Sources of acid insoluble ash as marker of corn digestibility in broilers

The objective was to evaluate three sources of acid insoluble ash (AIA) (celite, kaolin, and sand), as indicators, to determine the apparent metabolizable energy of corn on a natural matter (AME) basis, dry matter digestibility coefficient (DMDC), and crude protein digestibility coefficient (CPDC) using total and partial excreta collection methods. Two hundred and ten Ross broiler chicks of 18 to 27 days of age were used. Broilers were adapted to experimental the diet for four days, and excreta were collected for 5 days. A reference diet (RD) based on corn and soybean meal was prepared to meet the nutritional requirements of the birds. A test diet was prepared with 40% replacement of RD with corn. The formulated diets were: D1, 99% Reference diet + 1% celite; D2, 59.4% RD + 39.6 % corn + 1% celite; D3, 99% Reference diet + 1% kaolin; D4, 59.4% RD + 39.6 % corn + 1% kaolin; D5, 99% Reference diet + 1% sand; D6, 59.4% RD + 39.6 % corn + 1% sand. The treatments were distributed in a completely randomized design, with six diets and five replicates of seven birds each in a 2x3 factorial arrangement. There were significant interactions for all variables investigated. It was observed that the AME and DMDC values of corn were similar in the two methods of collection, and PDC values using kaolin and celite makers were similar. However, the AME and CPDC of corn using sand with partial collection method were underestimated by 17.70 and 15.53%, respectively compared to those with the total collection method. The AME values of corn with the collection methods using celite and, the DMDC using celite and sand were significantly different. It was observed that the DMDC using celite and sand provided significantly lower values (4.67 and 5.15%), respectively, and the AME using celite was 2.86% lower than that obtained by total collection. To determine the EMA, DMDC, and CPDC in broilers, it is more efficient to use celiteTM and kaolin as markers with partial collection of excreta. Sand should not be used with partial excreta collection method, because it provides lower values of AME and CPDC compared to with total excreta collection method.

Enzyme complex addition in barley or rye broiler diets with two energy levels fed from 1 to 21 days

Two experiments were conducted to evaluate diet digestibility, performance, digestive parameters, and blood parameters when an enzyme complex (EC) was used in barley- and rye-based diets with different energy levels. In the digestibility assay (exp. I), 108 seventeen-day-old Cobb male broilers were distributed in a completely randomized design in 2 × 2 × 2 + 1 factorial arrangement with two feeds (barley or rye), two EC levels (0% and 0.02%), and two energy levels [3025 and 3125 kcal apparent metabolizable energy (AME)·kg−1], plus a control treatment. In exp. II, 1080 one-day-old Cobb male broilers were distributed in a completely randomized design in 2 × 2 × 2 + 1 factorial arrangement with two feeds (barley or rye), two EC levels (0% and 0.02%), and two energy levels (2875 and 2975 kcal AME·kg−1). No interactions were observed for any variables (exp. I and II). Enzyme complex improved the apparent metabolizable coefficient of gross energy (P = 0.0432) of diets. The EC provided greater weight gain (P = 0.0003) and better feed conversion (P = 0.0025). Intestinal viscosity at 21 d was reduced (P < 0.0001) with the addition of the EC. The EC improved nutrient digestibility and performance, but the effects of energy reduction on performance could not be overcome.

Short communication: Pelleting increases the metabolizable energy of de-hulled sunflower seed meal for broilers

The study examined the effects of two methods of processing de-hulled sunflower seed meal (SFM) from the same batch of sunflower seeds. Sunflower seed meal was fed to broilers as meal (MSFM) or after it had been pelleted (PSFM) at 75 °C and 360 kPa pressure to pass through a 3 mm mesh. Three diets were prepared, namely a balancer feed (BF) and two diets containing 200 g/kg MSFM or 200 g/kg PSFM. They were fed to 30 pens (two birds each) with male Ross 308 broilers, from 8 to 21 days old, following randomization. Data were analysed by ANOVA. Two pre-planned orthogonal contrast tests were performed to compare overall differences between the diets containing SFM and BF and between diets containing the MSFM and PSFM. The BF had a very different nutrient composition from the complete feeds containing SFM so, as expected, there were differences in growth performance and nutrient retention. The diet containing PSFM had greater apparent metabolizable energy corrected for N retention (AMEn) and dry matter retention (DMR) than that containing MSFM. The use of the substitution method showed the PSFM had AMEn that was 18% greater than the MSFM (8.79 vs 7.47 MJ/kg DM). Under the conditions of the current study, incorporating PSFM in a mash broiler feed increased dietary AMEn compared with the same feed containing MSFM. Further studies are needed to identify whether the benefits of pre-pelleting SFM remain after this product has been incorporated in complete pelleted broiler feeds.

Application of Apparent Metabolizable Energy versus Nitrogen-Corrected Apparent Metabolizable Energy in Poultry Feed Formulations: A Continuing Conundrum

In the present investigation, N retention, AME, and AMEn data from six energy evaluation assays, involving four protein sources (soybean meal, full-fat soybean, rapeseed meal and maize distiller’s dried grains with solubles [DDGS]), are reported. The correction for zero N retention, reduced the AME value of soybean meal samples from different origins from 9.9 to 17.8% with increasing N retention. The magnitude of AME penalization in full-fat soybean samples, imposed by zero N correction, increased from 1.90 to 9.64% with increasing N retention. The Δ AME (AME minus AMEn) in rapeseed meal samples increased from 0.70 to 1.09 MJ/kg as N-retention increased. In maize DDGS samples, the correction for zero N retention increased the magnitude of AME penalization from 5.44 to 8.21% with increasing N retention. For all protein sources, positive correlations (p < 0.001; r = 0.831 to 0.991) were observed between the N retention and Δ AME. The present data confirms that correcting AME values to zero N retention for modern broilers penalizes the energy value of protein sources and is of higher magnitude for ingredients with higher protein quality. Feed formulation based on uncorrected AME values could benefit least cost broiler feed formulations and merits further investigation.

Evaluation of Nitrogen-Corrected Apparent Metabolizable Energy and Standardized Ileal Amino Acid Digestibility of Different Sources of Rice and Rice Milling Byproducts in Broilers

Rice, broken rice (BR), and full-fat rice bran (FFRB) from six different origins were analyzed for their chemical composition, nitrogen-corrected apparent metabolized energy (AMEn), and standardized amino acid digestibility (SIAAD) in 14-day-old and 28-day-old Arbor Acres broilers. Results showed broilers fed with rice and BR had a similar AMEn regardless of the rice and BR having different CP, EE, NDF, ADF, and ash content. FFRB containing significantly different CP, EE, NDF, ADFm and starch presented variable AMEn (p < 0.05), suggesting that starch content in rice and its byproducts contributed most to the AMEn of broilers. The regression equation of AMEn = 14.312 − (0.198 × NDF) and AMEn = 6.491 + (0.103 × Starch) were feasible to integrally predict AMEn of broilers fed to rice and its byproducts. Moreover, 28-day-old broilers had higher SIAAD than 14-day-old ones. The SIAAD of rice were higher than BR and FFRB except for Met, Cys, Thr, and Tyr in 14-day-old broilers (p < 0.05), and the SIAAD of His, Asp, and Ser in BR were higher than FFRB (p < 0.05). In 28-day-old broilers, the SIAAD of Leu, Trp, Asp, Gly, and Pro of rice were still higher than BR and FFRB (p < 0.05), but BR and FFRB had no significant differences (p > 0.05). The regression equations to estimate the SIAAD of Thr, Lys, and Met were: Met = 81.46 + (0.578 × CP), Thr = 0.863 + (6.311 × CP), and Trp = 102.883 − (1.77 × CP), indicating that CP content in rice and its byproducts was likely a major factor for prediction of SIAAD.

Energetic values of animal by-products for broiler chickens of different ages

The objective of this study was to determine the chemical composition and apparent metabolizable energy (AME), AME corrected for nitrogen balance (AMEn) and its respective metabolizable coefficients of animal byproducts for broiler chickens with different ages. Meat and bone meal, poultry by-product meal, tilapia processing residue and poultry fat were evaluated. A total of 760 male broiler chickens were used and evaluated and the phases: pre-starter (1 to 8 d of age); starter (11 to18 d); grower 1 (21 to 28 d); grower 2 (31 to 38 d), and finisher (41 to 48 d). Total excreta collection method was performed in five metabolism assays. The experimental design was completely randomized, and data were submitted to analysis of variance, posteriorly, the four feeds were compared by Tukey test and a regression analysis was performed with broiler chickens age. The significance was considered at 5% probability. The values of AME and AMEn were higher in older birds for all ingredients. The lesser CAME and CAMEn were obtained for meat and bone meal, for the regression analysis poultry by-product meal, tilapia processing residue and poultry fat had an increased linear effect with birds age and there was no adjust for meat and bone meal for regression analysis.

Effects of feed particle size on energy values for broiler chickens at various ages

The objective of this study was to evaluate the effects of various geometric mean diameters (GMDs) of particles of corn, pelleted soybean meal and a corn-soy mixture in the proportion of 70% and 30%, respectively, on the nutritional value of the feeds. The study evaluated energy consumption, the contents of apparent metabolizable energy (AME) and AME corrected for nitrogen balance (AMEn) and the metabolizability coefficients for broiler chickens at various ages. A total of 540 Cobb 500 male broilers were housed in metabolic cages (experimental units). Trials were performed separately with each feed. A completely randomized design was used with four treatments, namely corn with 573, 636, 851, and 1012 μm GMDs; pelleted soybean meal with 538, 550, 665, and 741 μm GMDs; and the corn-soy mixture with 627, 658, 893, and 1040 μm GMDs. Birds were evaluated on days 1 - 10, 11 - 20, 21 - 30, and 31 - 40. Larger GMDs resulted in lower energy consumption. From 1 to 10 days, birds consumed less metabolizable energy than older birds. Birds fed corn from days 1 to 10 had higher metabolizable energy (P <0.05) with increasing GMD up to 1042 μm. However, the results varied, depending on the feed and its combinations. The use of coarse particles could reduce the costs of grinding, and would have few effects on the metabolizable energy of broiler chickens.