Studies on the measurement of ileal calcium digestibility of calcium sources in broiler chickens

Results from 3 experiments relating to the measurement of ileal calcium (Ca) digestibility in 4 different Ca sources for broiler chickens are presented herein. The first experiment was conducted to determine the effect of basal diet composition on the true Ca digestibility of limestone, meat and bone meal (MBM), monocalcium phosphate (MCP), and dicalcium phosphate (DCP). Eight experimental diets were developed based on 2 basal diets (corn-based or corn starch-based) with each of the 4 Ca sources. Two Ca-free diets representing both basal diets were used to determine the endogenous Ca losses. Each diet was randomly allotted to 6 replicate cages (6 birds per cage) and fed from 21 to 24 D post-hatch. Calcium digestibility of corn-based diet was higher (P < 0.05) than the corn starch-based purified diet. The average true Ca digestibility coefficients of limestone, MBM, MCP, and DCP were determined to be 0.51, 0.41, 0.43, and 0.32, respectively. The second experiment was conducted to examine the effect of indicator type on the apparent Ca digestibility of limestone. Two experimental diets with either titanium dioxide or acid insoluble ash (Celite) were developed. Each diet was randomly allotted to 6 replicate cages (8 birds per cage) and fed from 21 to 24 D post-hatch. Total tract Ca retention was also measured using the indicator ratios. Indicator type had no influence (P > 0.05) on the digestibility measurements. Ca retention determined using acid insoluble ash was higher (P < 0.05) compared to that determined using titanium dioxide. The third experiment was conducted to determine the effect of dietary adaptation length on apparent Ca digestibility of limestone. The experimental diet was offered from day 21 to 6 replicates (6 birds per cage) each for 24, 72, 120, or 168 h and the ileal digesta were collected. Calcium digestibility at 24 h was higher (P < 0.05), and increasing the adaptation length from 72 to 120 h had no effect (P > 0.05) on the digestibility.

Influence of inclusion level of barley in wheat-based diets and supplementation of carbohydrase on growth performance, nutrient utilisation and gut morphometry in broiler starters

1. The influence of barley inclusion level and supplementation of a multi-component non-starch polysaccharide degrading enzyme on performance and nutrient utilisation in broilers was investigated. Normal-starch hulled barley was evaluated with five levels of inclusion (0, 141, 283, 424 and 565 g/kg) in a wheat-based diet and two levels of enzyme supplementation (0 and 150 g/tonne of feed; a 5 × 2 factorial arrangement of 10 dietary treatments). All diets were equivalent in metabolisable energy and digestible amino acid contents. 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, weight gain (WG) increased up to 283 g/kg of barley and was reduced afterwards (P < 0.01). Increasing levels of barley resulted in greater (P < 0.001) gain per feed (G/F). Enzyme addition increased WG (P < 0.05) and G/F (P < 0.001) at each barley inclusion level.3. Birds fed diets with 0 and 565 g/kg barley showed the lowest and highest (P < 0.001to 0.05) digestibility for all nutrients measured, respectively. Digestibility of all nutrients was improved by enzyme supplementation at each barley inclusion level (P < 0.05). The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of barley (P < 0.001) and supplemental enzyme (P < 0.01). Increasing inclusion of barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.001). Supplemental enzyme (P < 0.001) reduced digesta viscosity.4. The optimum inclusion level of barley, with respect to growth performance, was 283 g/kg of diet. Increasing barley inclusion improved nutrient and energy utilisation, possibly through lowered digesta viscosity and better function of the gizzard. Feed efficiency and nutrient and energy utilisation can benefit from carbohydrase supplementation in barley-based diets, regardless of barley inclusion level.

Nutritional evaluation of two barley cultivars, without and with carbohydrase supplementation, for broilers: metabolisable energy and standardised amino acid digestibility

1. Two experiments were conducted to assess the nitrogen-corrected apparent metabolisable energy (AMEn; Exp. 1; 288 Ross 308 male broilers at d 14; 36 cages with eight birds each) and coefficient of standardised ileal digestibility (CSID) of amino acids (AA; Exp. 2; 336 Ross 308 male broilers at d 21; 42 cages with eight birds each) of two barley cultivars for broilers in comparison to wheat, without or with a multi-component non-starch polysaccharide (NSP) degrading enzyme. A 3 × 2 factorial arrangement of treatments was used in both experiments with three types of grains (normal starch hulled barley [NSH], waxy starch hull-less barley [WSHL], and wheat) and two levels of enzyme supplementation (0 and 200 g/tonne of feed). Enzyme supplemented diets contained 406 and 128 of endo-1, 4-β-xylanase and endo-1, 3 (4)-β-glucanase units per kg of feed, respectively. 2. Analysis showed that the starch content was higher in NSH (610 g/kg) than in wheat (537 g/kg) and WSHL (554 g/kg), and the composition of starch differed markedly among the grain types. The β-glucan content was considerably higher in WSHL (68.6 g/kg) compared to NSH (38.5 g/kg) and wheat (7.74 g/kg). The contribution of soluble fraction to the total non-starch polysaccharides was higher in WSHL (38.2%) compared to NSH and wheat (17.1% and 13.3%, respectively). 3. A significant (P < 0.01) interaction was observed between the grain type and enzyme supplementation for AMEn. The WSHL, with the highest content of β-glucan, showed the greatest response to enzyme supplementation for AMEn. 4. Birds fed wheat- and WSHL-based diets had the highest and lowest CSID of nitrogen and most of AA, respectively, with NSH diets being intermediate. Regardless of grain type, enzyme supplementation increased (P < 0.05) the CSID of nitrogen. 5. These data suggest that β-glucan content plays an important role in determining the digestibility of nutrients in barley for broilers, resulting in a better feeding value for NSH over WSHL. Supplementation of a multi-component NSP-degrading enzyme can improve the feeding value of barley in broiler diets by increasing the digestibility with the effect being more pronounced in WSHL barley.

Effect of limestone particle size and calcium to non-phytate phosphorus ratio on true ileal calcium digestibility of limestone for broiler chickens

The purpose of this study was to determine the effect of limestone particle size and calcium (Ca) to non-phytate phosphorus (P) ratio on the true ileal Ca digestibility of limestone for broiler chickens. A limestone sample was passed through a set of sieves and separated into fine (<0.5 mm) and coarse (1-2 mm) particles. The analysed Ca concentration of both particle sizes was similar (420 g/kg). Six experimental diets were developed using each particle size with Ca:non-phytate P ratios of 1.5:1, 2.0:1 and 2.5:1, with ratios being adjusted by manipulating the dietary Ca concentrations. A Ca-free diet was also developed to determine the basal ileal endogenous Ca losses. Titanium dioxide (3 g/kg) was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to 6 replicate cages (8 birds per cage) and fed from d 21 to 24 post hatch. Apparent ileal digestibility of Ca was calculated using the indicator method and corrected for basal endogenous losses to determine the true Ca digestibility. The basal ileal endogenous Ca losses were determined to be 127 mg/kg of dry matter intake. Increasing Ca:non-phytate P ratios reduced the true Ca digestibility of limestone. The true Ca digestibility coefficients of limestone with Ca:non-phytate P ratios of 1.5, 2.0 and 2.5 were 0.65, 0.57 and 0.49, respectively. Particle size of limestone had a marked effect on the Ca digestibility, with the digestibility being higher in coarse particles (0.71 vs. 0.43).

Measurement of true ileal phosphorus digestibility in meat and bone meal for broiler chickens

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.

Influence of cereal type and fat source on the performance and fat utilisation of broiler starters

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.

Measurement of true ileal digestibility of phosphorus in some feed ingredients for broiler chickens

An experiment was conducted to estimate the true ileal digestibility of P in wheat, sorghum, soybean meal, and corn distiller's dried grains with solubles (DDGS) in broiler chickens. Four semipurified diets were formulated from each ingredient (wheat and sorghum: 236.5, 473, 709.5, and 946 g/kg; soybean meal and corn 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 corn DDGS differed (P<0.05) at different P concentrations. Apparent ileal P digestibility in broilers fed diets with soybean meal and corn DDGS linearly (P<0.001) increased with increasing P concentrations. True ileal P digestibility coefficients of wheat, sorghum, soybean meal, and corn 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 corn 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 corn DDGS were determined 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 corn 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.

Influence of prepelleting inclusion of whole corn on performance, nutrient utilization, digestive tract measurements, and cecal microbiota of young broilers

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.

Digestion of fat and fatty acids along the gastrointestinal tract of broiler chickens

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.

Measurement of true ileal digestibility and total tract retention of phosphorus in corn and canola meal for broiler chickens

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.

Influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers fed on wheat-based diets

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.

The effect of manipulation of pellet size (diameter and length) on pellet quality and performance, apparent metabolisable energy and ileal nutrient digestibility in broilers fed maize-based diets

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.

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.

Influence of conditioning temperature on the performance, nutrient utilisation and digestive tract development of broilers fed on maize- and wheat-based diets

1. The influence of conditioning temperature on the performance, nutrient utilisation and digestive tract development of broilers fed on maize- and wheat-based diets was examined up to 21 d of age. The experimental design was a 2 × 3 factorial arrangement of treatments evaluating two grain types (maize and wheat) and three conditioning temperatures (60°C, 75°C and 90°C). Broiler starter diets, each based on one grain (maize or wheat), were formulated and pelleted at the three temperatures. 2. Increasing conditioning temperature decreased the body-weight gain and feed intake in wheat-based diets, but birds fed on maize-based diets conditioned at 60°C and 90°C had higher body-weight gain and feed intake than those fed on the diet conditioned at 75°C. Increasing conditioning temperature increased feed per body-weight gain in both grain-type diets but improved pellet durability index (PDI) only in wheat-based diets; PDI was unaffected in maize-based diets. 3. In wheat-based diets, increasing conditioning temperature decreased the ileal digestibility of nitrogen and starch. Ileal nitrogen digestibility of maize-based diets conditioned at 60°C and 90°C was higher than at 75°C. Starch digestibility was unaffected by conditioning temperature in maize-based diets. No effect of conditioning temperature was found for apparent metabolisable energy (AME). Increasing conditioning temperature decreased digestible protein and AME intakes in wheat-based diets but, in maize-based diets, birds fed on the diet conditioned at 75°C had lower digestible protein and AME intakes compared to those fed on diets conditioned at 60°C and 90°C. 4. Small intestine was longer in birds fed on diets conditioned at 75°C and 90°C compared with those fed on diets conditioned at 60°C. 5. Overall, the data suggest that while the effects of conditioning temperature on body-weight gain and feed intake of broilers to 21 d of age differed depending on the grain type, feed per body-weight gain was adversely affected by higher conditioning temperatures.

Nutritional value of peas (Pisum sativum L.) for broilers: apparent metabolisable energy, apparent ileal amino acid digestibility and production performance

Two experiments were conducted to evaluate the nutritional value of four cultivars (Santana, Miami, Courier and Rex) of peas (Pisum sativum L.) for broilers. In Experiment 1, the apparent metabolisable energy (AME) and the apparent ileal amino acid digestibility of these four cultivars were determined. The cultivar effects were found to be not significant (P > 0.05) for the AME and apparent ileal digestibility of amino acids, with the exception of arginine, which was lower (P < 0.05) in Courier than other cultivars. In Experiment 2, using the energy and digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of the four cultivars of peas were formulated and the effects of feeding these diets on the performance and digestive tract development of broiler starters was investigated. Weight gain, feed intake and feed per gain of broiler starters fed diets containing peas were similar (P > 0.05) to those fed the maize-soybean meal diet. In general, the digestive tract development was unaffected (P > 0.05) by the inclusion of peas. The excreta scores of birds fed diets based on Santana, Miami and Rex were similar (P > 0.05) and that of the Courier-based diet was lower (P < 0.05) than those fed the maize-soy control diet. These results suggest that peas are good sources of metabolisable energy and digestible amino acids, and that they can be included at 200 g/kg level as a partial replacement for soybean meal in broiler starter diets without adverse effects on performance.

Detrended Fluctuation Analysis of EEG in detecting cross-modal plasticity in brain for blind

Cross-modality is the development of cross link between the modalities in the brain following sensory deprivation in the early stage. Cross modality analysis was previously done with fMRI, MEG and PET images for studying the changes in cerebral activities. Instead of these imaging techniques, this work involves in deriving self similarity parameter using Detrended Fluctuation Analysis of EEG from blind and blind folded normal individuals. This paper presents a novel technique of nonlinear spectral analysis to extract the information from electro encephalograms of humans for the detection of cross- modality existence in blind subjects.

Performance evaluation of feature extraction methods for classifying abnormalities in ultrasound liver images using neural network

Image analysis techniques have played an important role in several medical applications. In general, the applications involve the automatic extraction of features from the image which is further used for a variety of classification tasks, such as distinguishing normal tissue from abnormal tissue. In this paper, the classification of ultrasonic liver images is studied by using texture features extracted from Laws' method, autocorrelation method, Gabor wavelet and edge frequency method. The features from these methods are used to classify three sets of ultrasonic liver images-normal, cyst and benign and how well they suit in classifying the abnormalities is reported. A neural network classifier is employed to evaluate the performance of these features based on their recognition ability.

A Spiking neural network of the CA3 of the hippocampus can be a neural prosthesis for lost cognitive functions

The role of the hippocampus in associative memory is the establishment of long-term, declarative memories. For example, memories for facts, name and life experiences. Damage to the hippocampus leads to loss of ability to convert short-term memory to new long-term memories. This can happen due to epilepsy, stroke, dementia or head injuries. One of the possibilities of providing a solution to this problem is by prosthesis. The first step towards this is building of biomimetic model of the region. A system modeling approach is used to build the biomimetic model of the CA3 by the use of biological repetitive firing neurons of R.J.Macgregor. The output of the neuron model is a spiking output so there is no need for a separate spike producing circuitry. The electronic model is also presented with a possible circuit for realization of the plasticity. The weights of the network are updated by the synaptic activity plasticity rule (SAPR), which has weight updation depending on the value of the post synaptic potential of the spiking neurons. The various paths of the flow of information in and out of the hippocampus and the possible connections for the prosthesis are presented. The project takes into consideration the various experimental finding and the advances in synaptic plasticity published so far for building this biomimetic model.

Endogenous amino acid flow in the avian ileum: quantification using three techniques

The aim of the present study was to compare the protein-free diet, guanidinated casein (GuC) and enzyme hydrolysed casein (EHC) methods for the quantification of endogenous amino acid (AA) flow in the avian ileum. Growing broiler chickens (5 weeks old) were used. All three assay diets were based on dextrose, and in the GuC and EHC diets GuC or EHC were the sole source of N. Endogenous AA flows determined with the use of protein-free diet were considerably lower (P>0·05) than those determined by the GuC and EHC methods. The total endogenous AA flows determined by the GuC and EHC methods were almost 3-fold greater (P>0·05) than those determined by the protein-free diet. The endogenous AA values obtained from GuC and EHC methods were similar (P<0·05), except for the flow of arginine, which was lower (P>0·05) in the EHC method. Glutamic acid, aspartic acid, threonine and glycine were the predominant endogenous AA present in digesta from the distal ileum. The contents of methionine, histidine and cystine were lower compared with other AA. The method of determination had no effect on the AA composition of endogenous protein, except for threonine, glutamic acid, lysine, arginine and cystine. The concentrations of threonine and arginine were lower (P>0·05) and that of lysine was higher (P>0·05) with the EHC method compared with the other two methods. The concentration of glutamic acid was greater (P0·05) and that of cystine was lower (P>0·05) in the EHC and GuC methods compared with the protein-free diet method. The results showed that the ileal endogenous flows of N and AA are markedly enhanced by the presence of protein and peptides, above those determined following feeding of a protein-free diet. It is concluded that the use of EHC and GuC methods enables the measurement of ileal endogenous losses in chickens under normal physiological conditions.

Apparent ileal digestibility of amino acids in dietary ingredients for broiler chickens

The apparent ileal digestibility coefficients of amino acids in 107 samples representing 22 food ingredients were determined using 6-week-old broiler chickens. The ingredients assayed included five cereals (barley, maize, sorghum, triticale and wheat), two cereal by-products (rice polishings and wheat middlings), four oilseed meals (canola, cottonseed, soya-bean and sunflower meals), full-fat canola, maize gluten meal, four grain legumes (chickpeas, faba beans, field peas and lupins) and five animal protein sources (blood, feather, fish, meat and meat and bone meals). The mean ileal digestibility coefficients of amino acids in wheat and maize were higher than those in sorghum, triticale and barley. However, variations observed in individual amino acid digestibilities among samples within cereal type were greater than those determined between cereals. Threonine and lysine were the least digestible indispensable amino acids in the five cereals evaluated. The most digestible indispensable amino acid was phenylalanine in wheat and, leucine in maize and sorghum. In the case of the wheat middlings and rice polishings, threonine was the least digestible indispensable amino acid and arginine was the best digested.

In the oilseed meals assayed, amino acid digestibility was highest for soya-bean and sunflower meals, intermediate for canola meal and lowest for cottonseed meal. Ileal digestibility coefficients of amino acids in lupins were found to be slightly lower than those in soya-bean meal. The amino acid digestibilities of field peas, faba beans and chickpeas were considerably lower than those of lupins. Digestibility of arginine was the highest and that of threonine was the lowest of the indispensable amino acids in oilseed meals and grain legumes, except in cottonseed meal. Lysine was the least digestible amino acid in cottonseed meal.

In the animal protein sources assayed, digestibility coefficients of amino acids in blood meal were high, intermediate in fish meal, and low in meat meal, meat and bone meal and feather meal. Variation in amino acid digestibility coefficients determined for blood meal samples was small. However, wide variations in amino acid digestibilities were observed for other animal protein sources, highlighting significant batch-to-batch differences. In particular, marked variations were determined for meat meal and meat and bone meal samples. Cystine was the least digested amino acid in animal protein meals, with the exception of blood meal in which isoleucine had the lowest digestibility. The limitations of using apparent digestibility values in diet formulations and the concept of the standardized digestibility system to overcome these limitations are discussed.

Ambulatory electroencephalographic monitoring system for the analysis of brain waves

This work is concerned with the development of a special equipment to monitor the brain waves of the patients even when he is under mobility in his locality and transmit them to the hospital or any monitoring station and record the electroencephalogram (EEG) of those patients and to diagnose the presence of epileptic seizures if any with an intelligent software and to store these details which may be useful for further analysis or expert consultations. This may prove very useful for the epileptic patients especially when the patient develops occasional problems related to his neural activities; bedside monitoring is not feasible both physically and economically. Under such conditions, ambulatory electroencephalographic monitoring provides an efficient and effective solution for this problem. This unit is equipped with a sophisticated hardware to acquire, amplify and transmit EEG and receive them through an interface unit and a software module to denoise and analyse them with epileptic seizure and spike detection algorithms coded with discrete wavelet transformation technique.