Effect of food enzymes on utilisation of lupin carbohydrates by broilers

1. The effects of 3 commercial enzyme products on the nutritive value of 2 lupin species were investigated with the emphasis on changes in composition of non-starch polysaccharides (NSPs) along the digestive tract. Enzyme A contained primarily cellulase, beta-glucanase and xylanase activities, enzyme B primarily hemicellulase, pentosanase and xylanase activities, and enzyme C primarily hemicellulase, pectinase and beta-glucanase activities. 2. The enzymes were added to semi-purified diets based on sorghum and casein containing 35% whole seed lupins (Lupinus angustifolius cv Gungurru or Lupinus albus cv Kiev mutant). Control diets contained no lupins. 3. Food conversion ratio (FCR), excreta moisture content and apparent metabolisable energy (AME) were affected by lupin species but not by enzyme supplementation. 4. In diets with L. angustifolius, enzyme C significantly increased digesta viscosity and increased the concentration of soluble NSPs in all sections of the intestine. 5. Digestibility of protein and NSPs in the ileum and microbial fermentation in the ileum and caeca were not affected by adding enzymes to diets containing L. angustifolius. 6. Enzyme addition to diets with L. albus did not affect digesta viscosity nor concentration of soluble NSPs but caused a significantly (P<0.05) reduced concentration of insoluble NSP in the ileum. 7. Enzyme addition to L. albus significantly (P<0.05) increased NSP digestibility in the ileum but had no effects on protein digestibility and fermentation in the ileum and caeca.     

Effects of enzyme supplementation on the nutritive value of dehulled lupins

1. Separate balance experiments were conducted to assess the potential of 2 commercial enzyme supplements to improve the nutritive value of dehulled lupin kernels. One supplement (enzyme A) contained primarily xylanase, pen‐tosanase, hemicellulase activities and the other (enzyme B) primarily ß‐glucanase, hemicellulase and pectinase activities.

2. The enzymes were added at 0, 025, 0.50, 0.75 and 1.00 g/kg in diets containing (g/kg) lupins 300, sorghum 543, casein 91, celite (as marker) 20, and vitamins and minerals 46. Control diets, with and without enzyme supplementation contained sorghum and casein at 800 and 134 g/kg, respectively, and no lupins.

3. Growth rates and food conversion ratios (FCR) of birds over 7 days were not affected by lupin inclusion or enzyme supplementation. FCR of broilers fed on the sorghum diet was improved by enzyme A but not by enzyme B.

4. Heal starch digestibilities were slightly lower in birds fed on the lupin control diet (no enzyme) compared to the basal control diet.

5. Enzyme A increased the AME of the lupins from 10.01 MJ/kg DM to 11.65 MJ/kg DM when added at 0.5 g/kg. Higher rates of supplementation did not lead to further increases in AME values.

6. Enzyme A did not improve starch digestion in the diets but insoluble non‐starch polysaccharides concentration in the digesta decreased (50–41–42–71 g/g acid insoluble ash marker) with increasing enzyme supplementation, suggesting that the improvement in AME was the result of increased fermentation of fibre in the hindgut.

7. Enzyme B did not affect the AME of lupins nor the ileal digestibility of nutrients, but caused an increase in the concentrations of soluble non‐starch polysaccharides in the ileal digesta of chickens (19.21.35.77 mg/ml). This was accompanied by an increase in ileal digesta viscosity (11.4.34.2 m.Pa/s).     

The incorporation of whole grain into pelleted broiler chicken diets. II. Gastrointestinal and digesta characteristics

1. Pelleted diets, incorporating whole or ground wheat or barley in the pellets, were fed to broiler chickens and the performance, gastrointestinal development and digesta characteristics of those chickens recorded. 2. Body weight was similar with whole grain incorporation or enzyme application. Food conversion efficiency was improved by addition of enzyme to a full wheat diet. 3. Whole grain inclusion in pellets reduced proventriculus proportional mass and increased gizzard proportional mass with no apparent effects of exogenous feed enzyme addition. 4. Relative ileal mass was reduced by enzyme inclusion in a wheat diet and by inclusion of whole barley in the pellets. 5. Digesta viscosity was increased by whole wheat inclusion but reduced by enzyme inclusion irrespective of grain processing. Inclusion of 200 g/kg of barley did not alter viscosity of digesta beyond the duodenum. 6. Fresh excreta pH was higher with both cereals in the grower phase when whole grain was fed. On the barley diet, this was affected by enzyme addition, which created higher pH from a point earlier in the grower phase than when no enzyme was employed. 7. Evidence of a complex interaction between higher viscosity and pH being involved in differences in ileal relative mass was found through significant relationships being produced by enzyme use on the wheat diet alone.     

Rapeseed napin and cruciferin are readily digested by poultry

Rapeseed proteins have been considered as being poorly digestible in the gut of non‐ruminants. The aim of the study was to assess the digestibility of napin and cruciferin in ileal digesta of broiler chickens, testing sixteen samples of rapeseed co‐products with protein levels ranging from 293 g/kg to 560 g/kg dry matter. Each sample was included into a semi‐synthetic diet at a rate of 500 g/kg and evaluated with broiler chickens in a randomised design. Dietary and ileal digesta proteins were extracted and identified by gel‐based liquid chromatography–tandem mass spectrometry (LC‐MS/MS). Three isomers of napin (a 2S albumin) and nine cruciferins (an 11S globulin) were identified in the rapeseed co‐products, whereas six endogenous enzymes such as trypsin (I‐P1, II‐P29), chymotrypsin (elastase and precursor), carboxypeptidase B and α‐amylase were found in the ileal digesta. It is concluded that as none of the rapeseed proteins were detected in the ileal digesta, rapeseed proteins can be readily digested by broiler chickens, irrespective of the protein content in the diet.     

Effects of feeding growing broiler chickens with practical diets containing sweet lupin (Lupinus angustifolius) seed meal

1. Two experiments with growing broiler chickens were carried out to study the effects of the inclusion in their diets of whole or dehulled lupin (Lupinus angustifolius) seed meal on productive and physiological parameters. The effects of the addition of a commercial protease (1 g/kg, Bio-Feed Pro, Novo. Nordisk, Madrid) were also tested. 2. Diets were formulated to contain the same amounts of energy (12.55 kJ/g) and protein (210 g/kg). Raw whole (not heat treated) or dehulled sweet (low in alkaloids) lupin seed meal (400 and 320 g/kg, respectively) were used to formulate the lupin-based diets, and the protein content was completed with either defatted soybean or casein. 3. Final body weight and feed intake of chickens fed diets containing whole lupin seed meal (400 g/kg) were lower than controls, but gain:feed ratios were not different. The presence of soybean or casein in the diet did not affect productive parameters. Birds fed dehulled (320 g/kg) instead of whole lupin seed meal had similar body weight, feed intake and gain:feed values to controls. The addition of a commercial protease (1 g/kg, Bio-Feed Pro CT) to whole lupin/soy or whole lupin/casein diets tended to increase feed intake and final weight of the birds. 4. Plasma uric acid concentration was higher, and plasma cholesterol and triglycerides lower, in chicks fed whole lupin but not in those fed dehulled lupin seed meal. Plasma amino acid concentrations were not different from controls in birds fed lupin diets. 5. Apparent ileal digestibility of amino acids was not different from controls for the different lupin diets. The relative weight of the liver was higher than controls in lupin-fed birds, but not in those fed enzyme supplemented lupin-based diets. Liver concentrations of DNA tended to rise, while those of glycogen tended to decrease and liver RNA was lower in lupin-fed chicks.     

Strategies to improve the nutritive value of rice bran in poultry diets. I. The addition of food enzymes to target the non-starch polysaccharide fractions in diets of chickens and ducks gave no response

1. Three experiments were undertaken to test the efficacy of 2 enzymes targeting mainly the non-starch polysaccharides (NSPs) in rice bran. 2. In experiment one, 400 g rice bran/kg depressed chick performance and there was a significant decline in growth rate and food intake with increasing inclusion of rice bran (0, 200, 400 g). Neither enzyme had any benefit. 3. In experiment two, rice bran (inclusion 200 and 400 g/kg), did not alter growth rate, food intake or food conversion ratio of duckling (3 to 17 d of age). Again enzyme addition gave no response. 4. In experiment three, 300 g rice bran/kg stimulated duck (19 to 35 d of age) growth while 600 g rice bran/kg depressed growth but not food intake. Enzymes gave no response. 5. Relative gut viscosity declined with increasing rice bran inclusion as did dry matter in ileal digesta. There were differences between ducklings and chickens. 6. It was concluded that NSPs were not a significant factor in altering the nutritive value of rice bran and the enzymes used were therefore unlikely to be of benefit.     

Importance of amino-acid and electrolyte balance in experimental diets used to determine the apparent metabolisable energy (AME) value of wheat

1. An experiment was done with male, Ross broiler chicks to study the effect of diet composition and electrolyte balance on the measurement of diet AME and performance parameters in diets containing high levels of wheat inclusion. 2. The control diet (G) was based on wheat (667 g/kg) with full-fat soya, soyabean meal, Extrupro and herring meal providing the protein supplements. The experimental treatments were based on 2 diets, one based on wheat (790 g/kg) with casein as the protein supplement and the other containing 667 g/kg wheat plus casein, cellulose and starch. Each of these was formulated to contain one of three concentrations of sodium and potassium bicarbonate giving final values for dietary electrolyte balance of approximately 90, 180 and 280 meq/kg diet. 3. DM intake was numerically lower with the lower level of wheat inclusion and LWG (P < 0.05) and gain:food (P < 0.001) were reduced. ME:GE was similar for the two levels of wheat/casein but higher (P < 0.001) than for the control diet. 4. The two higher electrolyte balances improved DM intake (P < 0.01), LWG and gain:food (P < 0.01) compared with the diets containing no added bicarbonate. ME:GE was unaffected by electrolyte inclusion. 5. Viscosity of ileal digesta supernatant fell (P < 0.01) with increasing bicarbonate inclusion but the value for the highest electrolyte level was still higher than for the control diet. 6. It is concluded that addition of both arginine and electrolyte is needed with a wheat/casein diet to improve performance to levels seen with a more commercial diet but that the determination of diet AME, with the type of fat addition used in this study, is unaffected by electrolyte balance. The interaction between electrolyte balance and in vivo viscosity requires further study.     

Lactobacilli counts in crop,ileum and caecum of growing broiler chickens fed on practical diets containing whole or dehulled sweet lupin (Lupinus angustifolius) seed meal

1. Four experiments with growing broiler chickens were carried out to study the effects of the inclusion in their diets of lupin (Lupinus angustifolius ) seed meal on E. coli and lactobacilli counts in crop, ileum and caeca at 3 or 4 weeks of age. 2. Diets were formulated to contain the same amounts of metabolisable energy (12.55 MJ/kg) and protein (210 g/kg). Raw whole (heat-untreated) or dehulled sweet (low in alkaloids) lupin seed meal (400 and 320 g/kg respectively) were used to prepare the lupin-based diets, whose protein content was completed with either defatted soyabean meal or casein. 3. Final body weight and food intake of chickens fed on whole lupin seed meal diets were lower than controls, but gain: food ratios were not different. However, birds given the diet with dehulled lupin seed meal had similar body weight, food intake and gain: food values as those of controls. 4. While E. coli counts were not affected, lactobacilli numbers were consistently increased compared to controls in all intestinal sections of chickens fed on the whole or dehulled lupin-based diets, irrespective of the age of the birds or the presence of soyabean meal or casein in the diet. The lactobacilli species isolated were: Lactobacillus fermentum, L. acidophilus, L. salivarius and L. brevis 5. The results suggest that the use of whole or dehulled sweet lupin seed meal in diets for growing broilers might enhance the growth of lactic acid-fermenting bacteria in the gut.     

Nutritional value of narrow-leafed lupin (Lupinus angustifolius) for broilers

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.     

The effect of date fibre supplemented with an exogenous enzyme on the performance and meat quality of broiler chickens

1. Two experiments were conducted to evaluate the use of date fibre as a partial replacement of maize as a source of energy for growing broiler chicken. In experiment 1, date fibre was given alone to determine apparent metabolisable energy (AME) and apparent ileal digestibility of amino acids and crude fibre. 2. Date fibre had lower AME content (8.7 vs 13.6 MJ/kg) and apparent ileal digestibility coefficients for dry matter (0.35 vs 0.83), crude fibre (0.20 vs 0.54) and amino acids. 3. Based on the results of experiment 1, a growth study was conducted to test the effect of exogenous enzymes on the nutritive value of date fibre (experiment 2). 4. Three date fibre contents (5, 10 and 15%) with and without enzyme supplementation were evaluated. Daily feed intake, body weight gain and feed conversion ratio were measured. At the end of experiment 2, 160 birds were randomly selected and slaughtered to evaluate carcase and meat quality traits as well as measuring ileal viscosity. 5. Substitution of maize by 10 and 15% date fibre significantly depressed AME. Enzyme supplementation did not improve crude fibre digestibility. The inclusion of date fibre in the diets except at 5% decreased average daily gains, feed intake and feed conversion ratio. 6. Addition of date fibre caused a significant increase in the weights of total digestive tract, pancreas and caecum. Addition of date fibre or the exogenous enzyme had no significant effect on carcase or meat quality characteristics. 7. Date fibre increased ileal digesta viscosity compared to the control. Addition of the exogenous enzyme decreased the viscosity of the basal diets but had no effect on the date fibre diets.8. This study indicated that date fibre can be included at levels of 5% in broiler diets without affecting performance.     

Effect of wheat content, fat source and enzyme supplementation on diet metabolisability and broiler performance.

1. A 3x3x2 factorial experiment studied the interactions of fat source (tallow, soya, tallow:soya [2:1] blend), wheat level (700, 350, 0 g/kg) and enzyme inclusion (Avizyme 1300, absent, present) in diets for broilers fed ad libitum in individual cages from 7 to 35d. Bird performance, fat digestibility, viscosity of ileal contents and diet metabolisability (AME) were measured. 2. There were no significant effects of fat source on bird performance. However, there was a significant effect on fat digestibility, which was highest for soya and lowest for tallow. Diet AME content was also significantly affected by fat source and reflected differences in fat digestibility. 3. Dry matter (DM) intake, liveweight gain (LWG) and gain:food were all reduced at 700 g wheat/kg. Viscosity of ileal contents increased with increasing wheat inclusion. 4. There were no significant effects of enzyme on DM intake or LWG but gain:food was improved by 2%. Diet AME content was increased with enzyme addition, the effect being greatest (9%) with tallow at 700 g wheat/kg. 5. Viscosity of ileal contents was reduced and fat digestibility increased with enzyme addition and there were significant wheat enzyme interactions attributable to no differences with zero wheat but marked responses to enzyme at 700 g wheat/kg. 6. The results confirm important interactions between wheat content and fat composition in relation to fat digestibility, AME content and food efficiency.     

Effects of dietary phytase on performance and nutrient metabolism in chickens

1. A broiler growth study was conducted to compare the effect of different concentrations of an Escherichia coli-derived phytase on performance, apparent metabolisable energy (AME), nitrogen (N), amino acid and mineral metabolisability, sialic acid excretion and villus morphology when fed to broiler chickens. 2. Female Ross 308 broilers (480) were reared in floor pens from 0 to 28 d of age. All birds were fed on nutritionally complete starter (0 to 21 d of age) and grower diets (21 to 28 d of age) with the exception that they were low in P (28 and 23 g/kg available P, respectively). These maize-soy diets were supplemented with 0, 250, 500 or 2500 phytase units (FTU)/kg feed. 3. Between 21 and 28 d of age, two birds from each floor pen were selected, and each pair placed in one of 32 metabolism cages (two birds per cage). Feed intake was recorded and excreta collected for the last 2 d of the feeding period, and AME, N, amino acid and mineral metabolisability coefficients and endogenous losses were determined following a total collection procedure. 4. Feed intake and weight gain increased in a linear manner in response to phytase dose, with an average increase of approximately 11.7 and 13.5%, respectively, compared with chickens fed on the low-P diet. Birds given diets with 2500 FTU weighed 6.6% more and had a 2.4% higher feed conversion efficiency (FCE) than those fed on diets containing 500 FTU. 5. Enzyme supplementation increased the intake of AME and metabolisable N by 10.3 and 3.9%, respectively, principally through increases in feed intake. Birds given enzyme-supplemented diets also improved their intake of metabolisable amino acids and P by approximately 14 and 12.4%, respectively, compared with birds fed on the control diet. Enzyme supplementation did not affect ileal villus morphometry of the birds.     

Evaluation of homoarginine as a marker for the determination of endogenous amino acid concentrations in poultry excreta

1. Endogenous amino acid losses in ileal digesta and excreta of adult cockerels fed on diets containing guanidinated forms of casein, soyabean meal and cottonseed meal were determined using homoarginine as a marker.

2. The ileal endogenous amino acid losses were markedly higher (P< 0–001) in birds given the cottonseed meal diet compared to those given the other two diets. The ileal endogenous protein was rich in aspartic acid, serine and glutamic acid.

3. Negative values were obtained for endogenous amino acid output in excreta. These aberrant values were caused by high concentrations of homoarginine in the excreta. A subsequent study with broiler chickens showed that the homoarginine in excreta was of urinary origin.

4. These results indicate that the homoarginine technique is not suitable for determining endogenous amino acid losses in excreta, but applicable when determinations are made in the terminal ileum.     

Evaluation of an intestinal Lactobacillus reuteri strain expressing rumen fungal xylanase as a probiotic for broiler chickens fed on a wheat-based diet

1. This study was conducted to evaluate the feasibility of using a transformed Lactobacillus reuteri Pg4 strain harbouring a rumen fungal xylanase gene as a probiotic supplement in a wheat-based poultry diet. 2. A total of 400 broiler chicks was allocated to two treatment groups with or without supplementation with 10(6) colony forming units (cfu)/g of transformed L. reuteri Pg4 in a wheat-based regimen to investigate the performance, intestinal microflora populations, digesta viscosity and excreta ammonia concentrations in these broiler chickens. 3. Supplementation of the wheat-based diet with transformed L. reuteri Pg4 decreased intestinal viscosity, caecal coliform population, and increased body weight gain and ileal villus height and crypt depth from 0 to 21 d of age. It also decreased excreta ammonia concentrations, and increased the caecal total volatile fatty acid (VFA) and lactic acid concentrations from 0 to 21 d and 22 to 37 d of age. 4. Further, it was demonstrated that 40% of the Lactobacillus cells randomly isolated from the digesta of the ileum and caecum of the supplemented group possessed xylanase secretion capability. 5. It appears reasonable to assume, therefore, that the derived benefit is a result of the organism surviving, and the associated performance of some function in the intestinal tract which benefits gut health.     

Influence of method of whole wheat inclusion and xylanase supplementation on the performance, apparent metabolisable energy, digestive tract measurements and gut morphology of broilers

1. The aim of the present study was to examine the influence of whole wheat inclusion and xylanase supplementation on the performance, apparent metabolisable energy (AME), digesta viscosity, and digestive tract measurements of broilers fed on wheat-based diets. The influence of the method of whole wheat inclusion (pre- or post-pelleting) was also compared. A 3 x 2 factorial arrangement of treatments was used with three diet forms (648 g/kg ground wheat [GW], GW replaced by 200 g/kg of whole wheat before [WW1] or after cold-pelleting [WW2]) and two xylanase levels (0 and 1000 XU/kg diet). 2. Birds given diets containing whole wheat had improved weight gains, feed efficiency and AME compared to those fed on diets containing ground wheat. The relative gizzard weight of birds fed WW2 diets was higher than in those fed GW and WW1 diets. Pre-pelleting inclusion of whole wheat had no effect on relative gizzard weight. Post-pelleting inclusion of whole wheat resulted in greater improvements in feed efficiency and AME than the pre-pelleting treatment. 3. Xylanase supplementation significantly improved weight gain, feed efficiency and AME, irrespective of the wheat form used. Viscosity of the digesta in the duodenum, jejunum and ileum were reduced by xylanase addition. Xylanase supplementation reduced the relative weight of the pancreas. 4. Neither xylanase supplementation nor whole wheat inclusion influenced the relative weight and length of the small intestine. 5. Xylanase supplementation increased ileal villus height. A significant interaction between diet form and xylanase was observed for ileal crypt depth. Xylanase supplementation had no effect on crypt depth in birds fed on diets containing GW, but increased the crypt depth in WW2 diets. No significant effects of diet form and xylanase supplementation were observed for the thickness of the tunica muscularis layer of gizzard or villus height, crypt depth, goblet cell numbers or epithelial thickness in the ileum. 6. Improved performance observed with post-pelleting inclusion of whole wheat was associated with increased size of the gizzard and improved AME. The gizzard development hypothesis, however, will not explain the improvements observed with pre-pelleting inclusion of whole wheat, suggesting the involvement of other factors.     

Apparent metabolisable energy and amino acid digestibility of microalgae Spirulina platensis as an ingredient in broiler chicken diets

ABSTRACT

1. This work investigates the apparent metabolisable energy (AME), its nitrogen-corrected form (AMEn) and amino acid (AA) digestibility coefficients of the microalgae Spirulina platensis as an ingredient in broiler chicken diets.

2. One group of birds was fed with a basal control diet (BD), and another was fed with a test diet composed of the BD with the addition of the microalgae at a proportion of 200 g/kg. AME and AMEn were assessed by total excreta collection and indigestibility analysis using acid-insoluble ash (AIA) as a marker.

3. The microalgae comprised 888.0 g/kg dry matter (DM), 18.42 MJ/kg gross energy, 514.7 g/kg crude protein, 9.9 g/kg ether extract, 10.6 g/kg crude fibre, 94.4 g/kg ash, 3.1 g/kg Ca and 11.0 g/kg P.

4. The values obtained for AME (13.48 MJ/kg DM) and AMEn (11.72 MJ/kg DM) were higher (p < 0.01) than those obtained using the AIA method (9.39–8.29 MJ/kg DM). The microalgae ileal digestibility coefficients were 0.80 ± 0.04 and 0.78 ± 0.04 for essential and non-essential AA, respectively.

5. Overall, the metabolisable energy content and digestibility of AA for S. platensis indicated that the microalgae are potentially an alternative nutrient source for broilers. The AIA method underestimated AME and AMEn in comparison to the total excreta collection method.     

Influence of graded levels of meals from three lupin species on growth performance and nutrient digestibility in broiler chickens

1. This study investigated the effect of different levels of seeds of lupin species (Lupinus angustifolius, Lupinus luteus and Lupinus albus) on broiler growth performance, nutrient digestibility and apparent metabolisable energy of poultry diets.

2. A control diet containing corn–soybean meal and test diets containing 50, 100, 150, 200 and 250 g/kg of three lupin species were fed to broiler chickens during a 35-day study period. There were 10 replicate cages of 8 broiler chickens per treatment.

3. Growth performance of the birds fed with yellow and white lupin diets was found to be similar to that of the birds in the control group. The use of narrow-leaved lupin seeds in the diet quadratically decreased the body weight gain of birds and increased feed conversion ratio during all the experimental periods (0–14, 15–35 and overall 0–35 days of age).

4. A significant interaction between lupin species and their inclusion levels for apparent metabolisable energy and apparent ileal digestibility of starch was observed, showing a negative effect of increasing levels of narrow-leaved lupin. Pearson correlation coefficients demonstrated that the presence of raffinose and non-starch polysaccharides is a key factor affecting the nutritive value of lupin,

5. Yellow and white lupins could be utilised as an alternative ingredient for soybean meal in the diet of broiler chickens without any adverse effects on growth performance. The narrow-leaved counterpart diet reduced broiler performance, and hence did not provide a satisfactory outcome.     

Growth,nutrient digestibility,ileal digesta viscosity,and energy metabolizability of growing turkeys fed diets containing malted sorghum sprouts supplemented with enzyme or yeast

Growth, apparent nutrient digestibility, ileal digesta viscosity, and energy metabolizability of growing turkeys fed diets containing malted sorghum sprouts (MSP) supplemented with enzyme or yeast were investigated using 120, 28‐day‐old male turkeys. Six treatments were laid out in a 3 × 2 factorial arrangement of treatments with three dietary inclusion levels of MSP (0, 50, and 100 g/kg) and supplemented with 200 mg/kg yeast (Saccharomyces cerevisiae) or 200 mg/kg of a commercial enzyme. The experiment lasted for the starter (day 28–56) and grower phases (day 57–84) of the birds. Each treatment group consisted of 20 turkeys replicated four times with five birds each. Data were analysed using analysis of variance while polynomial contrast was used to determine the trends (linear and quadratic) of MSP inclusion levels. Irrespective of dietary supplementation with enzyme or yeast, final body weight (BW), total BW gain, and feed intake for turkey poults from day 29–56 was reduced (p < 0.05) with increasing inclusion level of MSP. Dietary supplementation with yeast resulted in increased (p < 0.05) feed intake while enzyme supplementation improved (p < 0.05) feed conversion ratio of the poults. Turkeys fed enzyme‐supplemented MSP diets had higher (p < 0.05) BW gain than their counterparts fed yeast‐supplemented MSP diets. Apparent ash digestibility reduced linearly (p < 0.05) with increasing inclusion levels of MSP. Apparent metabolizable energy (AME) did not vary significantly (p > 0.05) with MSP inclusion levels . Enzyme supplementation reduced (p < 0.05) ileal viscosity but had no effect (p > 0.05) on AME. Inclusion of MSP resulted in poor growth performance. This confirms earlier studies that utilization of MSP by poultry is rather poor. Supplementation with enzyme or yeast did not lead to any appreciable improvement in performance of turkeys in this study.     

Enzymes (beta-glucanase and arabinoxylanase) and/or sepiolite supplementation and the nutritive value of maize-barley-wheat based diets for broiler chickens

1. Two experiments were conducted to study the effects of crude enzyme preparations (beta-glucanase and arabinoxylanase) and/or 20 g/kg Sepiolite (Exal) on the performance and nutrient digestion of broiler chickens fed on maize-barley-wheat based diets. 2. In experiment 1, enzymes improved daily bodyweight gain (by 14%; P<0.001) and food:gain ratios (8%; P<0.001). Sepiolite improved bodyweight gain on the diets not supplemented simultaneously with enzymes (by 6% in 21-d-old chickens, P<0.05) but reduced it for enzymes-supplemeented diets. Changes in productive perfiormance with both additives were associated with changes in diet digestibility and nitrogen balance. 3. In experiment 2, enzyme supplementation reduced viscosity in jejunum and ileum and the mean retention time of digesta in the gut. Sepiolite inclusion significantly reduced the viscosity of jejunum digesta and modified the retention times of digesta in the gut, depending upon whether enzymes had been added. There was a decreased retention time without enzymes but an increase with enzyme supplementation. 4. Although different mechanisms are presumed for enzymes and sepiolite, both seem to counteract the negative effects of soluble, non-starch polysaccharides (NSP) in the diet by modifying jejunal viscosity and improving organic matter digestibility.     

Influence of phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digestive tract measurements and gut morphology in broilers fed wheat-based diets containing adequate level of phosphorus

1. The aim of the present study was to examine the influence of microbial phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digesta viscosity, digestive tract measurements and gut morphology in broilers fed on wheat-soy diets containing adequate phosphorus (P). The wheat-soy basal diet was formulated to contain 4.5 g/kg non-phytate P and the experimental diets were formulated by supplementing the basal diet with xylanase (1000 xylanase units/kg diet), phytase (500 phytase units/kg diet) or a combination of phytase and xylanase. 2. Supplemental phytase improved the weight gains and feed efficiency by 17.5 and 2.9%, respectively. Corresponding improvements due to the addition of xylanase were 16.5 and 4.9%, respectively. The combination of phytase and xylanase caused no further improvements in broiler performance. 3. Individual additions of xylanase or phytase resulted in numerical improvements in apparent metabolisable energy (AME), but the differences were not significant. The combination of the two enzymes significantly increased AME. Addition of xylanase and the combination of the two enzymes reduced the viscosity of digesta in all sections of the intestine. Phytase supplementation reduced digesta viscosity in the duodenum and ileum, but not in the jejunum. 4. Enzyme supplementation lowered the relative weight and length of the small intestine. Additions of xylanase and phytase reduced the relative weight of the small intestine by 15.5 and 11.4%, respectively, while the corresponding reductions in the relative length of the small intestine were 16.5 and 14.1%, respectively. The combination of phytase and xylanase had no further effects on the relative weight and length of the small intestine compared with the xylanase group. 5. The addition of phytase increased villus height in the duodenum and decreased the number of goblet cells in the jejunum compared with those on the unsupplemented basal diet. Xylanase supplementation tended to increase goblet cell numbers in the duodenum and decreased crypt depth in thejejunum. The combination of phytase and xylanase increased villus height in the ileum and crypt depth in thejejunum and ileum. 6. In summary, the present results showed that the addition of a microbial phytase, produced by solid state fermentation and containing significant activities of beta-glucanase and xylanase, was as effective as xylanase in improving the performance of broiler chickens fed on wheat-based diets containing adequate levels of P. Improved performance with enzyme supplementation was generally associated with reduced digesta viscosity, increased AME, and reduced relative weight and length of small intestine.