Apparent Ileal Digestibility Coefficients Research Articles

Dietary inclusion of fibrous ingredients and bird type influence apparent ileal digestibility of nutrients and energy utilization

The interaction between inclusion of fibrous ingredients and bird type on the coefficient of apparent ileal digestibility (CAID) of nutrients and energy utilization was investigated in the current study. A 2 × 3 factorial arrangement of treatments was utilized with 2 fiber contents (10.3 and 19.3 g/kg neutral detergent fiber) and 3 bird types (broilers, pullets and layers). The low-fiber diet was based on corn and soybean meal, and the high-fiber diet was developed by the inclusion of palm kernel meal, canola meal, and oat hulls. Titanium dioxide was used as an inert marker to calculate the CAID. The digesta were collected from the terminal ileum following the feeding of experimental diets for 7 d. Significant interactions (P < 0.05) between dietary fiber content and bird type were observed for the CAID of DM, starch, fat, neutral detergent fiber and energy, and AMEn. In general, the CAID coefficients were higher in broilers, intermediate in pullets, and lowest in layers at both fiber contents. The CAID of nutrients in the 3 bird types was higher (P < 0.05) in the high-fiber diet than in the low-fiber diet, but the magnitude of responses differed. Layers showed markedly higher digestibility responses to increased dietary fiber content compared to broilers and pullets. There were interactions (P < 0.05 to 0.001) between the dietary fiber content and bird type for the CAID of nitrogen and all amino acids, except for Asp and Lys. The CAID of Asp and Lys was highest (P < 0.05) in broilers, intermediate in pullets, and lowest digestibility in layers. The CAID coefficients of nitrogen and amino acid increased with increased fiber content, with distinctly greater responses in layers compared to broilers and pullets. Overall, layers showed greater digestibility of nutrients in response to the increased fiber content, suggesting that layers require high-dietary fiber contents to efficiently utilize nutrients compared to broilers and pullets.

Effect of Conditioning Temperature on Pellet Quality, Diet Digestibility, and Broiler Performance

SUMMARY Pelleting is the most common heat processing method used in the poultry feed industry and the quality of feed processing directly impacts the efficiency of the utilization of feedstuffs by broilers, and consequently, their performance. The objective of this experiment was to evaluate the influence of conditioning temperature on pellet physical quality, and on the apparent ileal digestibility coefficients of dry matter (CIADDM), crude protein (CIADCP) and starch (CIADstarch), coefficient of apparent metabolizability of dry matter (CAMDM), and the apparent metabolizable energy content (AME) of the diets. The live performance of broilers (feed intake, FI; weight gain, WG; and feed conversion ratio, FCR) was evaluated. Treatments consisted of a mash diet and pelleted/crumbled corn-soybean meal based diets submitted to different conditioning temperatures (no conditioning or conditioned at 60, 70, 80, and 90°C). Feed was steam-conditioned for 15 s at a 1.5 kgf/cm2 for all pelleted treatments. Pellet quality was determined as a function of Pellet Durability Index (PDI), percentage of fines, and pellet hardness. Conditioning temperature linearly increased (P

Predicting the standardized ileal digestibility of crude protein in feather meal fed to broiler chickens using a pH-stat and a FT-Raman method

The present study assessed the suitability of a three-enzyme pH-stat method and of novel FT-Raman methods to predict the ileal digestibility of crude protein (CP) in feather meals (FeMs). A broiler digestibility trial was conducted to assess the ileal digestibility of crude protein in nine FeMs of different origins. One of the nine FeMs (FeM9) was the pre-treated ingredient stream of a commercially available FeM (FeM8). The pre-treatment was previously developed in our laboratory and consists of incubating FeM in 200% distilled water (%FeM w/w), with 0.5% of a commercial protease (%FeM w/w) and 2% sodium sulphite (%FeM w/w) at 55 °C for 24 hr in a shaking incubator. The degree of hydrolysis (DH) was measured after 10 minutes using a three-enzyme pH-stat method. Levels of disulphide conformers trans-gauche-trans (SStgt), gauche-gauche-trans (SSggt) and gauche-gauche-gauche (SSggg) in the nine FeMs were studied by means of FT-Raman. The effects of the disulphide conformers and of their interactions on AIDCP and SIDCP in FeM were assessed by analysis of variance (ANOVA) and fitted using a third-order interaction model.The coefficient of apparent ileal digestibility of CP (AIDCP) in the FeMs ranged from 0.368 to 0.594, whereas the coefficient of standard ileal digestibility of CP (SIDCP) ranged from 0.398 to 0.644. The pre-treatment significantly improved (P < 0.05) the AIDCP and SIDCP in FeM8 from 0.499 to 0.594 and from 0.546 to 0.644, respectively. DH correlated positively with AIDCP (R2 = 0.50, P < 0.05) and SIDCP (R2 = 0.49, P < 0.05). Significant (P < 0.05) positive linear relationships existed between total disulphide bonds and the ileal digestibility of CP in FeMs. All three types of disulphide conformers, as well as their interactions, had a significant effect (P < 0.05) on the ileal digestibility of CP in FeM. Third-order interaction models enabled predictions equation based on all three disulphide levels, with regression coefficients (R2) of 0.675 for AIDCP (P < 0.05) and 0.674 (P < 0.05) for SIDCP. Positive linear regression analysis of the predicted values of ileal digestibility of CP with the observed values of ileal digestibility of CP in FeMs in the two models revealed significant (P < 0.05) correlation coefficients (R2) of 0.96 and 0.93 for AIDCP and SIDCP, respectively.This study highlights that the ileal digestibility of CP in FeM is greatly affected by the disulphide bond conformers present, which can be used as predictors of AIDCP and SIDCP.

Impact of corn particle size on nutrient digestibility varies depending on bird type

The interaction between bird type (broilers and layers) and corn particle size (fine, medium, and coarse) on the coefficient of apparent ileal digestibility (CAID) of DM, nitrogen (N), starch, fat, gross energy (GE), calcium (Ca) and phosphorus (P), and AMEn was investigated in a 2 by 3 factorial study of 6 dietary treatments. Whole corn was ground in a hammer mill to pass through screen sizes of 2.0, 5.0, and 8.0mm for fine, medium, and coarse grades, respectively. A corn-soybean meal diet, mixed using the same batch of ingredients, was fed to both bird types. Titanium dioxide was included in all diets for digestibility measurements. 35-day-old Ross 308 male broilers and 59-wk-old Hy-Line Brown layers were used in this study. For each bird type, 108 birds of uniform body weights were accommodated in 18 replicates (6 replicates per particle size and 6 birds per replicate). The treatment diets were offered ad libitum for 7 d prior to the collection of ileal digesta. A bird type by particle size interaction was observed (P < 0.001) for the CAID of DM, starch and GE. In broilers, CAID of DM, starch and GE was unaffected by particle size, whilst in layers, increasing the corn particle size to medium and coarse resulted in a greater (P < 0.05) CAID for DM, starch and GE compared to fine particles. The CAID of N and fat was greater (P < 0.05) in broilers than layers and the opposite was observed (P < 0.05) for Ca and P. Regardless of bird type, coarse and medium-ground corn resulted in a greater (P < 0.05) Ca digestibility compared to finely-ground corn. Overall, broilers had a greater digestibility of nutrients than layers, except for Ca and P. Feeding medium and coarse corn particles benefited the CAID of DM, starch and GE in layers, suggesting that digestive system in these birds is probably more sensitive to feed particle size than broilers.

Thermostable xylanase derived from Trichoderma citrinoviride increases growth performance and non-starch polysaccharide degradation in broiler chickens

ABSTRACT1. The aim of this trial was to determine the optimal supplementation level of a xylanase enzyme from Trichoderma citrinoviride on growth performance, apparent ileal and total tract nutrient retention, intestinal morphology, and intestinal concentration of volatile fatty acids in broiler chickens.2. A total of 600 broiler chickens (Ross 308) of mixed sex were randomly allotted to four treatments, on the basis of similar body weight. The dietary treatments were made from a corn-wheat-soy based diet supplemented with either 0, 3750, 7500, or 11 250 XU/kg xylanase and were fed to 32 d of age.3. A linear response to increasing dietary xylanase was demonstrated for overall weight gain (P < 0.05) and feed conversion ratio (P < 0.05). The apparent total tract digestibility of dry matter and gross energy, and the coefficient of apparent ileal digestibility (CIAD) of N and soluble non-starch polysaccharides were linearly improved when xylanase was added to the diet (P < 0.05). Moreover, a linear increase (P < 0.05) was observed in the CIAD of Arg, Lys, and Try with increasing dietary levels of xylanase.4. The viscosity of digesta in ileum was linearly decreased when dietary xylanase level increased (P < 0.05).5. An increase in villus height of the duodenum and jejunum were observed with increasing dietary levels of xylanase (linear, P < 0.05).6. Overall, the results showed that the effects of dietary xylanase supplementation on broiler performance was determined through effects on nutrient availability and intestinal morphology.

The influence of exogenous phytase on the post-enteral availability of amino acids in broiler chickens offered wheat-based diets

To investigate the influence of exogenous phytase inclusions in poultry diets on the post-enteral availability of amino acids, wheat-soybean meal diets containing 0, 500, 1000 and 2000 phytase units (FTU)/kg were offered to eight replicate cages (six birds per cage) or a total of 192 male Ross 308 chicks from 7 to 28 days post-hatch. The parameters determined included growth performance, nutrient utilisation, bone mineralization, parameters of gizzard functionality, apparent ileal digestibility coefficients and disappearance rates (g/bird/day) of amino acids, plus concentrations of amino acids, glucose and ammonia in plasma from the portal circulation (anterior mesenteric vein). The inclusion of 500 FTU/kg significantly improved weight gain by 8.39% (1485 versus 1370 g/bird) and feed conversion ratio (FCR) by 5.10% (1.397 versus 1.472 g/g) in comparison to the control. Phytase inclusions significantly increased gizzard pH but not toe ash. The 2000 FTU/kg phytase inclusion significantly increased digestibility of 15 from 16 amino acids by an average of 5.29% (0.716 versus 0.680) and significantly increased apparent metabolisable energy (AME) by 0.45 MJ (12.43 versus 12.88 MJ) and N-corrected AME (AMEn) by 0.45 MJ (11.43 versus 11.88 MJ) relative to the control. The 500 FTU/kg phytase inclusion significantly increased free concentrations of seven amino acids (isoleucine, leucine, lysine, phenylalanine, tryptophan, valine and serine) in plasma from the anterior mesenteric vein based on pairwise comparisons and numerically increased concentrations of a further six amino acids. Phytase inclusions linearly reduced concentrations of glutamic acid and glutamine in the portal circulation, and there was a logarithmic relationship between phytase inclusions and increased plasma glucose concentrations. Reductions in the ratio of glutamate plus glutamine to glucose concentrations in portal plasma were significantly related to improvements in FCR. The outcomes of this study indicate that phytase can positively influence the post-enteral availability of amino acids. The inference is that phytase is manipulating the metabolic fates of amino acids and glucose in the gut mucosa and consideration is given to the possible responsible mechanisms for the observed outcomes.

Evaluation of broiler chickens’ digestibility of Neurospora intermedia biomass

A total of 70 broiler chickens were used to evaluate the apparent ileal digestibility coefficient (AIDC) of protein and amino acids, and apparent digestibility coefficient (ADC) of energy in the protein rich Fungal Biomass of Neurospora intermedia (FBN) obtained from bioethanol production. The chickens were housed in 10 pens with seven chickens per pen and fed one of two experimental diets between day 28 and 35 of age. The experimental diets were wheat-soybean meal-based control diet and a diet composed of 70% control diet and 30% of FBN. There were no difference (P > 0.05) between the control and FBN diet on chick feed intake and body weight at day 35. However, the AIDCs of crude protein and amino acids were significantly (P < 0.01) higher in control diet than in the FBN diet except for proline and phenylalanine. The AIDC of CP (0.74), cysteine (0.68), methionine (0.70), AME (15.6), and threonine (0.69) in FBN were comparable to the corresponding values in other protein-rich feedstuffs such as soybean meal and fish meal. The results from this study show that FBN may be an alternative protein source for poultry.

Phosphorus bioavailability, amino acid digestibility and metabolizable energy of broiler chick diets supplemented with low-oil distiller’s dried grains with solubles

Phosphorus (P) bioavailability, crude protein (CP), amino acid (AA) digestibility, and apparent metabolizable energy (AMEn) were determined in broiler chick diets, supplemented with one of two low-oil distiller´s dried grains with solubles (oil contents 6.54% and 5.35% for DDGS A and B, respectively). Diets were provided ad libitum in a mash form, from days 8 to 21 of age. In Experiment 1, one day old male broiler chicks (n=210) were assigned to one of 7 treatments, with 3 replicates of 10 birds each. Animals in treatment 1 (T1) were fed a basal diet formulated to be deficient in nonphytate P (0.14%). Birds in T2 and T3 received the basal diet supplemented with 0.05% or 0.10% of P from monodicalcium phosphate (MCP), respectively. Phosphorus from DDGS was added to diets in T4 (0.05% from DDGS A), T5 (0.1% from DDGS A), T6 (0.05% from DDGS B) and T7 (0.1% from DDGS B). Percent of inclusion of DDGS was dictated by total P content as determined by chemical analyses. Growth performance and P intake were assessed in all birds. Phosphorus bioavailability was determined using the slope ratio assay, with tibia ash as the response variable. For Experiment 2, one-day-old male broiler chicks (n=200), were assigned to 5 treatments with 4 replicates of 10 birds each. A sorghum-soya control diet was given to animals in T1. Treatments 2 and 3 included this same diet supplemented with either 5% or 10% of DDGS A. Birds in T4 and 5 received the control diet with either- 5% or 10% of DDGS B. Amino acid digestibility was measured from ileal contents in 7 euthanized birds from each group at day 21. Apparent metabolizable energy was determined in oven dried feces from all animals during the last 3 days of the experiment. Weight gain and feed consumption increased (P &lt;0.001) with larger inclusion of dietary P in birds from experiment 1. Relative P bioavailability for DDGS A and B was 72% and 86% respectively, from a P total content of 0.85% and 0.94%.,. Growth performance was similar for all treatment groups in experiment 2 (P &gt;0.05). The average apparent ileal amino acid digestibility coefficient for DDGS A 76.5% and B was 76.4%. No differences were found for essential AA coefficients between the two DDGS (P &gt;0.05). The AMEn values on a dry matter basis were 2828 and 2854 kcal/kg for DDGS A and B, respectively.

Ileal digestibility of amino acids in corn condensed distiller’s solubles and whole stillage for pigs

The immense growth in global bioethanol production has greatly increased the supply of by-products such as whole stillage and condensed distiller’s solubles, which could be potentially used for animal feeding. The objective of this experiment was to determine apparent ileal digestibility coefficients (AID) and standardized ileal digestibility coefficients (SID) of crude protein and amino acids in corn condensed distiller’s solubles (CCDS) and corn whole stillage (CWS) when fed to pigs. A total of 18 finishing barrows with an average initial body weight 79.4 ± 4.5 kg and a simple T cannula in the distal ileum were used in this experiment. Two test diets were formulated with CCDS or CWS as the sole source of amino acids, and a nitrogen free diet was used for estimation of basal ileal endogenous losses of crude protein and amino acids. The direct procedure was employed for calculation of AID and SID in the two by-products. Compared with CWS, CCDS had higher SID of crude protein (0.864 vs. 0.796; P = 0.03) and lysine (0.821 vs. 0.743, P = 0.10), but lower SID of methionine (0.730 vs. 0.831, P = 0.009), and similar SID of threonine (0.762 vs. 0.710, P = 0.26), tryptophan (0.862 vs. 0.863, P = 0.98), and cysteine (0.675 vs. 0.686, P = 0.74). The information generated from this experiment can be used for formulation of swine diets containing these two ethanol by-products.

Enhancing nutrient utilization in maize for broiler chickens by superdosing phytase

Objective was to determine the effects of increasing level of phytase in maize-based diet for broilers from 1000 FTU/kg (the industry recommended level) to 2500 FTU/kg (super dose level) on coefficient of apparent ileal digestibility (CAID) of nutrients, and dietary apparent metabolizable energy corrected for nitrogen balance (AMEn) value. One hundred and eighty male broiler chicks were divided into 30 groups and fed 3 diets in a completely randomized design (10 groups/diet) from day 15 to day 21 of age. The diets were positive control (PC) diet, and negative control (NC) diet with phytase at 1000 or 2500 FTU/kg. The PC diet was formulated to meet or exceed the NRC (1994) recommended Ca and non-phytate requirements for broiler chickens. The NC diet was same as the PC diet except for Ca and non-phytate P contents, which were reduced 1.80 and 1.50 g/kg, respectively. Birds fed the PC diet had greater (P < 0.05) CAID of gross energy and crude protein than birds fed NC diet. The CAID of starch, Ca and P for PC diet did not differ from those for NC diet. However, the AMEn for PC diet was lower (P < 0.05) than that for NC diet (13.34 vs. 14.46 MJ/kg). An increase in level of phytase in the NC diet from 1,000–2,500 FTU/kg resulted in an increase (P < 0.05) in CAID of gross energy and crude protein by 2.5 and 7.1%, respectively, and tended to increase (P = 0.082) the CAID of P by 10.4%. An increase in level of phytase in the NC diet from 1,000–2,500 FTU/kg did not affect the CAID of starch and dietary AMEn value. In conclusion, an increase in level of phytase in a low Ca and non-phytate P maize-based diet improved ileal digestibility of gross energy, crude protein and P. This indicate that supplementation of phytase at super dose levels (≥2500 FTU/kg) is more beneficial with regard to improving ileal digestibility of energy, protein, and P in maize for poultry than supplementation of phytase at the industry recommended level.

Nutritive value of plantain and chicory for pigs

Many feedstuffs used in pig diets are in direct competition with human food, the overall objective of the research is look at alternative ingredients, such as forages. The first step in feed evaluation is to determine the nutritive value of a potential ingredient. In the present study the effects of chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) on (1) total tract energy digestibility, (2) ileal amino acid digestibility, and (3) morphology of distal ileum were investigated. Fifteen intact male pigs were blocked according to initial body weight (23 ± 2.89 kg) and allocated to three different diets: a wheat-based basal diet (basal diet), and two diets with inclusion of 250 g/kg chicory (chicory diet) or plantain (plantain diet). The experiment was conducted over a 10 day period, with 3–4 days of acclimatisation, followed by 5 days of adaptation and 5 days of faecal collection. Inclusion of chicory in the diet reduced the apparent ileal digestibility coefficient (AIDC) of crude protein (CP) and indispensable AA, including methionine + cysteine, threonine and tryptophan (P < 0.05); whereas, only the values of AIDC for CP and tryptophan were decreased by plantain inclusion (P < 0.05). The apparent total tract digestibility coefficient (ATTDC) of chicory and plantain diets were reduced for dry matter (DM), CP, starch, and energy (P < 0.05). A greater ATTDC for cellulose was observed in pigs fed chicory diet (P < 0.05). However, no difference in ATTDC for hemicellulose and lignin were observed (P > 0.05). Growth performance did not alter from inclusion of chicory and plantain after 10 days of feeding (P > 0.05). However, pigs fed the plantain diet had narrower distal ileum mucosal villus width (P = 0.02). Overall results show that inclusion of chicory and plantain forages at 250 g/kg in grower diets had a negative impact on digestibility of some nutrients, but had no impact on overall animal performance. To obtain a better understanding of the potential effects of chicory and plantain, adjustments in nutrient concentration and long-term on-farm experiments need to be performed.

Effects of inclusion rate of high fiber dietary ingredients on apparent ileal, hindgut, and total tract digestibility of dry matter and nutrients in ingredients fed to growing pigs

An experiment was conducted to determine if values for the coefficient of ileal apparent digestibility (CIAD), the coefficient of hindgut apparent disappearance (CHAD), and the coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM) and nutrients in high-fiber ingredients measured at 150 g/kg inclusion are also accurate if measured at 300 g/kg inclusion in diets fed to pigs. The second objective was to confirm that most of the insoluble dietary fiber (IDF) is not fermented by growing pigs. Twenty ileal-cannulated pigs (BW: 30.64 ± 2.09 kg) were allotted to a replicated 10 × 4 incomplete Latin Square design with 10 diets and four 26-d periods. There were 2 pigs per diet in each period for a total of 8 replications per diet. A corn and soybean meal (SBM) basal diet and a corn-SBM diet with 300 g/kg corn starch were formulated. Six diets were formulated by replacing 150 or 300 g/kg corn starch by 150 or 300 g/kg corn germ meal (CGM), sugar beet pulp (SBP), or wheat middlings (WM). Two additional diets were formulated by adding 150 or 300 g/kg canola meal (CM) to the diet containing corn, SBM, and 300 g/kg corn starch at the expense of corn and SBM. Effects of inclusion rate of each fiber source in the diet on CIAD, CHAD, and CTTAD of DM and nutrients were analyzed using orthogonal contrasts. Independent t-tests were used to compare inclusion rates within each ingredient. Results indicated that CIAD and CHAD of CP, acid hydrolyzed ether extract (AEE), and most fiber fractions in CM decreased (P<0.05) as inclusion level increased from 150 to 300 g/kg, but that was not the case for CGM, SBP, or WM. The CTTAD of DM, organic matter (OM), AEE, and soluble dietary fiber (SDF) in CGM increased (P<0.05) if 300 g/kg rather than 150 g/kg was included in the diet and CTTAD of DM, OM, acid detergent fiber, and SDF in WM increased (P<0.05) as inclusion level increased. No differences in CTTAD of DM and nutrients in CM and SBP were observed between inclusion rates. The CTTAD of IDF ranged from 0.529 in WM included at 150 g/kg to 0.862 in SBP included at 300 g/kg in the diet. In conclusion, CIAD, CHAD, and CTTAD of most nutrients in test ingredients is not different between 150 and 300 g/kg inclusion rate. Under the conditions of this experiment, there was relatively high digestibility of IDF.

Bacillus subtilis in broiler diets with different levels of energy and protein.

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

Ileal digestibility of calcium and phosphorus in broilers fed diets with different phytases and Ca:available P ratios

Abstract: The objective of this work was to determine the apparent ileal digestibility of calcium and phosphorus in broilers fed diets with different phytases and calcium:available phosphorus (Ca:aP) ratios. Two experiments were carried out: one with broilers with 22 to 33 days of age, and the other with broilers with 35 to 42 days. The Ca:aP ratios used were 4.5:1.0, 6.0:1.0, and 7.5:1.0 in the first period, and 3.5:1.0, 5.0:1.0, and 6.5:1.0 in the second. All diets were supplemented with 1,500 units of phytase activity per kilogram of six different sources of microbial phytase. At the end of each experiment, two broilers per replicate were slaughtered to collect the ileal content. In the samples of digested food, the Ca and P contents were determined for later calculation of the apparent ileal digestibility coefficients of these minerals. The Ca:aP ratio influenced the activity of phytases, and the highest digestibility was observed with lower ratios, in both experiments. The phytases that provided greater digestibility coefficients were A, D, and E. In both ages evaluated, the inclusion of phytases in the feed improved the digestibility of Ca and P, which was also affected by the content of calcium and by the phytase source used.

Growth performance, nutrient digestibility and carcass characteristics of finisher pigs offered either a by-product or cereal based diet at two different concentrations of net energy

A 2 (cereal plus soybean meal (SBM) and by-product based diets) × 2 (9.3 MJ NE (net energy)/kg and 9.9 MJ NE/kg) factorial experiment was used to investigate the inclusion effects of a combination of rapeseed meal (RSM) and maize distillers dried grain with solubles (MDDGS) at two NE concentrations in diets offered to finisher pigs on growth performance, nutrient digestibility and carcass characteristics. One hundred and sixty pigs (80 males, 80 females) with an initial live weight of 47.5 kg (SD 3.93 kg) were assigned to one of four dietary treatments: (T1) a cereal based diet formulated to give 9.3 MJ NE/kg; (T2) a cereal based diet formulated to give 9.9 MJ NE/kg; (T3) a by-product based diet formulated to give 9.3 MJ NE/kg; (T4) a by-product based diet formulated to give 9.9 MJ NE/kg. The by-product diet included 350 g/kg MDDGS and 210 g/kg of RSM. The diets were formulated to contain similar levels of standardized ileal digestible lysine (8.5 g/kg). Soya oil was included in the diet to increase the NE content. Pigs offered the cereal based diet had a higher (P < 0.001) average daily gain (ADG), average daily feed intake (ADFI) and a poorer feed conversion ratio (FCR) compared to the by-product based diet. The diets containing the high energy concentration decreased ADFI (P < 0.010) and improved FCR (P < 0.002). Pigs offered the cereal based diet had increased coefficient of apparent ileal digestibility (CAID) (P < 0.001) and coefficient of apparent total tract digestibility (CATTD) (P < 0.001) of nitrogen (N) and gross energy (GE) compared with pigs offered the by-product based diet. The diets containing the high energy concentration had increased CATTD of dry matter (DM) (P < 0.045) and GE (P < 0.014) as well as the digestible energy (DE) (P < 0.001) and predicted NE (P < 0.008) values compared to the low energy concentration diets. Pigs offered the cereal based diet had a higher carcass weight (P < 0.050), carcass ADG (P < 0.024) and kill out percentage (P < 0.050) compared to pigs offered the by-product based diet. In conclusion, including high levels of by-product feeds negatively affected animal performance, nutrient digestibility and carcass characteristics. The high energy concentration of the diets reduced ADFI but improved FCR.

High levels of dietary phytase improves broiler performance

The objective of this study was to evaluate the effects of dietary phytase on broilers from 1 to 42 days of age. Five treatments were distributed in a completely randomized design, with eight replicates of 23 birds per experimental unit (per averages). The treatments consisted of a positive control diet (PC), a negative control diet (NC); and the NC diet + 1000, 2000 and 3000 FYT kg−1 phytase. The effects of dietary treatments on performance, bone quality and blood minerals were determined. From 1 to 21 days of age, WG, FI and FCR increased with increasing levels of phytase (P < 0.05), and from 1 to 42 days, body weight peaked with 2000 FTY kg−1 (P < 0.05). The best results for WG, FI and FCRC were obtained using 2051, 1992 and 2101 FTY kg−1, respectively. At 42 days of age, the Seedor Index (SI) and bone-dry matter (DM) were maximized at lower levels of phytase than for WG or FCR. The highest SI and DM values were obtained with 1553 and 1765 FTY kg−1, respectively. At 21 days of age, blood Ca content decreased with increasing phytase levels. Blood P exhibited quadratic behavior, with the maximum recorded at 1680 FYT kg−1 phytase. Tibia Ca increased with increasing phytase at 21 days of age (P < 0.05). Blood P at 42 days of age was lower than at 21 days, but did not vary between treatments. The apparent ileal digestibility coefficients of dry matter, mineral matter, crude protein and crude energy showed quadratic responses, with the highest coefficients obtained for the inclusion of 1164, 1592, 1085 and 1342 FYT kg−1 phytase, respectively. It is concluded that phytase improves broiler performance based on regression analyses. A high dose of 2973 FYT kg−1 had the best weight gain from 1 to 21 days of age. From 21 to 42 days, 2051 FYT kg−1 and 2101 FYT kg−1 showed the best weight gain and feed conversion ratio, respectively. These recommendations did not negatively affect the parameters evaluated.

Nutrient and energy digestibility, and microbial metabolites in weaned pigs fed diets containing Lactobacillus–fermented wheat

The objective of this study was to investigate the effects of nursery diets containing fermented wheat, with or without enzyme complex, on nutrient and energy digestibility as well as microbial metabolites in weaned pigs. Wheat was fermented using either L. plantarum (Homo) or L. buchneri (Hetero), with or without an enzyme complex (multicarbohydrases + phytase) for a 90-d of period. The Homo produces lactic acid during fermentation whereas Hetero can further convert the lactic acid into volatile fatty acids and alcohol. Control diets were formulated with unfermented wheat without (negative control) or with (positive control) 0.5 g/kg of the enzyme complex whereas the treatment diets contained fermented wheat at 437.5 g/kg without enzymes. A casein (50 g/kg)-corn starch-based diet was used to estimate the basal endogenous amino acids losses. Fourteen weaned piglets (7.8 ± 0.3 kg initial body weight) were surgically fitted with a T-cannula at the distal ileum and allocated as per an incomplete replicated 7 × 3 Latin square design with 7 dietary treatments and 3 periods. The inclusion of fermented wheat increased (P < 0.05) the coefficient of apparent ileal digestibility (CAID) of GE and starch, and coefficient of apparent total tract digestibility (CATTD) of dry matter (DM), organic matter (OM), gross energy (GE), and phosphorus. Further, pigs fed fermented wheat diets showed greater (P < 0.05) CAID of methionine, cysteine, and tyrosine, and coefficient of standardized ileal digestibility (CSID) of methionine, alanine, and proline than those fed unfermented wheat diets. Pigs fed Hetero-fermented wheat diets demonstrated greater (P < 0.05) CAID of DM, OM, and GE, and CATTD of calcium and phosphorus than those fed Homo-fermented wheat diets. However, no differences in amino acids digestibility were observed between the inoculants. The addition of an enzyme complex for wheat fermentation increased (P < 0.05) the CATTD of calcium and phosphorus; the CAID of isoleucine, phenylalanine, valine, and tyrosine; as well as the CSID of isoleucine, phenylalanine, valine, and tyrosine. However, any changes in the volatile fatty acids and lactic acid concentrations and pH of the feces or the ileal digesta were not observed among treatment. In conclusion, feeding a nursery diet comprising fermented wheat increased the nutrient and energy digestibility. Inoculating wheat with Hetero is more beneficial than inoculating it with Homo in terms of energy and mineral digestibility. The addition of an enzyme complex to wheat fermentation increased mineral and amino acids digestibility.

Amino acid digestibility of larval meal (Musca domestica) for broiler chickens

Work was undertaken to investigate the potential use of housefly (Musca domestica) larvae reared on broiler manure as a source of nutrition for poultry production in the United Kingdom. Nutritional analysis showed that larvae have a high (>45% dry wt.) protein content and a favorable amino acid profile that is rich in key amino acids, such as lysine and methionine. A broiler digestibility trial was carried out to determine the apparent ileal digestibility coefficients (AIDC) and true ileal digestibility coefficients (TIDC) of amino acids (AA) from insect larval meal (ILM) from M. domestica and fishmeal (FM) in broiler chickens. This was calculated using multiple linear regression technique based upon 3 inclusions of each protein source in a semisynthetic diet. One-hundred-forty-four day-old male (Ross 308) broilers were fed from hatch on a commercial starter diet for 20 days. Experimental diets were fed from d 21 to 28, and feed intakes were measured daily. On d 28, the trial was terminated, ileal digesta were collected for the determination of AIDC and TIDC of AA, and inflammatory responses (gizzard erosion and eye discharge) were measured. No significant differences were observed in digestibilities between protein sources for any AA. Furthermore, ILM feeding did not induce gizzard erosion or eye discharge at any inclusion. These results provide strong evidence to suggest that ILM of the common housefly can provide a successful alternative protein source to FM in broiler diets.

Responses in digestibilities of macro-minerals, trace minerals and amino acids generated by exogenous phytase and xylanase in canola meal diets offered to broiler chickens

Atypical diets based on canola meal (584 g/kg) and dextrose, supplemented with phytase and xylanase individually and in combination, were offered to 120 male Ross 308 broiler chicks with six replicates for each of the four treatments. The objective was to determine the effects of phytase and xylanase on the apparent digestibility coefficients of macro-minerals, trace minerals and amino acids along the small intestine of broiler chickens. The combination increased phosphorus digestibility by a two-fold factor (0.694 versus 0.324), calcium digestibility by a three-fold factor (0.527 versus 0.178), increased zinc from -0.141 to 0.324 and increased sodium digestibility coefficients from -1.402 to -0.359 in comparison to the control diet. Similarly, phytase and xylanase in tandem generated better responses in the apparent ileal digestibility coefficients of amino acids. The enzyme combination significantly increased the digestibility of nine essential amino acids by from 5.47% (methionine) to 35.4% (threonine), and seven non-essential amino acids by from 13.9% (glutamic acid) to 32.9% (proline). The better responses in apparent ileal digestibilities of phosphorus, calcium, sodium, zinc and five other trace minerals in broiler chickens offered the combination diet was confounded by its higher enzyme recovery activities in comparison to the individual supplemented diets and the study may suggest that the inclusions of phytase and xylanase in tandem should be considered in diets containing canola meal for broiler chickens.

The interactive influence of dietary nutrient density and feed form on the performance of broiler chickens

The present study investigates the interactions between dietary nutrient density and feed form on the growth performance, coefficient of apparent ileal digestibility (CAID) of dry matter (DM), nitrogen (N), starch, fat, calcium (Ca) and phosphorus (P), and N-corrected apparent metabolisable energy (AMEn) in broiler chickens to 21d post-hatch. Maize-soybean meal diets with five tiers of nutrient density were formulated and mixed. The diets were then divided into two equal batches; the first batch was offered as unprocessed mash and the second batch was steam-pelleted at a conditioning temperature of 75 °C. A 5 × 2 factorial array of ten dietary treatments were offered to a total of 480, day-old male broiler (Ross 308) chicks accommodated in 60 cages (eight birds per cage). Significant (P < 0.001) interactions between nutrient density and feed form were observed for weight gain, feed intake and feed per unit gain. While birds fed pelleted diets outperformed those fed mash diets at each nutrient density level, the pellet-associated benefits were more pronounced at the lowest nutrient density. Increasing nutrient density increased (P < 0.001) N digestibility from 0.772 to 0.811, but decreased (P < 0.001) that of starch from 0.969 in very low density diets to 0.943 in very high density diets. No significant (P > 0.05) effect of nutrient density on the CAID of DM and fat was found. Feeding pelleted diets, regardless of nutrient density, reduced (P < 0.001) the CAID of DM, N, starch and fat. Significant nutrient density × feed form interactions were observed for the CAID of Ca (P < 0.001) and P (P < 0.01). Pelleting enhanced (P < 0.05) the CAID of Ca and P in the diet with lowest nutrient density but reduced (P < 0.05) the digestibility of these minerals in all other nutrient density diets. Increasing dietary nutrient density progressively increased the AMEn, but feeding of pelleted diets, regardless of nutrient density, reduced (P < 0.001) the AMEn. Overall, the present data showed that the magnitude of pelleting-induced benefits on broiler performance varied depending on dietary nutrient density, with responses to pelleting decreasing with increasing dietary nutrient density. The present study highlights that dietary nutrient density must be taken into consideration if the full benefits associated with feeding pelleted diets are to be achieved.