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1. The aim of the present study was to test the ability of an in-feed modified clinoptilolite zeolite-based mycotoxin binding substance (Minazel® Plus, Patent Co, Misicevo, Serbia; MP) to prevent g...

Supplementation of pharmacological levels of ZnO (3000 ppm) is widely used for prevention and treatment of diarrhea in weaning piglets and to improve their performance. However, this practice has raised concerns about environmental impact, antimicrobial resistance and nutritional interactions. In this study we compared graded amounts of regular ZnO to equivalent levels of potentiated ZnO (HiZox), added to the piglet’s diets. Our aim was to assess possible advantages of different Zn sources as well as a reduction potential regarding the supplemented dose. Therefore, 1440 piglets (initial BW 10.1 ± 1.55 kg) were randomly allotted to 12 dietary treatments: supplementation of 150, 300, 600, 900, 1500 and 3000 ppm of Zn from regular ZnO or equivalent from HiZox. From day 1 to day 14, piglets were fed dietary treatments accordingly; from day 15 to day 28 all groups received HiZox at 150 ppm. Performance was recorded on d 1, 14 and 28 on trial.The highest (P < 0.001) ADG was observed for piglets fed HiZox at 3000 ppm (247 g/d), while HiZox at 900 ppm and regular ZnO at 3000 ppm presented the same ADG values. The subsequent 14-day levelling to 150 ppm of HiZox led on average to similar body weight gains (ZnO: 7.05 kg; HiZox: 6.93 kg). ADFI increased (P < 0.001) in the first 14 d of trial with increasing Zn levels for both sources. Comparison of ZnO at 3000 ppm and HiZox at 900 ppm showed similar effects on improving fecal consistency during the first two weeks after weaning, which may be due to the more effective surface specific area of HiZox than regular ZnO. In conclusion, HiZox at 900 ppm can be used for improving growth performance and fecal consistency during the first two weeks after weaning as an alternative to the pharmacological level of regular ZnO.

The current study evaluated the effects of different inclusion levels of microbial muramidase (Muramidase 007, DSM Nutritional Products) on gastrointestinal functionality by determination of apparent ileal digestibility (AID) of nutrients, investigation of intestinal histomorphology, and quantification of resulting growth performance. Four maize-wheat-soybean experimental diets were produced without (C) and with different dosages of muramidase: low (L, 25,000 LSU(F)/kg), medium (M, 35,000 LSU(F)/kg), and high (H, 45,000 LSU(F)/kg); diets were fed to broilers for 35 d. At the end of the experiment, AID of ether extract (EE), crude protein (CP), Ca, and P were determined and samples of the mid-jejunum and -ileum were collected for histomorphological observations. Data were subjected to ANOVA analysis using the GLM procedure. Orthogonal polynomial contrasts were used to assess linear and quadratic effects of different levels of the muramidase. At the end of the trial, Muramidase 007 supplementation linearly increased body weight gain and decreased feed conversion ratio (FCR) (P ≤ 0.05). Adding the muramidase to broiler diets also linearly increased the European poultry efficiency factor (P ≤ 0.05). Inclusion of the muramidase in broiler diets linearly increased AID of CP, EE, and P (P ≤ 0.05), and the H group had a higher AID of EE and CP compared to C group (P ≤ 0.05). Microbial muramidase supplementation linearly increased ileal villus length to crypt depth ratio and decreased the number of ileal CD45 cells (P ≤ 0.05). Broilers fed M and H diets had fewer number of CD45 cells in the ileum compared to those in C group (P ≤ 0.05). In conclusion, the results of the present study demonstrated that inclusion of the microbial muramidase in broiler diets could increase AID of key nutrients and improve growth performance in broilers. Adding microbial muramidase to broiler diets can therefore be considered as an interesting prospect to improve gastrointestinal functionality. Biological mechanisms causing these improvements need to be studied further.

1. The aim of the present study was to test the ability of an in-feed modified clinoptilolite zeolite-based mycotoxin binding substance (Minazel® Plus, Patent Co, Misicevo, Serbia; MP) to prevent gastrointestinal absorption of aflatoxin B

1. Two series of studies were conducted to determine the effects of a combination of ground plant material derived from Quillaja saponaria trees and Yucca schidigera plants (QY) as sources of saponin, on performance, productivity, nutrient digestibility and ileal morphology of growing broilers. In each trial, 480 Cobb male birds were allocated equally to 24 pens at one-day-of-age according to body weight 2. The studies consisted of two identical floor pen trials in which performance and nutrient digestibility were assessed and two trials where performance and ileal morphology were determined. In each trial, 0, 250 or 500 ppm QY were included in feed given to the broilers from 1-35 or 1-42 d of age, respectively. Eight (digestibility) or 12 (morphology) randomised replicate pens were used. 3. In the digestibility trials, two birds per pen were moved to metabolism cages at d 21. Excreta was collected for a five-day period (d 21 to 25) for the determination of apparent total tract digestibility of dry and organic matter, fat and ash and nitrogen retention. For intestinal morphology, ileal segments were collected from four birds/pen on d 21 to determine villus height and crypt depth. Performance data were collected in each trial series. 4. Results showed that feeding graded levels of QY produced significant linear improvements in performance and productivity at d 35, and similar linear effects were observed for N retention and all apparent digestibility measurements. Morphology data showed that birds receiving 250 and 500 ppm QY had significantly increased villus height 5. These results indicated that QY exerted a positive influence on the intestinal tract by increasing the absorptive surface and improving nutrient digestibility. These effects were considered to be associated with the performance improvements recorded in both experiments.

The current study investigated the impacts of supplementation of post-weaning piglet diets with Macleaya cordata extract (MCE) and naringin (NAR) on performance, nutrient digestibility and intestinal histomorphology. Post-weaning crossbred piglets (28 males and 28 females; age at weaning 25 d) were randomly allotted to 28 pens. The experiment consisted of a control and three treatment groups (MCE60, MCE120 and NAR). For diets MCE60 and MCE120, the control diet was supplemented with 60 and 120 mg Sangrovit® Extra (a standardised premixture of MCE) per kg diet, respectively. Group NAR received 50 mg pure NAR per kg diet. The experiment lasted 42 d (d 25 - 66 of age). At d 66, apparent pre-caecal digestibility (APD) of nutrients was determined and histomorphological changes in mid-jejunum were evaluated. Feeding diets MCE120 and NAR improved body weight gain and feed conversion ratio of piglets. After feeding diets MCE120 and NAR, the APD of phosphorus and different single and total amino acids were greater than after feeding the control diet. The present data demonstrated that supplementation of post-weaning piglet diets with 120 mg MCE or 50 mg NAR per kg diet could improve growth performance and nutrient digestibility and had no impact on histomorphological variables in the jejunum. These findings indicate the potential of these products to be used as growth promoters in pig nutrition.

The present study evaluated effects of fermentation with or without enzymes (phytase, pectinase and β-glucanase) on the nutritional quality of rapeseed cake (RSC). The impact on growth performance and nutrient digestibility in broilers as a consequence of substituting soybean meal (SBM) in the diet with fermented RSC was also investigated. A standard maize-wheat-SBM diet was used as the control (CON). Second experimental diet was produced using untreated RSC (NR; 150 g/kg) as a substitute for SBM. Third and fourth diets were produced using RSC that had been fermented either without (SFR; 321.8 g/kg) or with (EFR; 312.8 g/kg) enzymes. For these two diets, the same diet formulations as NR diets were used. However, since DM content of the fermented products was considerably lower than untreated RSC (355 and 345 vs. 928 g/kg), the inclusion rate of the fermented products in the EFR and SFR diets were adjusted to have the same amount of rapeseed cake DM in the SFR and EFR diets as it was included in the NR diets. A fifth diet (NRE) was produced using 150 g/kg untreated RSC and in-feed inclusion of the same enzymes (at the same inclusion level) as present in the EFR diet. Performance variables were recorded and the coefficient of apparent ileal digestibility (CAID) of crude protein, fat, amino acids, Ca and P was determined at the end of the trial (d 35). Data were subjected to ANOVA using the GLM procedure. Fermentation of RSC with enzymes effectively reduced its phytate and insoluble-NSP content, but in the absence of enzymes, fermentation had only a moderate effect on reducing insoluble-NSP concentration. The dietary treatments had no impact on body weight gain or feed intake in this study (P > 0.05). At the end of the starter period (d 1-21) and entire experiment (d 1-35), feed conversion ratio (FCR) in broilers fed the NRE diet was lower compared with those receiving the CON or NR diet (P ≤ 0.05). At d 1-21, broilers in the EFR treatment group displayed lower FCR than those in the CON or NR group, but at d 35, birds fed the EFR diet showed lower FCR compared with those fed the NR diet (P ≤ 0.05). The experimental diets had no impact on CAID of crude protein, fat and all of the amino acids, except cysteine and glycine (P > 0.05). Birds receiving the EFR and NRE diets showed higher CAID of P compared with those fed the CON, NR or SFR diet. Birds in the NRE group showed higher CAID of Ca compared with those in the NR or SFR group, with those in the NR group presenting the lowest CAID of Ca (P ≤ 0.05). In conclusion, enzymatic fermentation of RSC effectively reduced its anti-nutrient content. Partial replacement of SBM with RSC in broiler diets had no negative impact on digestibility of the nutrients and growth performance of broilers. Furthermore, inclusion of enzymatically fermented RSC in broiler diets and supplementation of the diets containing untreated RSC with a mixture of phytase, pectinases and β-glucanase could improve the CAID of some of the nutrients and led to better feed efficiency for these diets.

This study evaluated the effects of phytogenics on performance, stool firmness, mortality and morbidity of weaned pigs housed in a commercial farm with historic incidence of post-weaning diarrhea associated with pathogenic E. coli. A total of 540 pigs (BW 7.34±0.9kg;) were used in a 42-day trial. Pigs were allotted by BW and sex into 30 pens (18pigs/pen). Pigs were fed a 2-phase feeding program, with each period being 14 and 28-d, respectively. Dietary treatments were: 1) Control and 2) Phytogenics (1,000 ppm Fresta®Protect, Delacon Biotechnik GmbH). Fecal score was determined daily by pen during the first 14-days (1=liquid diarrhea; 2=pasty feces; 3=formed feces; 4=well-formed feces; 5=hard feces). At day 42, fecal samples (n=15) were analyzed for copy numbers of the virulence factor genes fae (F-4 fimbria) and est-II (heat-stable toxin) by qPCR. Growth performance was not affected by treatments during phase 1. The ADG during phase 2 and overall period increased for pigs supplemented with phytogenics compared to control treatment (531 vs 501 g, P=0.015; 394 vs 375 g, P=0.025; respectively). Consequently, phytogenics tended to improve feed conversion during phase 2 and overall period compared to control treatment (1.48 vs 1.52, P=0.08; 1.46 vs 1.50, P=0.10). Phytogenics improved fecal score (3.8 vs 3.6, P< 0.001), livability (97.4% vs 96%) and decreased the percentage of pigs that required medicine to control post-weaning diarrhea (1.8% vs 2.9%) compared to the control treatment. E. coli virulence factors in feces of animals supplemented with phytogenics were numerically lower than those fed the control treatment (8.5 vs 8.9 log10/g fae gene, P=0.32; 6.8 vs 7.2 log10/g est-II gene, P=0.50). Results suggest that the phytogenics used in this experiment is beneficial during post-weaning diarrhea outbreaks by improving performance and livability and by reducing the cost associated with medical treatments in weaned pigs

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. The present study examined the impacts of native, fermented or enzymatically treated peas (Pisum sativum L.) inclusion in broiler diets, on growth performance and nutrient digestibility. For the fermentation process, Madonna pea was mixed with water (1/1) containing 2.57×108 Bacillus subtilis (GalliPro®) spores/kg pea and then, incubated for 48 h at 30 °C. For the enzymatic treatment process, the used water for dough production contained three enzymes, AlphaGalTM (α-galactosidase), RONOZYME® ProAct and VP (protease and pectinases respectively – DSM, Switzerland) and the pea dough incubated for 24 h at 30°C. Nine corn-wheat-soybean diets were formulated by supplying 10%, 20% and 30% of the required CP with either native, fermented or enzymatically treated peas. Performance was recorded weekly and at the end of the experiment (day 35), apparent ileal digestibility (AID) of CP, amino acids (AA), crude fat, starch, Ca, P and K were determined. Data were subjected to ANOVA using GLM procedure with a 3×3 factorial arrangement of treatments. Both processes reduced α-galactosides, phytate, trypsin inhibitor activity and resistant starch in peas. Increasing levels of pea products up to 300 g/kg diet, reduced BW gain and feed intake (P⩽0.05). Broilers fed diets containing enzymatically treated pea had the best feed conversion ratio at day 35. Different types of pea product and their inclusion levels had no effect on AID of all nutrients. The interaction between type of the pea products and inclusion levels was significant for AID of starch. For native pea diets, 10% group showed similar AID of starch to 20% native pea but it had higher AID than 30% native pea. For fermented and enzymatically treated groups, all three levels displayed similar AID of starch. In conclusion, enzymatic treatment and fermentation could improve the nutritional quality of pea. Inclusion of enzymatically treated pea in broiler diets could improve broiler performance compared with other pea products while, it displayed neither positive nor negative impact on nutrient digestibility. The present findings indicate the feasibility of these processes, particularly enzymatic treatment, for improving the nutritional quality of pea as a protein source for broiler nutrition.

Inclusion of phytogenic feed additives (PFA) in feed may enhance performance of broilers. Levels of essential oils in powdered form (characterized by menthol and anethole) at 150 mg/kg (P-150) and matrix-encapsulated form (characterized by carvacrol, thymol, and limonene) at 100 mg/kg (ME-100) were supplemented in diet to investigate their effect on performance (trial 1) and apparent ileal digestibility (AID) of nutrients (trial 2) in broilers. A total of 480 1-day-old broilers (Cobb 500) were used in trial 1 and 120 broilers in trial 2. Broilers were distributed in 24 pens with 8 pens per treatment (trial 1) and 6 pens with 2 pens per treatment (trial 2), with 20 birds per pen. Feed and water were offered ad libitum throughout the experimental periods in both trials. In trial 1, body weight of birds at d 42 and overall body weight gain from d 1 to d 42, was higher in treatment ME-100 than birds in control treatment (P = 0.023 and P = 0.024, respectively). Feed efficiency during finisher phase was improved in treatment ME-100 relatively to control and P-150 treatments (P = 0.035). At d 21 in trial 2, the apparent ileal digestibility of crude protein was higher in ME-100 treatment in comparison with control and P-150 treatments (P < 0.001). Apparent ileal absorption (AIA) of phosphorus was higher in ME-100 treatment than control treatment (P = 0.028). AID of cysteine was higher in both phytogenic additive supplemented treatments in comparison with control treatment (P = 0.001). In conclusion, inclusion of a powdered phytogenic additive characterized by menthol and anethole at 150 mg/kg had no effect but only a tendency towards improved performance and AIA of phosphorus, whereas essential oils addition in encapsulated form characterized by caravacol, thymol, and limonene at 100 mg/kg improved performance as well as apparent ileal digestibility of nutrients in broilers, possibly due to improved secretion of digestive enzymes.

The aim of the present in vivo study was to evaluate the efficacy of a novel multicomponent mycotoxin detoxifying agent, as mineral premix consisting of modified zeolite, Bacillus spp., yeast cell wall and silymarin (MMDA; Patent Co, Misicevo, Serbia), in-feed to adsorb mycotoxins zearalenone (ZEN) and T-2, administered through feed in weaned pigs. In total, 112 post-weaning barrows and gilts (Danbred x Pietrain) from the 25th day of age (day 0 of the trial) until 66th day of age (end of trial) were allocated in four trial groups. Each group consisted of 28 pigs placed in seven pens (replicates) with four animals in each pen. Group G1 served as control group that received feed without any mycotoxins or MMDA; Group G2 received feed with spiked corn and wheat reaching contamination levels of 0.35 mg ZEN/kg and 0.5 mg T2/kg feed. Group G3 received contaminated feed (similar contamination levels with G2 group) with the additions of 1 g MMDA/kg, whereas G4 group received also contaminated feed (similar contamination levels with G2 group) with the addition of 3 g MMDA/kg. Growth performance (body weight, average daily gain, feed conversion ratio), as well as hematological and serum biochemical parameters, fecal scoring, gross pathology, and mycotoxins residue levels in liver, spleen, kidneys and muscle tissue were assessed. Results suggested that inclusion of MMDA in trial diets induced dose-dependent reduction of genital organs (sum of ovaries, cornu uteri and vagina-vestibule) relative weight and vulva size, which had been increased due to ZEN ingestion in G2 group. Additionally, in both groups that received MMDA, significantly reduced residue levels of ZEN in liver and kidney samples were observed, in comparison with G2 group. Significant residue levels reduction of T-2/HT-2 toxins was also observed in kidney samples of MMDA-fed groups when compared with G2 group. Taken together MMDA added to diets containing ZEN and T-2 toxin has a dose dependent affinity for ZEN and to a lower extend for T2 toxin, whereas such effect seems greater at inclusion level of 3 g MMDA/kg feed.

The grinding of cereals by various milling methods as well as thermal treatment of feed may influence mineral digestibility and egg quality. The present study investigated the effect of feed produced by disc mill (D) and wedge-shaped disc mill (WSD), as mash (M) or expandate (E) on apparent ileal absorption (AIA) and apparent total digestibility (ATD) of calcium, phosphorus, magnesium, zinc, manganese, copper and iron, as well as on egg quality in laying hens. A total of 192 hens (Lohmann Brown) aged 19 wk, were assigned using a randomized design with a 2 × 2 factorial arrangement. Four experimental diets were offered ad libitum. Eggs were analyzed for weight, shape index, area, shell weight per unit surface area, yolk color, air cell, blood spot, Haugh unit, albumen and yolk measures (index, weight, height, width and length), shell measures (surface area, stability, density, thickness and membrane weight), as well as percent contents of albumen, yolk, shell, and shell membrane. The ATD for phosphorus, manganese, and copper was higher in WSD compared with D treatment (P = 0.028, P = 0.028 and P = 0.016, respectively). The interaction between milling methods and thermal treatment influenced ATD of copper (P = 0.033), which was higher in WSD+M group (41.0 ± 20.2) compared with D+E group (-3.21 ± 25.1), whereas no differences were observed for D+M (1.90 ± 37.8) and WSD+E (8.02 ± 36.2) groups. Egg stability tended to be higher in E compared with M treatment (P = 0.055). Albumen weight, percentage albumen weight, and albumen: yolk were higher and percentage yolk weight was lower in D compared with WSD treatment (P = 0.043, P = 0.027, P = 0.024, and P = 0.041, respectively). Number of blood spots was higher in E than M treatment (P = 0.053). In conclusion, use of a wedge-shaped disc mill resulted in higher ATD for phosphorus, manganese, and copper than use of a disc mill; however, digestibility for majority of minerals as well as egg quality parameters was comparable. Therefore, feed produced by either disc mill or wedge-shaped disc mill as mash or expandate may be used for laying hens without negative effects on egg quality.

The immune response of piglets to a vaccination against the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) was tested after feeding different feed additives. The trial included four groups of ten piglets and lasted 39 days. Feed additives were added to a control diet (C). Tested substances included an autolyzed yeast preparation from Saccharomyces cerevisiae (YA) at 0.2%, dried bovine colostrum (CM) at 0.9% and the probiotic Bacillus cereus var. toyoi NCIMB 40112 (BC) at 109 colony forming units/kg diet. Three-week-old piglets were vaccinated against PRRS-Virus, blood samples were taken before vaccination and 7, 21, and 35 days after vaccination for complete blood counts, flow cytometry for phenotyping of different lymphocyte subsets in peripheral blood, measurement of specific IgG antibodies and ELISpot assay to detect specific interferon γ-producing lymphocytes. Animal performance was not affected by the experimental diets. Hematological parameters and complete blood counts displayed time-dependent changes, feed-related effects were not observed. The analysis of the expressed lymphocyte surface markers showed distinct time dependent shifts but no dietary effects. CD4−CD8α+ cells reached highest levels on day 21 post vaccination and decreased thereafter (P=0.037), the CD2+CD5− cells decreased in all groups towards day 35 (P

The present study evaluated the impacts of Bacillus subtilis (BAS) inclusion in broiler diets with standard nutrient content or nutrient deficiency (ND) on growth performance (GP) and nutrient digestibility. The 42 d experiment consisted of 6 experimental diets, a diet with standard nutrient content, and 2 diets with different levels of energy and protein deficiency, without or with BAS. At the end of experiment, apparent ileal digestibility coefficients (AIDC) of starch, crude protein (CP), and gross energy (GE) were determined. Furthermore, impacts of BAS supplementation in standard diets on gut histomorphology, bacterial metabolic activity, and composition were evaluated. Performance and AIDC data were subjected to ANOVA using GLM procedure with a 3 (nutrient levels) × 2 (BAS presence/absences) factorial arrangement of treatments. Gut histomorphology and microbiology data, obtained from broilers fed standard diets without (S) and with BAS (SB), were assessed by an independent Student's t-test. The ND in diets was effective enough to cause nutritional stress and negatively affect performance. Inclusion of BAS in both types of diet improved GP, which was due to the fact that adding BAS in these diets led to improvements in AIDC of CP, starch, and GE (P ≤ 0.05). Comparing only 2 experimental groups, S and SB, revealed no impact on bacterial composition and metabolism in the ileum and cecum, except a reduction in ileal lactobacilli number for SB group. Adding BAS to standard diet reduced crypt depth (CD) and increased villus length to CD ratio in the duodenum, whereas it had no impact on other histomorphological variables in the duodenum, jejunum, and ileum. In conclusion, supplementation of broiler diets with probiotic BAS can positively affect growth performance and nutrient digestibility and this positive impact might even be more pronounced in nutrient-deficient diets. However, the extent of the alleviating ability of BAS in nutrient-deficient diets as well as the biological mechanisms for such a phenomenon needs to be studied further.

Phytogenic feed additives represent a potential alternative to antibiotics with attributed health and growth-promoting effects. Chickens supplemented with an essential oil blend, a Quillaja saponin blend, or a combination of both phytogenic preparations showed a comprehensively and significantly improved apparent ileal digestibility of crude protein and amino acids compared to control birds. Accordingly, holistic transcriptomic analyses of jejunum and liver samples indicated alterations of macromolecule transporters and processing pathways likely culminating in an increased uptake and metabolizing of carbohydrates and fatty acids. Complementary analyses in Caco-2 showed a significant increase in transporter recruitment to the membrane (SGLT1 and PEPT1) after addition of essential oils and saponins. Although the penetrance of effects differed for the used phytogenic feed additives, the results indicate for an overlapping mode of action including local effects at the intestinal border and systemic alterations of macronutrient metabolism resulting in an improved performance of broilers.

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.

Poultry feed is a potential vector for pathogens. Heat processing and organic acid treat- ments may decontaminate feed and can affect bird performance as well as feed digestibility. The present study was performed to investigate the effect of differ- ent 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) with- out or with 0.75 and 1.5% organic acid supplementa- tion (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 vari- ables 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 digest- ibility 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 nutri- ent digestibility, whereas pelleting and expansion, in- dependently of organic acid addition, seemed to have no negative impact on broiler performance and nutri- ent digestibilities. Moreover, adding a blend of organic acids to broiler diets had neither positive nor negative effects on nutrient digestibility and final broiler per- formance. This indicates the feasibility of short-term thermal treatment and acid supplementation for hy- gienization of broiler feed without negatively influenc- ing performance.

1. The present study investigated the effects of encapsulated benzoic acid (BA) supplementation in broiler feed on performance and gastrointestinal microbiota. 2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize-soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix. 3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum. 4. Growth performance variables and pH were not significantly different. 5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum. 6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment. 7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified. 8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum. 9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens.

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

Eleven mature, non-lactating, non-pregnant, Holstein-Friesian crossbred cows were given, via a ruminal cannula, 2000mEq of one of three chloride salts, four sulfate salts, two combinations of anionic salts (AS), sodium chloride (as neutral salt), or water as control. The salts and controls were assigned in an 11x11 Latin square and the cows were randomly distributed. All of the AS induced a metabolic acidosis that resulted in a small reduction of blood pH, base excess, and bicarbonate (P0.001), and notable changes in urinary pH, net acid base excretion (P0.001), and urinary calcium excretion (P0.001). Only calcium chloride had a significantly greater impact on acid-base status (ABS) than the sulfate salts. The effect of other chloride salts did not differ from calcium sulfate. There was no indication that chloride salts in general have a greater impact than sulfate salts on the ABS.

Zusammenfassung 4 times 6 LSL Hybridlegehennen wurden ab der 15. Lebenswoche (LW) auf eine Se-Mangeldiat mit 0,06 mg Se/kg Alleinfutter gesetzt. Mit Ausnahme der Kontrollgruppe A erhielten ab der 19. LW die Versuchsgruppen B = 0,3, C = 0,9 und D = 1,5 mg Se als Na2SeO3/kg Alleinfutter zugemischt. Die Glutathionperoxidase-Aktivitaten wurden in der 19., 23., 29. und 33. LW im Plasma und die spezifischen Aktivitaten im Maximum der Legeleistung in der 33. LW in Erythrozyten und Leber bestimmt. Im Plasma zeigte die selenabhangige Glutathionperoxidase (Se-GSH-Px) mit Eintritt der depletierten Junghennen in die Geschlechtsreife in Gruppe A einen Aktivitatsabfall von 2 auf 1 U37/ml Plasma. Bei den repletierten Tieren ergaben samtliche Zusatze ein einheitliches Plateau im Bereich von 3 U37/ml Plasma. Diese Befunde korrespondieren mit den in der Leber gemessenen Aktivitaten und zeigen an, das legende Hennen einen deutlich hoheren Se-Bedarf haben als Junghennen. Weiterhin war festzustellen, das der Anteil der Se-GSH-Px Aktivitat an der Gesamt-GSH-Px Aktivitat in der Leber von Legehennen von der Hohe der Se-Versorgung abhangt. — Im Gegensatz zum Verhalten der Se-GSH-Px Aktivitaten in Plasma und Leber, die bei zunehmender Se-Versorgung eine Plateaubildung erkennen lassen, steigt die Se-GSH-Px Aktivitat in den Erythrozyten mit steigender Se-Dosis signifikant linear an. Summary Influence of selenium supplements on glutathion-peroxidase activities in erythrocytes, plasma and liver of young and laying hens 4 times 6 LSL hybrid laying hens, from the 15th week of life, were kept on a Sedeficient diet with 0.06 mg Se/kg. Except for the control group A, the experimental groups received from the 19th week of life added Se — Group B 0.3, Group C 0.9 and Group D 1.5 mg Se as Na2SeO3/kg. The glutathion peroxidase activity was measured at weeks 19, 23, 29 and 33 in the plasma and the specific activity in red cells and liver was determined at the height of egg-laying in the 33rd week. The Se-dependent glutathion-peroxidase (Se-GSH-Px) in plasma when the young hens that were depleted of Se became sexually mature in Group A showed a fall in activity from 2 to 1 U37/ml plasma. In the supplemented birds the Se supplements produced a raised plateau of around 3 U37/ml plasma. These findings corresponded with the activities measured in the liver and showed that laying hens have a markedly higher requirement of Se than young hens. It was also established that the amount of Se-GSH-Px activity in the total GSH-Px activity in the liver of laying hens depends on the intake of Se — in contrast to the behaviour of Se-GSH-Px activities in plasma and liver, which form a plareau with increasing Se supply, the Se-GSH-Px activity in the erythrocytes shows a significant rising linear relationship with increasing dosage of se. Resume Influence d'addition de selenium sur les activites de la glutathion-peroxydase dans les erythrocytes, le plasma et le foie chez des poules jeunes et pondeuses 4 times 6 poules LSL ont recu a partir de la 15e semaine de vie une alimentation unique carencee en selenium avec 0,06 mg Se/kg. A l'exception du groupe de controle A, les groupes d'experience ont recu des la 19e semaine pour B = 0,3, C = 0,9 et D = 1,5 mg Se sous forme de Na2SeO3/kg d'aliment unique. Les activites de la glutathionperoxydase ont ete determinees dans le plasma a la 19e, 23e, 29e et 33e semanine de vie et les activites specifiques au maximum de la periode de ponte dans les erythrocytes et le foie durant la 39e semaine. La glutathion-peroxydase dependante du selenium (Se-GSH-Px) dans le plasma a montre une chute d'activite de 2 a 1 U37/ml de plasma avec l'entree des jeunes poules carencees dans la maturation sexuelle pour le groupe A. Tous les supplements chez les animaux compenses ont donne un plateau uniforme dans la marge de 3 U37/ml de plasma. L'activite s'est reduite a 0,1 U37/ml de plasma chez les controles carences apres l'installation en production de ponte. Seulement des supplements de 0,9 et 1,5 mg dans les groupes C et D ont conduit a la formation d'un plateau aux alentours de 2 U37/ml de plasma. Ces resultats correspondent avec les activites mesurees dans le foie et montrent que des poules pondeuses ont un besoinnettement plus eleve Se que les jeunes poules. On a etabli de plus que la part de l'activite de Se-GSH-Px sur l'activite de GSH-Px total depend dans le foie des pondeuses de la quantite d'approvisionnement en Se. Contrairement au comportement des activites de Se-GSH-Px dans le plasma et le foie qui laissent apparaitre la formation d'un plateau avec un approvisionnement en Se progressif, l'activite de Se-GSH-Px dans les erythrocytes augmente significativement et lineairement avec une dose progressive de Se. Resumen El influjo de la adicion de selenio sobre las actividades de la glutationperoxidasa en los eritrocitos, plasma e higado de pollitas jovenes y ponedoras 4 × 6 pollitas ponedoras hibridas LSL se pusieron a partir de la 15a semana de vida (SV) a dieta carencial de Se con 0,06 mg Se/kg pienso unico. Excepcion hecha con el grupo testigo A, se les mezclo a partir de la SV 19a a los grupos de ensayo B = 0,3, C = 0,9 y D = 1,5 mg de Se en forma de Na2SeO3/kg de pienso unico. Las actividades de la glutation-peroxidasa fueron valoradas en la 19a, 23a, 29a y 33a SV en el plasma sanguineo y las actividades especificas en el maximo de la puesta en la 33a SV en los eritrocitos e higado. En el plasma mostraba la glutation-peroxidasa dependiente del selenio (Se-GSH-Px) con la entrada de las pollitas jovenes depletadas en la madurez sexual en el grupo A un descenso en la actividad de 2 a 1 U37/ml de plasma. En los animales repletados ofrecieron todos los suplementos una meseta uniforme en el ambito de 3 U37/ml de plasma. Correspondian estos hallazgos con las actividades medidas en el higados y senalan que las pollitas ponedoras tienen una demanda de Se mucho mayor que las pollitas jovenes. Se comprobo ademas que la fraccion de la actividad Se-GSH-Px en la actividad GSH-Px total en el higado de las ponedoras depende del nivel del abastecimiento de Se. Contrariamente al porte de las actividades de la Se-GSH-Px en el plasma e higado, las cuales permiten reconocer con abastecimiento creciente de Se la formacion de una meseta, aumenta la actividad de la Se-GSH-Px en los eritrocitos con dosis crecientes de Se de forma lineal significativa.

Zusammenfassung Der Einfluβ der Futterungsintensitat auf den Energiestoffwechsel bei der Legehenne vor Legebeginn Sechs weiβe Leghorn-Junghennen erhielten ein handelsubliches Futter und sechs weitere Tiere 80% der ad libitum verzehrten Futtermenge. Die Versuchsperiode lag zwischen der dritten und der dreizehnten Lebenswoche. In vier aufeinander folgenden Bilanzperioden wurde die Protein- und Fettretention sowie die Verwertbarkeit der umsetzbaren Energie in Korperenergie gemessen. Auβerdem wurde vor Legebeginn der Gehalt an 17-β-Estradiol im Blutplasma bestimmt. Die restriktive Futterung fuhrte zu niedrigeren Korpergewichtszunahmen und verzogerte das Eintreten der Geschlechtsreife. Vor Legebeginn erhohte sich der Energieansatz auf der Basis der umsetzbaren Energie bei ad libitum gefutterten Hennen von 29 auf 37%, bei den restriktiv gefutterten Hennen nur von 21 auf 29%. Entsprechend war der energetische Ansatz fur Protein und Fett, bezogen auf das metabolische Korpergewicht (kg0.75), bei den ad libitum gefutterten Hennen deutlich hoher als bei restriktiv gefutterten Tieren. Unmittelbar vor Legebeginn sank bei allen Hennen der energetische Ansatz in Form von Protein deutlich ab. Im Gegensatz hierzu erhohte sich der energetische Ansatz fur Fett signifikant. Mit zunehmendem Fettansatz stiegen die 17-β-Estradiol-werte im Blutplasma bei ad libitum gefutterten Junghennen von 49 auf 596 pg/ml und bei restriktiv gefutterten Junghennen von 36 auf 212 pg/ml.

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.

We evaluated the impact of the dietary cation-anion difference (DCAD) on the influence of anionic salts (AS) on the metabolism of dairy cows using a study-design that included control of feed intake. Ten mature, non-lactating, non-pregnant, Holstein-Friesian-crossbreed cows received 2000 mEq of either one of the seven anionic salts tested, two combinations of the anionic salts or water as control via a rumen cannula. Salts and controls were assigned in a 10×10 Latin square design. Whole blood, serum and urine samples were taken during treatment (TP) and washout period. Samples of whole blood were tested for pH, base-excess and bicarbonate concentrations. In urine, pH and net acid-base excretion (NABE) were analysed. Calcium was measured in serum and urine. According to the different batches of hay, five groups of DCAD were created regarding cluster analysis. Changes in urine and blood parameters were statistically analysed for each DCAD group separately. The different DCAD had an impact on the amount of change in acid-base balance (ABB) and calcium metabolism and for how long these changes lasted. In the DCAD group receiving the highest amount of AS (239 mEq/kg dry matter with AS), changes of ABB were only noticeable in urine and these changes only differed from day zero in the first week of TP (PPPPP

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.

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.

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.

Feed production with different milling methods, thermal treatment, and particle size may influence mineral digestibility and retention in eggs. The present study investigated the impact of roller (R) and hammer (H) mills, mash (M) and expandate (E) with fine (F) and coarse (C) particle sizes, on apparent ileal absorption (AIA) and apparent total digestibility (ATD) and retention of calcium, phosphorus, magnesium, zinc, manganese, copper and iron in yolk, albumen, and shell. A total of 384 hens (Lohmann Brown), 19 weeks old, were assigned using a randomized design with a 2×2×2 factorial arrangement. Eight experimental diets were offered ad libitum during the whole experimental period and one week before for diet adaption. The AIA of magnesium, zinc, copper, and iron was higher in treatment R in comparison with treatment H (P

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.

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.

The efficacy of a thermotolerant 6-phytase on performance and apparent total tract digestibility (ATTD) of P and Ca was evaluated in 96 crossbred barrows (8 replicates with 3 pigs each) fed 4 diets. Diets based on corn (Zea mays), a heat-treated grain mix, and soybean (Glycine max) meal with recommended [positive control (PC)] or reduced [negative control (NC)] P and Ca levels were fed from 25 to 115 kg BW. The PC diets contained 0.61% P and 0.72% Ca from 25 to 45 kg, 0.59% P and 0.66% Ca from 45 to 70 kg, and 0.48% P and 0.51% Ca from 70 kg to final BW. The NC diets were reduced in digestible P by 2.0, 2.0, and 1.1 g/kg and in Ca by 1.4, 1.0, and 0.8 g/kg, respectively, for the 3 phases. Phytase was added at 0, 250, and 500 phytase units (FTU)/kg to the NC diet. Performance was measured at the end of each feeding period and ATTD of P and Ca evaluated for a 3-d collection following a 7-d adaptation at an average BW of 45, 70, and 116 kg. Final BW of NC pigs (111.9 kg) was increased (P < 0.05) by P addition (120.3 kg; PC) and by phytase inclusion at both rates (116.5 and 117.6 kg, respectively). The ADG of NC pigs (781 g) was increased (P < 0.05) by both phytase levels (5.5 and 6.6%); pigs fed 500 FTU/kg achieved similar ADG as PC pigs (833 and 858 g, respectively). The G:F was reduced (P < 0.05) in NC pigs (0.308) compared to pigs fed the PC diet (0.328) or diets with 250 or 500 FTU phytase/kg (0.324 and 0.330, respectively). The ATTD of P was lowest in all periods for pigs fed NC diets (35.5% in starter, 32.2% in grower, and 32.1% in finisher period). Phytase increased (P < 0.05) ATTD of P in all periods at both application rates. Pigs fed 500 FTU/kg diet had a higher (P < 0.05) ATTD of P than pigs fed 250 FTU/kg and an ATTD of P at least similar to pigs fed PC. Similar but less pronounced effects were observed for ATTD of Ca. The phytase added to grower-finisher diets with reduced P and Ca nearly restored performance to the level of pigs fed diets with adequate P and Ca.

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.

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.

To evaluate whether the different anionic salts used in the prevention of parturient paresis have an impact on the ruminal pH and the production of short-chain fatty acids (SCFA) in mature non-pregnant, non-lactating cows.Eleven Holstein-Friesian crossbred cows were administered 2,000 mEq of either one of three chloride salts, viz CaCl2, MgCl2, or NH4Cl; four sulphate salts, viz CaSO4, CaSO4 with a grain size of 10 microm, MgSO4, or (NH4)2SO4; two combinations of anionic salts, viz CaCl2+MgSO4, or CaSO4+NH4Cl; NaCl; or water, via a ruminal cannula over a 14-day treatment period. The salts and controls were assigned in an 11 x 11 Latin square, and the cows were distributed randomly. Ruminal fluid was collected four times in each treatment period for monitoring the ruminal pH, and four times a day at Days 7 and 14 for monitoring any changes in the concentrations of SCFA.Feeding anionic salts did not change the ruminal pH, total concentration of SCFA, or distribution pattern of the main SCFA acetic acid, propionic acid, butyric acid or valeric acid (p0.05).Feeding anionic salts has no negative side effect on the ruminal pH and concentrations of SCFA in mature non-pregnant, non-lactating cattle. Impaired function of the rumen due to the feeding of anionic salts is not likely.

Two experiments with a total of 100 White Leghorn hens (26 to 59 wk of age) and 120 Rhode Island Red chickens (4 to 12 wk of age) were conducted to study the effect of 100 mg zinc bacitracin (ZBA)/kg of feed on hens and chickens acclimatized to 20 or 34 C environments. Layers were provided ad libitum access to a diet containing 11.12 MJ ME/kg (1 MJ = .239 Mcal) and 174 g CP/kg supplemented with 0 and 100 mg ZBA/kg. Body weight gain, egg number, total egg mass, and feed efficiency of ZBA-treated hens kept at a moderate temperature (20 C) were not significantly improved by 3.5, 2.6, 3.3, and 3.1%, respectively. However ZBA supplementation induced a more pronounced increase in performance in heat-stressed hens. The respective traits were significantly improved by 66.3, 15.4, 16.9, and 5.9%. Additionally, treated hens maintained at 34 C consumed significantly more feed than untreated hens. Eggshell breaking strength of treated hens held under normal conditions was not significantly improved. Feeding ZBA to heat-stressed hens led to a statistically higher breaking strength. Supplementation with ZBA for hens acclimatized to 20 and 34 C reduced fasting heat production by 4.1 and 7.6%, respectively. However, in the 20 C environment the differences were significant at only one of seven ages. The upper critical temperature (UCT) of ZBA-treated hens increased significantly at both temperatures from 34 to 42 wk of age relative to the control group. No significant effects of ZBA on UCT were observed at 24 to 32 wk and 40 to 52 wk of age.(ABSTRACT TRUNCATED AT 250 WORDS)

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 (Por = 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 (Por = 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.

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.

Zusammenfassung In 2 Versuchen mit insgesamt 108 Rhodelander-Hennen in Einzelhaltung wurde der Energiestoffwechsel untersucht. Es sind jeweils 4 Gruppen gebildet worden. Gruppe A wurde bei 20°C, Gruppe A* bei 34°C gehalten. Die ubrigen Tiere erhielten in das Legehennen-Alleinfutter 100 mg Zinkbacitracin Albac® (ZBA)/kg Futter eingemischt; Gruppe B ist bei 20°C, Gruppe B* bei 34°C gehalten worden. Im 1. Versuch von 20 Wochen Dauer waren Gesamteimasse und Futteraufwand durch ZBA in beiden Temperaturbereichen signifikant verbessert. Die bei Nuchterung (0 bis 24 Std.) nach Brouwer berechnete Warmeproduktion ergab nur einen qualitativen Hinweis auf die Begunstigung der Energieverwertung durch ZBA. Im 2. Versuch war durch ZBA die Gesamteimasse signifikant bei 20°C um 4% erhoht, der Futteraufwand um 5% erniedrigt. Die ME-Aufnahme je kg metabolisches Korpergewicht (W0,75) verringerte sich um 5%, der nach der Regression errechnete Aufwand fur die Erhaltung von 435 auf 392 kJ/W0,75 um 10%. Gleichzeitig waren die Teilwirkungsgrade fur den energetischen Ansatz im Ei (ko) von 0,67 auf 0,71 verbessert. Bei 34°C bewirkte der Zusatz von ZBA gegenuber der unbehandelten Kontrolle signifikant eine Erhohung der Gesamteimasse von 5,6% und des Futteraufwandes von 9,9%. Die ME-Aufnahme je kg W0,75 war um 5,1% erniedrigt, der Aufwand fur die Erhaltung signifikant von 365 auf 332 kJ/W0,75 um 9% reduziert. Die Teilwirkungsgrade fur den energetischen Ansatz im Ei (ko) verbesserten sich von 0,70 auf 0,73. Die durch ZBA induzierten Verbesserungen der Energieverwertung waren mit einer Erhohung der N-Retention verbunden, die ausschlieslich die Eibildung begunstigte. – Hierdurch werden die durch ZBA induzierten Leistungssteigerungen trotz verringerter Futteraufnahme erklarbar.