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1. An experiment was conducted to determine the effect of the source of fat (soybean oil or tallow) on the ileal endogenous amino acid (EAA) losses in broilers. 2. Three nitrogen (N)-free diets; a control diet with no added fat and test diets with 60 g/kg of either soybean oil or tallow were formulated. Titanium dioxide (5 g/kg) was added to all diets as an indigestible marker. Each diet was assigned to six replicate cages (eight birds per cage) from d 18 to 21 post-hatch. On d 21, the digesta were collected from the lower half of the ileum. 3. The endogenous losses of nitrogen and amino acids (AA) were lower (p = 0.08; p = 0.001) in broilers fed diets with soybean oil or tallow, respectively, compared to those fed the diet with no fat. Source of fat had no influence (p > 0.05) on EAA losses. 4. The most abundant AA in the ileal endogenous protein was glutamic acid, followed by aspartic acid, threonine, leucine, serine, valine and proline. In general, the concentrations of AA in the endogenous protein were lower (p < 0.05) with added fat. The exceptions were methionine, cysteine, proline and serine, which were unaffected. The effect of fat source on the AA contents of endogenous protein were inconsistent and differed depending on the AA. 5. The inclusion of fats decreased EAA losses which implied they have beneficial effects beyond direct energy contribution. It can be proposed that the reduction of EAA flow may be an additional mechanism contributing to the extra-caloric effect of dietary fats. [ABSTRACT FROM AUTHOR]

1. Two experiments were conducted to determine the apparent metabolisable energy (AME) and standardised amino acid digestibility coefficients (SIDC) of black soldier fly larvae (BSFL) for broiler chickens. 2. The BSFL contained, on a g/kg dry matter basis: crude protein, 486; crude fat, 320; ash, 58.5; neutral detergent fibre, 181; calcium, 6.8 and phosphorus, 9.1. 3. In Experiment 1, an AME assay was performed wherein broilers were fed two experimental diets (a maize-soy basal diet and a test diet containing 250 g/kg BSFL) for 4 d from d 18 posthatch. The AME of BSFL was calculated based on the difference between the AME values of basal and test diets. The AME and nitrogen-corrected AME were determined to be 19.1and 18.0 MJ/kg of dry matter, respectively. 4. In Experiment 2, the ileal amino acid (AA) digestibility of BSFL was determined using 22-d-old broilers by the direct method and the digesta was collected on d 25. The ratios between the AA and titanium in the diet and digesta were used to calculate the apparent digestibility and then standardised using previously published endogenous losses to estimate the SIDC of AA. The SIDC of Lys, Met, Thr, Val and average SIDC of AA in our BSFL sample were 0.85, 0.90, 0.91, 0.87 and 0.84, respectively. 5. The findings showed that the BSFL meal is a good source of available energy and digestible AA, and could be a potential substitute for soybean meal in broiler diets. [ABSTRACT FROM AUTHOR]

1. The proximate composition and, amino acid, fatty acid and mineral profiles of gallbladder bile of 35 d old broiler chickens were determined. 2. The dry matter (DM) content of the bile was determined to be 19.8 g/100 g. Fat, protein and ash contents in the bile were 24.9, 23.0 and 6.6 g/100 g DM, respectively. 3. The content of total fatty acids (FA) in the bile was determined to be 17.68 g/100 g DM. Unsaturated FA dominated the profile in the bile, with an unsaturated: saturated FA ratio of 1.36. Oleic, linoleic, and arachidonic acids were the main unsaturated FA, whereas palmitic and stearic acids were the major saturated FA. 4. A major finding was that the data established taurine as the primary amino acid in chicken bile and not glycine, as previously assumed. Taurine was the dominant amino acid, constituting 62% of bile protein. 5. Among the major minerals, sodium (2.56 g/100 g DM) was in the greatest concentration. The concentrations of other major minerals were relatively low. 6. The present work provided, for the first time, preliminary data on reference values for nutrients in the chicken gallbladder bile. [ABSTRACT FROM AUTHOR]

1. A 21-d experiment was conducted to investigate the effect of graded inclusions of waxy starch hull-less (WSHL) barley and a multi-component exogenous carbohydrase on the growth performance, nutrient digestibility and intestinal morphometry of broiler chickens. Five levels of WSHL barley inclusion (0, 65, 130, 195 and 260 g/kg) in a wheat-based diet, and two levels of enzyme supplementation (0 and 150 g/tonne of feed) were evaluated in a 5 × 2 factorial arrangement of 10 dietary treatments. All diets were equivalent in metabolisable energy and digestible amino acid content. A total of 400, one-d-old male broilers (five cages/treatment; eight birds/cage) were used in the experiment. 2. Regardless of enzyme supplementation, feed intake declined (P < 0.001) with increasing inclusion of WSHL barley. Increasing levels of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.01) increased gain to feed ratio. 3. Birds fed diets with 0 g/kg WSHL barley showed the lowest (P < 0.001 to 0.01) digestibility for all nutrients except starch. Only starch digestibility was improved (P < 0.05) by enzyme supplementation. The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.001). Increasing inclusion of WSHL barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.01). Supplemental enzyme (P < 0.001) reduced digesta viscosity. 4. All levels of WSHL barley inclusion improved digestibility of dry matter, nitrogen and fat, whilst energy utilisation improved at inclusions of 130 g/kg WSHL and above, probably due to lowered digesta viscosity and better development of the gizzard. Gain to feed ratio, starch digestibility, energy utilisation and jejunal digesta viscosity can benefit from carbohydrase supplementation in wheat-based diets, regardless of barley inclusion level. [ABSTRACT FROM AUTHOR]

Results from three experiments relating to the measurement of ileal calcium (Ca) digestibility in feed ingredients for broiler chickens are presented herein. The first experiment was conducted to determine the true ileal Ca digestibility of dicalcium phosphate (DCP), monocalcium phosphate (MCP), poultry by-product meal (PBPM), fish meal (FM) and canola meal (CM). Five semi-purified diets containing DCP, MCP, PBPM and FM with a dietary Ca concentration of 9 g/kg, and CM with a dietary Ca concentration of 5.71 g/kg were generated. A Ca- and phosphorus (P)-free diet was used to determine the basal ileal endogenous Ca losses. Titanium dioxide was incorporated in all diets as an indigestible marker. Each diet was randomly allotted to six replicate cages (eight birds per cage) and fed from 21 to 24 days post-hatch. True Ca digestibility coefficients of DCP, MCP, PBPM, FM and CM were determined to be 0.28, 0.33, 0.29, 0.24 and 0.31, respectively. These lower digestibility coefficients were unexpected and it was speculated that this finding may be due to the length of adaptation to assay diets and/or assay methodology. To investigate these possibilities, two more experiments were conducted. In the second experiment, the influence of dietary adaptation length was examined with DCP and MCP. The assay diets with DCP and MCP, and the Ca- and P-free diet were similar to those used in Experiment 1. Each diet was randomly allocated to four replicate cages (15 birds per cage) and fed from 21 to 24 days post-hatch. Digesta samples of five birds from each replicate were collected after 24, 48 and 72 h of feeding. Dietary adaptation length had no influence (P > 0.05) on the true Ca digestibility of MCP, but increased that of DCP at 24 h. True ileal Ca digestibility of DCP and MCP after 24, 48 and 72 h of adaptation were 0.45, 0.36, and 0.35, and 0.30, 0.32 and 0.34, respectively. The third experiment was conducted to determine the effect of assay methodology (direct, regression and difference methods) and Ca:non-phytate P ratio (2:1 and 1.16:1) on the Ca digestibility of DCP. The true Ca digestibility coefficients of DCP determined by the direct, difference and regression methods with Ca:non-phytate P ratio of 1.16:1 were 0.34, 0.21 and 0.13, respectively. The true Ca digestibility of DCP determined by the direct method was higher (P < 0.05) than those determined by difference and regression methods The true Ca digestibility coefficient of DCP with Ca:non-phytate P ratios of 2:1 and 1.16:1 were 0.25 and 0.21, respectively, and was not influenced (P > 0.05) by the Ca to non-phytate P ratio. [ABSTRACT FROM AUTHOR]

The influence of calcium (Ca) source and particle size on true ileal digestibility coefficient (TIDC) of Ca and apparent total tract retention coefficient (ATTRC) of Ca in broilers was assessed. Four experimental diets containing limestone and oyster shell, each as fine (<0.5 mm) and coarse (1–2 mm) particles, were fed to broiler chickens from 21 to 24 days of age. A Ca- and phosphorus-free diet was used to determine the ileal endogenous Ca losses. Limestone and oyster shell were obtained from commercial sources and ground to pass through a set of sieves to obtain the fine and coarse particles. Titanium dioxide was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to six replicate cages (eight birds per cage). Apparent ileal digestibility coefficient and ATTRC of Ca were calculated using the indicator method and the TIDC values were calculated by correcting for endogenous Ca losses. Ileal endogenous Ca losses were determined to be 115 mg/kg of dry matter intake. The main effect of Ca source and the interaction between Ca source and particle size were not significant (P > 0.05) for the TIDC and ATTRC of Ca. Both TIDC and ATTRC of Ca were influenced (P < 0.05) by particle size, with coarser particles increasing the digestibility and retention values. Increased particle size increased the TIDC of Ca in limestone from 0.38 to 0.62 and that of oyster shell from 0.33 to 0.56. The corresponding increases in ATTRC of Ca were from 0.44 to 0.66 in limestone and from 0.40 to 0.60 in oyster shell. Calcium concentration in the gizzard contents of birds was higher (P < 0.05) for limestone as compared to oyster shell and increased with increase in particle size. Calcium concentration in the gizzard contents was strongly correlated with the TIDC (r = 0.81; P < 0.01) and ATTRC (r = 0.82; P < 0.01) of Ca. A strong correlation (r = 0.80, P < 0.01) was also observed between TIDC and ATTRC of Ca. [ABSTRACT FROM AUTHOR]

This study investigated the influence of pre-pelleting inclusion of whole wheat ( WW) and exogenous enzyme supplementation on growth performance, coefficient of apparent ileal nutrient digestibility ( CAID) and apparent metabolizable energy ( AME) in broilers fed wheat-based pelleted diets. A 2 × 3 factorial arrangement of treatments was used with two methods of wheat inclusion [622 g/kg ground wheat ( GW) and 250 g/kg WW replaced GW (wt/wt) pre-pelleting ( PWW)] and three enzymes (xylanase, phytase and xylanase plus phytase). A total of 288, one-day-old male broilers (Ross 308) were individually weighed and allocated to 36 cages (8 broilers/cage), and the cages were randomly assigned to the six dietary treatments. Birds fed PWW diets gained more (p < 0.05) weight than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on feed intake ( FI). Phytase alone increased (p < 0.05) FI compared to xylanase or the combination. Whole wheat inclusion increased (p < 0.05) the gain-to-feed ratio (G:F). Feeding xylanase plus phytase and phytase-added diets resulted in the greatest and lowest G:F, respectively, with xylanase supplemented diets being intermediate. Birds fed PWW diets had greater (p < 0.05) relative gizzard weights than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on the CAID of nitrogen (N), starch and fat. Combination of xylanase and phytase resulted in greater (p < 0.05) digestibility of N, starch and fat than that of individual additions. Feeding PWW diets resulted in greater (p < 0.05) AME values than GW diets. Combination of xylanase and phytase increased (p < 0.05) the AME compared to the diets with individual additions of xylanase or phytase. The current results suggest that the influence of pre-pelleting WW inclusion and exogenous enzymes on nutrient digestibility and broiler performance is not additive. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate the influence of palm kernel meal (PKM) inclusion and exogenous enzyme supplementation on growth performance, nitrogen-corrected apparent metabolizable energy (AMEn), coefficient of apparent ileal digestibility (CAID) and total tract retention of nutrients in young broilers fed corn-based diets. Four inclusion levels of PKM (no PKM [PKM0], 8% [PKM8], 16% [PKM16], and 24% [PKM24]) and two enzyme additions were evaluated in a 4×2 factorial arrangement of treatments. A total of 384, one-d-old male broilers (Ross 308) were individually weighed and allocated to 48 cages (eight broilers/cage), and cages were randomly assigned to eight dietary treatments. Results indicated that the inclusion of 8% and 16% PKM increased (p<0.05) the weight gain compared to the PKM0 diet. Birds fed the PKM8 diets had the highest (p<0.05) feed intake. Weight gain and feed intake were severely reduced (p<0.05) by feeding the PKM24 diet. Enzyme supplementation increased weight gain (p<0.05), independent of PKM inclusion level. In PKM0 and PKM8 diets, enzyme addition significantly (p<0.05) lowered feed conversion ratio (FCR); whereas enzyme addition had no effect on FCR of birds fed PKM16 and PKM24 diets. In PKM0 and PKM16 diets, enzyme addition significantly (p<0.05) increased CAID of nitrogen and energy but had no effect in the PKM8 and PKM24 diets. Inclusion of PKM into the basal diet, irrespective of inclusion level, enhanced (p<0.05) starch and fat digestibility. Inclusion of PKM at 16% and 24% resulted in similar CAID of neutral detergent fiber (NDF) but higher (p<0.05) than that of the PKM0 and PKM8 diets. Enzyme addition, regardless of the level of PKM inclusion, significantly (p<0.05) increased CAID of NDF. There was a significant (p<0.05) decrease in AMEn with PKM inclusion of 24%. The present data suggest that inclusion of PKM in broiler diets could be optimized if PKM-containing diets are formulated based on digestible amino acid contents and supplemented with exogenous enzymes. If amino acid digestibility and AME of PKM considered in the formulation, it can be included in broiler diets up to 16% with no deleterious effects on growth performance. [ABSTRACT FROM AUTHOR]

The objective of the study that is presented herein was to determine the true ileal calcium (Ca) digestibility in meat and bone meal (MBM) for broiler chickens using the direct method. Four MBM samples (coded as MBM-1, MBM-2, MBM-3 and MBM-4) were obtained and analyzed for nutrient composition, particle size distribution and bone to soft tissue ratio. The Ca concentrations of MBM-1, MBM-2, MBM-3 and MBM-4 were determined to be 71, 118, 114 and 81 g/kg, respectively. The corresponding geometric mean particle diameters and bone to soft tissue ratios were 0.866, 0.622, 0.875 and 0.781 mm, and 1:1.49, 1:0.98, 1:0.92 and 1:1.35, respectively. Five experimental diets, including four diets with similar Ca concentration (8.3 g/kg) from each MBM and a Ca and phosphorus-free diet, were developed. Meat and bone meal served as the sole source of Ca in the MBM diets. Titanium dioxide (3 g/kg) was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to six replicate cages (eight birds per cage) and offered from d 28 to 31 post-hatch. Apparent ileal Ca digestibility was calculated by the indicator method and corrected for ileal endogenous Ca losses to determine the true ileal Ca digestibility. Ileal endogenous Ca losses were determined to be 88 mg/kg dry matter intake. True ileal Ca digestibility coefficients of MBM-1, MBM-2, MBM-3 and MBM-4 were determined to be 0.560, 0.446, 0.517 and 0.413, respectively. True Ca digestibility of MBM-1 was higher (P < 0.05) than MBM-2 and MBM-4 but similar (P > 0.05) to that of MBM-3. True Ca digestibility of MBM-2 was similar (P > 0.05) to MBM-3 and MBM-4, while that of MBM-3 was higher (P < 0.05) than MBM-4. These results demonstrated that the direct method can be used for the determination of true Ca digestibility in feed ingredients and that Ca in MBM is not highly available as often assumed. The variability in true Ca digestibility of MBM samples could not be attributed to Ca content, percentage bones or particle size. [ABSTRACT FROM AUTHOR]

The effects of high dose of microbial phytase and an emulsifier on the performance, apparent metabolisable energy (AME) and nitrogen (N) retention in broilers fed on diets containing different fat sources were examined in a 5-week trial. Two fat sources (soy oil and tallow), two inclusion levels of E. coli phytase (500 or 1000 phytase units (FTU)/kg diet) and two inclusion levels of lysolecithin emulsifier (0 or 3.5 g/kg of diet) were evaluated in a 2 × 2 × 2 factorial arrangement of treatments.Throughout the 5-week trial, soy oil supplementation improved weight gain and feed per gain compared with tallow, but had no effect on feed intake.The high dose of phytase increased the weight gain and feed intake and lowered the feed per gain during d 1–21, but had no effect on performance parameters over the whole trial period.An effect of emulsifier was observed for feed intake during d 1–21 and over the whole trial period. Addition of emulsifier increased feed intake compared with diets without emulsifier.During weeks 1, 2, 3 and 5, birds fed on soy oil–based diets had higher nitrogen-corrected AME (AMEN) compared with those fed on tallow-based diets. During weeks 2, 3 and 5, the effect of phytase was significant for AMEN, with the high dose increasing the AMEN. During week 2, AMEN was increased with emulsifier addition.During weeks 1, 2, 3 and 5, birds fed on soy oil–based diets had higher fat retention compared with those fed on tallow-based diets. The high dose of phytase improved the retention of fat during week 5 and the addition of emulsifier resulted in higher fat retention during week 1.During weeks 2, 3 and 5, an interaction between fat source × phytase × emulsifier was observed for N retention. In soy oil–based diets, emulsifier plus 1000 FTU/kg phytase increased N retention compared with other groups, while in tallow-based diets, emulsifier addition increased N retention in diets with 500 FTU/kg, but not in 1000 FTU/kg diet.Overall, the present data suggest that the dietary fat source influenced performance, AMEN and fat retention in broiler chickens. There is opportunity to improve bird performance during d 1–21, AMEN and fat retention with higher doses of microbial phytase. Addition of the emulsifier increased the AMEN during week 2 and tract retention of fat during week 1, but this effect was not translated into improvements in performance. [ABSTRACT FROM PUBLISHER]

An experiment was conducted to determine the true ileal P digestibility of maize and soybean meal for broiler chickens using two methodologies based on the regression method. The two methods differed in dietary protein content and dietary Ca:P ratios in the assay diets used. In Method 1, the test ingredient was used as the sole dietary source of protein and P and a dietary Ca:non-phytate P ratio of around 2:1 was maintained by the addition of limestone. In Method 2, dried egg albumen was used as the additional protein supplement and a dietary Ca:total P ratio of 1.3:1 was maintained by the addition of limestone. For the maize-based diets, disodium phosphate was used as an additional P supplement. Two sets of sequential semi-purified diets containing 200, 460 and 720 g/kg of maize or 400, 510 and 620 g/kg of soybean meal were formulated. Each set was evaluated as a 2 × 3 factorial arrangement of treatments, which included two methods and three inclusion levels. The experiment was conducted as a randomised complete block design and a total of 288 of 21-day old male broilers (Ross 308) were assigned to four blocks based on body weights. Each block had 12 cages (six birds per cage) and the 12 test diets were assigned to a cage within each block. Apparent ileal digestibility coefficient of P was determined by the indicator method and linear regression was used to determine true ileal P digestibility. In both methods, ileal P output and ileal digestible P increased linearly with increasing inclusion levels of maize ( P < 0.01) and soybean meal ( P < 0.001). Apparent ileal P digestibility coefficients of P determined for maize were higher ( P < 0.001) in Method 2 compared with Method 1 whereas the opposite trend was observed for soybean meal. True ileal P digestibility coefficients determined for maize in Methods 1 and 2 were 0.728 and 0.426, respectively, and were different ( P < 0.01). True ileal P digestibility coefficients determined for soybean meal in Methods 1 and 2 were 0.740 and 0.523, respectively, and were different ( P < 0.01). The present findings showed that estimation of true ileal P digestibility in maize and soybean meal was influenced by the assay methodology employed. [ABSTRACT FROM AUTHOR]

The objective of the present experiment was to determine the true ileal calcium (Ca) digestibility in three samples of meat and bone meal (coded as MBM-1, MBM-2 and MBM-3) for broiler chickens. Four experimental diets, containing graded concentrations of Ca, were formulated from each MBM sample with inclusion levels of 20, 40, 60 and 80 g/kg diet. Each experimental diet was randomly allotted to four replicate cages (six birds per cage) and fed for three days from day 28 post-hatch. Apparent ileal digestibility coefficient of Ca was measured by the indicator method and linear regression analysis was used to determine the true Ca digestibility coefficient. Apparent Ca digestibility was unaffected ( P > 0.05) by increasing Ca concentrations. The apparent digestibility coefficients in MBM-1, MBM-2 and MBM-3 were 0.50, 0.44 and 0.45, respectively. Significant linear ( P < 0.001) relationship was observed between dietary Ca intake and digesta Ca output for MBM-1, MBM-2 and MBM-3 with R 2 values of 0.82, 0.93 and 0.95, respectively. The true ileal digestibility coefficients of Ca in MBM-1, MBM-2 and MBM-3 were determined to be 0.60, 0.46 and 0.50, respectively. The corresponding ileal endogenous Ca losses were 292, 123 and 174 mg/kg dry matter intake, respectively. [ABSTRACT FROM AUTHOR]

An experiment was conducted to estimate true ileal phosphorus (P) digestibility of 3 meat and bone meal samples (MBM-1, MBM-2, and MBM-3) for broiler chickens. Four semipurified diets were formulated from each sample to contain graded concentrations of P. The experiment was conducted as a completely randomized design with 6 replicates (6 birds per replicate) per dietary treatment. A total of 432 Ross 308 broilers were assigned at 21 d of age to the 12 test diets. The apparent ileal digestibility coefficient of P was determined by the indicator method, and the linear regression method was used to determine the true P digestibility coefficient. The apparent ileal digestibility coefficient of P in birds fed diets containing MBM-1 and MBM-2 was unaffected by increasing dietary concentrations of P (P > 0.05). The apparent ileal digestibility coefficient of P in birds fed the MBM- 3 diets decreased with increasing P concentrations (linear, P < 0.001; quadratic, P < 0. 01). In birds fed the MBM-1 and MBM-2 diets, ileal endogenous P losses were estimated to be 0.049 and 0.142 g/kg DM intake (DMI), respectively. In birds fed the MBM-3 diets, endogenous P loss was estimated to be negative (--0.370 g/kg DMI). True ileal P digestibility of MBM-1, MBM-2, and MBM-3 was determined to be 0.693, 0.608, and 0.420, respectively. True ileal P digestibility coefficients determined for MBM-1 and MBM-2 were similar (P < 0.05), but were higher (P < 0.05) than that for MBM-3. Total P and true digestible P contents of MBM-1, MBM-2, and MBM-3 were determined to be 37.5 and 26.0; 60.2 and 36.6; and 59.8 and 25.1 g/kg, respectively, on an as-fed basis. [ABSTRACT FROM AUTHOR]

The aim of the present experiment was to examine the effect of coccidia challenge and natural betaine supplementation on performance, nutrient utilization, and intestinal lesion scores of broiler chickens fed suboptimal level of dietary methionine. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two levels of betaine supplementation (0 and 960 g betaine/t of feed) without or with coccidia challenge. Each treatment was fed to 8 cages of 8 male broilers (Ross 308) for 1 to 21d. On d 14, birds in the 2 challenged groups received mixed inocula of Eimeria species from a recent field isolate, containing approximately 180,000 E. acervulina, 6,000 E. maxima, and 18,000 E. tenella oocysts. At 21d, digesta from the terminal ileum was collected for the determination of dry matter, energy, nitrogen, amino acids, starch, fat, and ash digestibilities. Lesion scores in the different segments of the small intestine were also measured on d 21. Performance and nutrient digestibility data were analyzed by two-way ANOVA. Lesion score data were analyzed using Pearson chi-square test to identify significant differences between treatments. Orthogonal polynomial contrasts were used to assess the significance of linear or quadratic models to describe the response in the dependent variable to total lesion scores. Coccidia challenge reduced (P < 0.0001) the weight gain and feed intake, and increased (P < 0.0001) the feed conversion ratio. Betaine supplementation had no effect (P > 0.05) on the weight gain or feed intake, but lowered (P < 0.05) the feed conversion ratio. No interaction (P > 0.05) between coccidia challenge and betaine supplementation was observed for performance parameters. Betaine supplementation increased (P < 0.05) the digestibility of dry matter, nitrogen, energy, fat, and amino acids only in birds challenged with coccidia as indicated by the significant interaction (P < 0.0001) between betaine supplementation and coccidia challenge. The main effect of coccidia challenge reduced (P < 0.05) starch digestibility. Betaine supplementation improved (P < 0.05) starch digestibility regardless of the coccidia challenge. For each unit increase in the total lesion score, there was a linear (P < 0.001) decrease in digestibility of mean amino acids, starch, and fat by 3.8, 3.4 and 16%, respectively. Increasing total lesion scores resulted in a quadratic (P < 0.05) decrease in dry matter digestibility and ileal digestible energy. No lesions were found in the intestine or ceca of the unchallenged treatments. In the challenged treatments, betaine supplementation reduced (P < 0.01) the lesion scores at the duodenum, lower jejunum, and total lesion scores compared to the treatment without supplements. In conclusion, coccidia challenge lowered the digestibility of energy and nutrients and increased the feed conversion ratio of broilers. However, betaine supplementation reduced the impact of coccidia challenge and positively affected nutrient digestibility and the feed conversion ratio. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the influence of cereal type and fat source on performance and utilisation of fat in young broiler chickens. The experimental design was a 3 × 2 factorial arrangement of treatments, which included three cereals (wheat, maize or sorghum) and two fat sources (soybean oil or tallow). Broiler starter diets, based on each cereal and supplemented with 60 g/kg of soybean oil or tallow, were fed during the 21-day experimental period. Weight gain was increased (P < 0.05) with soybean oil supplementation compared with tallow supplementation in wheat- and maize-based diets, but was unaffected (P > 0.05) by fat source in sorghum-based diets. Feed per gain was lower (P < 0.05) in birds fed soybean oil diets than those fed tallow-supplemented diets. Coefficients of total tract retention and ileal apparent digestibility of fat were higher (P < 0.05) in birds fed soybean oil diets than in those fed tallow-supplemented diets. Overall, the results suggest that the effect of fat source on weight gain of broiler starters differed depending on the cereal base used, and that soybean oil is a better fat source than tallow for young broilers. [ABSTRACT FROM AUTHOR]

An experiment was conducted to estimate the tme ileal digestibility of P in wheat, sorghum, soybean meal, and com distiller's dried grains with solubles (DDGS) in broiler chickens. Four semipurified diets were fonnulated from each ingredient (wheat and sorghum: 236.5,473,709.5, and 946 g/kg; soybean meal and com DDGS: 135,270,405, and 540 g/kg) to contain graded concentrations of nonphytate P. The experiment was conducted as a randomized complete block design with 4 weight blocks of 16 cages each (5 birds per cage). A total of 320 21-d-old broilers (Ross 308) were assigned to the 16 test diets with 4 replicates per diet. Apparent ileal digestibility coefficients of P were determined by the indicator method and the linear regression method was used to determine the true P digestibility coefficients. The results showed that the apparent ileal P digestibility coefficients of wheat-based diets were not influenced (P > 0.05) by increasing dietary P concentrations, whereas those of diets based on sorghum, soybean meal, and com DDGS differed (P < 0.05) at different P concentrations. Apparent ileal P digestibility in broilers fed diets with soybean meal and com DDGS linearly (P < 0.001) increased with increasing P concentrations. True ileal P digestibility coefficients of wheat, sorghum, soybean meal, and com DDGS were determined to be 0.464, 0.331, 0.798, and 0.727, respectively. Ileal endogenous P losses in birds fed diets with wheat, soybean meal, and com DDGS were estimated to be 0.080, 0.609, and 0.418 g/kg DMI, respectively. In birds fed sorghum-based diets, endogenous P losses were estimated to be negative (-0.087 g/kg DMI). True digestible P contents of wheat, sorghum, soybean meal, and com DDGS were detenuined to be 1.49, 0.78, 5.16, and 5.94 g/kg, respectively. The corresponding nonphytate P contents in wheat, sorghum, soybean meal, and com DDGS were 1.11,0.55,2.15, and 4.36 g/kg, respectively. These differences between digestible P and nonphytate P contents may be suggestive, at least in part, of overestimation of P digestibility under the calcium-deficient conditions used in the regression method. [ABSTRACT FROM AUTHOR]

The objective of the present study was to examine the effects of prepelleting inclusion of graded levels of whole corn on performance, digestive tract measurements, nutrient utilization, and cecal microbiota in broiler starters. Five diets, containing 600 g/ kg of ground corn or 150, 300, 450, and 600 g/kg of whole corn replacing (wt/wt) ground corn, were formulated and cold-pelleted at 65°C. Each diet was offered ad libitum to 6 replicates (8 birds per replicate cage) from d 1 to 21 posthatch. The proportion of coarse particles (>1 mm) increased with increasing prepelleting inclusion of whole corn. Pellet quality, measured as pellet durability index, increased (quadratic effect, P < 0.001) with the inclusion of whole corn to 450 g/kg and then plateaued. Weight gain and feed intake decreased (linear effect, P < 0.001) with increasing prepelleting inclusion of whole corn. Feed per gain (quadratic effect, P < 0.05) increased as the inclusion level of whole corn increased to 300 g/kg and then plateaued with further inclusions. Relative gizzard weight (quadratic effect, P < 0.05) increased with increasing inclusion of whole corn up to 300 g/kg and then levelled off. The AME (quadratic effect, P < 0.05) increased up to 300 g/kg of whole corn inclusion and then decreased with further inclusion. Apparent ileal digestibility of DM (P < 0.001), N (linear effect, P = 0.07), and starch (linear effect, P < 0.001) increased with increasing inclusion levels of whole corn. Based on the fluorescence in situ hybridization method, a linear (P < 0.05) effect was determined for cecal microbiota numbers. Lactobacillus spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of whole corn. The present data showed that, despite increased gizzard weight and nutrient utilization, weight gain of broilers was poorer with prepelleting inclusion of whole corn due to reductions in the feed intake. [ABSTRACT FROM AUTHOR]

Nutrient composition, ileal amino acid (AA) digestibility, and AME of 55 soybean meal (SBM) samples from the United States (US; n = 16), Argentina (ARG; n = 16), Brazil (BRA; n = 10), and India (IND; n = 13), collected from commercial mills in Southeast Asia, were compared using laboratory analyses and animal studies. There were significant (P < 0.05 to 0.001) differences due to origin in CP, fat, ash, fiber, and nonstarch polysaccharide (NSP) contents of SBM. The average CP content of US, ARG, BRA, and IND samples was determined to be 47.3, 46.9, 48.2, and 46.4% (as-fed basis), respectively. Compared with SBM from other origins, crude fiber and NSP contents were lower (P < 0.05) and sucrose content was higher (P < 0.05) in the US samples. The IND samples had the highest (P < 0.05) contents of fiber, ash, and NSP, and lowest (P < 0.05) contents of fat and sucrose. Differences (P < 0.0001) were observed among origins for in vitro protein quality measures (urease index, KOH protein solubility, and trypsin inhibitor activity). Significant (P < 0.001) effects due to origin were observed for all minerals. Soybean meal from the US and IND had higher (P < 0.05) calcium contents (0.45%) compared with those from ARG and BRA (0.28-0.31%). Phosphorus and potassium contents were lowest (P < 0.05) in SBM from IND, and no differences (P > 0.05) were observed in SBM from other origins. Iron content was markedly high (928 mg/kg) in SBM from IND compared with those from other origins (103-134 mg/ kg). Major origin-related differences (P < 0.0001) were observed in the AME of SBM. The average AME content of US, ARG, BRA, and IND samples was 2,375, 2,227, 2,317, and 2,000 kcal/kg (as-fed basis), respectively. Total AA contents of US, ARG, BRA, and IND samples were similar (P > 0.05) for 9 of the 17 amino acids. Major differences (P < 0.05 to P < 0.001) due to origin were determined for the digestibility of all AA. The IND samples had the lowest (P < 0.05) digestibility and no differences (P > 0.05) between samples from other 3 origins. However, the digestible CP content of US SBM was higher (P < 0.05) than those of ARG and IND, but similar (P > 0.05) to that from BRA. The digestible CP contents of SBM from the US, ARG, BRA, and IND were 40.0, 38.6, 39.8, and 36.7%, respectively. Digestible contents of indispensable AA, in general, followed the same trend as that of digestible CP. In conclusion, the present evaluation showed that major differences in nutritive value do exist between SBM from different origins in terms of nutrient contents, AME, and digestible AA. Overall, SBM originating from the US had better nutritive value compared with those from ARG and IND, on the basis of AME and contents of digestible CP and digestible AA. [ABSTRACT FROM AUTHOR]

A 2 x 4 factorial arrangement of treatments was used to evaluate the effects of two pellet diameters and four pellet length-week combinations on the growth performance and carcass characteristics of broilers (days 22 to 42). A broiler finisher diet based on wheat and soybean meal was formulated. Pelleted diets were manufactured in four different sizes: (i) 3 mm diameter (D3) and 7 mm length (L7), (ii) D3, 9 mm length (L9), (iii) 4.76 mm diameter (D4.76), L7, (iv) D4.76, L9. The four pellet sizes were then used to develop eight feeding treatments: (i) D3 and L7 pellets during weeks 4, 5, and 6 (L777); (ii) D3 and L7 during weeks 4 and 5, and L9 during week 6 (L779); (iii) D3 and L7 during week 4, and L9 during weeks 5 and 6 (L799); (iv) D3 and L9 during weeks 4, 5, and 6 (L999); (v) D4.76 and L7 during weeks 4, 5 and 6 (L777); (vi) D4.76 and L7 during weeks 4 and 5, and L9 during week 6 (L779); (vii) D4.76 and L7 during week 4, and L9 during weeks 5 and 6 (L799); (viii) D4.76 and L9 during weeks 4, 5, and 6 (L999). Increasing the pellet length from 7 to 9 mm increased pellet hardness at both pellet diameters and improved the pellet durability index in D3 pellets but had no effect in D4.76 pellets. Over the whole trial period (days 22-42), birds fed D3 pellets were heavier and had lower feed per gain and higher carcass yield than those fed D4.76 pellets. Feeding length-week combination L999 resulted in lower carcass yield than L777, L779, and L799. Overall, it is concluded that whilst broiler finishers express a preference for a smaller pellet diameter, there is no negative effect of pellet length (up to 9 mm) on performance parameters even when offered as early as day 21. It is well established that broilers show better performance when offered pelleted diets. This study examined the growth responses of broiler finishers to changes in pellet size, and showed that while broilers express a preference for a smaller pellet diameter, there is no negative effect of pellet length on performance. This approach suggests that only the manipulation of pellet length may be used to improve broiler production. [ABSTRACT FROM AUTHOR]

Abstract: A broiler starter (1–21d) diet based on a finely ground red sorghum was used to develop 3 feed forms: (1) unprocessed mash, (2) pellets steam-conditioned at 70°C, and (3) re-ground pellets following steam-conditioning at 70°C. The influence of dietary treatments on the growth performance, coefficient of apparent ileal digestibility (CAID) of N, starch, fat, Ca, and P, and apparent metabolisable energy (AME) in broiler starters was evaluated. A total of 144 one-day-old male broilers (Ross 308) were individually weighed and allocated to 18 cages (8 broilers/cage), and cages were randomly assigned to 3 dietary treatments. Broilers fed the pelleted diet gained more (P<0.05) weight and had a greater (P<0.05) feed intake (FI) than those fed mash and re-ground pellet diets. Re-grinding the pellets resulted in similar weight gain and FI to the mash diet. Nitrogen digestibility tended (P=0.10) to be greater in broilers fed the mash diet compared to pellet and re-ground pellet diets. Pellet-feeding reduced (P<0.05) starch digestibility compared to the mash diet and re-ground pellet. Pellet feeding also reduced (P<0.05) CAID of fat compared to mash diet but re-grinding the pellets restored fat digestibility. Pelleting reduced (P<0.05) the CAID of Ca and re-grinding the pellets further decreased (P<0.05) Ca digestibility. Pelleting had no influence on the CAID of P, but re-grinding the pellets resulted in lower (P<0.05) P digestibility than that of the mash and pelleted diets. Feeding intact pellets reduced (P<0.05) the AME of the diet compared to the mash diet and the depression was maintained in re-ground pellets. Based on the greater nutrient intake of broilers offered intact pellets coupled with the lack of positive effect of pellet feeding on digestibility of nutrients, it can be suggested that an enhanced feed consumption was primarily responsible for the better performance of broilers fed sorghum-based pellets. [Copyright &y& Elsevier]

The influence of tallow and Ca concentra-tions on the performance, apparent ileal digestibility, and total tract retention of N, Ca, P, and AME in broiler starter diets fed corn-soy-based diets was ex-amined. The experimental design was a 3 x 3 factorial arrangement of treatments evaluating 3 inclusion levels of tallow (0, 40, and 80 g/kg) and 3 dietary concentra-tions of Ca (7, 10, and 13 g/kg). Nine treatment diets were formulated to meet the requirements for major nutrients for broiler starters, except for AME and Ca concentrations. The results showed that increasing tal-low inclusion increased (P < 0.001) the weight gain and lowered (P < 0.001) the feed to gain. Increasing dietary Ca concentrations decreased (P < 0.001) the weight gain. Birds fed diets containing 7 g/kg of Ca had similar (P > 0.05) feed to gain to 10 g/kg of Ca but lower (P < 0.05) than that of 13 g/kg of Ca. In diets with no tallow, increasing Ca concentrations decreased (P < 0.05) feed intake, whereas diets with 40 and 80 g/kg of tallow containing 13 g/kg of Ca showed lower (P < 0.05) feed intake than those of 7 and 10 g/kg of Ca. Diets supplemented with 40 and 80 g/kg of tallow containing 7 g/kg of Ca showed the lowest (P < 0.05) excreta soap content. Total tract retention of fat was higher (P < 0.001) in diets with 40 g/kg of tallow com-pared with those with 0 and 80 g/kg of tallow. Birds fed diets containing 7 g/kg of Ca had similar (P > 0.05) fat retention to that of 10 g/kg of Ca, but higher (P < 0.05) than that of 13 g/kg of Ca. Calcium retention decreased (P < 0.001) with increasing Ca concentra-tions. Diets containing 13 g/kg of Ca had the lowest (P < 0.01) P retention. Diets with no inclusion of tallow containing 7 g/kg of Ca had higher (P < 0.05) N reten-tion than that of 13 g/kg of Ca, but similar to 10 g/kg of Ca, whereas in 40 g/kg of tallow diets, 7 g/kg of Ca had the highest (P < 0.05) N retention. Increasing fat inclusion increased (P < 0.001) the soap content in ileal digesta. Diets with 40 g/kg of tallow had the highest ileal digestibility of fat (P < 0.001) and N (P < 0.01). Increasing inclusion of fat decreased (P < 0.001) ileal Ca digestibility. Diets containing 7 g/kg of Ca showed the highest ileal digestibility of fat (P < 0.01), N (P < 0.01), and P (P < 0.001). Birds fed diets containing 13 g/kg of Ca had higher ileal digestibility of Ca (P < 0.001) than those fed 7 and 10 g/kg of Ca diets. Over-all, present data showed that the total tract retention and ileal digestibility of fat were higher with supple-mentation of 40 g/kg of tallow compared with those of 0 and 80 g/kg of tallow. High dietary Ca concentrations adversely affected the performance and the utilization of energy, N, Ca, and P in broiler starters. [ABSTRACT FROM AUTHOR]

The objective of the present study was to examine the effects of feeding coarsely ground corn on performance, digestive tract measurements, nutrient utilization, and cecal microflora counts in broilers. Five diets containing 600 g/kg of finely ground corn (hammer milled) or 150, 300, 450, and 600 g/kg of coarse corn (cracked in roller mill) replacing (wt/wt) finely ground corn were formulated. Each diet in mash form was offered ad libitum to 6 replicate cages of broilers (8 birds per cage) from d 11 to 35 posthatch. Weight gain increased (linear effect, P < 0.01) with increasing inclusion levels of coarse corn. Feed intake (quadratic effect, P < 0.05) increased at 150 g/kg of coarse corn inclusion, plateaued until 450 g/kg, and then increased again to 600 g/kg. Feed per gain increased (quadratic effect, P < 0.05) as inclusion of coarse corn increased to 300 g/kg and then decreased with further inclusion. Apparent metabolizable energy and total tract DM retention (quadratic effect, P < 0.01) was unaffected up to 300g/kg inclusion, and then decreased with further inclusion of coarse corn. Relative gizzard weight increased (linear effect, P < 0.05) with increasing inclusion of coarse corn. Inclusion of coarse corn had no effect (P > 0.05) on ileal digestibility of DM, N, and starch. Breast meat yield decreased (linear effect, P < 0.05 and abdominal fat increased (linear effect, P < 0.001) with increasing inclusion levels of coarse corn, but there was no effect (P > 0.05) on the carcass yield. A linear (P < 0.05) effect was observed for cecal microflora counts. Lactobacillus spp. and Bifidobacteria spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of coarse corn. The present data showed that feeding of coarse corn increased weight gain and gizzard size, and modified gut microflora profile toward beneficial species and that it can totally replace ground corn in broilers fed mash diets. [ABSTRACT FROM PUBLISHER]

The study reported herein was conducted to determine and compare the nonphytate P, digestible P, and retainable P contents of corn and canola meal for broiler chickens. Four semipurified diets were formulated from each of ingredient to contain graded concentrations of nonphytate P. The experiment was conducted as a randomized complete block design with 4 weight blocks of 8 cages each (6 birds per cage). A total of 192 broilers (Ross 308), 21 d old, were assigned to the 8 test diets. Ileal digestibility and total tract retention coefficients of P were determined by the indicator and total collection methods, respectively, and linear regression method was used to determine the true P digestibility and true P retention coefficients. The apparent ileal digestibility of P in corn was influenced (quadratic, P < 0.05) by increasing dietary nonphytate P concentrations, whereas P retention was unaffected (P > 0.05). The apparent ileal P digestibility in broilers fed diets based on canola meal was similar (P > 0.05) at different P concentrations. Phosphorus retention in broilers fed diets based on canola meal (linear, P < 0.01) decreased with increasing P concentrations. True ileal P digestibility and true P retention coefficients of corn were determined to be 0.676 and 0.632, respectively. The corresponding values for canola meal were 0.469 and 0.486, respectively. In both ingredients, the determined true ileal digestibility and total tract retention coefficients were not different (P > 0.05). Total P, nonphytate P, true digestible P, and true retainable P contents of corn were determined to be 2.5, 0.8, 1.7, and 1.6 g/kg (as received), respectively. The corresponding values for canola meal were 9.7, 2.8, 4.6, and 4.7 g/kg (as received), respectively. The present data demonstrated that the regression method can be successfully used to measure true P digestibility of low and high P feed ingredients and that both true ileal digestibility and retention coefficients are suitable to assess P availability in broilers. [ABSTRACT FROM AUTHOR]

Two experiments were conducted. The first experiment investigated the digestion of fat and fatty acids (FA) from soybean oil and tallow along the gastrointestinal tract of broiler chickens. The second experiment was conducted to determine endogenous fat and FA losses and the FA profile of chicken bile. In experiment 1, 2-wk-old broilers were fed corn-soy diets supplemented with 50 g/kg of soybean oil or tallow for 7 d and digesta were collected from the duodenum, upper jejunum, upper ileum, and lower ileum. Apparent digestibility coefficients were calculated using the titanium marker ratio in diets, and digesta. Digestibility of fat was determined to be negative in the duodenum, indicating marked net secretion of fat into this segment. Fat was rapidly digested in the jejunum, with digestibility coefficients of 0.60 to 0.64 being determined at the end of the jejunum. The digestion of fat continued in the upper ileum. The apparent digestibility coefficient of fat determined at lower ileum in soybean oil diets was higher (P < 0.05) than that in tallow diets (0.82 vs. 0.74). Linoleic acid was digested throughout the intestinal tract, whereas the digestion of palmitic, stearic, and oleic acids started only in the jejunum. Measurements at the lower ileal level showed that the unsaturated FA (linoleic and oleic acids) were well digested (0.90 to 0.94), irrespective of the source of fat. In contrast, the digestibility of saturated FA (palmitic and stearic acids) was influenced (P < 0.05) by the fat source. Digestibility coefficients of palmitic and stearic acids at lower ileum were markedly higher (P < 0.05) in the diet containing soybean oil (0.77 to 0.85) compared with that containing tallow (0.58 to 0.68). In experiment 2, ileal endogenous fat loss was determined to be 1,714 mg/kg of DM intake. Endogenous fat was composed mainly of palmitic (75 g/kg), stearic (131 g/kg), oleic (73 g/kg), linoleic (133 g/kg), and arachidonic (60 g/kg) acids. Fatty acid profile of endogenous fat was found to be remarkably similar to that of the bile, suggesting that the reabsorption of fat and FA from the bile was incomplete in growing broiler chickens. [ABSTRACT FROM AUTHOR]

Abstract: The influence of age of broilers on the apparent metabolisable energy (AME) and total tract digestibility of fat in five fat sources (tallow, soybean oil, poultry fat, palm oil and a 50:50 blend of tallow and soybean oil) was investigated. The assay diets were developed by substituting the different fats for 40g/kg (w/w) of a maize-soy basal diet and the measurements were made during weeks 1, 2, 3 and 5 posthatch. The AME of fats was influenced (P<0.001) by the age of broilers. The AME was markedly lower (P<0.05) during week 1, but improved during week 2. There were no further improvements (P>0.05) in the AME after week 2. There was no interaction (P>0.05) between fat source and age of broilers for the AME, indicating that the effect of age on the AME was similar for all fat sources. The effect of age on the apparent total tract digestibility of fat generally followed the same trend as that on the AME. The AME of palm oil, soybean oil and poultry fat were determined to be similar (P>0.05), but higher (P<0.05) than that of tallow. The AME of the 50:50 blend of tallow and soybean oil was determined to be 9% higher than the arithmetic averages of tallow and soybean oil, suggesting a synergistic effect. Overall, the present data highlight the physiological limitation in newly hatched chicks to effectively digest and utilise fats. [Copyright &y& Elsevier]

Abstract: The influence of grain type and feed form on performance, apparent metabolisable energy (AME) and coefficient of ileal apparent digestibility (CIAD) of nitrogen (N), starch, fat, calcium (Ca) and phosphorus (P) in broiler starters was examined in this study. Two grain types (maize and wheat) and three feed forms (mash, pellet and re-ground pellet) were evaluated in a 2×3 factorial arrangement of treatments. In both maize- and wheat-based diets, pellet-fed birds had higher (P<0.05) weight gain and feed intake than those fed mash and re-ground pellets. In both grain types, feed per unit gain of birds fed mash and pelleted diets was similar (P>0.05), but lower (P<0.05) than those fed re-ground pellets. However, dramatic decrease in the weight gain and feed intake, and a marked rise in the feed per unit gain of birds fed re-ground wheat-based pellets resulted in a significant (P<0.001) grain type and feed form interaction. In maize-based diets, pelleting had no influence (P>0.05) on the CIAD of N, but re-grinding the pellets resulted in higher (P<0.05) N digestibility than that of the mash diet. Feed form had no effect (P>0.05) on the CIAD of starch in maize-based diets. Ileal apparent digestibility coefficient of fat was improved (P<0.05) by the pelleting of maize-based diet compared to the mash diet with the improvement in fat digestibility maintained in re-ground pellets. In maize-based diets, pelleting increased (P<0.05) the CIAD of Ca and P, and the digestibility coefficients were further improved by re-grinding the pellets. In wheat-based diets, pelleting reduced (P<0.05) the CIAD of N and re-grinding the pellets resulted in the highest (P<0.05) N digestibility. Pelleting reduced (P<0.05) starch digestibility in wheat-based diets. While pelleting reduced (P<0.05) CIAD of fat, Ca and P in wheat-based diets, re-grinding the pellets improved fat, Ca and P digestibility to an extent higher than the mash diet. Feed form had no effect (P>0.05) on the AME of maize-based diets, but pelleting reduced (P<0.05) the AME of wheat-based diets. Overall, the current results suggest that effects of feed form on CIAD of nutrients depend on the cereal used and the nutrient considered. In maize-based diets, there was no negative impact of pellet feeding on CIAD of nutrients. In contrast, in wheat-based diets, feeding pelleted diets had negative effects on the digestibility of all nutrients. These negative effects on nutrient utilisation, however, are compensated by increased feed intake and the resultant higher nutrient intake in pellet-fed broilers. [Copyright &y& Elsevier]

1. The effects of microbial phytase on the performance and nutrient utilisation in broilers fed on phosphorus-adequate starter diets were examined in this study. The effect of phytase on the apparent ileal digestibility of fatty acids was of particular interest. Two grain types (maize and wheat) and two inclusion concentrations of a phytase enzyme fromEscherichia coliexpressed inSchizosaccaromyces pombe(0 or 500 phytase units (FTU)/kg of feed) were evaluated in a 2 × 2 factorial arrangement of treatments. 2. Supplemental phytase improved the weight gain and feed per gain, but had no effect on the feed intake of young broilers receiving phosphorus-adequate diets. 3. Phytase supplementation improved the apparent ileal digestibility of nitrogen and phosphorus in both diet types. Phytase supplementation tended to improve the apparent ileal digestible energy in wheat-based diets, but had no effect on the apparent metabolisable energy in both diet types. 4. Supplementation of phytase increased the apparent ileal digestibility of fat, with similar effects for the different fatty acids measured. Increments on ileal fat digestibility due to phytase were not dependent on the type of diet. 5. Dietary supplementation of microbial phytase enhanced not only the digestibility of phosphorus, but also that of nitrogen and fat, exhibiting increased ileal digestibility for all fatty acids in P-adequate maize- and wheat-based diets. [ABSTRACT FROM AUTHOR]

1. The influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers given wheat-based diets was examined from 10 to 42 d of age. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two pellet diameters (3 and 4.76 mm) and two pellet lengths (3 and 6 mm). From 0 to 9 d of age, all birds were offered a common starter diet pelleted with a 3-mm diameter die and 3-mm length. Broiler grower (d 10 to 21) and finisher (d 22 to 42) diets, based on wheat, were formulated and then subjected to the 4 different treatments. 2. In grower diets, increasing pellet diameter and pellet length reduced the gelatinised starch (GS) content of the diets. In finisher diets, GS content of 3-mm diameter pellets did not change with increasing pellet length but decreased in 4.76-mm diameter pellets. 3. In grower and finisher diets, increments in intact pellet weight, pellet durability index and pellet hardness with increasing pellet length were greater in 3-mm diameter pellets than those with 4.76-mm diameter. 4. Increasing pellet length from 3 to 6 mm increased apparent metabolisable energy values. Neither the interaction nor main effects were significant for the ileal digestibility of nitrogen and starch. 5. During the grower period (d 10 to 21), birds given pellets of 6-mm length had greater body-weight gain than those given 3-mm length pellets. Feeding 6-mm length pellets decreased feed per body-weight gain compared to 3-mm length pellets. During the finisher (d 22 to 42) and whole grow-out (d 10 to 42) periods, while different pellet lengths had no effect on feed per body-weight gain values at 3-mm pellet diameter, increasing the pellet length decreased feed per body-weight gain at 4.76-mm pellet diameter. 6. Increasing pellet diameter and pellet length reduced the relative length of duodenum. Birds given 3-mm diameter pellets had heavier proventriculus compared to those given 4.76-mm diameter pellets. 7. Overall, the data suggest that increasing the pellet length from 3 to 6 mm improved the body-weight gain and feed per body-weight gain during the grower period (d 10 to 21). While the positive effect on body-weight gain disappeared as the birds grew older, improvements in feed per body-weight gain were maintained over the finisher and whole grow-out periods only in 4.76-mm diameter pellets. Small diameter die holes and longer pellet lengths may be considered as potential manipulations to manufacture high-quality pellets under low conditioning temperatures. [ABSTRACT FROM PUBLISHER]

A 2 by 2 factorial arrangement of treatments was used to evaluate the effect of pellet diameter (3 and 4.76 mm) and pellet length (3 and 6 mm) on pellet quality and performance, apparent metabolisable energy and ileal digestibility of nitrogen and starch in broilers. From 0 to 9 days of age, all birds were offered a common starter diet. Broiler grower (Days 10-21) and finisher (Days 22-42) diets, based on maize, were formulated and then allocated to the four different treatments. All diets were steam-conditioned at 60°C before pelleting. In grower diets, increasing pellet diameter and pellet length reduced (P < 0.001) the gelatinised starch content of the diets. In finisher diets, gelatinised starch content of pellets was not influenced (P > 0.05) by main effects or the interaction. In grower and finisher diets, increments in pellet durability index and pellet hardness with increasing pellet length were greater in pellets with a 3-mm diameter than those with a 4.76-mm diameter. During the grower period (Days 10-21), birds fed the 3-mm-diameter pellets had lower (P < 0.01) feed per gain than those fed pellets with a 4.76-mm diameter. During the finisher (Days 22-42) and whole trial (Days 10-42) periods, neither main effects nor the interaction were significant (P > 0.05) for weight gain, feed intake and feed per gain. Increasing pellet diameter from 3 to 4.76 mm decreased (P < 0.001) apparent metabolisable energy values. Neither main effects nor the interaction were significant (P > 0.05) for the coefficient of ileal apparent digestibility of nitrogen. Increasing pellet length from 3 to 6 mm decreased (P < 0.05) relative weight of gizzard in 3-mm-diameter pellets but not in the 4.76-mm-diameter pellets (P > 0.05). Overall, when low conditioning temperatures are used to optimise nutrient availability, small diameter die holes and longer pellet lengths can favour creating high physical quality pellets. The present study also showed that feeding lower diameter pellets to broilers during the grower period (Days 10-21) only improved feed per gain, a response which disappeared as the birds grew older. The importance of pellet quality in improving broiler performance is well recognised. This study examined the effect of pellet diameter and length on pellet quality, and showed that manipulation of pellet size can be considered as a potential strategy to improve pellet quality. This approach can be used to manufacture highly digestible high quality pellets at low conditioning temperatures. [ABSTRACT FROM AUTHOR]

Abstract: Pelleting is the most prevalent heat treatment in the production of poultry feed. The objective of pelleting is to agglomerate smaller feed particles into larger particles as pellets to enhance the economics of production by increasing the feed intake, and thus growth performance and feed efficiency. However, due to the heat, moisture and mechanical pressure applied during conditioning and pelleting, some chemical and physical alterations occur that may have beneficial or detrimental effects on feed components, gastrointestinal development and subsequent bird performance. Pelleting process has been shown to gelatinise starch, but only to a small extent, and thus may be of modest relevance in starch digestion. Pelleting process may also result in partial denaturation of proteins; a process which can potentially improve protein and to some extent starch digestibility due to inactivation of proteinaceous enzyme inhibitors. Cell wall breakage, as a result of the physical stress of pelleting, may also provide greater accessibility of nutrient contents, previously encapsulated within endosperm sub-aleurone, to digestive enzymes. In diets based on viscous cereals, nutrient availability may be negatively affected through increased digesta viscosity as a result of either an increase in soluble carbohydrate concentration or changes in the molecular weight of soluble fibres or both, due to pelleting. Pelleting process also remains a potentially aggressive process on the stability of exogenous feed enzymes and vitamins, a major concern of feed manufacturers. Particle size-reducing property of the pelleting process may result in a suboptimal gizzard development and thus reduced nutrient digestibility of diets for poultry. While physical pellet quality is a critical factor to optimise feed efficiency and growth response of broilers, the present review highlights that it is the balance between nutrient availability and physical quality of pellets which is critical in determining the actual performance of broilers. Under the conventional pelleting process, good pellet quality is usually obtained at the expense of nutritional quality. Research is warranted to identify and evaluate possible strategies to manufacture highly digestible high quality pellets. Such strategies will require novel approaches of improving feed hygiene which are not detrimental to feed nutrients. [Copyright &y& Elsevier]

Two experiments were conducted to evaluate the nutritional value of three cultivars (Promore, Kiev mutant and Ultra) of white lupins (Lupinus albus L.) for broilers. In experiment 1, the apparent metabolisable energy (AME) and ileal amino acid digestibility coefficients of the three cultivars were determined. The cultivar effects were significant (P < 0.05) for AME, but the ileal amino acid digestibility coefficients were similar (P > 0.05) between cultivars. The AME value of Ultra cultivar was lower (P < 0.05) than those of Promore and Kiev mutant cultivars. In Experiment 2, using the AME and ileal digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of lupin were formulated and the effects of feeding these diets on performance, digestive tract development and excreta quality of broiler starters were investigated. Weight gain, feed intake and feed per gain of broilers fed diets containing white lupins were similar (P > 0.05) to those fed the maize–soybean meal diet. The performance of birds fed diets containing different cultivars of white lupins was similar (P > 0.05). Several digestive tract parameters were influenced by the dietary inclusion of white lupins. In particular, the relative liver weight and the relative empty weights of small intestine and caeca in birds fed diets containing white lupins were higher (P < 0.05) than those fed the maize–soybean meal diet. No differences (P > 0.05) were observed in the excreta quality scores between the birds fed the maize–soybean meal diet and those fed diets containing white lupins. [ABSTRACT FROM PUBLISHER]

1. Two experiments were conducted to evaluate the nutritional value of three cultivars (Wallan, Tanjil and Borre) of narrow-leafed lupin (Lupinus angustifolius) for broilers. 2. In Experiment 1, the apparent metabolisable energy (AME) and the apparent ileal amino acid digestibility of the three cultivars were determined. The cultivar effects were not significant for AME and apparent ileal amino acid digestibility coefficients. In general, amino acids in narrow-leafed lupin were well digested, with the notable exception of methionine. Among the indispensable amino acids, arginine had the highest digestibility coefficient (0·92–0·95), while the lowest was for methionine (0·74–0·83). 3. In Experiment 2, using the energy and digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of the three lupin cultivars were formulated and the effects of feeding these diets on the performance and the digestive tract development of broiler starters were investigated. 4. Weight gain, feed intake and feed per gain of broilers fed narrow-leafed lupins diets were similar to those fed on the maize-soy basal diet. The performance of birds fed on diets containing different cultivars of lupins was also similar. Birds fed on lupin diets had similar excreta scores to those fed on the basal diet. 5. Inclusion of 200 g/kg lupins in broiler diets had no effects on the relative weight and length of the intestinal tract. Broilers fed on lupin diets, however, had higher relative weights of liver. 6. These results suggest that narrow-leafed lupins are good sources of protein, but poor sources of AME and sulphur-containing amino acids. It is concluded that, when diets are properly balanced in terms of AME and digestible amino acids, lupins can be included at 200 g/kg inclusion level in broiler starter diets with no adverse effects on performance. [ABSTRACT FROM PUBLISHER]

1. A total of 240 Ross 308 broilers were used to investigate the effect of sodium (1·5 or 2·5 g/kg), phytate-P (0 or 3·2 g/kg), and phytase (0 or 1000 FTU/kg; 2x2x2 factorial) on endogenous amino acid flow using the enzyme-hydrolysed casein method. 2. The ingestion of phytate increased endogenous amino acid flow (∼30%) compared with the phytate-free control diets. Phytase reduced endogenous amino acid flow only when fed in concert with phytate, resulting in a significant phytate x phytase interaction. 3. Increasing dietary sodium concentration from 1·5 to 2·5 g/kg reduced endogenous amino acid flow by around 10%. This reduction of endogenous flow was particularly evident in diets which contained phytate, resulting in a significant sodium x phytate interaction for several amino acids, including Thr and Ser. Further, high sodium concentrations muted the effect of phytase resulting in a significant sodium x phytase interaction for some amino acids. 4. The concentration of Asp, Thr, Ser and some other amino acids was increased in the endogenous protein in response to the ingestion of phytate. Both sodium and phytase essentially restored the composition of endogenous protein to that of the phytate-free control. Further, as both sodium and phytase had similar effects there were significant interactions between sodium and phytase for most amino acids, such that one was only effective in the absence of the other. 5. These data confirm previous reports that phytate is a nutritional aggressor, causing quantitative and qualitative changes in endogenous protein flow. However, this is the first report which has shown that dietary sodium concentrations play a role in the severity of this antinutritional effect and consequently may blunt the efficacy of exogenous phytase. The mechanism is obscure, though it has been previously demonstrated that sodium can disrupt phytate:protein complexes, thus mitigating one of the mechanisms by which phytate exerts its antinutritional effect. [ABSTRACT FROM PUBLISHER]

Abstract: The influence of feed form and conditioning temperature on performance, apparent metabolisable energy (AME) and ileal digestibility of starch and nitrogen in broilers fed wheat-based starter diet were examined in this study. Two feed forms (mash and pellet) and four conditioning temperatures: 20°C (dry-conditioning), 60, 75 and 90°C (steam-conditioning) were evaluated in a 2×4 factorial arrangement of treatments. In mash diets, weight gain of birds fed the diet conditioned at 60°C was higher (P<0.05) than those fed diets conditioned at 75 and 90°C and similar (P>0.05) to those fed diet conditioned at 20°C. In pelleted diets, while steam-conditioning increased (P<0.05) the weight gain compared to dry-conditioning, birds fed diets conditioned at 60, 75 and 90°C had similar (P>0.05) weight gains. Pelleting increased (P<0.001) the feed intake. Birds fed diets conditioned at 20°C had lower (P<0.01) feed intake than those fed diets conditioned at 60 and 90°C and similar (P>0.05) to those fed diets conditioned at 75°C. In mash diets, birds fed the diet conditioned at 90°C had higher (P<0.05) feed per unit gain than those fed diets conditioned at 20 and 60°C, but similar (P>0.05) to those fed the diet conditioned at 75°C. In pelleted diets, while steam-conditioning decreased (P<0.05) the feed per unit gain, birds fed steam-conditioned diets (at 60, 75 and 90°C) had similar (P>0.05) feed per unit gain. Pellet durability and hardness increased (P<0.001) with increasing conditioning temperatures. Pelleting reduced (P<0.001) the coefficient of ileal apparent digestibility (CIAD) of nitrogen of the diets. Coefficient of ileal apparent nitrogen digestibility of the diets conditioned at 60 and 75°C was similar and higher (P<0.01) than those conditioned at 20 and 90°C. In mash diets, the CIAD of starch in the diet conditioned at 60°C was higher (P<0.05) than diet conditioned at 90°C, but similar to those conditioned at 20 and 75°C. In pelleted diets, those conditioned at 60 and 90°C had higher (P<0.05) CIAD of starch than the diet conditioned at 20°C, but similar to the diet conditioned at 75°C. Higher (P<0.001) apparent metabolisable energy values were determined for mash diets. The AME content of diets conditioned at 60°C was similar to those conditioned at 75°C and higher (P<0.05) than diets conditioned at 20 and 90°C. In both feed forms, the diet conditioned at 90°C had the highest (P<0.05) gelatinised starch content. In mash diets, while the diets conditioned at 20, 60 and 75°C had similar resistant starch content, the diet conditioned at 90°C had the highest (P<0.05) resistant starch content. In pelleted diets, the diets conditioned at 20 and 90°C had higher (P<0.05) resistant starch content than the diet conditioned at 60°C, but similar to the diet conditioned at 75°C. Overall, the current results suggest that while in mash diets steam-conditioning at 60°C improved weight gain and feed intake, increasing conditioning temperatures per se had negative effects on nutrient utilisation and, weight gain and feed per unit gain of broiler starters. But the deterioration in performance parameters caused by conditioning at higher temperatures was restored when steam-conditioned mash diets were pelleted. [Copyright &y& Elsevier]

1. The aim of the present experiment was to examine the influence of whole wheat inclusion and a blend of essential oils (EO; cinnamaldehyde and thymol) supplementation on the performance, nutrient utilisation, digestive tract development and ileal microbiota profile of broiler chickens. 2. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two wheat forms (ground wheat [GW] and whole wheat [WW]; 100 and 200 g/kg WW replacing GW during starter [1 to 21 d] and finisher [22 to 35 d] diets respectively) and two levels of EO inclusion (0 or 100 g/tonne diet). All dietary treatments were supplemented with 2000 xylanase units/kg feed. Broiler starter and finisher diets based on wheat and soybean meal were formulated and each diet fed ad libitum to 6 pens of 8 male broilers. 3. During the trial period (1-35 d), wheat form had no significant effect on weight gain or feed intake. However, WW inclusion tended (P = 0.06) to improve feed per gain. Essential oil supplementation significantly improved weight gain in both diets, but the improvements were greater in the GW diet as indicated by a significant wheat form × EO interaction. 4. Main effects of wheat form and EO on the relative weight, length and digesta content of various segments of the digestive tract were not significant. Significant interactions, however, were found for relative gizzard and caecal weights. Essential oil supplementation significantly increased the relative gizzard weight and lowered relative caecal weight in birds fed on the GW based diet, but had no effect in those fed on the WW based diet. 5. Whole wheat inclusion and EO supplementation significantly improved apparent ileal nitrogen digestibility. Apparent ileal digestible energy was not significantly influenced by the dietary treatments. 6. Ileal microbiota profiling, using denaturing gradient gel electrophoresis, showed that the ileal microbiota composition was influenced by feed form. The mean numbers of bacterial species in the ileal contents of birds fed on the GW diet supplemented with EO tended (P = 0.07) to be higher than those of the ileal contents of birds fed on unsupplemented GW based diet. 7. The present data suggested that dietary addition of EO improves broiler weight gain and ileal nitrogen digestibility both in GW and WW based diets, but that the magnitude of the response to EO for weight gain was greater in GW based diet. Whole wheat feeding was found to be beneficial in terms of feed efficiency. [ABSTRACT FROM AUTHOR]

1. The effect of various doses of xylanase and glucanase on the performance and ileal nutrient digestibility of broiler chickens fed on maize/soy-based diets was evaluated. 2. A total of 960 male broilers were used in separate growth and digestibility trials with each involving 10 treatments and 6 replicates. The 10 treatments included a positive control reference diet, a negative control diet with a lower energy density and 8 further diets where xylanase and glucanase were added to the negative control, individually and in combination. 3. Birds which received the negative control diet returned poorer (6 points; P < 0·05) feed conversion ratios compared with those fed on the positive control, confirming the lower energy density of the negative control diet. Ileal digestibility of energy determined at 21 and 42 d was also significantly lower for the negative control compared with the positive control. At d 21 birds that received the negative control diet returned lower ileal amino acid digestibility (for most amino acids) compared with their counterparts fed on the positive control whereas at d 42 this effect was not apparent. 4. Supplementation of the negative control with both glucanase and xylanase improved feed conversion ratio (FCR) and ileal nutrient digestibility. When both enzymes were added simultaneously a sub-additive effect (i.e. simultaneous use resulted in benefits greater than either enzyme independently but less than the sum of the individual effects) was observed, with the best performance achieved with the combination of xylanase (16 000 BXU/kg) and glucanase (30 000 BU/kg). 5. It can be concluded that the removal of oil to accommodate the anticipated energy digestibility improvement with enzymes can have deleterious effects on FCR and ileal amino acid digestibility in young broilers which enzymes may not adequately mitigate. Thus, in order to maximise the response to non-starch polysaccharide degrading enzymes in maize/soy-based broiler diets, it may be beneficial to consider a combination of xylanase and glucanase and to apply moderation when removing added fat in the starter diets. [ABSTRACT FROM AUTHOR]

Abstract: Two experiments were conducted to evaluate the nutritional value of four cultivars (PGG Tic, Spec Tic, South Tic and Broad) of faba beans (Vicia faba L.) for broilers. In experiment 1, the apparent metabolisable energy (AME) and ileal amino acid digestibility coefficients of these four cultivars were determined. The cultivar effects were significant (P<0.05) for AME, but ileal amino acid digestibility coefficients were not different (P>0.05) between the four cultivars. The AME value of South Tic cultivar was higher (P<0.05) than those of Spec Tic and Broad cultivars, but similar (P>0.05) to that of PGG Tic. In Experiment 2, using the AME and ileal digestible amino acid values determined in Experiment 1, diets containing 200gkg−1 of the four cultivars of faba beans were formulated and the effects of feeding these diets on the performance and the digestive tract development of broiler starters were investigated. Weight gain, feed intake and feed per gain of broilers fed faba bean diets were similar (P>0.05) to those fed the maize–soybean meal diet. The performance of birds fed diets containing different cultivars of faba beans was similar (P>0.05). In general, the digestive tract development was unaffected (P>0.05) by the inclusion of faba beans. The exceptions were the relative empty weight and digesta weight of gizzard which were found to be higher (P<0.05) in birds fed diets containing faba beans than those fed the maize–soy diet. Birds fed faba bean diets had better (P<0.05) excreta quality scores than that of the basal diet. These results suggest that faba beans are good sources of energy and amino acids, and that faba beans can be included at 200gkg−1 inclusion level as a partial replacement for soybean meal in broiler diets without any adverse effects on the performance. [Copyright &y& Elsevier]

The effects of individual and combined inclusions of xylanase and phytase in broiler diets based on a characterised wheat were evaluated. The positive control diet was formulated to be adequate for phosphorus (P) with 3.8gkg−1 nonphytate P and the low-P, negative control diet contained 2.6gkg−1 nonphytate P. The negative control diet was supplemented with xylanase (2000XUkg−1), or phytase (500FTUkg−1), or xylanase plus phytase (2000XUkg−1 and 500FTUkg−1). Treatment effects on ileal digestibility of amino acids, energy and nitrogen utilisation, ileal digestibility and total tract retention of minerals, toe ash content and the growth performance were determined. In combination, xylanase plus phytase increased mean apparent ileal digestibility (AID) coefficients of 17 amino acids by 8.6%, which exceeded the increases of 4.8% and 5.5% generated by xylanase and phytase, respectively. Increases in AID were significant (P<0.05) for the majority of amino acids in response to enzyme inclusions with indications of synergistic responses for five amino acids. Xylanase plus phytase increased (P<0.05) nitrogen-corrected AME by 0.63MJkg−1, ileal energy digestibility by 0.89MJkg−1 and energy AID coefficient by 6.7% relative to the negative control diet. The enzyme combination increased (P<0.05) coefficients of ileal nitrogen digestibility by 9.1% and 8.0% relative to positive and negative control diets, respectively. Phytase increased (P<0.05) ileal calcium digestibility by 32.2% and ileal P digestibility by 28.0% relative to the negative control. Also, phytase increased (P<0.05) the AID coefficient of sodium to −0.038 from −0.516 in the negative control diet and the combination increased the same coefficient to 0.043. P reduction in the control diet lowered (P<0.05) bone mineralisation, but toe ash contents were restored by phytase and xylanase plus phytase. P status of the control diets had no effect (P>0.05) on the efficiency of feed conversion, but xylanase (6.2%), phytase (2.5%) and xylanase plus phytase (3.9%) enhanced (P<0.05) feed efficiency relative to the negative control. The low-P diet depressed (P<0.05) weight gain and feed intake but phytase and xylanase plus phytase restored both weight gain and feed intake. Overall, the present data indicate that the simultaneous inclusion of xylanase plus phytase in wheat-based broiler diets was beneficial in terms of nutrient utilisation and growth performance. [Copyright &y& Elsevier]

The aim of the present experiment was to examine the interaction between particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract development of broiler starters fed maize-based diets. The experimental design was a 2 x 2 factorial arrangement of treatments evaluating two maize particle sizes (medium and coarse) and two levels of phytase supplementation (without or with 500 phytase units/kg diet). The two particle sizes were achieved by grinding the whole maize in a hammer mill to pass through 3- and 7-mm screens, respectively. Broiler starter diets, based on maize and soybean meal, were formulated to meet recommended requirements for major nutrients, except phosphorus. Each of the four diets was fed ad libitum to six pens of eight male broilers each, from day 1 to day 21 post-hatching. Phytase supplementation increased (P < 0.001) the feed intake and weight gain, and lowered (P < 0.05) feed per gain in both medium and coarse particle size diets. Coarse grinding improved (P < 0.05) weight gain, but had no effect (P > 0.05) on feed intake and feed per gain. No interactions (P > 0.05) between phytase supplementation and particle size were observed for any of the performance parameters. Phytase supplementation increased (P < 0.001) ileal phosphorus digestibility and toe ash content of birds fed the medium particle size diet, but had no effect in those fed the coarse particle size diet. Apparent metabolisable energy and ileal digestibility of calcium and nitrogen were not influenced by particle size or phytase supplementation. The present findings suggest that the effectiveness of supplemental phytase on broiler performance is not influenced by the particle size of maize. [ABSTRACT FROM AUTHOR]

1. An experiment of 21-d duration was conducted to examine the effects of diluting wheat-based diets with insoluble fibre sources and whole wheat inclusion on the performance, nutrient utilisation, digestive tract development and ileal microbiota profile of broiler chickens. The treatments were as follows: Treatment 1, control diet based on ground wheat; Treatment 2, where 200 g/kg whole wheat replaced the ground wheat pre-pelleting; and Treatments 3 and 4 where the control diet was diluted with fine cellulose and wood shavings, respectively, at a ratio of 6 : 100 (w/w). 2. Weight gains and apparent metabolisable energy were unaffected by dietary treatment. Gain : feed ratio was not influenced by the inclusion of whole wheat or wood shavings, but decreased with cellulose inclusion. However, when gain:feed of birds was corrected by subtracting the amount of cellulose and wood shavings from the total feed consumption, it was found that the inclusion of wood shavings increased gain : feed, while cellulose inclusion had no effect. Similarly, AMEN was unaffected by dietary treatment. However, when AMEN was corrected for energy contribution from cellulose or wood shavings, improvements in AMEN were observed in these two treatments. 3. Wood shavings increased the relative gizzard weights and improved ileal starch digestibility compared to other dietary treatments. All gut components were shorter in birds given diets containing cellulose and wood shavings compared to those receiving the control and whole wheat diets. 4. Ileal microbiota profiling, using denaturing gradient gel electrophoresis, showed that microbial composition was affected by dietary treatment and that the treatments were grouped into two main clusters. The two groupings showed similarity between birds receiving the control and cellulose diets and similarity between birds fed on the whole wheat and wood shavings diets. 5. The findings suggest that the effects of insoluble fibre on broiler performance differed depending on the fibre particle size. [ABSTRACT FROM AUTHOR]

Abstract: The present study was conducted to investigate the effects of feeding whole wheat either through a mixed feeding (MF) or free choice feeding (FCF) system on the performance, digestive tract development and carcass traits of broiler chickens. The following three treatments, based on wheat and soybean meal, were employed: GW, ground-wheat diet with 600–690gwheatkg−1; MF, GW diet with 490–500gwheatkg−1 and 100–200g whole wheat kg−1; and FCF, whole wheat and a protein concentrate offered in separate feeders. Each diet was fed to six pens of 36 birds each from day 7 to 35 post-hatch. Over the 7–35-day trial period, no differences (P>0.05) were observed between the weight gain, feed intake and feed per gain of broilers receiving the GW and MF treatments. Birds receiving the FCF treatment had the lowest (P<0.05) weight gain and feed intake, and the highest (P<0.05) feed per gain. During week 1 of the trial, the protein concentrate was consumed more than the whole wheat (0.69 vs. 0.31) in the FCF treatment, resulting in the amount of concentrate offered being restricted during subsequent weeks. Over the trial period, the average consumption of protein concentrate remained high (0.56 of the total intake). Both whole-wheat treatments increased (P<0.05) the relative gizzard weights. Factors that affect diet selection such as learning and previous experience, visual differences between the foods, texture and flavour of the food, and palatability may explain the lower whole-wheat intake in the FCF treatment. In this study, whole wheat was introduced only on day 7 and it is possible that the birds may have to be trained to experience choice feeding from the first week of life. However, the present results suggest that FCF may not be an appropriate feeding system for fast growing modern broilers. [Copyright &y& Elsevier]

The influence of particle size and grain type on the performance, AMER, and on gross morphological and histological parameters of the various segments of the digestive tract of broilers fed wheat- or corn-based diets was investigated. The experimental design was a 2 x 2 factorial arrangement of treatments evaluating 2 particle sizes (fine and coarse) and 2 grain types (wheat and corn). The 2 particle sizes were achieved by grinding the whole grains in a hammer mill to pass through 1-mm and 7-mm screen sizes. Broiler starter diets, based on wheat- or corn-soybean meal, were formulated, pelleted, and each diet was offered to 6 cages of 8 male broilers each from d 1 to 21 posthatching. The results showed that the differences in particle size distribution still existed between diets after pelleting especially in the proportion of coarse particles (1 mm and over). In corn-based diets, coarse grinding improved (P 0.06) weight gains compared with fine grinding, but this particle size effect was not observed in wheat-based diets. In both diets, coarse grinding lowered (P < 0.001) feed per gain of broilers compared with fine grinding. In wheat-based diets, coarse grinding improved (P = 0.06) AMER compared with fine grinding. Heavier (P < 0.05) gizzard weights were observed in birds fed the coarse corn-based diet, but particle size had no effect on the gizzard size in birds fed wheat-based diets. Villus height, crypt depth, and epithelial thickness in the duodenum were unaffected (P > 0.05) by particle size and grain type. Overall, the present results showed that the effect of feed particle size varies depending on grain type. [ABSTRACT FROM AUTHOR]

The effects of phytic acid and 2 sources of exogenous phytase (bacterial vs. fungal) on the flow of endogenous amino acids at the terminal ileum of broilers were assessed using the enzyme-hydrolyzed casein method. Phytic acid (as the sodium salt) was included in a purified diet at 8.5 and 14.5 g/kg, and each diet was fed without or with a fungal (Aspergillus niger-derived) or a bacterial (Escherichia coli-derived) microbial phytase at 500 phytase units/kg of diet. Increasing the concentration of phytic acid in the diet from 8.5 to 14.5 g/kg increased (P < 0.001) the flow of all measured amino acids by an average of 68%, with a range from 17% for proline to 145% for phenylalanine. The flow of endogenous aspartic acid, serine, glutamic acid, glycine, leucine, tyrosine, phenylalanine, and histidine were increased by more than the mean, indicating changes in the composition of endogenous protein in response to the presence of higher concentrations of phytic acid. Supplementation of both phytases reduced (P < 0.001) the flow of endogenous amino acids, but the reduction (P = 0.06) was greater for the bacterial phytase compared with the fungal phytase. These data suggest that a substantial part of the amino acid and energy responses observed following phytase supplementation in broiler chickens stems from reduced endogenous amino acid flows and that the capacity of different phytases to counteract the antinutritive properties of phytic acid vary. [ABSTRACT FROM AUTHOR]

1. Two experiments were conducted to measure changes in nutrient utilisation in the newly hatched broiler chicken. The first experiment determined the nitrogen-corrected apparent metabolisable energy (AMEN) and total tract digestibility of starch and fat in diets based on wheat, sorghum and maize during the first two weeks post-hatch. The second experiment was conducted to confirm the results of Experiment 1 using wheat- and maize-based diets and was of 21 d duration. 2. In both experiments, changes to AMEN with age were similar irrespective of the diet type, declining from d 3 to d 5-9 and then increasing after d 9. 3. In Experiment 1, the total tract digestibility of starch and fat exhibited a pattern similar to that of AMEN. 4. In Experiment 1, cereal effects were significant, with maize- and sorghum-based diets having higher AMEN values than the wheat-based diet. Total tract starch digestibility determined for d 5, 7 and 14 showed no cereal differences. Total tract fat digestibility on d 7 was significantly lower for the wheat- and sorghum-based diets than for the maize-based diet, but no cereal differences were observed on d 5 or 14. 5. In Experiment 2, cereal effects were significant, with the maize-based diet having a higher AMEN than the wheat-based diet. 6. These results showed that nutrient utilisation is compromised during the first week of life of the broiler chick. [ABSTRACT FROM AUTHOR]

1. The aim of the present experiment was to examine the influence of particle size and xylanase supplementation on the performance, energy utilisation, and gross morphological and histological parameters of the digestive tract of broiler starters fed wheat-based diets. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two wheat particle sizes (medium and coarse) and two levels of xylanase supplementation (without or with 1000 xylanase units/kg diet). The two particle sizes were achieved by grinding the whole wheat in a hammer mill to pass through 3 and 7 mm screens, respectively. Broiler starter diets, based on wheat and soybean meal, were formulated and each diet was fed ad libitum to 6 pens of 8 male broilers each from d 1 to 21 post-hatch. 2. Wheat particle size had no effect on the performance of broilers. Xylanase supplementation had no effect on weight gain and feed intake. However, a significant particle size × xylanase interaction was observed for feed per unit gain with xylanase lowering feed per gain only in the coarse particle size diet. Xylanase supplementation improved the nitrogen-corrected apparent metabolisable energy at both particle sizes. 3. Xylanase supplementation decreased the relative weight and relative length of all gut components. Villus height and crypt depth and total extent of the mucosal layer were unaffected by both wheat particle size and xylanase supplementation. 4. The apparent viscosity of intestinal digesta, determined over the physiological range of shear rates, was not influenced by xylanase addition or particle size. 5. The findings of this study suggest that the effectiveness of exogenous xylanase in broiler diets is influenced by wheat particle size. [ABSTRACT FROM AUTHOR]

1. The aim of the present study was to investigate the effect of an enzyme cocktail composed of xylanase, amylase and protease on the performance and nutrient utilisation of broiler starters fed on a maize-based diet. A maize/soy-based control diet was formulated to be marginal in apparent metabolisable energy (AME) and amino acids and this diet was fed without or with two concentrations (250 and 500 g/tonne) of the exogenous enzyme cocktail. 2. Growth performance was measured over a 21-d period after which ileal contents were collected for measurement of digestible energy, nitrogen and dry matter. Excreta were collected from d 17 to 20 post-hatch and used to determine the AME, and retention of nitrogen and dry matter. 3. Supplementation of the control diet with 250 and 500 g/tonne of the enzyme cocktail resulted in enhanced performance of the chicks (1·4 and 8·3%, respectively, for weight gain and 1·2 and 2·2%, respectively, for feed per gain), but the improvements were significant (P < 0·05) only at 500 g/tonne. 4. Addition of both 250 and 500 g/tonne improved AME, nitrogen-corrected AME and dry matter retention compared with the control though the improvements were greater with the higher dose. These effects were also reflected in the apparent ileal digestibility coefficients of dry matter, nitrogen and energy, with 500 g/tonne of the enzyme cocktail improving ileal digestible energy by 3·4%. 5. These results demonstrate that a cocktail of exogenous enzymes containing xylanase, amylase and protease is effective in improving the performance of broiler chicks fed on a maize/soybean-meal-based diet. However, these benefits may be dose-dependent and so an economic analysis involving ingredient and enzyme pricing and the relative performance and digestibility enhancements could allow the end user to select the most economical dose to maximise return on investment. [ABSTRACT FROM AUTHOR]

The possible interaction between dietary electrolyte balance (DEB = Na + K - Cl, mEq/kg of diet) and microbial phytase on the performance and nutrient utilization of broiler starters and litter quality was examined in this study. A 4 × 2 factorial arrangement of treatments was used with 4 levels of DEB (150, 225, 300, and 375 mEq/kg of diet) and 2 levels of phytase (0 and 500 phytase units/kg of diet). Experimental diets were based on corn, soybean meal, and canola meal and were formulated to contain a nonphytate P level of 3 g/kg. The DEB levels were altered by the use of sodium bicarbonate and ammonium chloride. Each diet was offered to 6 replicates of 8 birds each from d 1 to 21. Increasing the DEB values from 150 to 300 mEq/kg had no effect (P > 0.05) on the weight gains and feed per gain, but the gains were lowered (P < 0.05) and the feed per gain was increased (P < 0.05) at 375 mEq/kg. Feed intake was unaffected (P > 0.05) by DEB levels. Supplemental phytase improved (P <0.05) the weight gains and feed intake at all DEB levels. Feed per gain was lowered (P < 0.05) by phytase addition, but a tendency for a DEB × phytate interaction (P = 0.06) was also observed, indicating that the responses to phytase may be affected by DEB level. The responses in feed per gain were greater at the lowest DEB level, and phytase addition had no effect on feed per gain at the highest DEB level. Dietary electrolyte balance levels had no effect on the AMEn and ileal N digestibility to 300 mEq/kg, but lowered (P <0.05) both criteria at 375 mEq/kg. Phytase addition improved (P < 0.05) the AMEn and ileal N digestibility. The improvements in AMEn with 500 U/kg of phytase addition in 150, 225, and 275 mEq/kg DEB were 53, 60, and 38 kcal/kg of DM, respectively. The main effect of DEB was significant (P < 0.05) only for the ileal availability of Na and Cl, whereas added phytase influenced (P <0.05) the ileal availability of Ca, F, Na, K, and Cl. The effects of DEB were significant (P < 0.05) for apparent ileal digestibility of all amino acids, except Ala (P = 0.09), Arg, Met, and cystine. In general, the digestibilities of amino acids were unaffected when the DEB level was increased from 150 to 225 mEq/kg of diet, but decreased at the 300 and 375 mEq/kg levels. Phytase addition improved (P < 0.06 to 0.05) ileal digestibility of all amino acids, except Met and Tyr. Increasing DEB had adverse effects on excreta scores and DM content. Phytase addition, however, had no effect on excreta quality. The overall results of the present study suggest that variability in phytase responses in nutrient utilization may be explained, in part, by differences in dietary electrolyte levels. [ABSTRACT FROM AUTHOR]

1. A total of 192 male broilers (Cobb 500) were used in a growth and digestibility assay, involving a 2 × 2 factorial arrangement of treatments, to assess the effects of an enzyme cocktail of xylanase, amylase and protease in maize-based diets. 2. The following two diets were formulated: a positive control diet containing adequate nutrient concentrations for broiler starters as per breeder recommendations and a negative control diet to contain approximately 0·63 MJ/kg apparent metabolisable energy (AME) and 3% amino acids less than the positive control. 3. A further two dietary treatments were developed by supplementing each control diet with an enzyme product containing xylanase, amylase and protease. 4. Birds fed on the negative control diet had poorer weight gain and feed efficiency than those given the positive control diet. There was no effect of diet or enzyme on feed intake. The digestibility of nitrogen, calcium, phosphorus and most amino acids were unaffected by dietary nutrient density. 5. Supplementation of both the positive and negative control diets with the enzyme improved weight gain and feed efficiency compared with the unsupplemented diets. In the case of the negative control, supplemental enzyme improved performance to that of the unsupplemented positive control diet. There was no interaction between diet and enzyme for either weight gain or FCR, suggesting similar beneficial responses regardless of the nutrient density of the diet. 6. In both diets, enzyme supplementation improved AME by an average of 3% (0·35 MJ/kg DM) and nitrogen retention by an average of 11·7% (26 g/kg DM intake vs 29 g/kg DM intake). There was no interaction between diet and enzyme for AME or nitrogen retention. 7. Ileal digestibilities of calcium and phosphorus were not influenced by supplemental enzyme, whereas the digestibility of nitrogen and most amino acids was improved by enzyme addition compared with the unsupplemented control diets. There was no interaction between diet and enzyme for the ileal digestibility of nitrogen and amino acids. 8. These data demonstrate that it is possible to improve the nutritional value of a maize/soy-based diet for broiler starters through the use of exogenous enzymes. The nutrient density of the diet does not appear markedly to influence the response to enzyme, offering flexibility in the use of enzymes for maize-based diets. 9. It is concluded that the energy and amino acid values of maize-based diets for broilers can be enhanced by supplementation with an enzyme cocktail of xylanase, amylase and protease, offering potential economic benefits to producers. [ABSTRACT FROM AUTHOR]

This study investigated the influence of particle size and feed form on the performance, the AMEn, and the gross morphological and histological parameters of various segments of the digestive tracts of broilers fed wheat-based diets. The experimental design was a 2 x 2 factorial arrangement of treatments evaluating 2 wheat particle sizes (medium and coarse) and 2 feed forms (mash and pellet). The 2 particle sizes were achieved by grinding the whole wheat in the hammer mill to pass through 3- and 7-mm sieves. Broiler starter diets, based on wheat and soybean meal, were formulated and each diet was fed to 6 pens of 8 male broilers each from d 1 to 21 posthatching. Broiler performance was superior (P < 0.05) in birds fed pelleted diets compared with those on mash diets. Pelleting evened out the differences in particle size distribution between treatments and, as a result, wheat particle size had no effects (P > 0.05) on the performance of broilers fed pelleted diets. In mash diets, coarse grinding of wheat improved (P < 0.05) weight gain and feed:gain compared with medium grinding. Pelleting had a negative effect (P < 0.05) on AMEn. The improvement in bird performance with pelleting was accompanied by a decrease in the relative length of all components of the digestive tract. Conversely, the extent of the mucosal layer was greater (P < 0.05) in both the duodenum and jejunum of birds fed pelleted feeds. Feed form influenced (P < 0.05) the particle size of duodenal digesta, whereas particle size had no effect (P > 0.05). Overall, the current results showed that feed form had a greater influence on the different measured parameters than did particle size. [ABSTRACT FROM AUTHOR]

Abstract: The influence of β-glucanase supplementation on the nitrogen-corrected apparent metabolisable energy (AME n ) and apparent ileal digestibility (AID) coefficient of starch, protein and amino acids in four barley cultivars that differed in fibre contents (hulls) and starch characteristics (waxiness), was investigated. The cultivars included a conventional, hulled normal starch barley (C-NS), a hull-less normal starch barley (H-NS) and two hull-less waxy barleys (H-W1 and H-W2). The AME n of the two hull-less waxy cultivars were determined to be lower (P<0.05) than those of C-NS and H-NS. The AME n of the C-NS and H-NS barleys, irrespective of the presence or lack of hulls, were similar (P>0.05). β-Glucanase supplementation improved the AME of all barley cultivars, but the magnitude of response was markedly greater (P<0.05) in waxy genotypes compared to the normal starch genotypes. The cultivar type had no influence (P>0.05) on the AID of protein and most amino acids. Enzyme supplementation improved (P<0.001) the AID of protein and amino acids in all barley cultivars. The average AID of the 18 amino acids was increased by 11.9% by enzyme addition, ranging from 5.1% for methionine to 18.1% for threonine. These data suggest that starch characteristics and type of β-glucan may influence the available energy in barley for broiler chickens. These characteristics may be equally or more important than fibre contents in determining the feeding value of barley for poultry. [Copyright &y& Elsevier]