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1. An investigation was conducted on the effects of aflatoxin (AFL)-contaminated diets and feed withdrawal periods from 0 to 12 h in broiler chickens at 28 d of age. Both factors can potentially affect liver colour and can cause failure at veterinary inspection in the slaughterhouse. 2. A total of 240, one-d-old female Cobb 500 broiler chickens were fed a common corn-soy pre-starters (d 1–7) and then either a non-contaminated control (CON) or feed with 1 ppm AFL (AFL) from d 8 to 28. The inoculum of AFL had 792 ppb of aflatoxin B1, 35 ppb of aflatoxin B2 and 219 ppb of aflatoxin G1. On d 28, all broilers were weighed and euthanised for necropsy following three different feed withdrawal time periods (0, 6 or 12 h), in a 2 × 3 factorial arrangement. 3. Body weight gain, liver weight and liver fat content decreased as feed withdrawal lengthened, whereas FCR and gallbladder weight increased (P ≤ 0.05). AFL-fed birds had reduced body weight and proportion of liver fat and increased FCR, liver and gallbladder weights (P ≤ 0.05). 4. Livers from fed broilers (0 h withdrawal) showed more lightness (L*) and yellowness (b*) than livers of broilers from 6 or 12 h withdrawal (P ≤ 0.05). The L* and redness (a*) values of livers from broilers fed diets COB were lower than those from AFL fed broilers (P ≤ 0.05). 5. Prolonging pre-slaughter feed withdrawal decreased liver L*, whereas feeding AFL increased liver b*. These findings can be used to support veterinary assessment in slaughterhouses as shackled birds move on line through the inspection site. Since chicken liver is a valuable organ and an indicator of animal health, attention must be paid to these differences to ensure consumer safety. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the effects of a supplemental α-amylase on energy and nutrient utilization of broiler chickens fed diets with variable amounts of corn. A total of 480 slow feathering Cobb × Cobb 500 male broilers were randomly distributed into 10 treatments with 8 replicates of 6 birds each. Birds were fed a common starter to 14 D post-hatch. The experimental diets were provided subsequently until 25 D, which were a conventional corn-soy basal diet (CS) and a corn-soy diet displaced with 40% of corn (CN). These were fed as-is or supplemented with 40, 80, 120, or 160 kilo-Novo α-amylase units (KNU)/kg. Dietary treatments were distributed factorially as a 2 × 5 arrangement (diet type vs. amylase). Samples of feed, excreta, and ileal digesta were analyzed for determination of ileal digestible energy (IDE), ME, total tract retention, and digestibility of dry matter, protein, and fat. No interactions between diet type and amylase were observed. The CN diet had lower (P < 0.05) energy utilization and nutrient digestibility when compared to the CS diet. AMEn and IDE increased (P < 0.05) by 110 and 207 kcal/kg, respectively, when CS and CN diets were supplemented with 80 KNU/kg. The amylase added to the CS diet led to quadratic increases (P < 0.05) on growth performance, IDE, AME, and AMEn, as well as in dry matter, protein, and fat digestibility. Energy utilization and crude protein digestibility were linearly increased (P < 0.05) when amylase was added to the CN diet or the extrapolated 100% of corn. In conclusion, energy utilization, digestibility of crude protein, fat, and dry matter increased with amylase supplementation in corn-soy-based diets. When amylase was tested in a complete diet having 53.6% corn, 100 and 105 KNU/kg maximized AMEn and IDE, respectively; however, the maximum energy response in the CN diet or 100% of corn was not achieved until 160 KNU/kg, suggesting an association between amylase dose optimization and dietary starch concentration. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the effects of dietary α-amylase and β-xylanase, in single or combined supplementation, on growth performance of broiler chickens fed maize-soy diets. A total of 1800 slow feathering, Cobb × Cobb 500 male broilers were randomly distributed to 8 treatments with 9 replicates of 25 birds each. Broilers were fed starter and finisher diets respectively from 1 to 21 and 22 to 40 d Broilers were fed starter and finisher diets respectively from 1 to 21 and 22 to 40 d. A negative control (NC) diet was formulated to contain 12.35 MJ/kg and 12.85 MJ/kg in the starter and finisher phases, respectively. A further four control diets were formulated with orthogonal energy density increases in increments of 0.21 MJ/kg to a maximum of 13.17 MJ/kg (starter) and 13.67 MJ/kg (finisher). All control diets were formulated to be equivalent in amino acids and minerals. The NC diet was supplemented with α-amylase (80 kilo-Novo α-amylase units/kg), β-xylanase (100 fungal β-xylanase units/kg), or both enzymes combined at the same supplementation levels. Increasing AME n resulted in a linear increase (P < 0.01) in BWG and a linear decrease (P < 0.01) in FCR from 1 to 40 d. Corresponding AME n estimates for BWG and FCR from 1 to 40 d were, respectively 0.41, 0.35, and 0.57 and 0.18, 0.11, and 0.21 MJ/kg for amylase, β-xylanase and amylase + β-xylanase. In conclusion, supplementing maize-soy diets with α-amylase and β-xylanase led to increased estimated energy yields. A marked difference occurred in favor of α-amylase when compared to β-xylanase supplementation whereas adding both enzymes in the same feed generated similar AME n to the single addition of α-amylase. Growth performance responses corresponded to findings in the AME n assay. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the effects of an exogenous protease added to diets having soybean meal (SBM) from two geographic areas in Brazil (South or North). Evaluation was conducted on energy utilisation and nutrient digestibility using 224 slow feathering Cobb × Cobb 500 male broilers. Birds were fed a common starter diet to d 15. Semi-purified experimental diets containing 555 g/kg SBM and 408 g/kg maize starch plus minerals and vitamins were provided afterwards until 24 d. Diets had 0.1 g/kg phytase and 10 g/kg Celite (indigestible marker). Birds were randomly distributed in a 2 × 2 factorial arrangement of the two SBM with or without protease supplementations (0 or 15,000 protease units/kg) from 17 to 24 d. Excreta were collected from 21 to 23 d and ileal content was collected from all birds. Samples of feed, excreta, and ileal content were analysed for determination of total tract retention and ileal apparent digestibility. No interactions between SBM and protease were observed. Broilers fed semi-purified diets formulated with South SBM had lower (P < 0.05) ileal digestibility of crude protein and also from most amino acids (AA) when compared with birds fed North SBM. Ileal digestible energy was increased (P < 0.01) by 0.51 MJ/kg when birds were fed the diet supplemented with protease. Indispensable and dispensable AA digestibility also increased (P < 0.05) with protease supplementation. Ileal digestibility coefficients of Met, Lys, Thr and Val were increased (P < 0.05) by 3.1%, 3.1%, 4.8%, and 3.3%, respectively when birds were fed the diet supplemented with protease. Results from this experiment show that utilisation of energy and AA from SBM depends on its origin, but protease supplementation improved their utilisation regardless of the SBM source. [ABSTRACT FROM AUTHOR]

Responses of broilers to dietary amino acids (AA) have been extensively studied especially after their synthetic and crystalline forms became available. Synthetic (DL-Met and Met analogue) as well as crystalline ( l -Lys and l -Thr) AA are now widely used in commercial production diets to reduce crude protein (CP) levels to allow competitive bird performance. In parallel, birds diets formulated without excess CP have reduced nitrogen excretion as well as lower costs. Diet composition affects the order of limiting AA after Thr and this has led to some debate on the feasibility of including the next limiting AA, which would be the fourth, in most of the scenarios. Using maize-soy type diets, the literature suggests that Val is the fourth AA limiting. As the commercial cost of l -Val is progressively reduced, concerns have been raised on the effectiveness of its supplementation to produce broiler responses that are similar compared with feed that does not contain this AA. Antagonisms between branched-chain amino acids (BCAA) have been reported in the past; however, their use in the current maize-soy diet commercial setting is unlikely. Formulation of diets with crystalline l -Val can potentially modify the ratio between BCAA as it is supplemented in diets that are further reduced in CP. Increased availability of AA can also be achieved when diets are supplemented with exogenous proteases; however, the resulting impact in the total profile of AA is different because a wider group of AA becomes simultaneously available when compared to diets receiving addition of synthetic/crystalline AA one by one. A scenario of CP reduction in diets seems clear with the increasing use of supplemental AA along with protease in broiler diets. The knowledge of CP reduction strategies, such as protease and synthetic AA supplementation, can be a valuable asset due to the competitive nature of broiler meat production business. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the ileal digestible energy (IDE), ME, and MEn contents of bakery meal using the regression method and to evaluate whether the energy values are age-dependent in broiler chickens from zero to 21 d post hatching. Seven hundred and eighty male Ross 708 chicks were fed 3 experimental diets in which bakery meal was incorporated into a corn-soybean meal-based reference diet at zero, 100, or 200 g/kg by replacing the energy-yielding ingredients. A 3 x 3 factorial arrangement of 3 ages (1, 2, or 3 wk) and 3 dietary bakery meal levels were used. Birds were fed the same experimental diets in these 3 evaluated ages. Birds were grouped by weight into 10 replicates per treatment in a randomized complete block design. Apparent ileal digestibility and total tract retention of DM, N, and energy were calculated. Expression of mucin (MUC2), sodium-dependent phosphate transporter (NaPi-IIb), solute carrier family 7 (cationic amino acid transporter, Y+ system, SLC7A2), glucose (GLUT2), and sodium-glucose linked transporter (SGLT1) genes were measured at each age in the jejunum by real-time PCR. Addition of bakery meal to the reference diet resulted in a linear decrease in retention of DM, N, and energy, and a quadratic reduction (P < 0.05) in N retention and ME. There was a linear increase in DM, N, and energy as birds' ages increased from 1 to 3 wk. Dietary bakery meal did not affect jejunal gene expression. Expression of genes encoding MUC2, NaPi-IIb, and SLC7A2 linearly increased (P < 0.05) with age. Regression-derived MEn of bakery meal linearly increased (P < 0.05) as the age of birds increased, with values of 2,710, 2,820, and 2,923 kcal/kg DM for 1, 2, and 3 wk, respectively. Based on these results, utilization of energy and nitrogen in the basal diet decreased when bakery meal was included and increased with age of broiler chickens. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the effects of dietary α-amylase and β-xylanase supplementation of corn-soy diets, formulated with or without supplemental phytase, on growth performance, energy utilization, and starch digestibility in broiler chickens. A total of 336 slow-feathering, Cobb × Cobb 500 male broilers were randomly distributed to 6 treatments having 8 replicates of 7 birds each. Birds were fed a common starter diet to d 14 post-hatch (3,050 kcal/kg AMEn, 21.7% CP, 1.05% Ca, and 0.53% nPP). The experimental diets were provided afterwards until d 25. A 2 × 3 factorial arrangement of 2 control diets (basal = corn-soy diet without added phytase or PHY = cornsoy diet formulated with 1,000 phytase units/kg) and 3 carbohydrase supplementations (0, 80 kilo-Novo α-amylase units/kg, or 80 kilo-Novo α-amylase units/kg + 100 fungal β-xylanase units/kg) was used from d 14 to 25. Excreta were collected from 21 to 24 d and all birds were euthanized at 25 d for jejunum and ileum content collection. Samples of feed, excreta, and jejunal and ileal digesta were analyzed for determination of total tract retention and ileal apparent digestibility. No interactions between diet and carbohydrase were observed. Broilers fed diets formulated with phytase or supplemented with amylase + xylanase had higher BW gain (BWG) and lower FCR (P < 0.05) when compared with birds fed diets without carbohydrases. Relative to the basal diet, AMEn was increased (P < 0.01) by 70 kcal/kg and 99 kcal/kg when birds were fed the diet supplemented with amylase and amylase + xylanase, respectively. Starch digestibility in the jejunum and ileum was increased (P < 0.05) by 3.5% and 2.4%, respectively, when birds were fed the diet supplemented with amylase + xylanase. Results from this experiment show that corn-soy diets having phytase and supplemented with amylase and xylanase led to increased growth performance, AMEn, and starch digestibility in broilers. Furthermore, the efficacy of exogenous amylase and xylanase was independent of the presence of microbial phytase. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the effects of dietary iron (Fe) from inorganic and organic sources on breeder hen chicks originated from Pale and Dark eggs. A total of 640 40-wk-old Cobb 500 broiler breeder hens were randomly distributed into 32 floor pens (20 females and 2 males per pen) and fed ferrous sulfate (Fe-S) at 40 ppm Fe; Fe-amino acid complex (Fe-AA) at 40 ppm Fe, or Fe-S and Fe-AA (Fe-S + Fe-AA) at 90 ppm Fe, 50 ppm provided by Fe-S and 40 ppm by Fe-AA. Breeder performance was evaluated from 40 to 67 wk, and laid eggs were separated by color (Pale and Dark) to compose 6 treatments. A total of 600 hatching eggs from each treatment were collected at 65 wk and incubated. Hemoglobin and hematocrit were analyzed from 100 hatched chicks per treatment. In parallel, 1,200 1-day-old male chicks were randomly distributed in a 3 × 2 (Fe fed to hens and eggshell color) factorial arrangement (48 floor pens; 25 birds/pen) and fed common diets. Hens fed the Fe-AA diet produced more eggs per hen housed and had higher fertility compared to hens fed Fe-S whdereas those fed Fe-S + Fe-AA had intermediate results. Chick hemoglobin and hematocrit were not affected by dietary Fe and eggshell color. Breeder hens fed diets with Fe-AA and Dark eggs originated broilers that had improved growth performance and carcass and breast weights. [ABSTRACT FROM AUTHOR]

As the first limiting amino acid in cornsoy broiler diets, methionine (Met) is supplemented using commercial synthetic sources as demanded to obtain economic feed formulations. The Met analogue DL-2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) is largely utilized with that objective. This study intended to obtain responses of broilers fed with increasing levels of HMTBA, from 28 to 42 d, such that economic returns can be calculated. A total of 2,106 Cobb x Cobb 500 one-day-old male broilers was randomly placed in 81 floor pens (2.7 m² each). Birds were fed conventional starter (zero to 14 d) and grower (14 to 28 d) diets. Starting at 28 d of age, pens of 26 birds were randomly allocated into 9 feed treatments with 9 replications having increasing supplementations with HMTBA (0.00, 0.07, 0.14, 0.21, 0.28, 0.35, 0.42, 0.49 and 0.56%). These were prepared by mixing different proportions of corn-soy dilution and summit diets, which had the same formulated concentration of nutrients and energy [19.7% CP, 0.90% Ca, 0.45% Av. P, 0.95% digestible Lys, and 3,150 kcal/kg AMEn], with the exception of HMTBA [0.56% in the summit but not supplemented in the corn-soy dilution diet (0.52% digestible TSAA)]]. Growth performance was evaluated until 42 d when carcass yield and commercial cuts were evaluated using 6 birds randomly taken from each pen. Body weight gain (BWG), feed conversion ratio (FCR), proportion of breast fillets, and abdominal fat were adjusted using linear broken-line, exponential asymptotic and quadratic polynomial regression models (P < 0.05). Estimations of maximum responses for supplemented HMTBA by the linear broken-line model were 0.17% for BWG, 0.14% for FCR, and 0.29% for breast fillets. Using exponential and quadratic regressions, optimized HMTBA supplementations were obtained at 0.34 and 0.35% for BWG, 0.20 and 0.33% for FCR, and 0.31 and 0.36% for breast fillets, respectively. Supplemental levels of HMTBA that optimize growth performance and breast meat in male broilers from 28 to 42 d, using different regression models, varied from 0.14 to 0.36%. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the AMEn contents of fat by-products from the soybean oil industry for broiler chickens. A total of 390 slow-feathering Cobb x Cobb 500 male broilers were randomly distributed into 13 treatments having 6 replicates of 5 birds each. Birds were fed a common starter diet from placement to 21 d. Experimental corn-soy diets were composed of four fat sources, added at 3 increasing levels each, and were fed from 21 to 28 d. Fat sources utilized were acidulated soybean soapstock (ASS), glycerol (GLY), lecithin (LEC), and a mixture (MIX) containing 85% ASS, 10% GLY and 5% LEC. A 4 x 3 + 1 factorial arrangement was used with 4 byproducts (ASS, GLY, LEC, or MIX), 3 inclusion levels and 1 basal diet. Each of the four fat by-product sources was included in the diets as follow: 2% of byproducts (98% basal + 2% by-product), 4% (96% basal + 4% by-product), or 6% (94% basal + 6% by-product). Birds were submitted to 94, 96, 98, and 100% of ad libitum feed intake; therefore, the differences in AMEn consumption were only due to the added by-product. Total excreta were collected twice daily for 72 h to determine apparent metabolizable energy contents starting at 25 d. The AMEn intake was regressed against feed intake and the slope was used to estimate AMEn values for each fat source. Linear regression equations (P < 0.05) estimated for each by-product were as follow: 7,153X - 451.9 for ASS; 3,916X - 68.2 for GLY; 7,051X - 448.3 for LEC, and 8,515X - 622.3 for MIX. Values of AMEn were 7,153, 3,916, 7,051, and 8,515 kcal/kg DM for ASS, GLY, LEC, and MIX, respectively. The present study generated AMEn for fat by-products data that can be used in poultry feed formulation. It also provides indications that, by adding the 3 by-products in the proportions present in the MIX, considerable economic advantage can be attained. [ABSTRACT FROM AUTHOR]

• Growth performance was improved when broiler chickens were fed maize-soy diets with increasing levels of choline chloride. • Broiler chickens receiving the diet without choline chloride supplementation exhibited the greatest varus (5.7%) and rotated tibia (19.3%) scores. • The average of total choline requirement estimates were 2,516 ppm for body weight gain and 2,533 ppm for feed conversion. An experiment was conducted to evaluate responses of broiler chickens fed a corn-soy (soy protein isolate) choline-deficient diet that was gradually supplemented with choline chloride to a content expected to exceed usual choline concentrations. A total of 525 one-day-old slow feathering male chicks were randomly distributed to 5 treatments and 15 replicates of 7 broiler chickens each. Broilers were fed diets having dietary choline supplementations at 0, 700, 1,400, 2,100 and 2,800 ppm from choline chloride, totalizing formulated concentrations at 727, 1,427, 2,127, 2,827 and 3,527 ppm, respectively. The non-supplemented diet had 736 ppm analyzed choline. Growth performance was weekly evaluated until d 21 when leg deviations were evaluated and liver and tibia were collected. Broiler chicken responses were fitted to quadratic polynomial (QP) and quadratic broken-line (QBL) models. Broilers fed the diet without choline supplementation had the lowest BWG and FI, greaterr FCR as well as greater varus and rotated tibia frequency (P < 0.05) compared to broiler chickens fed diets at any supplemental concentration of choline. Estimations of maximum responses for choline requirements from d 1 to 21 using the QP and QBL regressions were of 2,936 and 2,077 ppm for BWG and 2,827 and 1,627 ppm for FCR, respectively. Broiler chickens fed the diet without choline chloride supplementation had the greatest varus (5.7%) and rotated tibia scores (19.3%) (P < 0.01). The average of total choline requirement estimates obtained were 2,516 ppm for BWG and 2,533 ppm for FCR, whereas 2,202 ppm was needed to minimize the locomotor disorders. [ABSTRACT FROM AUTHOR]

A total of 4,800 one day (d) old Cobb 500 male broilers was used in a study with the objective of evaluating dietary programs formulated with different degrees of restriction in crude protein (CP) and the supplementation of L-valine and L-isoleucine. Four feeding programs (PRG) reflecting different strategies to deliver amino acids (AA) to broilers were used, respectively from d 1 to 7, 8 to 21, 22 to 35 and 36 to 42, as follow: PRG 1, CP restricted to 224, 211, 198 and 184 g/kg with minimum digestible AA to lysine (Lys) ratios only set for total sulfur AA (TSAA) (0.72) and threonine (Thr) (0.65); PRG 2, as PRG 1 without CP restriction with AA ratios to Lys extended to valine (Val) (0.77) and isoleucine (Ile) (0.67); PRG 3, as PRG 2 supplemented with L-Val and PRG 4, as PRG 3 supplemented with L-Ile. Replications of the 4 PRG provided from 1 to 21 d were further divided into the 4 respective PRG given from 22 to 42 d for total of 16 treatments. The study was conducted as a completely randomized block design with 2 time blocks and 24 replications per treatment per block from 1 to 21 d and 12 replications from 22 to 42 d. Overall, there were no effects for time block or interaction between PRG fed from 1 to 21 and 22 to 42 d of age. Performance and processing data demonstrated benefits of formulating diets using minimum ratios of Val and Ile. Body weight gain was higher when both AA were supplemented together (PRG 4). On the other hand, feed conversion ratio (FCR) was improved when the ratios Val and Ile to Lys were obtained without the use of synthetic sources. Carcass yield data was not affected by PRG with the exception of the proportion of abdominal fat that was reduced (P<0.05) when broilers were fed diets with minimum ratios of Val and Ile without using synthetic sources. In conclusion, formulation of diets for broilers without minimum CP level but using AA to Lys ratios as in PRG 2, 3 and 4, allowed competitive growth performance and carcass yield results. Using L-Val and L-Ile led to improved FCR and, therefore, this possibility should be explored to maintain the efficiency of broiler meat production. [ABSTRACT FROM AUTHOR]

• Selenium supplementation improved body weight gain and feed conversion ratio of broilers. • Selenium from hydroxy-selenomethionine that optimized body weight gain was 0.48 ppm. • Effects of dietary selenium on carcass and meat quality of broilers were measured. • Selenium supplementation increased activity of glutathione peroxidase in erythrocytes. Selenium (Se) is essential and usually deficient in corn-soy feeds for broiler chickens. Hydroxy-selenomethionine (OH-SeMet) is a commercial organic source that has not been thoroughly evaluated as a single supplemental source of Se. The objective of this study was to evaluate the increasing dietary Se supplementation from OH-SeMet on broiler growth performance, meat yields, wooden breast (WB) and glutathione peroxidase responses in tissues. A total of 1,500 Cobb vs. Cobb 500 slow feathering one-day-old male chicks were allocated to five treatments with 12 replicates of 25 broilers each in a 3-phase feeding program from d 1 to 42 (0.0, 0.15, 0.30, 0.45 and 0.60 mg/kg of Se supplemented from OH-SeMet). Supplemental Se levels were chosen in order to provide a robust dose-response adjustment and were based on known deficient and excessive dietary contents for broiler chickens. The non-supplemented starter, grower, and finisher feeds had analyzed 0.03, 0.03, and 0.02 mg/kg Se, respectively. At 35 and 42 d of age, five broilers per pen were processed for meat evaluation and scored for WB. Samples from blood, liver, jejunum, and ileum as well as breast meat samples were taken at 42 d for evaluation of glutathione peroxidase (GSH-Px) activity and lipid oxidation (TBARS), whereas breast meat was also analyzed for cooking loss (CL) and water-holding capacity (WHC). Statistical analysis was conducted using the quadratic polynomial regression model. Increasing Se from OH-SeMet led to quadratic increases (P < 0.05) in BWG from d 1 to 42, with optimal concentration at 0.47 mg/kg Se as well as optimized estimations for FCR at 0.42 mg/kg Se. Dietary Se that maximized carcass and breast meat yields at 42 d were 0.41 and 0.48 mg/kg Se, respectively (P < 0.05). Dietary Se that maximized GSH-Px activity in erythrocytes was at 0.27 mg/kg (P < 0.05). No effects of Se were observed on WB scores at 35 and 42 d of age, CL and WHC as well as on TBARS in intestine, liver and breast muscle samples (P > 0.05). Supplementation of Se from OH-SeMet in corn-soy feeds improved broiler performance, carcass and breast yields. Average Se that optimized BWG was 0.48 mg/kg, whereas 0.46 mg/kg was needed for carcass and 0.40 mg/kg for breast yield. These are total Se contents acceptable in the European Union and frequently below commercially used contents in countries that do not have a limit on minerals in feeds. [ABSTRACT FROM AUTHOR]

Two experiments (Exp.) were conducted to evaluate effects of a lysophospholipid-based bio-emulsifier (LPL) on growth performance, nutrient digestibility and energy utilization of broilers as well as the return on investment (ROI). In Exp. 1, 392 chicks were housed in battery cages in a completely randomized design with 8 treatments and 7 replicates of 7 birds each from d 0 to 21 posthatch. In Exp. 2, 1,400 chicks were allocated in floor pens and fed the same 8 treatments, with 7 replicates and 25 birds each from d 0 to 43 posthatch. Treatments consisted of 6 degummed soybean oil-based diets: positive control (PC1) ; PC1 formulated with 500 g/ton LPL (PC1+LPL on top) ; PC1 formulated with 60 kcal LPL matrix (PC1+LPL60) ; PC1 formulated with 100 kcal LPL matrix (PC1+LPL100) ; and two negative controls NC-60 and NC-100 with reductions of 60 and 100 kcal/kg ME, respectively. Two other diets were formulated with acid soybean oil: positive control (PC2) and PC2 formulated with 60 kcal LPL matrix (PC2+LPL60). In Exp. 1, performance was evaluated from d 0 to 21, ME and ileal digestibility of DM, CP and energy were determined on d 21. In Exp. 2, growth performance was evaluated from d 0 to 42, and on d 43 carcass and abdominal fat yields were calculated. There were no effects of soybean oil sources in any parameter. Inclusion of LPL increased (P < 0.05) BW gain and ileal digestibility of DM, fat and CP. Broilers fed the PC1+LPL on top diet had increased (P < 0.05) performance, ileal digestibility and energy utilization as well as decreased abdominal fat compared to NC-60 or NC-100. The use of LPL on top had a ROI of 8:1 vs. PC1, considering the gains in revenue of the slaughtered broilers in relation to the investment with LPL in feed. In conclusion, a lysophospholipid-based bio-emulsifier increased performance, digestibility and return on investment of broilers fed standard or reformulated diets. [ABSTRACT FROM AUTHOR]

• The regression method allowed to determine metabolizable energy of insect meal and tilapia byproduct meal for broilers. • The metabolizable energy of Tenebrio molitor larvae meal for broilers was 21.93 MJ/kg. • The metabolizable energy of tilapia byproduct meal for broilers was 14.29 MJ/kg. A study was conducted to determine ileal digestible energy (IDE), metabolizable energy (ME), and nitrogen-corrected ME (ME n) of Tenebrio molitor larvae meal and Nile tilapia byproduct meal for broiler chickens using the regression method. A total of 315 slow feathering Cobb 500 male broilers were fed 5 experimental diets with 9 replicate cages of 7 birds each, in a completely randomized design. Broilers were fed a maize-soybean meal reference diet (RD) and 4 test diets (TD) from d 14 to 21 posthatch. The TD consisted of Tenebrio molitor larvae meal and tilapia byproduct meal that partly replaced the energy sources in the reference diet at 100 or 200 g/kg and 75 or 150 g/kg, respectively, such that equal ratios were maintained for all energy containing ingredients across all experimental diets. Excreta samples were collected twice daily from d 19 to 21, and ileal digesta were collected on d 21. Apparent ileal digestibility of DM, N, amino acids as well as metabolizability coefficients of DM, N, and energy were calculated. Addition of Tenebrio molitor larvae meal to the RD linearly increased (P < 0.05) ileal and total tract of DM and N digestibilities as well as IDE, ME, and ME n. For diets with Tenebrio molitor larvae meal substitution, regression equations were IDE = 21.52x – 0.0234, ME = 21.93x – 0.0189, and ME n = 20.62x – 0.0241. Addition of tilapia byproduct meal to the RD linearly decreased (P < 0.05) ileal and total tract coefficients of DM and IDE, ME, and ME n , as well as ileal digestibility of amino acids (P < 0.001). The equations for the tilapia byproduct meal diets were IDE = 12.49x – 0.0264, ME = 14.29x – 0.0152, and ME n = 11.94x – 0.0129. In conclusion, the current study showed that broiler chickens can utilize a considerable amount of energy and amino acids from insect meal or fish meal. The IDE, ME, ME n values (MJ/kg of DM) were 21.52, 21.93 and 20.62 for Tenebrio molitor larvae meal, and 12.49, 14.29 and 11.94 for tilapia byproduct meal, respectively. [ABSTRACT FROM AUTHOR]