Standardized ileal amino acid digestibility of meat and bone meal and soybean meal in laying hens and broilers

The beneficial effect of nanomethionine supplementation on growth performance, gene expression profile, and histopathology of heat-stressed broiler chicken

This study investigated the effects of nanomethionine (nano-meth) on performance, antioxidants, and gene expression of HSP70, HSP90 and Heat Shock factor-1 (HSF-1) from the liver, and TLR4 from the jejunum, of broiler chickens reared under normal temperatures or under heat stress. Three hundred 1-day-old chicks were randomly assigned to 5 treatment groups. Group 1 served as control. Under normal temperature, birds in group 2 received nano-meth (10 mL/L of drinking water) from d1 until the experiment ended. Group 3 birds were heat-stressed (HS) and did not receive any supplementation. Group 4 received nano-meth in the same dose from d1 old until experiment ended, and the birds were exposed to HS. Group 5 birds were HS and received supplementation of nano-meth during the HS period only. Nano-meth improved (P < 0.0001) final body weight, weight gain, feed conversion ratio, and also decreased (P < 0.0001) the effect of HS on growth performance. Reduction (P < 0.0001) in malondialdehyde and changes in antioxidant enzymes GPX and CAT activity indicated the antioxidant effect of nano-meth. Nano-meth supplementation caused an increase in the expression of HSP70 , HSP90 and HSF1, and a downregulation of TLR4 gene expression. Additionally, nano-meth-supplemented groups showed marked improvement in the histological liver structure, intestinal morphology and villus height compared to control or HS groups.

Standardized ileal amino acid digestibility of high-oleic full-fat soybean meal in broilers

High-oleic (HO) soybean may serve as a value-added feed ingredient to enrich poultry meat due to its fatty acid content. However, the amino acid (AA) nutrient digestibility of soybean meal (SBM) made from these soybeans has yet to be determined. The objective of this study was to determine apparent ileal AA digestibility (AID) and standardized ileal AA digestibility (SID) of high-oleic full-fat (HO-FF) SBM compared to normal oleic full-fat (NO-FF), normal oleic extruded expeller (NO-EE), and solvent-extracted SBM (SE-SBM) in broilers. A nitrogen-free basal diet (NFD) was fed to 1 treatment group with 10 chicks/cage to determine basal endogenous losses (BEL). Titanium dioxide was used as an inert marker. The test diets contained 57.5% of the basal NFD and 42.5% of 1 of the 4 soybean sources. A total of 272 Ross-708 male broilers were placed in 40 battery cages with 5 treatments and 8 replicates per treatment. A common starter diet was provided to all the chickens for 14 d. Experimental diets were provided as a mash for 9 d before sample collection. Chickens were euthanized with CO2 on d 23, and contents of the distal ileum were collected, frozen, and freeze-dried. The BEL were similar to the values found in the literature. At d 23, broilers fed the SE-SBM had the highest body weight gain and best FCR compared to chickens fed the HO-FF and NO-FF treatments (P < 0.001). Broilers fed the SE-SBM and NO-EE experimental diets had (P < 0.001) higher apparent ileal AA digestibility and AA SID than broilers fed the HO-FF and NO-FF treatments. In conclusion, the SID of AA from HO-FF is similar to the digestibilities of other full-fat soybeans found in the literature and is lower than that of NO-EE and SE-SBM.

Growth performance, liver and kidney functions, blood hormonal profile, and economic efficiency of broilers fed different levels of threonine supplementation during feed restriction

The objective of the existing investigation was to determine the effect of dietary inclusion of threonine amino acid at different levels during feed restriction on growth indices, liver and kidney function parameters, and some hormonal profiles along with economic indicators in broiler chickens. A total of 1,600 from 2 different breeds (800 Ross 308 and 800 Indian River) at 21-day-old age were incorporated. Chicks were randomly assigned into 2 main groups, control and feed-restricted (8 h/d), during the fourth week of age. Each main group was subdivided into 4 groups. The first group was fed a basal diet without adding extra threonine (100%), the second, third, and fourth groups were fed a basal diet with extra threonine levels of 110, 120, and 130%, respectively. Each subgroup consisted of 10 replicates of 10 birds. We noticed that the dietary inclusion of threonine at extra levels in the basal diets significantly enhanced final body weight, body weight gain, and better feed conversion ratio. This was mainly due to the enhanced levels of growth hormone (GH), insulin-like growth factor (IGF1), triiodothyronine (T3), and thyroxine (T4). Moreover, the lowest feed cost per kilogram body weight gain and improved return parameters were reported in control and feed-restricted birds fed higher levels of threonine than other groups. Also, a significant increase in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and urea levels was observed in feed-restricted birds supplemented with 120 and 130% levels of threonine. Hence, we recommend supplementing threonine at levels of 120 and 130% in the diet of broilers to promote growth and profitability.

Comparison of amino acid digestibility of soybean meal, cottonseed meal, and low-gossypol cottonseed meal between broilers and laying hens

OBJECTIVE

This study aimed to determine and compare the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of amino acids (AA) in soybean meal (SBM), cottonseed meal (CSM), and low-gossypol cottonseed meal (LCSM) fed to broiler chickens and laying hens.

METHODS

Three semi-purified diets containing the identical crude protein concentration at 20% were formulated to contain SBM, CSM, or LCSM as the sole source of N. A N-free diet was also formulated to estimate the basal ileal endogenous losses of AA for broilers and hens. A total of 300 male Ross 308 chicks at one-day-old and 144 Hy-Line Brown laying hens at 30-week-old with initial egg production rate of 88.3%±1.0% were randomly allocated into 1 of 4 dietary treatments, respectively.

RESULTS

CSM and LCSM showed more Arg and Cys+Met while less Lys, Ile, Leu, and Thr relative to SBM. Significant interactions existed between species and experimental diets for AID (except for Arg, Asp, Glu, Gly, and Pro) and SID (except for Arg, His, and Phe) of most AA. Most AA in diets showed higher AID (except for Lys) and SID (except for Lys, Met, and Ser) in broilers relative to laying hens. The AID and SID of all AA were significantly different between the three diets. In broilers, the AID and SID of most indispensable AA except for Arg in SBM and LCSM was higher than CSM. In laying hens, the AID and SID of most indispensable AA except for Arg, Met+Cys, and Phe in SBM was higher than CSM and LCSM.

CONCLUSION

The accurate determination of AID and SID of AA in CSM and LCSM for broilers and layers benefits the application of CSM and LCSM in chicken diets. The cottonseed by-products CSM or LCSM showed the species-specific AA digestibility values for broilers and layers.

Amino acid digestibility and metabolizable energy of soybean meal of different origins in cecectomized laying hens

This study investigated the variation in amino acid (AA) digestibility and MEn of 18 samples of solvent-extracted soybean meal (SBM; 6 European, 7 Brazilian, 2 Argentinian, 2 North American, 1 Indian) in cecectomized laying hens. The experimental diets contained either 300 g/kg of cornstarch or one of the SBM samples. Pelleted diets were fed to 10 hens in two 5 × 10 row-column designs so that 5 replicates were obtained from each diet during 5 periods. A regression approach and the difference method were used to determine AA digestibility and MEn, respectively. The variation in the digestibility of SBM differed among AA with ranges in digestibility of 6 to 12%-units for most AA. Among the first-limiting AA, the digestibility was 87 to 93%, 63 to 86%, 85 to 92%, 79 to 89%, and 84 to 95% for Met, Cys, Lys, Thr, and Val, respectively. The range of MEn for the SBM samples was 7.5 to 10.5 MJ/kg DM. Indicators of SBM quality (including trypsin inhibitor activity, KOH solubility, urease activity, and in vitro N solubility) and analyzed SBM constituents were significantly correlated (P ≤ 0.05) with AA digestibility or MEn only in a few cases. No differences were observed in AA digestibility and MEn between countries of origins, except low digestibility of some AA and MEn for the 2 Argentinian SBM samples. These results suggest that the precision of feed formulation benefits from considering the variations in AA digestibility and MEn. Often used indicators for SBM quality and analyzed constituents were not suitable to explain variations in AA digestibility and MEn, suggesting that AA digestibility and MEn are determined by other factors.

Nutritional Value of Duckweed as Protein Feed for Broiler Chickens-Digestibility of Crude Protein, Amino Acids and Phosphorus

Duckweed is gaining attention in animal nutrition and is considered as a potential alternative protein source for broiler chickens. In order to evaluate the nutritional value of duckweed, three individual batches were investigated. They consisted of a mixture of Lemna minuta and Lemna minor (A, 17.5% crude protein), Spirodela polyrhiza (B, 24.6% crude protein) and Lemna obscura (C, 37.0% crude protein). Treatment diets contained 50% batch A, 50% batch B, and 25, 50 and 75% of batch C. All diets were fed to broiler chickens (Ross 308) from an age of 21 to 27 days. Diets with a share of 50 and 75% of batch C led to decreased feed intake (109.3 and 74.9 g/day, respectively) compared to the control. Standardized ileal digestibility of crude protein and amino acids differed significantly between duckweed batches, at values for methionine between 49.9 and 90.4%. For all amino acids, batch A consistently had the lowest and batch C the highest digestibility. Batches had different tannin contents of 2943, 2890 and 303 mg/kg for batches A, B and C, respectively. The apparent ileal digestibility of phosphorus differed significantly between all batches (50.8-78.9%). Duckweed can be used as a protein feed for broiler chickens. However, a defined and stable biomass composition optimized for the requirements of broiler chickens is needed.

Comparison of endogenous amino acid losses in broilers when offered nitrogen-free diets with differing ratios of dextrose to corn starch

The nitrogen-free diet (NFD) method is widely used to determine the ileal endogenous amino acids (IEAAs) losses in broiler chickens. Starch and dextrose are the main components of NFD, but the effects of their proportion in the NFD on the IEAAs and the digestive physiology of broilers are still unclear. This preliminary study aims to explore the best proportion of glucose and corn starch in NFD to simulate the normal intestinal physiology of broilers, which helps to improve the accuracy of IEAAs determination. For this purpose, 28-day-old broiler chickens were allocated to five treatment groups for a 3-day trial, including a control group and four NFD groups. The ratios of dextrose to corn starch (D/CS) in the four NFD were 1.00, 0.60, 0.33, and 0.14, respectively. Results noted that NFD significantly reduced serum IGF-1, albumin, and uric acid levels compared with the control (P < 0.05), except there was no difference between group D/CS 0.33 and the control for IGF-1. The increased Asp, Thr, Ser, Glu, Gly, Ala, Val, Ile, Leu, His, Tyr, Arg, and Pro contents of IEAAs were detected in broilers fed the NFD with a higher ratio of D/CS (1.00 and 0.60) compared to the lower ratio of D/CS (0.33 and 0.14). Moreover, ileal digestibility of dry matter and activity of digestive enzymes increased as the D/CS elevated (P < 0.001). Further investigation revealed that the number of ileal goblet cells and Mucin-2 expression were higher in the group with D/CS at 1.00 when compared with group D/CS 0.33 and the control (P < 0.05). Microbiota analysis showed that NFD reshaped the gut microbiota, characterized by decreased microbial diversity and lower abundance of Bacteroidetes, and increased Proteobacteria (P < 0.05). Our results indicate that a higher D/CS ratio (1.00 and 0.60) in NFD increases IEAAs by promoting digestive enzymes and mucin secretion. However, the excessive proportion of starch (D/CS = 0.14) in NFD was unsuitable for the chicken to digest. The chickens fed with NFD with the D/CS ratio at 0.33 were closer to the normal digestive physiological state. Thus, the ratio of D/CS in NFD at 0.33 is more appropriate to detect IEAAs of broiler chickens.

Determination of metabolizable energy and amino acid digestibility in various hatchery byproducts for broiler chickens

The objective of the present experiment was to determine ME concentrations and amino acid (AA) digestibility in various hatchery byproducts (HBPs) for broiler chickens. In experiment 1, a total of forty 60-day-old female broiler chickens were allotted to 1 of 5 dietary treatments with 8 replicates and used to measure ME concentrations in HBPs. The basal diet was prepared to contain corn, soybean meal, corn oil, and other non-energy ingredients. Additional 4 experimental diets were prepared to contain 10% of infertile eggs (IFE), unhatched eggs (UHE), low-grade or dead chicks (LDC), and mixture (MIX; 55% IFE, 10% UHE, 10% LDC, and 25% hatched eggshells). In experiment 2, a total of seven hundred and sixteen 1-day-old mixed-sex broiler chickens (1:1 ratio of males and females) were allotted to 1 of 5 dietary treatments with 7 replicates per treatment and used to determine apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA in HBPs. The experimental diets consisted of a nitrogen-free diet and 4 diets containing IFE, UHE, LDC, or MIX as a sole source of AA. Results indicated that AME and AME_n values were greater (P < 0.05) for LDC than for IFE, which had greater (P < 0.05) AME and AME_n values for UHE and MIX. The AID and SID of most AA in LDC were greater (P < 0.05) than those in MIX, whereas IFE and UHE had intermediate AID and SID of those AA as compared to LDC and MIX. Average SID of essential AA in LDC was greater (P < 0.05) than in UHE and MIX, but the average SID of nonessential AA did not differ among 4 HBPs. In conclusion, LDC has the greatest ME concentrations and AA digestibility among 3 individual HBPs (IFE, UHE, and LDC). The mixture of HBPs has the least ME concentrations and AA digestibility in broiler chickens. The ME and AA digestibility of HBPs are likely affected by inclusion amounts of hatched eggshells. However, high concentrations of ME and available AA demonstrate that individual HBPs and their mixture are potential protein ingredients for broiler diets.

Effect of Dietary Mineral Content and Phytase Dose on Nutrient Utilization, Performance, Egg Traits and Bone Mineralization in Laying Hens from 22 to 31 Weeks of Age

Simple Summary

The aim of this work was to elucidate how the dietary inclusion of phytase, at a normal dose and overdosed, could affect the utilization of nutrients and performance in young laying hens. When a diet deficient in Ca and P was applied, the dietary inclusion of phytase at low doses (500 FTU/kg) led to an improvement in the digestive efficiency of P in the first weeks after introduction. However, when these deficient diets were maintained in the long term, laying hens improved their digestive utilization of both Ca and P, a higher dose of phytase (1000 FTU/kg) being required to achieve greater P availability. This overdosage also provided additional extraphosphoric advantages, slightly improving access to other nutrients and the feed conversion rate of the hens.

Abstract

A total of 192 laying hens were used to evaluate the effect of dietary mineral content and phytase dose on nutrient utilization, egg production and quality and bone mineralization of young laying hens. Four dietary treatments were studied: PC, positive control with no added phytase, 4.07% Ca and 0.61% P; NC, negative control with no added phytase, 2.97% Ca and 0.37% P; and P500 and P1000, where NC diet was supplemented with phytase at 500 and 1000 FTU/kg, respectively. Hens’ performance and egg traits were controlled from 22 to 31 weeks of age. Coefficients of total tract apparent digestibility (CTTAD) of nutrients were determined at 25 and 31 weeks of age. Apparent ileal digestibility (AID) and blood content of Ca and P, as well as bone traits, were determined at 31 weeks of age. Ca and P retention was higher in birds on PC diet at 25 weeks, but not at 31 weeks of age compared to those on NC diet (p < 0.05). P1000 birds had the highest CTTAD values for dry and organic matter at both ages (p < 0.001). CTTAD of Ca was significantly higher in P1000 diet than in NC diet at 31 weeks of age (p < 0.001). Birds fed with P500 diet at 25 weeks of age and P1000 at 31 weeks of age showed higher CTTAD and retention of P, but lower excretion of P than those fed NC diet (p < 0.05). Phytase inclusion linearly increased AID of dry matter and P (p < 0.001). P500 hens fed had the greatest body weight at the end of the trial (p < 0.05) and P1000 birds had the best feed conversion ratio (p < 0.05). Fowl fed a PC diet produced eggs with higher shell thickness and yolk color than those fed on NC diet (p < 0.05). Phytase inclusion linearly increased the yolk color (p < 0.05). Tibia of laying hens fed with PC had significantly higher ash content than those on NC diet (p < 0.05), and birds fed with P1000 presented intermediate values. It can be concluded that it would be advisable to increase the dose of phytase in the feed of laying hens to obtain long-term benefits.

Standardized ileal amino acid digestibility of protein sources for broiler chickens is influenced by the feed form

The aim of present study was to determine the influence of the feed form (FF) on standardized ileal digestibility (SID) of nitrogen (N) and amino acids (AA) in 3 protein sources (PS) for broiler chickens. Six diets were tested in a 3 × 2 factorial arrangement of treatments involving 3 PS (meat and bone meal [MBM], soybean meal [SBM], and canola meal [CM]) in mash and pelleted forms. The basal endogenous N and AA losses were determined by offering a N-free diet in the mash form. From day 1 to 18, the birds were offered a broiler starter diet. The diets and the N-free diet were randomly assigned to 6 replicate cages (8 birds per cage) and fed from day 19 to 23. The ileal digesta were collected on day 23. The SID of N was higher (P < 0.05) in SBM followed by MBM and CM. The average SID of AA in SBM and MBM were similar (P > 0.05), and greater (P < 0.05) than that in CM. The FF had no influence (P > 0.05) on the SID of indispensable AA, the only exception being His, which was reduced (P < 0.05) by pelleting. Pelleting, however, resulted in reduction (P < 0.001) in the SID of all dispensable AA and average of AA. The AA most affected by pelleting was Cys, with a 15.4% decrease in the SID. The standardized ileal digestible contents of protein and the average of indispensable AA and dispensable AA were higher in MBM than in SBM, with CM being the lowest. Pelleting decreased (P < 0.05) the digestible protein and total digestible AA contents. These findings reveal that the FF has a substantial impact on AA digestibility estimates of feed ingredients and it must be considered in AA digestibility assays of ingredients with high protein and AA contents.

Comparative amino acid digestibility between broiler chickens and pigs fed different poultry by-products and meat and bone meal

The objective of this study was to compare the standardized ileal digestibility (SID) of amino acids (AA) in 3 poultry by-products including hydrolyzed feather meal (HFM), flash dried poultry protein (FDPP), and poultry meal (PM) and also a meat and bone meal (MBM) between broiler chickens and pigs. Experimental diets consisted of 4 diets containing each test ingredient as a sole source of nitrogen and a nitrogen-free diet. In experiment 1, 416 male broiler chickens with a mean initial body weight (BW) of 705 ± 100 g were allotted to 5 diets with 8 replicate cages per diet in a randomized complete block design with BW as a blocking factor at day 18 posthatching. After 5 d of feeding experimental diets, birds were euthanized by CO2 asphyxiation, and ileal digesta samples were collected from distal two-thirds of the ileum. In experiment 2, 10 barrows with a mean initial BW of 22.1 ± 1.59 kg were surgically fitted with T-cannulas at the distal ileum and allotted to a duplicate 5 × 4 incomplete Latin Square design with 5 diets and 4 periods. Each period lasted for 7 d including 5 d of adaptation and 2 d of ileal digesta collection. Data from experiments 1 and 2 were pooled together and analyzed as a 2 × 4 factorial arrangement with the effects of species (broiler chickens or pigs) and 4 experimental diets (HFM, FDPP, PM, or MBM). There were interactions (P < 0.05) between experimental diets and species in the SID of His, Lys, Thr, Trp, Val, and all dispensable AA except Tyr. In broiler chickens, the SID of Lys in FDPP (73.3%) was greater (P < 0.05) than in HFM (55.7%) but was lower (P < 0.05) than in MBM (86.5%), which was not different from PM (78.7%). In pigs, however, the SID of Lys in FDPP and PM (70.0 and 70.1%, respectively) were greater (P < 0.05) than in HFM (39.0%) but were lower (P < 0.05) than in MBM (79.2%). Broiler chickens fed FDPP and PM had lower (P < 0.05) SID of His, Thr, and Trp than those fed MBM; however, there was no difference in the SID of His, Thr, or Trp among pigs fed FDPP, PM, or MBM. The SID of Val in MBM was greater (P < 0.05) than in the other test ingredients for broiler chickens, but there was no difference in the SID of Val among test ingredients for pigs. Pigs had greater (P < 0.05) SID of Ile and Met than broiler chickens. In conclusion, the pattern of differences in the SID of His, Lys, Thr, Trp, and Val, but not the other indispensable AA, among poultry by-products and MBM were different between broiler chickens and pigs.

Variation in lysine, threonine, and tryptophan availability in meat and bone meal as estimated by the slope-ratio growth assay technique in growing rats

Meat and bone meal (MBM) is an important protein source used in animal feeds. However, as the composition and availability of amino acids (AAs) in MBM fluctuate markedly, it is important to verify the magnitude of these parameters in different MBMs. In this study, the AA compositions of 19 MBMs were analyzed to confirm variations in lysine (Lys), threonine (Thr), and tryptophan (Trp), then which were compared with those of soybean meal (SBM) and fish meal (FM). Instability in Lys, Thr, and Trp availabilities in six MBMs were also considered after estimation using the slope-ratio growth assay technique in rats. Variations in AA composition were evaluated using the coefficient of variance (CV: Standard deviation/Mean). CVs for Lys, Thr, and Trp content were 9.40, 11.83, and 18.12 in MBM, 2.71, 2.48, and 3.19 in SBM, and 10.09, 10.44, and 13.47 in FM. Furthermore, means and SDs for Lys, Thr, and Trp availabilities in MBM were 53.3 ± 10.4% (CV: 19.5), 65.9 ± 17.6% (CV: 26.6), and 83.2 ± 11.2% (CV: 13.5), respectively. These results provide the first evidence that variations in MBM AA compositions were 3.5 to 5.7 times higher than those in SBM, but similar to FM, and that the large variation in availability substantially existed.

Egg production and quality responses to increasing isoleucine supplementation in Shaver white hens fed a low crude protein corn-soybean meal diet fortified with synthetic amino acids between 20 and 46 weeks of age

The present study evaluated production performance responses to Ile supplementation in laying hens fed low crude protein (LCP), amino acid (AA) balanced diets. A total of 179 Shaver white pullets were distributed into 30 battery cages (6 birds/cage, n = 6) and observed over the course of 27 wk in a 2-phase (20 to 27 and 28 to 46 wk of age) feeding program. Five isocaloric diets were formulated for standardized ileal digestible (SID) Lys intake of 750 and 710 mg/D in phase 1 and 2, respectively, and included a positive control with standard levels of crude protein (CP) (CON; 18 and 16% CP for phases 1 and 2), and 4 LCP diets (16 and 14% CP for phase 1 and 2, respectively) with graded levels of Ile to satisfy SID Ile:Lys ratios of 70 (Ile70), 80 (Ile80), 90 (Ile90), and 100% (Ile100). Based on analyzed dietary AA, the calculated SID Ile:Lys of LCP diets were 75, 84, 88, 99% and 66, 72, 82, 95% for phase 1 and 2, respectively. Dietary treatments significantly (P < 0.05) affected feed intake, hen-day egg production (HDEP), egg weight (EW), feed conversion ratio, and egg quality (Haugh unit) and composition (yolk to albumen). Lowering dietary CP negatively affected HDEP with a 3.3 and 1.5% reduction in phase 1 and 2, respectively, and this was restored with the addition of Ile (P < 0.001) suggesting that Ile was limiting in the LCP basal diet. Average EW was reduced in Ile100 only; however, the Ile:Lys appeared to influence egg size uniformity, with Ile90 producing a greater proportion of large (56 g ≤ EW > 63 g) eggs, suggesting that Ile may be used to manipulate EW at the expense of HDEP. Overall, the results indicated that CP in laying hen diets can be reduced by 2% units if fortified with synthetic AA (Met, Lys, Thr, Trp) + Ile, with optimal responses observed between 82 and 88% SID Ile:Lys.

Additivity of apparent and standardized ileal digestibility of amino acids in wheat, canola meal, and sorghum distillers dried grains with solubles in mixed diets fed to broiler chickens

An experiment was conducted to investigate which method, apparent ileal digestibility (AID) or standardized ileal digestibility (SID), more accurately predicts the digestibility of crude protein (CP) and amino acids (AA) in mixed diets fed to broiler chickens. Male Ross 308 broiler chickens received a standard starter diet from d 0 to 16 post hatching, thereafter grouped into 8 blocks, based on body weight (BW), of 10 birds/cage, and randomly allotted to 6 diets in a randomized complete block design. The 6 diets consisted of a nitrogen-free diet, 3 semi-purified diets, and 2 mixed diets to test the additivity of AID and SID in mixed diets. On d 21 post hatching, digesta from two-thirds of the distal ileum was collected. Using the determined AID or SID for CP and AA in wheat, canola meal (CM), or sorghum distillers dried grains with solubles (DDGS), the AID or SID for 2 mixed diets based on wheat-CM or wheat-CM-DDGS were predicted and compared with determined AID or SID, respectively. The results revealed that the predicted SID of CP and AA in the wheat-CM mixed diet were consistent with determined values except for Asp and Ser, and all the predicted SID of CP and AA were consistent with the determined values in the wheat-CM-DDGS mixed diet. The determined AID of Ile, Met, Thr, Val, Ala, Cys, Ser, and Tyr in the wheat-CM mixed diet were greater (P < 0.05) than predicted AID values. For the wheat-CM-DDGS mixed diet, the determined AID of Trp, Cys, and Glu were greater (P < 0.05) than the predicted AID values. However, there were more inconsistencies between the determined and predicted values in AID values for wheat-CM than the wheat-CM-DDGS mixed diet than SID values for both diets. In conclusion, the present study confirmed that the SID of CP and AA was more additive than the AID of CP and AA when a mixed diet contained wheat, CM, and DDGS as protein sources in broiler chickens.

Comparison of amino acid digestibility in full-fat soybean, two soybean meals, and peanut flour between broiler chickens and growing pigs

The aim of this study was to determine the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of CP and AA in full-fat soybean (FFSB), solvent-extracted soybean meal containing 430 g/kg CP (SBM-43), solvent-extracted soybean meal containing 470 g/kg CP (SBM-47), and peanut flour (PNF) fed to broiler chickens and pigs and to compare the digestibility of CP and AA between broiler chickens and pigs. Four diets were prepared to contain FFSB, SBM-43, SBM-47, and PNF as the sole source of N. A N-free diet was formulated to estimate the basal ileal endogenous losses of CP and AA for broiler chickens and pigs. In Exp. 1, a total of four hundred sixteen 21-d-old male broiler chickens (922.1 ± 79.9 g initial BW) were assigned to 5 experimental diets in a randomized complete block design with BW as a blocking factor. After 5 d of adaptation, ileal digesta samples were collected after birds were euthanized by CO asphyxiation. In Exp. 2, twenty barrows (62.0 ± 6.9 kg initial BW) surgically fitted with T-cannulas at the distal ileum were allotted to 5 experimental diets with 2 consecutive 7-d experimental periods. After 5 d of adaptation, ileal digesta samples were collected at d 6 and 7. For statistical analysis, treatments were considered a 2 × 4 factorial arrangement with effects of species and experimental diets (Exp. 1 vs. Exp. 2). There were no interactions between species and diets for the digestibility of CP and AA except for Cys ( < 0.01). The AID of CP and indispensable AA in pigs were greater ( < 0.01) than in broiler chickens. In both broiler chickens and pigs, the AID of CP and indispensable AA in SBM-47 were greater ( < 0.05) than in FFSB, and the AID of Lys in PNF was the least ( < 0.05) among ingredients. The SID of CP and indispensable AA in pigs were greater ( < 0.05) than in broiler chickens except for Trp. In both broiler chickens and pigs, the SID of Lys in PNF was the least ( < 0.05) among ingredients. In broiler chickens, the SID of CP, Ile, Leu, Thr, Trp, and Val in FFSB were less ( < 0.05) than that in SBM-43, SBM-47, and PNF. In pigs, the SID of Arg, Ile, Leu, Met, Phe, and Val in FFSB were less ( < 0.05) than in SBM-43, SBM-47, and PNF. In conclusion, the digestibility of CP and most AA were less in broiler chickens than in pigs, but the pattern of differences in the AA digestibility among ingredients was similar between broiler chickens and pigs.

Standardized Ileal Amino Acid Digestibility of Corn, Corn Distillers' Dried Grains with Solubles, Wheat Middlings, and Bakery By-Products in Broilers and Laying Hens

Standardized ileal amino acid digestibility (SIAAD) of 5 samples of corn distillers dried grain with solubles (DDGS), 5 samples of bakery by-products (BBP), 3 samples of corn, and 1 sample of wheat middlings (WM) were evaluated in broilers and laying hens. Diets containing each of the 14 feed ingredients were evaluated in 21 day-old broiler chickens. The DDGS and BBP containing diets were fed to 30-week-old laying hens, while corn and wheat middling were evaluated in 50-week-old laying hens. All the diets were semi-purified with each feed ingredient being the only source of amino acid (AA). To obtain SIAAD values, apparent ileal AA digestibility was corrected for basal ileal endogenous AA losses using values generated from broilers and laying hens fed a nitrogen-free diet. Ileal crude protein digestibility for the 5 DDGS samples was higher (P < 0.05) in broilers than in laying hens. Broilers had higher SIAAD for DDGS 2, 3, 4, and 5 while there was no difference for DDGS 1 except for 4 AA where broilers had higher (P < 0.05) SIAAD values. Standardized ileal AA digestibility values for broilers were higher (P < 0.05) for BBP 1 and 4. Ileal CP digestibility for corn 1 was higher (P < 0.05) for broilers compared to laying hens, and SIAAD values for the 16 AA (9 indispensable and 7 dispensable) evaluated in this study were higher (P < 0.05) in broilers. Broilers had higher (P < 0.05) SIAAD values for 4 (histidine, leucine, phenylalanine, and valine) and 6 (histidine, leucine, methionine, phenylalanine, threonine, and valine) indispensable and 3 (cysteine, glutamic acid, and proline) and 4 (cysteine, glutamic acid, proline, and serine) dispensable AA for corn 2 and corn 3, respectively. No difference in SIAAD between broilers and laying hens was observed for WM. Results from this study confirm that high variability in digestibility exists between different samples of DDGS. Differences in SIAAD between broilers and laying hens were observed in some samples of DDGS and BBP.

Formulating poultry diets based on their indigestible components

Since it started as an organized economic activity, poultry production has been undergoing an evolution toward the optimization of its feed formulation features. Notably, advances in the knowledge of birds' nutrient requirements have allowed recommendations that are increasingly closer to the needs of the birds. Over time, availability of nutrients and energy has been incorporated into those recommendations, especially to compensate for the variability in the digestibility of nutrients originating from variable feed ingredient sources. Instead of using the total energy and nutrient content, current tables of nutrient recommendations provide an estimate of the digestible fractions of the nutrients in ingredients. For instance, nonphytate P is preferred instead of total P to account for the unavailable phytate P, and digestible amino acids to account for the differences in digestibility of amino acids in different ingredients, whereas energy is usually expressed as a proportion that has been digested and metabolized (AME). With the increasing interest in the use of exogenous enzymes in poultry feeds, special attention is directed to the feed substrates such that an added enzyme can match it, forming an enzyme-substrate complex that will be followed by a chemical reaction within the gastrointestinal tract. As a consequence of a degradation reaction, nutrients released can be absorbed and metabolized. In general, nutritional data banks used in linear feed formulation software have limited data on the proportions of fractions of ingredients that are indigestible. Therefore, estimations of the presence of many substrates in the feeds, and therefore the benefits of adding exogenous enzymes, are frequently limited because of the scarcity of adequate information. The objective of this review paper is to provide insights into the use of expanded nutrient databanks to include all the molecules considered potentially indigestible for poultry such that the inclusion of exogenous enzymes allows the estimation of the values of the product originated by their hydrolysis.