets fed inulin. The pH was lower in the rectum contents in group I57 compared to the control piglets (P=0.026), but lactic acid and total short-chain fatty acid concentrations were not affected. The molar ratios of propionic acid increased in the caecal contents (P=0.040) and in both, the ascending and descending colonic digesta (P=0.017 and 0.013, respectively) in group I57 compared to the control group, while acetic acid decreased (P<0.001) and n-valeric acid increased (P<0.001 and P=0.011, respectively) in the digesta of the ascending and descending colon in group I57. In conclusion, the microbial degradation of inulin was dependent on its chain length. Long-chain inulin affected the microbial fermentation more pronounced compared to short-chain inulin. The effects were already observed after 6 d, a relatively short application period, indicating that inulin may be used specifically during the sensitive post-weaning period for piglets.
[Show abstract][Hide abstract] ABSTRACT: Fenugreek seed has been shown to affect the intestinal microbiota and immunological responses in animals. A feeding trial with male castrated piglets was performed over 28 d without or with the addition of 1·5 g fenugreek seeds/kg complete diet in ten and eleven piglets, weaned at 21 d. In the intestinal tract, pH, lactate and SCFA were measured as major bacterial metabolites. Immune cell phenotypes, phagocytic activity and lymphocyte proliferation after stimulation with pokeweed mitogen, concanavalin A and phytohaemagglutinin M were measured by flow cytometry. Health status and performance of the piglets were not affected by fenugreek. The pH in the caecum and colon were reduced compared with the control (P < 0·05). Higher concentrations of l-lactic acid were recorded in the small-intestinal digesta (average concentrations from the duodenum, jejunum and ileum; P < 0·05), while the concentrations of SCFA remained unchanged except an increase in n-butyric acid in colon contents (P < 0·05). The piglets fed the fenugreek diet had higher Lactobacillus and clostridium cluster I concentrations and lower Escherichia, Hafnia and Shigella concentrations in the small intestine. The addition of fenugreek increased the relative concentration of the γδ T-cell population (TCR1+CD8α-) in the blood with a simultaneous reduction of antigen-presenting cells (MHCII+CD5-) (P < 0·05). Proliferation rate and phagocytosis activity of monocytes were not affected by the additive. In conclusion, fenugreek seeds might be interesting as a feed ingredient for young piglets due to their effects on the intestinal microbiota and immunological variables. The impact on performance and animal health has to be further evaluated.
The British journal of nutrition 07/2012; · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The influence of low dietary levels of free and encapsulated medium-chain fatty acids on their concentrations in the digesta, the gastric microbial ecology and bacterial metabolic products in the gastrointestinal tract (GIT) in weaned piglets was studied. Starting after weaning, 36 piglets were fed a diet without (Control) or with medium-chain fatty acids uncoated (MCFA) or coated with vegetable fat and lecithin (MCFAc). After 4 weeks, the animals were killed, and digesta from the stomach and different sections of the GIT were collected. The concentrations of caprylic (p < 0.001) and capric (p = 0.001) acids were higher in the stomachs of piglets fed diets MCFA and MCFAc compared to the Control group. The concentrations dropped rapidly along the GIT, regardless of encapsulation, and tended to be higher in groups MCFA and MCFAc compared to the Control. Compared to the Control group, ingestion of diet MCFAc led to an increase in the number of eubacteria (p = 0.001), enterobacteriaceae (p < 0.001), clostridial clusters I (p = 0.001) and IV (p = 0.019), Lactobacillus johnsonii (p < 0.001) and Lactobacillus amylovorus (p = 0.001) in gastric contents. A similar trend was seen with diet MCFA. Relative concentrations of short-chain fatty acids were characterised by lower propionic acid levels (p = 0.045), numerically (p < 0.1) higher acetic, lower n-butyric and i-valeric acid concentrations in the small intestine. Lactic acid concentrations were not significantly changed in the GIT, but ammonia concentrations increased (p < 0.001) in the distal small intestine in the MCFA and MCFAc groups. In conclusion, medium-chain fatty acids affected microbial ecology parameters in the gastric contents and bacterial metabolites in the small intestine. At low dietary levels, medium-chain fatty acids may be regarded as modulators of the gastric microbiota in weaned piglets.
Archives of animal nutrition 02/2012; 66(1):14-26. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A study was undertaken to examine the effects of a phytogenic feed additive (PFA) containing essential oils of thyme and star anise as lead active components on the growth performance and apparent ileal nutrient digestibility in broiler chickens. In total, 528 one-day-old Cobb male broilers were randomly divided into 4 dietary treatment groups with 6 replicate pens per treatment group (22 birds each). The dietary treatments were a control starter and grower basal diet without PFA or 150, 750, or 1,500 mg/kg of PFA. Body weight, weight gain, and feed intake were not significantly influenced by the feed additive, but the feed conversion ratio during the grower (22-42 d) and overall (1-42 d) periods improved linearly (P < 0.05) by the administration of PFA compared with that of the control diet. The average weights of the liver, heart, kidneys, and spleen were not significantly affected by the PFA. The results of the apparent ileal digestibility of crude ash, CP, crude fat, calcium, and phosphorus showed a linear increase (P < 0.05) related to the increase of PFA dose in the diet. Therefore, the means of digestibility of these nutrients were significantly higher in birds fed the PFA for all categories of age compared with the digestibility of these nutrients in the controls. In conclusion, the mode of action of the tested PFA can be explained by an improvement in the nutrient digestibility in the small intestine. The underlying physiological mechanisms, however, need to be characterized further.
[Show abstract][Hide abstract] ABSTRACT: N,N-Dimethylglycine (DMG) is a tertiary amino acid that naturally occurs as an intermediate metabolite in choline-to-glycine metabolism. The objective of the present trial was to evaluate tolerance, safety and bioaccumulation of dietary DMG in broilers when supplemented at 1 g and 10 g Na-DMG/kg. A feeding trial was conducted using 480 1-d-old broiler chicks that were randomly allocated to twenty-four pens and fed one of three test diets added with 0, 1 or 10 g Na-DMG/kg during a 39 d growth period. Production performance was recorded to assess tolerance and efficacy of the supplement. At the end of the trial, toxicity was evaluated by means of haematology, plasma biochemistry and histopathology of liver, kidney and heart (n 12), whereas bioaccumulation was assessed on breast meat, liver, blood, kidney and adipose tissue (n 8). Carcass traits were similar between the control and 1 g Na-DMG/kg feed groups (P>0·05), but the feed:gain ratio was significantly improved at 1 g Na-DMG/kg feed compared with the control or the 10-fold dose (P=0·008). Histological examinations showed no pathological effects and results of haematology and plasma biochemistry revealed similar values between the test groups (P>0·05). Bioaccumulation occurred at the 10-fold dose, but the resulting DMG content in breast meat was comparable with, for instance, wheat bran and much lower than uncooked spinach. In conclusion, DMG at 1 g Na-DMG/kg improved the feed:gain ratio in broilers without DMG being accumulated in consumer parts. Furthermore, dietary supplementation with DMG up to 10 g Na-DMG/kg did not induce toxicity or impaired performance in broilers.
The British journal of nutrition 09/2011; 107(11):1635-44. · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess the effects of 2 different phytogenic products on performance, ileal nutrient digestibility, and composition of the intestinal microbiota. The 2 phytogenic products contained different essential oil mixtures (EOM) characterized by either menthol (Mentha arvensis; EOM-M) or cinnamon aldehyde (Cinnamomum aromaticum; EOM-C) as main constituents. Three treatments consisted of control diet without EOM addition and diets supplemented with EOM-M or EOM-C. Reproducibility of the effects was examined in 4 trials with a total of 300 male castrated and female piglets weaned at 25 d of age. The number of pens per treatment in trials I through III were 7, 9, and 9, respectively, for research station conditions, and 10 in trial IV for simulated farm conditions. In research station conditions, the experimental unit consisted of flat deck pens with 2 piglets per pen, whereas it consisted of floor pens with straw bedding with 5 piglets per pen in farm conditions. The feed additives had no effect on feed intake or BW gain. Improvements (P < 0.05) in G:F were observed for EOM-M supplemented diets in 2 of 4 trials as well as for the combined data of all trials. These improvements were associated with greater (P<0.05) apparent ileal digestibility of CP and of most AA. The effect of EOM-C on these response criteria was intermediate between control and EOM-M. Real-time PCR analysis of the gastrointestinal contents for 7 bacterial groups (Lactobacillus spp., Enterococcus spp., Clostridium coccoides and Clostridium leptum cluster, Escherichia spp., and Escherichia coli toxin estII) indicated no effect of treatments on the gastrointestinal microbiota. It was concluded that EOM-M consistently improved feed efficiency in weaned piglets, and it was associated with improved ileal protein and AA digestibility. In general, however, the effectiveness of EOM as feed additives differs considerably depending on the constituents.
Journal of Animal Science 02/2011; 89(7):2106-12. · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present report demonstrates the effect of alpha toxin from Clostridium perfringens on electrophysiological indexes of jejunal mucosa from laying hens pretreated with inulin and N-acetyl-l-cysteine (ACC), a mucolytic agent. In a first set of experiments, the effect of alpha toxin with or without pretreatment with ACC on the electrophysiological parameters was determined when jejunal tissues from laying hens were mounted in Ussing chambers. The short-circuit current remained unchanged when alpha toxin was added mucosally in the tissues whether pretreated with ACC or not. The change in the transmural tissue conductance (DeltaGt) was higher (P = 0.18) after 90 min exposure of toxin independent of pretreament with ACC. The effect of alpha toxin on DeltaGt became significant (P < or = 0.05) after 120 min of incubation. In the second set of experiments, the effect of alpha toxin on the jejunal tissues preincubated with inulin (0.1%) was investigated. The effect of toxin was also time dependent, and DeltaGt became significantly higher (P < or = 0.05) after 120 min of incubation independent of preinubation with inulin. Inulin did not influence the DeltaGt during the experimental period when compared with control tissues. In conclusion, alpha toxin from C. perfringens can impair the intestinal mucosal barrier. The effect is obviously not dependent on the presence of a mucolytic agent nor can it be affected by direct addition of inulin under in vitro conditions. Whether there is an effect of inulin after long-term supplementation in feeding trials or it is due to fermentation bacterial metabolites remains an open question.
[Show abstract][Hide abstract] ABSTRACT: 1. Three bacterial phytases derived from Bacillus, Escherichia coli or Klebsiella were compared with a phytase derived from Aspergillus niger in vitro and in vivo. 2. The in vitro results indicated that Aspergillus, E. coli and Klebsiella phytase displayed their activity optima in an acid pH range while Bacillus phytase did so in neutral pH. 3. The trials also revealed that only Bacillus phytase is more resistant to heat treatments, while E. coli and Klebsiella phytases are more stable against proteolytic inactivation. 4. In vivo phytases derived from Aspergillus, Bacillus, E. coli, Klebsiella or a combination of Bacillus and E. coli improved the utilisation of phosphorus (P balance) significantly to 0.54, 0.54, 0.55, 0.55 or 0.58, respectively, compared to 0.42 in the negative control. 5. The phytases used in this study seemed to be equally effective in improving P utilisation regardless of proposed intestinal site of activity. Combination of phytases acting in the gizzard with phytases acting in the intestine seems to be a promising way to further improving in vivo efficacy of phytases in poultry.
British Poultry Science 03/2007; 48(1):64-70. · 1.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Two 6-week feeding trials were conducted on a total of 112 newly weaned piglets to examine the recently reported growth promoting effects of dietary rare earth elements (REE) in European pig production. Rare earth element-diets were supplemented with a REE-citrate premix of lanthanum and the light lanthanoides cerium, praseodymium and neodymium at 200 mg/kg for 6 weeks after weaning. Overall for both trials, growth performance of REE-citrate and control fed piglets did not differ significantly (p > 0.05). An early enhancive tendency for REE-citrate in trial 1 (feed conversion ratio, FCR -3%, p = 0.15) proved irreproducible in trial 2. In the late period of trial 1, in-feed addition of REE-citrate significantly impaired piglet performance (FCR + 8%, p = 0.01). A cultivation-independent molecular approach, polymerase chain reaction-denaturing gradient gel electrophoresis was further applied to assess REE induced alterations in the predominant faecal microbiota from weaning pigs. Calculation of various ecological characteristics does not indicate (p > 0.05) an often discussed selective effect on local microbial composition of dietary REE.
[Show abstract][Hide abstract] ABSTRACT: An experiment was conducted to determine the effects of a probiotic on selected faecal bacteria of healthy dogs under different feed and environmental conditions. For the study 12 dogs kept in households were used for an 18-day supplementation with a patented commercially available strain of E. faecium NCIB 10415 (Enteroferm). In order to minimize losses the probiotic product was orally applicated once a day before meals at a dose of 2 g per dog (9.2 x 10(9) CFU). The faeces were collected before the beginning of the supplementation and at the end of the 18-day application period. In order to exclude contamination, all faeces were taken rectally. Before and at the end of the experimental period total Salmonella spp., Campylobacter spp. and Clostridium spp. counts were determined in fresh faeces using selective media. It was demonstrated that the 18-day application of the probiotic E. faecium product induced modifications on the gastrointestinal microflora in all dogs. While Salmonella spp. and Campylobacter spp. counts were in majority of the dogs higher than before the application. Clostridium spp. counts were significantly reduced in 10 of 12 dogs. According to the guidelines for the evaluation of the efficiency of microorganisms in dogs a relevant efficacy effect was supported by this data. However, a beneficial effect of the probiotic product on healthy dogs remains questionable.
Archives of Animal Nutrition 07/2003; 57(3):229-33. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the present study, laying hens received 29 g per kg diet of a preparation containing either 70% linoleic acid (LA) or approximately the same amount of conjugated linoleic acid (CLA) in the control and experimental treatments, respectively. The CLA preparation consisted predominantly of cis-9,trans-11 and trans-10,cis-12 fatty acid isomers as free fatty acids in a ratio of 1:1. The diets were fed for 8 wk to determine the effect of dietary CLA on quality characteristics of eggs. In addition, the fatty acid composition of liver and heart was analyzed. Performance parameters (egg weight, feed efficiency) were not significantly affected by feeding the diets supplemented with CLA. The overall amount of CLA that was incorporated into yolk was 7.95 g CLA/100 g total fatty acids, or approximately 400 mg CLA/egg. The transfer efficiency of the cis-9,trans-11 isomer was higher than that of the trans-10,cis-12 isomer; however, the transfer rate of CLA isomers into yolk and tissues was significantly lower than that of linoleic acid. Dietary CLA increased the concentration of saturated fatty acids in yolk and tissues at the expense of monounsaturated fatty acids. The proportions of myristic, palmitic, and stearic acids in yolk lipids were also changed by dietary CLA. Additionally, long-chain polyunsaturated fatty acids (arachidonic acid and docosahexaenoic acid) were decreased without changing the balance of the n-6/n-3 ratio in egg yolk. The inclusion of CLA in layer diets altered the shape of the yolk and various egg parameters (albumen height, foam index, and yolk index). The results of this study indicate that CLA induces various changes in lipid and fatty acid metabolism of laying hens and affects quality characteristics of eggs.
[Show abstract][Hide abstract] ABSTRACT: The effectiveness of an Escherichia coli phytase in comparison with a commercially available Aspergillus phytase in improving the bioavailability of phosphorus in broilers, layers and young pigs was studied in three separate experiments. Three basal diets, marginally deficient in dietary P mainly provided as phytate, were formulated. Both phytases were added to the diets at the rate of 500 U/kg diet. The phytases significantly (P < or = 0.05) improved the availability of phytate P to broilers, layers and young pigs. Aspergillus and E. coli phytases enhanced the pre-caecal digestibility of P by 11 and 29% for broilers and 18 and 25% for layers, respectively. Total tract digestibility of P (P balance) was also enhanced but with smaller magnitude. In pigs, total tract digestibility of P was improved by 33 and 34% by Aspergillus and E. coli phytases, respectively. Under the conditions of this study, it was observed that E. coli consistently, though with small magnitude in layers and pigs, enhanced the availability of phytate P at the same range or slightly better than Aspergillus phytase. It was only in pigs that the availability of Ca was significantly (P < or = 0.05) improved by addition of both phytases. It can be concluded that E. coli phytase is highly effective in improving the bioavailability of phytate P to broilers, layers and young pigs. This seems to be based on the high proteolytic stability of the enzyme in the digestive tract, as shown recently.
Archives of Animal Nutrition 01/2001; 54(2):117-26. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In a performance trial, broiler chickens received 29 g per kg feed of a preparation containing 70% linoleic acid (LA) in the control treatment and another preparation containing approximately the same amount of conjugated linoleic acids (CLA) in the experimental treatment. Diets of CLA treatment contained 18 g CLA per kg feed. The CLA preparation contained the isomers cis-9,trans-11 and trans-10,cis-12 at a proportion 1:1, other CLA isomers were quantitively negligible. Performance parameters (weight gain and feed conversion ratio over a 42 day period) were not significantly influenced by CLA intake. However, fat content of liver, breast, and leg muscles was reduced and protein contents in liver and leg muscles were elevated significantly. Fat to protein ratios in the main edible parts were shifted in favour of protein in CLA treated animals. In all analysed tissue lipids the content of saturated fatty acids was increased and that of monounsaturated fatty acids was decreased significantly. At the same time CLA was incorporated in tissue lipids effectively reaching more than 10 g per 100 g of total fatty acids. With regard to isomers the cis-9,trans-11 isomer was found in higher concentrations in tissue lipid fractions compared to the trans-10,cis-12 isomer. It was concluded that nutrient repartitioning due to CLA intake described for other species is also valid for broilers. Using appropriate feeding strategies it is possible to produce CLA enriched food from broilers.
European Journal of Lipid Science and Technology 07/2000; 102(6):402 - 410. · 2.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The physical and chemical properties of six crude phytase preparations were compared. Four of these enzymes (Aspergillus A, Aspergillus R, Peniophora and Aspergillus T) were produced at commercial scale for the use as feed additives while the other two (E. coli and Bacillus) were produced at laboratory scale. The encoding genes of the enzymes were from different microbial origins (4 of fungal origin and 2 of bacterial origin, i.e., E. coli and Bacillus phytases). One of the fungal phytases (Aspergillus R) was expressed in transgenic rape. The enzymes were studied for their pH behaviour, temperature optimum and stability and resistance to protease inactivation. The phytases were found to exhibit different properties depending on source of the phytase gene and the production organism. The pH profiles of the enzymes showed that the fungal phytases had their pH optima ranging from 4.5 to 5.5. The bacterial E. coli phytase had also its pH optimum in the acidic range at pH 4.5 while the pH optimum for the Bacillus enzyme was identified at pH 7.0. Temperature optima were at 50 and 60 degrees C for the fungal and bacterial phytases, respectively. The Bacillus phytase was more thermostable in aqueous solutions than all other enzymes. In pelleting experiments performed at 60, 70 and 80 degrees C in the conditioner, Aspergillus A, Peniophora (measurement at pH 5.5) and E. coli phytases were more heat stable compared to other enzymes (Bacillus enzyme was not included). At a temperature of 70 degrees C in the conditioner, these enzymes maintained a residual activity of approximately 70% after pelleting compared to approximately 30% determined for the other enzymes. Incubation of enzyme preparations with porcine proteases revealed that only E. coli phytase was insensitive against pepsin and pancreatin. Incubation of the enzymes in digesta supernatants from various segments of the digestive tract of hens revealed that digesta from stomach inactivated the enzymes most efficiently except E. coli phytase which had a residual activity of 93% after 60 min incubation at 40 degrees C. It can be concluded that phytases of various microbial origins behave differently with respect to their in vitro properties which could be of importance for future developments of phytase preparations. Especially bacterial phytases contain properties like high temperature stability (Bacillus phytase) and high proteolytic stability (E. coli phytase) which make them favourable for future applications as feed additives.
Archives of Animal Nutrition 02/2000; 53(4):353-73. · 1.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The effect of two microbial phytases of fungal origin (Peniophora and Consensus phytase) were evaluated for their effectiveness in improving performance and digestibility of P and Ca. A total of 44 multiparous sows were used during gestation (days 28 to 69) and lactation (days 1 to 19). Gestating and lactating sows were fed adequate P (9.9 and 27 g P per day) or low P diets (7.6 and 15.9 g per day) with or without supplementation of Peniophora (pregnancy) or Consensus phytase (lactation) providing 500, 750 and 1000 or 500 and 1000 units per kg diet, respectively. The obtained data generally indicated that graded levels of both phytases were effective in improving apparent phosphorus digestibility during gestation or lactation. The additional phosphorus release achieved when administering the recommended supply of Peniophora phytase (750 PPU/kg feed) was 0.1 g/kg feed in gestating sows, which is equivalent to 0.6 g of monocalcium-phosphate. Consensus phytase administered at the recommended dosage of 500 units per kg for lactating sows provided a release of 0.6 g P per kg feed from phytate, which corresponds to 2.5 g monocalcium-phosphate. The effectiveness of the studied phytases in pregnant or lactating sows is comparable to that in growing pigs.