Influence of age on the apparent ileal amino acid digestibility of feed ingredients for broiler chickens

Effect of age on the standardized ileal amino acid digestibility of soybean meal and canola meal in broilers

Standardized ileal digestibility coefficients (SIDC) of nitrogen (N) and amino acids (AA) in two protein sources (soybean meal [SBM] and canola meal [CM]) were investigated at six broiler ages (d 7, 14, 21, 28, 35, and 42). Two assay diets were formulated to contain either SBM (413 g/kg) or CM (553 g/kg) as the sole dietary AA source. Titanium dioxide (5 g/kg) was added as an indigestible marker. A total of 696 male broilers at 1 d old were allotted to 12 replicate cages per age group. Each assay diet was offered to birds for 4 d prior to the ileal digesta collection on d 7 (14 birds/cage), 14 (12 birds/cage), 21 (10 birds/cage), 28 (8 birds/cage), 35 (8 birds/cage) and 42 (6 birds/cage), respectively. The apparent digestibility coefficients were standardized using age-specific basal endogenous AA flows. In the SBM group, though the SIDC of N tended to be influenced (quadratic; P = 0.075) by age, no linear or quadratic response of age effect was observed on the average SIDC of indispensable (IAA) and total AA (TAA). An age effect (quadratic; P < 0.05) was observed on the average SIDC of dispensable AA (DAA) in SBM with the highest value recorded at d 7, followed by a decrease from d 14 to 28, which increased beyond d 35. The SIDC of some individual AA (Arg, Thr, Trp, Cys, Pro) were affected (P < 0.05 or P < 0.001) in a quadratic manner by age. In the CM, the SIDC of N, average SIDC of IAA, DAA and TAA were influenced (quadratic; P < 0.05 or P < 0.001) by age. The SIDC of N and average SIDC of DAA and TAA were higher from d 7 to 14, declined at d 21, and then increased beyond d 28. The average SIDC of IAA was low between d 7 and 28 and increased thereafter. The SIDC of individual AA were affected (linear or quadratic; P < 0.05 or P < 0.001) by different magnitudes by age. The age influence on the SIDC AA was variable, depending on the protein source and AA. The results demonstrate that age-specific SIDC AA data might need consideration in broiler feed formulations.

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.

Apparent Metabolizable Energy and Amino Acid Digestibility of Corn of Different Origin Fed to Male Broilers from 12 to 18 Days of Age

Apparent metabolizable energy (AME) and apparent ileal amino acid digestibility (AIAAD) of corn samples from the United States (USA), Argentina (ARG), and Brazil (BRA) fed to 432 and 324 YPM × Ross 708 male broilers from 12 to 18 d of age were evaluated using the total collection method (experiment 1) and index method (experiment 2), respectively. In experiment 1, broilers were fed either a basal diet with 30% dextrose inclusion, or a test diet obtained by the replacement of dextrose with corn from each origin. In experiment 2, broilers were fed one of three test diets in which corn from each origin was the only source of AA. All dietary treatments had 12 replicate cages. Similar (p > 0.05) AME (dry-matter basis) values were observed between corn samples. The highest gap in AME (43 kcal/kg) was found between corn from BRA (3694 kcal/kg) and corn from the USA (3651 kcal/kg). Likewise, similar (p > 0.05) AIAAD values were observed for all AA apart from tryptophan (Trp), as corn from BRA (77.45%) had a higher (p = 0.024) Trp digestibility than corn from the USA (72.53%). Overall, a similar nutrient utilization by the birds was observed for the corn samples, regardless of origin.

Comparison of standardized ileal digestibility of amino acids in faba beans and field peas in broiler chickens and pigs

An experiment, using the same set of five diets was conducted to determine and compare the standardized ileal digestibility (SID) of amino acids (AA) in faba beans and three cultivars of field peas in broiler chickens and pigs. Four test diets were prepared to contain faba beans, DS-Admiral field peas, Hampton field peas, or 4010 field peas as the sole source of nitrogen. A nitrogen-free diet (NFD), as the fifth diet, was prepared to estimate the basal endogenous losses of AA to determine the SID of AA in the test ingredients. A total of 416 male broiler chickens with an initial body weight (BW) of 951 ± 111 g were allotted to five diets in a randomized complete block design with BW as a blocking factor on day 21 posthatching. There were 8 replicate cages with 10 birds per cage for diets containing test ingredients and 12 birds per cage for NFD. All birds were allowed ad-libitum access to feed for 5 days. On day 26 posthatching, all birds were euthanized by CO2 asphyxiation and digesta contents were collected from the distal two-thirds of the ileum. Twenty barrows with an initial BW of 30.2 ± 1.58 kg, surgically fitted with T-cannulas in the distal ileum, were divided into four blocks according to BW and each block was assigned to a 5 × 2 incomplete Latin Square design that consisted of five dietary treatments and two experimental periods. For each experimental period, there was a 5-day adaptation period followed by a 2-day collection of ileal digesta samples. The data were analyzed as a 2 × 4 factorial treatment arrangement with the effect of species (i.e., broiler chickens and pigs) and test diets (i.e., four test ingredients). For broiler chickens, the SID of Lys in faba beans, DS-Admiral field peas, and Hampton field peas were above 90% but in 4010 field peas, it was 85.1%. The SID of Lys in faba beans, DS-Admiral field peas, and Hampton field peas for pigs was above 80% but was 78.9% in 4010 field peas. The respective SID of Met in faba beans, DS-Admiral field peas, Hampton field peas, and 4010 field peas were 84.1%, 87.3%, 89.8%, and 72.1% for broiler chickens, and 71.5%, 80.4%, 81.8%, and 68.1% for pigs. The SID of AA in 4010 field peas was the least (P < 0.05) for chickens, but in pigs, it was comparable with faba beans. In conclusion, the SID of AA in faba beans and field peas was greater in broiler chickens compared with pigs and there was a cultivar effect.

Effects of broiler chicken age and dietary protease on the standardised ileal digestibility of amino acids in seeds from two lupin species

The extent to which lupin seeds can replace soybean meal in diets for broiler chickens is limited, and one of the reasons for this may be a lack of careful consideration given to the age-related amino acid availability differences in the feed formulation process. This study aimed to determine and compare standardised ileal digestibility (SID) coefficients of amino acids (AA) in raw seeds of the Lupinus luteus (YL) and the Lupinus angustifolius (NLL) cultivars as sole sources of AA in the diet of broiler chickens aged 14 or 28 days. An additional purpose was to check the influence of exogenous mono-component protease added to lupin-based assay diets on AA SID in birds at both ages. Each assay diet was offered to six replicatecages. On both sampling days, the contents from the lower half of the ileum were collected for determination of the apparent digestibility values. The SID coefficients were calculated using the age-appropriate basal ileal endogenous AA losses determined from birds fed a N-free diet. Results indicated a substantial advantage of YL over the NLL in SID of Met, Cys, His, Leu, Gly, Asp, Glu, Pro, Tyr and the average of total AA for 14-d-old chickens. With the exception of Cys and Tyr, there was no significant difference between these Lupinus species in the SID of AA in 28-d-old birds. The significant age-related differences within species were found only for the seeds of NLL, where the higher SID for Met, His, Ala, Pro, and the averages of total and indispensable AA were noted in birds aged 28 d. The protease increased SID of most AA from L. luteus in older broilers, whereas for L. angustifolius its efficacy was more pronounced in younger birds, giving the SID values similar to those determined at 28 d on an enzyme-unsupplemented diet. In conclusion, the SID coefficients of indispensable AA determined at 14 or 28 days of age for yellow lupin should not be applied to the precise formulation of starter-type feeds containing seeds of NLL.

Influence of Age on the Standardized Ileal Amino Acid Digestibility of Corn and Barley in Broilers

The aim of this study was to determine the standardized ileal digestibility coefficients (SIDCs) of nitrogen (N) and amino acids (AAs) in corn and barley at six different ages (days 7, 14, 21, 28, 35 and 42) of broilers using the direct method. The apparent AA digestibility coefficients were corrected using age-appropriate basal endogenous AA losses. No age effect (p > 0.05) was noted for the SIDC of N in corn. The average SIDC of indispensable AAs (IAAs) and total AAs (TAAs) was influenced in a quadratic manner (p < 0.05) with the values being higher at day 7 that decreased at day 14, increased and plateaued between days 21 and 35 and dropped again at day 42. The average SIDC of dispensable AAs (DAAs) was influenced linearly (p < 0.05). In barley, the SIDC of N and average IAAs, DAAs and TAAs was affected (quadratic; p < 0.001) by age. The digestibility increased from day 7 to 21 and then plateaued up to day 42. The present findings confirm that the SIDC of AA in corn and barley are influenced by broiler age and that the age effect on AA digestibility may need to be considered for precise feed formulation.

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.

An investigation into the influence of age on the standardized amino acid digestibility of wheat and sorghum in broilers

Standardized ileal digestibility coefficients (SIDC) of nitrogen (N) and amino acids (AA) in wheat and sorghum at 6 different ages (d 7, 14, 21, 28, 35, and 42) of broilers were determined. Two assay diets were formulated to contain 93.8% of each grain as the sole source of AA in the diet. Titanium dioxide (0.5%) was added as an indigestible marker. Each assay diet was fed to 6 replicate cages housing 14 (d 7), 12 (d 14), 10 (d 21), 8 (d 28), 8 (d 35), and 6 (d 42) birds per cage for 4 d prior to ileal digesta collection. The apparent ileal digestibility coefficients (AIDC) were standardized by using the age-appropriate basal endogenous AA losses. In the case of wheat, AIDC of N and all AA increased (linear or quadratic, P < 0.05 to 0.001) with advancing age. No age effect was noticed on the SIDC of N, average of indispensable (IAA) and dispensable AA (DAA), though the average of total AA (TAA) tended (linear, P = 0.09) to increase as birds grew older. In sorghum, the AIDC of N, average of IAA and DAA were unaffected (P > 0.05) by age. The SIDC of N, average SIDC of IAA, DAA and TAA were higher at d 7, reduced at d 14 and then plateaued. Among the IAA, the SIDC of Arg, His, Ile, Leu, Lys, Thr, Val, and the SIDC of all individual DAA (except Cys) decreased with age (linear or quadratic, P < 0.05 to 0.001) with higher values at d 7. The higher SIDC values determined at d 7 were due to higher EAA losses during wk 1. The results showed that broiler age influences AA digestibility and this may need be considered in practical feed formulations. The age effect is variable depending on the grain type and specific AA.

Responses in growth performance and nutrient digestibility to a multi-protease supplementation in amino acid-deficient broiler diets

The present study was conducted to investigate the effect of a multi-protease on production indicators of broiler chickens fed a crude protein and amino acid deficient-diets for 35 days immediately after hatch. A total of 448 one-day-old Ross 308 male broiler chicks were allocated in a completely randomized design into one of eight dietary treatments (positive control [PC], negative control [NC: minus 0.5% from PC, and minus 2% of lysine, methionine, threonine and methionine plus cysteine], extreme negative control [ENC: minus 1% from PC, minus 4% of lysine, methionine, threonine and methionine plus cysteine], and plus multi-protease 150 or 300 g per ton [e. g., PC-150]; PC, PC-150, NC, NC-150, NC-300, ENC, ENC-150, ENC-300) to give eight replicates with seven birds in a battery cage. Body weight, average daily gain, average daily feed intake, feed conversion ratio, and mortality were measured every week. Carcass traits, proximate analysis of breast meat, and ileum digestibility were analyzed on day 21 and 35. Feeding a multi-protease (i.e., more than 150 g/ton) for 35 days immediately after hatching improved feed efficiency and ileum digestibility (i.e., dry matter, crude protein, and energy) compared to their counterparts (i.e., diets without multi-protease: PC, NC, and ENC). In conclusion, our results indicated that broiler chickens fed nutrients deficient-diet (i.e., crude protein and amino acids) supplemented a multi-protease had an ability to compensate and (or) improve their growth performance commensurate with increased ileal digestibility for 35 days immediately after hatch.

Standardised Ileal Amino Acid Digestibility in Field Pea Seeds of Two Cultivars Differing in Flower Colour for Broiler Chickens: Effects of Bird Age and Microbial Protease

Simple Summary

The extent to which field peas can replace soybean meal in diets for broiler chickens is limited, and one of the reasons for this may be a lack of careful consideration given to the age-related amino acid availability differences in feed formulations. As the digestibility of amino acids in feeds for poultry is a sensitive gauge of their bioavailability, this study has determined and compared standardised ileal amino acid digestibility estimates for whole (raw) seeds of white- and coloured-flowered pea cultivars fed to young and older chickens (14 or 28 days old) in the presence or absence of exogenous protease in their diet. The results demonstrate that when a digestible amino acid system is used, the coefficients of essential amino acids determined at 14 days of age in low-tannin white-flowered peas are not applicable to the formulation of grower-type feed mixtures containing seeds of coloured-flowered cultivars. The increased digestibility of nutritionally essential amino acids in white-flowered pea fed to bids at both ages and in coloured-flowered pea fed to chickens aged 28 days can be expected from protease supplementation. These results contribute to improved use of peas as an alternative to soybean meal vegetable protein sources in diets for broiler chickens.

Abstract

This study aimed to determine and compare standardised ileal digestibility (SID) coefficients of amino acids (AA) in raw seeds of the white-(WF) and the coloured-flowered (CF) field pea cultivar as sole sources of AA in the diets fed to broiler chickens aged 14 or 28 days. An additional purpose was to check the influence of exogenous protease added to pea-based assay diets on AA SID in birds at both ages. Each assay diet was offered to six replicate pens. On both sampling days, the contents from the lower half of the ileum were collected for determination of the apparent digestibility values. The SID coefficients were calculated using ileal endogenous AA losses determined from birds fed an N-free diet. Results indicated a substantial advantage of WF pea over CF pea as a source of digestible Lys, Met, Cys, His, Ile, Leu, Phe, Val, Asp and Glu for 14-day-old chickens. With the exception of methionine and cysteine, there was no significant difference between these two cultivars in the SID values of AA in 28-day-old birds. The protease increased SID of nutritionally essential AA from WF pea-based diet at both ages, and from CF pea-based diet in chickens aged 28 days. In conclusion, the SID coefficients of indispensable AA determined at 14 days of age in low-tannin WF peas are not applicable to the formulation of grower-type feeds containing seeds of CF cultivars.

Evaluation of feeding value of combination of alternate protein sources in White Leghorn layers

1. A study was conducted to evaluate the effects of including graded levels of an alternate protein mixture (APM) containing cottonseed meal, distillery dried grain with solubles and mustard seed meal in a fixed ratio as a substitute for soybean meal in layer diets (hens aged 27 to 46 weeks). The trial studied the possibility of higher inclusion levels of APM with increased dietary concentrations of crude protein (CP) or critical amino acids (CAA). 2. Maize-soybean meal diet was used as the control diet. In experiment 1, APM was included at 0, 120, 160 and 200 g/kg diet (145 g/kg CP). In experiment 2, the control and three test diets (200 g/kg APM) with three levels of CP (145, 155 and 165 g/kg) were used. In experiment 3, a control and four test diets (200 g/kg APM) with four concentrations of CAA (100%, 105%, 110% and 115% relative to the control) were used. In all experiments, each diet was fed ad libitum to nine replicates of 88 birds each, housed in colony cages. 3. In experiment 1, egg production (EP) and feed intake (FI) were not affected by feeding up to 160 g/kg APM, but, at 200 g/kg, EP was significantly reduced. Feed conversion ratio (FCR) for the hens fed the highest level of APM was similar to the control. Egg weight (EW) and egg mass (EM) in the 160 and 200 g/kg AMS groups were lower than the control group. 4. Increase in dietary CP from 145 to 155 g/kg improved EP and reduced FCR to levels similar to the control group. EM in hens fed 165 g/kg APM was similar to the control in experiment 2. 5. Increasing concentrations of CAA progressively improved EP and reduced FCR in experiment 3. The EP at CAA 110% and FCR at CAA 105% were similar to the control group. 6. Based on the results, it was concluded that the APM can be included up to 160 g/kg diet without affecting layer performance, as long as the diet supplied the recommended levels of protein and amino acids. By increasing either protein from 145 to 155 g/kg or CAA concentrations by 10%, the dietary levels of the APM could be increased to 200 g/kg without affecting the layer performance.

Determination and prediction of standardized ileal amino acid digestibility of corn distillers dried grains with soubles in broiler chickens

The experiment was conducted to evaluate ileal digestibility of amino acids (AA) in 8 corn distillers dried grains with solubles (DDGS) fed to broilers and to establish prediction equations for standardized ileal digestibility (SID) of AA for broilers based on the physicochemical properties. A total of 1,152 1-day-old male broilers were divided into 2 test stages (from day 9 to 14 and from day 23 to 28). In each stage, 576 broilers were randomly allotted to 1 of 9 diets (8 replicates, 8 birds per replicate) including a nitrogen-free diet and 8 corn DDGS test diets. Titanium dioxide (0.5%) was included in all diets as an external marker. In 8 corn DDGS samples, the contents of aflatoxin B1, deoxynivalenol, zearalenone, and zein were from 1.54 to 15.50 ppb, 0.44 to 5.12 ppm, 127.10 to 1062.46 ppb, and 3.10 to 26.89%, respectively; the content of lysine and methionine (Met) ranged from 0.36 to 0.67% (CV 21.51%) and from 0.16 to 0.74% (CV 58.04%), respectively. The SID of AA, except for valine and alanine, were significantly different (P < 0.05) at day 28. A positive correlation was observed (P < 0.05) between degree of lightness and SID of CP, Met, and total amino acid (TAA) at day 14. A negative correlation was observed (P < 0.05) between mycotoxins and SID of CP, lysine, Met, and TAA at day 28. The R² value of stepwise regression equations for predicting the SID of AA at day 14 and day 28 was best for glutamic acid (R² = 1.000 using ether extract, crude fiber, CP, aflatoxin B1, and neutral detergent fiber) and TAA (R² = 0.904 using ether extract), respectively. In conclusion, this experiment suggested mycotoxin can be used to predict the SID of AA in corn DDGS with reasonable accuracy, and the results of SID and prediction equations could be used to evaluate the digestibility of corn DDGS in broilers.

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.

The impact of age and feeding length on phytase efficacy during the starter phase of broiler chickens

Phytase is of importance to the poultry industry because of its ability to hydrolyze phytate and release phosphorus (P) for use by poultry. However, the effect of age on phytase efficacy is not fully understood. A total of 864 day-old broiler chicks were used to investigate the effect of age and feeding length on phytase efficacy using growth performance, mineral utilization, and tibia ash as response criteria of evaluation. The experiment was arranged as a 3 × 2 × 2 factorial in a randomized complete block design with 3 diets including; a positive control (PC; 0.4% non-phytate P (nPP)), a negative control (NC; 0.2% nPP) and a NC diet supplemented with phytase at 2,000 FYT/kg; 2 ages (i.e., days 14 and 22); and 2 feeding lengths (i.e., 2 and 5 D) with 8 replicates each. Birds fed the NC had decreased (P < 0.01) body weight gain and feed efficiency compared with birds fed the PC regardless of age or feeding length. Similarly, birds fed the phytase-supplemented diet had improved (P < 0.01) performance as compared to birds fed the NC regardless of age. There were no significant differences in P utilization between birds fed for 2 to 14 D or 22 D and birds fed for 5 D to both ages. However, phytase was more efficacious at day 14 than day 22 when mineral utilization was considered because the super dose of phytase elicited greater response in birds fed the phytase supplemented diet for 2 D until day 14. In contrast, percentage tibia ash improved (P < 0.01) in birds fed phytase supplemented diet for 5 D at both ages as compared with birds fed for 2 D. In conclusion, testing phytase products, even at high doses, for 2 D during the second week in the life cycle of broiler chicks, can be recommended from the results of this study.

Research Note: Effect of chicken genotype and white striping-wooden breast condition on breast meat proximate composition and amino acid profile

The present experiment compared the proximate composition, the amino acid content, and profile of the breast meat of a commercial broiler hybrid (Hybrid-Normal) vs. a broiler hybrid affected by the simultaneous presence of white striping (WS) and wooden breast (WB) myopathies (Hybrid-WSWB) vs. the Italian purebred Polverara chicken (Polverara). To this purpose, a total of n = 30 breast meat cuts from male chickens/group were subjected to meat quality evaluations. Chickens were slaughtered at their commercial age. The meat of the Polverara breed showed the highest protein (P < 0.0001) and the lowest lipids (P < 0.0001) contents, whereas that of the Hybrid-WSWB broiler chickens had the lowest protein and ash (P < 0.0001) contents and the highest (P < 0.0001) amount of fat. Meat of Hybrid-Normal chickens displayed intermediate values. Polverara meat was the richest in most amino acids (g/100 g meat), whereas Hybrid-WSWB one had the lowest content (P < 0.0001). Taurine was not detected in the meat of the Polverara chicken. The meat of Hybrid-Normal chickens was the richest in valine and taurine amino acids (P < 0.0001). Results on the amino acids proportions (% of total amino acids) highlighted that lysine, arginine, leucine, glutamic acid, aspartic acid, alanine, and serine were the most representative essential and nonessential amino acids, respectively, in all 3 meat-types chickens. The study confirmed that WS and WB myopathies negatively affect the meat proximate composition and the amino acid content. The meat of the Polverara breed displayed a remarkable meat quality including a high protein content of very good quality. This may represent a tool to promote its meat among consumers and help the survival of this endangered breed. Furthermore, research efforts should be conducted to understand why taurine was absent in the breast meat of Polverara chicken.

Lack of interactive effects between diet composition and acid addition with drying method on amino acid digestibility values in porcine ileal digesta

Two experiments were conducted to determine the effect of oven drying (OD) or freeze drying (FD) on apparent ileal digestibility (AID) of AA in diets fed to pigs. In experiment 1, 15 barrows (88.4 ± 6.4 kg) were allotted to either a corn starch-soybean meal (CST), potato starch-soybean meal (PST), or corn-soybean meal (CSBM) diet, over 2 collection periods. Following collection, samples were pooled within pig and subdivided into either OD or FD, resulting in 10 observations per diet by drying-method combination. In experiment 2, 11 barrows (63.3 ± 3.8 kg) were fed a CST diet, and, following collection, samples were pooled within pig and subdivided and either adjusted to pH 4 or remain unadjusted. Subsets of these samples were then subdivided to be either FD or OD, resulting in 11 observations per pH level by drying-method combination. OD was accomplished by drying samples in a forced air oven at either 100 °C (experiment 1) or 75 °C (experiment 2). In experiment 1, there was no diet type by drying-method interactions noted for any of the AA (P > 0.10).OD resulted in a higher AID of AA compared with samples which were FD (P ≤ 0.10), for all AA except for Gly and Tyr. Averaged across all AA, AID of AA was 3.3% greater if the sample was OD compared with FD. Differences in AID of AA among the 3 diets were noted for all AA (P ≤ 0.07), except for Cys (P = 0.33), due to the fact that CST and PST diets only contained soybean meal (SBM) as an AA-providing ingredient while the CSBM diet contained both corn and SBM. Pigs fed the PST diet had greater SID for all AA compared with pigs fed the CST diet (P ≤ 0.05), except for His, Lys, Cys, and Glu. In experiment 2, there were no pH-adjustment by drying-method interactions noted on AID for any of the AA (P > 0.10). Adjusting ileal digesta to a pH of 4.0 had little effect on AID for most of the AA, except for a lowered AID of Arg, His, Lys, Trp, and Ser (P ≤ 0.10). OD resulted in a higher AID for all AA (P ≤ 0.09) except for Ile, Thr, Val, Ala, Asp, Glu, and Gly. Averaged across all AA, the increase in AID of AA was 1.7% greater if the sample was OD compared with FD. On average, OD of ileal digesta resulted in a 2.5% greater estimate of AID of AA compared with samples that were FD, and was not diet-, pH-, or AA-dependent. Because the majority of the data on AA digestibility are based on FD, a bias factor may be necessary to adjust AA digestibility data obtained on an OD-basis relative to an FD-basis for use in feed formulation.

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 8.0 mm 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.

Effect of protein sources on performance characteristics of turkeys in the first three weeks of life

The effect of nutrition during the early life of turkey poults has a long-lasting impact on bird performance. This study assessed the digestibility of 5 high protein feed ingredients (soybean meal [SBM], corn gluten meal [CGM], canola protein concentrate [CPC], fish meal [FM], and porcine meal [PCM]) in broiler chickens, as well as their use in turkey pre-starter diets fed to 21 d of age. The first experiment (5 × 2 factorial arrangement) determined nitrogen corrected apparent metabolizable energy (AMEn) and apparent ileal amino acid digestibility (AIAAD) of each ingredient in broiler chickens at 5 and 21 d of age, using 6 replications of 30 and 8 chicks, respectively. In the second experiment (completely randomized design), 4 replication pens, containing 23 d-old poults, were randomly assigned to one of 5 dietary treatments. The diets were formulated based on the AMEn and AIAAD values derived in the first experiment, and consisted of a high SBM control diet, and 4 additional diets with either CPC, FM, PCM or CGM replacing 25% of the protein supplied by SBM in the control diet. Statistical analysis was completed using Proc Mixed in SAS 9.3. Planned contrasts were used to compare treatments in the second experiment. Trends were identified at P < 0.10 and significant differences identified at P ≤ 0.05. Bird age did not affect CPC, FM, CGM, and SBM AMEn, but the PCM value at d 5 was higher than that at d 21. Apparent ileal amino acid digestibility increased with age for most amino acids (AA), but the response was AA and protein source dependent. The largest average increase in AIAAD between 5 and 21 d of age was observed for CGM. Inclusion of CPC, FM, PCM, or CGM increased body weight up to 14 d, in comparison to poults fed the SBM diet, but feed efficiency and water consumption were not affected. Terminal ileum digesta moisture values were higher for birds fed SBM when compared to those fed PCM. These results demonstrate that combining SBM with CPC, FM, PCM, or CGM improves poult performance during the first 14 d of life in comparison to feeding SBM alone.

A revised representation of urea and ammonia nitrogen recycling and use in the Molly cow model

Accurately predicting nitrogen (N) digestion, absorption, and metabolism will allow formulation of diets that more closely match true animal needs from a broad range of feeds, thereby allowing efficiency of N utilization and profit to be maximized. The objectives of this study were to advance representations of N recycling between blood and the gut and urinary N excretion in the Molly cow model. The current work includes enhancements (1) representing ammonia passage to the small intestine; (2) deriving parameters defining urea synthesis and ruminal urea entry rates; (3) adding representations of intestinal urea entry, microbial protein synthesis in the hindgut, and fecal urea-N excretion; and (4) altering existing urinary N excretion equations to scale with body weight and adding purine derivatives as a component of urinary N excretion. After the modifications, prediction errors for ruminal outflows of total N, microbial N, and nonammonia, nonmicrobial N were 29.8, 32.3, and 26.2% of the respective observed mean values. Prediction errors of each were approximately 7 percentage units lower than the corresponding values before model modifications and fitting due primarily to decreased slope bias. The revised model predicted ruminal ammonia and blood urea concentrations with substantially decreased overall error and reductions in slope and mean bias. Prediction errors for gut urea-N entry were decreased from 70.5 to 26.7%, which was also a substantial improvement. Adding purine derivatives to urinary N predictions improved the accuracy of predictions of urinary N output. However, urinary urea-N excretion remains poorly predicted with 69.0% prediction errors, due mostly to overestimated urea-N entry rates. Adding representations of undigested microbial nucleic acids, microbial protein synthesized in the hindgut, and urea-N excretion in feces decreased prediction errors for fecal N excretion from 21.1 to 17.1%. The revised model predicts that urea-N entry into blood accounts for approximately 64% of dietary N intake, of which 64% is recycled to the gut lumen. Between 48 and 67% of the urea recycled to the gut flows into the rumen largely depending on diet, which accounts for 29 to 54% of total ruminal ammonia production, and 65 to 76% of this ammonia-N is captured in microbial protein, which represents 17% of N intake. Based on model simulations, feeding a diet with moderately low crude protein and high rumen-undegradable protein could increase apparent ruminal N efficiency by 20%.

Digestion dynamics in broilers fed rapeseed meal

Rapeseed proteins are described to be poorly digestible in chickens. To further identify some molecular locks that may limit their use in poultry nutrition, we conducted a proteomic study on the various chicken digestive contents and proposed an integrative view of the proteins recruited in the crop, proventriculus/gizzard, duodenum, jejunum, and ileum for digestion of rapeseed by-products. Twenty-seven distinct rapeseed proteins were identified in the hydrosoluble fraction of the feed prior ingestion. The number of rapeseed proteins identified in digestive contents decreases throughout the digestion process while some are progressively solubilized in the most distal digestive segment, likely due to a combined effect of pH and activity of specific hydrolytic enzymes. Fifteen chicken proteins were identified in the hydrosoluble proventriculus/gizzard content, including chymotrypsin-like elastase and pepsin. Interestingly, on the 69 distinct proteins identified in duodenum, only 9 were proteolytic enzymes, whereas the others were associated with homeostasis, and carbohydrate, lipid, vitamin and hormone metabolisms. In contrast, chicken proteins identified in jejunal and ileal contents were mostly proteases and peptidases. The present work highlights the relevance of using integrative proteomics applied to the entire digestive tract to better appreciate the protein profile and functions of each digestive segment.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility, apparent metabolizable energy and apparent ileal amino acid digestibility

BACKGROUND

The study aimed to determine the apparent total tract digestibility coefficients (ATTDC) of nutrients, the apparent metabolizable energy (AME and AMEn) and the amino acid (AA) apparent ileal digestibility coefficients (AIDC) of a partially defatted (BSFp) and a highly defatted (BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg (w/w) of the basal diet with BSFp or BSFh, respectively.

RESULTS

Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly (P < 0.05) different between the two BSF meals, with higher levels for BSFp (16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility (0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal (P < 0.05).

CONCLUSIONS

Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

Nutrients, amino acid, fatty acid and non-starch polysaccharide profile and in vitro digestibility of macadamia nut cake in swine

The highly variable cost and limited availability of conventional feedstuffs make it imperative to explore alternative feedstuffs to be used in swine. Macadamia nut cake (MNC), a coproduct of the macadamia nut oil industry, has not been well studied. MNC was analyzed for its nutrient profile, gross energy (GE), fibers, amino acids and fatty acids content. Dry matter (DM) and GE digestibility of MNC in swine was determined using an in vitro model. On a DM basis, ash, crude protein, ether extract, NDF, ADF, lignin and GE were found to be 3.7, 25.5, 11.9, 35.8, 28.0, 16.0% and 5581 kcal/kg, respectively. Total and soluble non-starch polysaccharide content were 32.2 and 11.8%, respectively. The concentration of lysine was found to be 0.7%. The DM and GE digestibility were found to be 75.7 and 71.4%, respectively. Gross energy content of MNC is comparable with that of corn and higher than soybean meal, while protein content is twice as high as corn but lower than soybean meal. In conclusion, MNC is not merely a good source of protein and energy but also has fairly high digestibility in swine. Hence, it can be used as a viable alternative source of energy and protein in swine diets.

Standardized Ileal Amino Acid Digestibility of Commonly Used Feed Ingredients in Growing Broilers

This experiment was conducted to determine standardized ileal amino acid digestibility (SIAAD) of commonly used feed ingredients in poultry diets in Pakistan. These feed ingredients included corn, rice broken (RB), rice polishings (RP), wheat bran (WB), sunflower meal (SFM), cottonseed meal (CSM), guar meal (GM), soybean meal (SBM) from India and Argentine and fish meal (FM). The SIAAD of each ingredient was determined in triplicate using 21-days-old broilers. Day-old male broiler chicks (Hubbard× Hubbard) were reared on corn-SBM based diet from 1 to 13 days and thereafter birds were fed experimental diets from day 14 to 21. Each diet was fed to 36 birds kept in six replicate cages, each cage had six birds. In cereals, the SIAAD of corn's amino acid (AA) (90.1%) was similar (p>0.05) to RB (89.0%). Isoleucine (97.8%) and lysine (96.9%) were highly digestible AA in corn and RB, respectively. Among cereal-by products, WB's SIAAD (76.9%) was same (p>0.05) as RP (71.9%). Arginine from WB (82.5%) and RP (83.2%) was highly digestible. However, threonine in WB (72.7%) and leucine in RP (69.6%) were the lowest digestible AAs. In plant protein meals, AAs from Argentine-SBM (85.1%) and Indian-SBM (83.4%) had higher (p<0.5) SIAAD than other protein meals. However, SIAAD of SFM (77.1%) and CSM (71.7%) was intermediate while GM (60.3%) exhibited the lowest (p<0.05) SIAAD among all ingredients. Arginine from GM (76.9%), CSM (85.8%), SBM-India (89.5%) and SBM-Argentine (91.5%) was highly digestible from indispensable AAs. In SFM, methionine (91.4%) SIAAD was the greatest. The average SIAAD of FM was 77.6%. Alanine from FM had the highest (84.0%) but cysteine (62.8%) had the lowest SIAAD. In conclusion, cereals i.e. corn and RB had higher (p<0.05) SIAAD of the cereals by-products. The SIAAD of RP and WB was same (p>0.05). The SBM from plant protein meals had higher (p<0.05) SIAAD than other studied feed ingredients. However, the GM had the lowest (p<0.05) SIAAD among protein meals.

Age and adaptation to Ca and P deficiencies: 2. Impacts on amino acid digestibility and phytase efficacy in broilers

A total of 1,152 straight-run hatchling Heritage 56M×fast feathering Cobb 500F broiler birds were used to determine Ca, age, and adaptation effects on apparent ileal digestibility of crude protein (AID of CP), amino acids (AID of AA) and phytase efficacy. Twelve treatments with 8 replicates, each were fed from 7 to 9 d (6 birds per replicate), 7 to 21 d (6 birds per replicate) and 19 to 21 d (3 birds per replicate) d of age. Diets were prepared with 3 Ca (0.65, 0.80, and 0.95%) and 2 non-phytate P, (0.20 and 0.40%) concentrations. A 6-phytase was added at 500 or 1,000 FTU/kg to the 0.20% nPP diet at each Ca concentration. The age and adaptation effects were determined by comparing the responses between birds fed from 7 to 9 and 19 to 21 d of age, 19 to 21, and 7 to 21 d of age, respectively. An age effect was observed regardless of Ca, nPP, or phytase concentration, with older birds (19 to 21 d) having greater apparent ileal digestibility (AID) of amino acids (AA) and CP than younger birds (7 to 9 d; P<0.05). Response to adaptation varied depending on Ca, nPP, and phytase concentrations. Constant lower AID of CP and AA was seen in adapted birds (7 to 21 d) compared to unadapted bird (19 to 21 d) when 0.20% nPP diets were fed at 0.95% Ca concentrations (P<0.05). At 0.40% nPP, there was no effect of adaptation on AID of CP and AA at any Ca concentration. Phytase efficacy was significantly lower in younger (7 to 9 d) compared to older birds (19 to 21 d; P<0.05), except at 0.65% Ca. Phytase inclusion increased AID of CP and AA regardless of Ca (P<0.05). In conclusion, the AID of CP and AA can be affected by diet, age, and adaptation.

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.

Standardized ileal amino acid digestibility of expeller-extracted canola meal subjected to different processing conditions for starter and grower broiler chickens

Six expeller-extracted canola meal (ECM) samples produced under different seed conditioning temperatures (90, 95, or 100°C) and screw torques in the second press (low or high) were evaluated in a 3 × 2 factorial arrangement of treatments to determine the effect of processing on standardized ileal amino acid digestibility (SID) in 10 and 24-day-old broilers. A nitrogen-free diet was fed to determine ileal endogenous amino acid flow. Each diet was fed for 5 d to 6 replicate cages of 10 or 7 chicks, and ileal samples were collected at 10 and 24 d, respectively. The endogenous flow (mg/kg DM intake) of CP and all amino acids except Cys decreased (P < 0.01) with age. Conditioning temperature by screw torque interactions were detected (P < 0.05) for apparent ileal digestibility (AID) of CP, Arg, Ile, Lys, Phe, Thr, Ala, Asp, Glu, Pro ,and Ser at d 10, and the same trend was observed at d 24 except for Ile, Phe, Ala, and Pro (P > 0.05). Meals processed under medium conditioning temperature (95°C) at either low or high screw torque had the greatest (P < 0.05) AID of CP and total amino acids. The SID values followed a similar pattern as AID at both ages. When corrected for endogenous losses, the average AID of total amino acids improved approximately 3.5 and 2.0 units, at 10 and 24 d, respectively. The AID and SID values increased (P < 0.05) with age for most AA, but the effect of age was not consistent between ECMs. A negative correlation was detected between NDF and neutral detergent-insoluble nitrogen (NDIN) content of the meals and SID values of Lys at d 24 (r = -0.79, r = -0.76; P = 0.001, respectively). Processing conditions affected CP and amino acid digestibility, likely because of alterations to the chemical composition of ECM and formation of indigestible complexes of amino acids with fiber. The AID and SID values increased with age independent of meal processing conditions.

Bioefficacy of a mono-component protease in the diets of pigs and poultry: a meta-analysis of effect on ileal amino acid digestibility

A meta-analysis of the effect of a mono-component bacterial protease (RONOZYME® ProAct) on the apparent ileal digestibility of amino acids in poultry and swine diets was conducted to examine functional patterns, mean effects and variability of response. A total of 25 independently-conducted experiments were included comprising a total of 804 datapoints. The mean response to protease was +3.74% (SE 1.1%, P < 0.001) and this ranged from +5.6% for Thr (SE 1.2%, P < 0.001) to +2.7% for Glu (SE 1.2%, P < 0.05). For the most economically critical amino acids (Lys, Cys, Met and Thr) the mean response was 4.5%. The effect of protease was independent of geography, animal species and diet composition (P > 0.05). However, the inherent digestibility of amino acids in the control diet as a single explanatory term explained around 47% of the variance (P < 0.001) in effect. When the inherent digestibility of amino acids in the control diet was less than 70% protease addition improved amino acid digestibility in 90% of cases with a mean improvement of around 10%. When the inherent digestibility of amino acids in the control diet was more than 90% there was a protease-mediated improvement in digestibility in only 60% of cases with a mean improvement of around 2%. It can be concluded that the inherent digestibility of amino acids in the diet without protease supplementation is the primary explanatory term for the efficacy of this exogenous protease, demonstrating that it is highly effective in improving the digestibility of amino acids across a wide range of feed ingredients. Benchmarking diets or feed ingredients as to their relative nutritional value would enhance the ability of nutritionists to determine the likely return on investment on use of bacterial proteases in their operation.

Comparative amino acid digestibility for broiler chickens and White Pekin ducks

A total of 608 three-week-old male broiler chickens and White Pekin ducks were used in a 5-d trial to compare ileal amino acid (AA) digestibility of soybean meal (SBM) and canola meal (CM) using the regression method. A corn-casein-cornstarch-based diet was mixed to contain 15% CP. Cornstarch was replaced with test ingredient (SBM or CM) to contain 18 or 21% of CP in 4 other diets. A nitrogen-free diet (NFD) was used for standardization of apparent digestibility. Birds received a standard starter diet (23% CP) from d 0 to 14 posthatch and then 6 experimental diets for 5 d. On d 19 posthatch, birds were asphyxiated with CO(2), and digesta from the distal section of ileum was collected. The ileal digestibility of AA from the test ingredients was assessed by multiple linear regression analysis using data on daily apparent ileal digestible AA and total AA intakes. The basal endogenous losses of N and all AA for ducks were significantly higher than those for broilers. For ileal AA digestibility by regression of apparent digestible AA intake against AA intake, there was a higher (P < 0.05) digestibility for Cys and Pro in ducks compared with broilers (P < 0.05). Within species, digestibility was not different between SBM and CM except for Lys of ducks, and Lys and Pro of broilers (P < 0.05). The results of this study showed that ducks have higher basal endogenous AA losses compared with broiler chickens as well as higher ileal Cys and Pro digestibility estimates derived from regression approach, indicating that data obtained from broilers should not be used to formulate diets for ducks.

Ileal digestibility of amino acids in pea protein isolates, wheat-corn distillers dried grains with solubles, and short-season corn fed to broiler chicks

The apparent ileal digestibility (AID) of amino acids (AA) in 4 pea protein isolates [PPI; experiment (Exp.) 1], 5 wheat- and corn-derived distillers grains with solubles (wcDDGS; Exp. 2), and 5 short-season corn (Exp. 3) samples for broiler chickens were determined. In addition, a reference wheat sample was included in each experiment to measure the repeatability of the ileal digestibility assay used. Birds (n = 180 for Exp. 1 and n = 216 for Exp. 2 or 3) were fed test diets from d 15 to 21 of age. Reference wheat and PPI were included in test diets at 91.7 and 25%, respectively, as the sole source of AA, whereas wcDDGS and corn were combined with wheat in test diets at 47.7% test ingredient (wcDDGS or corn) and 51% wheat as the sources of AA. Chromic oxide at 0.3% was added in all diets as the indigestible marker. Each test diet was randomly assigned to 6 cages of 6 male birds each. On d 21, birds were killed and ileal digesta were collected to determine the AID of AA. The mean AID values for indispensable AA ranged from 86.0% (Thr) to 94.7% (Arg) for PPI, 50.7% (Lys) to 79.8% (Leu) for wcDDGS, and 73.9% (Thr) to 95.3% (Arg) for corn. Overall, the CV range for AID of AA was widest for wcDDGS (8.1% for Met to 29.4% for Lys) followed by corn (3.0% for Met to 10.7% for Thr) and then PPI (2.7% for Lys to 6.1% for Thr). For wcDDGS and corn, the within-sample variation (assay condition) was more than between-sample variation (feed differences), whereas the reverse was true for PPI. No differences were detected in the AID of CP and AA for reference wheat among experiments.

Factors that affect the nutritive value of canola meal for poultry

This article reviews the factors affecting the nutritive value of canola meal (CM), including glucosinolates, sinapine, phytic acid, tannins, dietary fiber, and electrolyte balance. It also addresses the means of improving the nutritive value of CM throughout seed dehulling, development of low-fiber canola, or application of feed enzymes. Over the years, the glucosinolate content of canola has been declining steadily and is now only about one-twelfth of that of the older high-glucosinolate rapeseed (that is, 10 vs. 120 μmol/g). Therefore, the rations for broilers or laying hens could now contain 20% of CM without producing any adverse effects. Tannins are of lesser importance due to their presence in the hull fraction and thus low water solubility. Sinapine has been implicated with the production of a "fishy" taint in brown-shelled eggs, which results from a genetic defect among the strain of Rhode Island Red laying hens. The White Leghorns have been reported not to be affected. Although lower in protein, CM compares favorably with soybean meal with regard to amino acid content. Because CM contains more methionine and cysteine but less lysine, both meals tend to complement each other when used together in poultry diets. Canola meal is low in arginine (Arg) which could be of importance when introducing CM to broiler diets at high inclusion rates. The Arg content of CM is approximately two-thirds of that of soybean meal. Chickens fail to synthesize Arg and are highly dependent on dietary sources for this amino acid. Supplementation of Arg to CM-based diets has been shown to partly restore the growth performance. Dietary cation-anion difference in CM is also less than optimal due to the high sulfur and low potassium contents. Seed dehulling has not been very successful due to excessive fineness and thus difficulties with percolation of the miscella through the cake. Development of low-fiber, yellow-seeded canola and the use of enzymes have proven to increase the energy utilization and the nutritive value of CM for poultry.

Interactive effects of age, sex, and strain on apparent ileal amino acid digestibility of soybean meal and an animal by-product blend in broilers

The objectives of this study were to determine if age, sex, and strain of broilers affect the apparent ileal amino acid digestibility (AID) of soybean meal and an animal by-product blend. Chicks from 2 broiler strains, 1 commercially available and the other in the test phase, were obtained from a common hatchery, feather-sexed, and placed into floor pens. The birds received common diets while on floor pens. Birds were transferred to metabolism crates for 2 ileal digestibility trials conducted at 3 and 6 wk of age. Two semipurified diets were formulated with each of the feed ingredients providing all of the amino acids (AA) in the diets. Diets were formulated to contain 20% CP, with chromic oxide added to the diet at 0.30% as the indigestible marker. The experimental diets were fed for a 72-h period after an overnight fast to 8 replicate cages of 5 birds per cage. Upon completion of the experimental periods (i.e., d 22 and 43), birds were euthanized and ileal digesta samples were collected and pooled by pen, frozen, lyophilized, and analyzed for AA and chromium concentrations. For soybean meal, no main effects were observed for age, sex, or strain; however, significant (P ≤ 0.05) 3-way interactions were observed for several dispensable and indispensable AA. Statistical analyses of these interactions indicate the AID of soybean meal may be different for 42-d males of the test strain. For the animal by-product blend, only main effects were significant for each AA, with the exception of Ile and Tyr. Main effect of strain was observed for most of the AA, showing that the commercially available strain had higher AID than the test strain. Also, significant main effect of age indicated that the AID for animal by-product blend was higher at 42 d than at 21 d. Evaluation of these 2 ingredients showed that age, sex, and strain may affect digestibility of feedstuffs and should be considered independently or interactively, for some cases, in future investigations as sources of variation in AA digestibility.

Chemical composition and biological value of spray dried porcine blood by-products and bone protein hydrolysate for young chickens

The chemical composition of spray dried porcine blood by-products is characterised by wide variation in crude protein contents. In spray dried porcine blood plasma (SDBP) it varied between 670-780 g/kg, in spray dried blood cells (SDBC) between 830-930 g/kg, and in bone protein hydrolysate (BPH) in a range of 740-780 g/kg. Compared with fish meal, these feeds are poor in Met and Lys. Moreover, in BPH deep deficits of Met, Cys, Thr and other amino acids were found. The experiment comprised 7 dietary treatments: SDBP, SDBC, and BPH, each at an inclusion rate of 20 or 40 g/kg diet, plus a control. The addition of 20 or 40 g/kg of the analysed meals into feeds for very young chickens (1-28 d post hatch) significantly decreased the body weight (BW) of birds. Only the treatments with 40 g/kg of SDBP and SDBC showed no significant difference in BW as compared with the control. There were no significant differences between treatments and type of meal for feed intake, haematocrit and haemoglobin concentrations in blood. Addition of bone protein and blood cell meals to feed decreased the IgG concentration in blood and caused shortening of the femur and tibia bones. However, changes in the mineral composition of bones were not significantly affected by the type of meal used. The blood by-products, which are rich in microelements, improved retention of Ca and Cu only. In comparison to control chickens, significantly better accretion of these minerals was found in treatments containing 20 g/kg of SDBP or 40 g/kg of SDBC. Great variability in apparent ileal amino acid digestibility in chickens was determined. In this respect, some significant differences related to the type of meal fed were confirmed for Asp, Pro, Val, Tyr and His. In general, the apparent ileal digestibility of amino acids was about 2-3 percentage units better in chickens fed on diets containing the animal by products than in control birds.

Use of spray-dried porcine blood by-products in diets for young chickens

Spray-dried porcine blood plasma (SDBP) or blood cells (SDBC) at amounts of 20 or 40 g/kg were included to the feed mixtures that were given to young chickens within 1-28 (Exp. 1) or 1-30 (Exp. 2) days post-hatch. In comparison with the group fed mixtures containing plant components, chickens fed mixtures supplemented with 40 g/kg of SDBP significantly (p < 0.01) increased the body weight estimated on 14 day of life (Exp. 1). At the age of 28 or 30 days post-hatch, the body weight was improved significantly (p < 0.01 or 0.05) in both experiments. Significant differences (one-factorial anova) in feed conversion among particular feeding groups were stated in Exp. 1 only; however, calculations using two-factorial anova show insignificant differences depending on the used animal meal. In selected blood parameters (IgG, Ht, Hb), insignificant differences between feeding groups were stated. The use of SDBP in feed mixture significantly increased the Na retention in both experiments, and K accretion in Exp. 1 only. Application of SDBC and 40 g/kg of SDBP significantly or insignificantly improved Fe retention. Insignificant diversification of apparent ileal digestibility of nutrients was stated; the crude fat was significantly better digested in treatments fed mixtures with animal meals but kind of animal meal was without any significant effect. Significant differences in digestibility of amino acids were recorded for Pro, Cys, Val, His, Lys and Arg. In chickens fed mixture with SDBC, higher coefficients of apparent digestibility of Cys, Val and His (Exp. 1) and Cys and His (Exp. 2) than in other feeding groups were obtained. The kind of used blood by-products has not affected the histological structure of intestine wall.

Standardized ileal amino acid digestibility in wheat, barley, pea and flaxseed for broiler chickens

Bandegan A., Golian, A., Kiarie E., Payne R. L., Crow G. H., Guenter W. and Nyachoti C. M. 2011. Standardized ileal amino acid digestibility in wheat, barley, pea and flaxseed for broiler chickens. Can. J. Anim. Sci. 91: 103–111. Experiments were conducted to estimate ileal amino acids (AA) digestibility in six wheat (exp. 1; 288 birds), seven barley (exp. 2; 252 birds), five pea (exp. 3; 240 birds) and five flaxseed (exp. 4; 216 birds) samples in male Ross broiler chicks. Wheat, barley and pea were the sole source of dietary AA in exps. 1, 2 and 3, whereas, for exp. 4, flaxseed and wheat (50:50 wt/wt) or wheat provided dietary AA. Chromic oxide was the indigestible marker. Birds were fed chick starter for the first 14 d; on day 15 each test diet was randomly assigned to six cages, each with six (exps. 2 and 4) or eight (exps. 1 and 3) birds. On day 21, birds were killed and digesta were sampled to determine the apparent ileal AA digestibility (AID). The standardized ileal digestibility (SID) values were calculated using ileal endogenous AA losses previously determined in our laboratory from birds fed N-free diet. The mean SID values for indispensable AA ranged from 83.7% (Lys) to 93.8% (Phe), 80.4% (Arg) to 90.9% (Phe), 86.0% (Met+Cys) to 94.2% (Arg) and 47.4% (Thr) to 66.7% (Met) for wheat, barley, peas and flaxseed samples, respectively. Overall, SID AA estimates for flaxseed had higher (> 13%) coefficients of variation (CV) compared with other ingredients (CV<6%). These SID AA data will help nutritionists to formulate broiler diets that more closely match the birds' requirements and minimize nutrient excretion.

Nutritive value of single-screw extruded and nonextruded triticale distillers dried grains with solubles, with and without an enzyme complex, for broilers

The nutritive value of triticale distillers dried grains with solubles (DDGS) for broilers was investigated in 2 experiments. In experiment 1, four hundred male broilers housed in battery cages were fed diets including 15 or 30% triticale DDGS (extruded or not) or a basal diet, supplemented with or without a multi-enzyme complex from d 21 to 28. Birds were killed and ileal digesta was collected on d 28 to establish the apparent ileal nutrient digestibility (AID) coefficients for both assay diets and DDGS as test ingredients based on 5 cages per diet. In experiment 2, a 42-d performance study compared growth phase-specific diets formulated to similar levels of AME, CP, and digestible lysine with graded levels (0, 5, or 10%) of triticale DDGS inclusion based on a minimum of 4 pens per diet x sex combination. Breast muscle weight and percentage yield were determined on d 37 by sampling 5 birds per pen. In experiment 1, there was a significant (P < 0.05) DDGS level of inclusion x enzyme interaction for CP, lysine, methionine, tryptophan, isoleucine, histidine, and phenylalanine, such that the AID increased with enzyme supplementation based on 15% but not 30% DDGS inclusion. At 15% DDGS inclusion, enzyme supplementation increased the AID of these nutrients in DDGS between 6 and 19 percentage units. Extrusion of triticale DDGS increased (P < 0.05) the AID of GE, CP, methionine, tryptophan, branched-chain amino acids, and phenylalanine between 3 and 8 percentage units. In experiment 2, feeding up to 10% triticale DDGS had no adverse effect on feed intake, weight gain, or feed efficiency of broilers compared with controls over the 42-d study. Feeding up to 10% triticale DDGS did not affect breast weight or yield on d 37. In conclusion, feed enzyme complex supplementation and extrusion both increased the nutritive value of triticale DDGS for broilers. Triticale DDGS can be fed at up to 10% of practical broiler diets without adverse effect on performance and breast muscle yield.

Apparent ileal digestibility of amino acids in feedstuffs for White Pekin ducks

The apparent ileal amino acid digestibility of 6 feedstuffs, namely corn, wheat, corn distillers dried grains with solubles, canola meal, soybean meal (SBM), and meat and bone meal (MBM) were determined for White Pekin ducks in a 5-d experiment. The feedstuffs served as the sole source of amino acids in semipurified diets composed of dextrose, soy oil, Solka Floc, minerals, and vitamins, with the exception of corn and wheat, in which both lacked dextrose. The ducks received a standard duck starter diet during the first 14 d posthatch. On d 14, ducks were sorted by weight and allocated to 6 dietary treatments in a randomized complete block design. Each assay diet was fed to 8 replicates (6 ducks/replicate) from d 14 to 19 posthatch. Birds were killed on d 19 and digesta from the terminal ileum were collected. Ileal N digestibility was highest (P < 0.01) in SBM (88.3%) and lowest in MBM (72.4%). Ileal digestibility for all of the amino acids was highest in SBM among the feedstuffs. Lysine digestibility was highest (P < 0.01) for SBM followed by canola meal, corn, wheat, MBM, and distillers dried grains with soluble; the values were 90.3, 79.0, 78.0, 76.8, 75.6, and 69.2%, respectively. Methionine digestibility in SBM was highest (P < 0.01), whereas MBM had the lowest digestibility value for methionine (78.4%). For threonine, SBM (84.0%) had the highest digestibility and corn (61.6%) had the lowest digestibility (P < 0.01), but there were no differences among other feedstuffs. Ileal tryptophan digestibility was between 78.9 (MBM) and 93.0% (SBM). In conclusion, the data from the current study show that there are considerable differences among feedstuffs in the digestibility of their amino acids for ducks. Therefore, it is important to take the digestible amino acid content of feedstuffs into account during feed formulation.

Comparison of amino acid digestibility of feed ingredients in broilers, laying hens and caecectomised roosters

1. This study determined the effect of bird type (broilers, laying hens, or caecectomised roosters) on amino acid digestibility of feedstuffs from 5 plant sources and one animal source. 2. The standardised amino acid digestibility (SAAD) were obtained by correcting apparent ileal amino acid digestibility (AIAAD) values for basal ileal endogenous amino acid (EAA) flow obtained by feeding a N-free diet (NFD) to broilers and laying hens or from fasted EAA flow from caecectomised roosters. 3. The apparent total amino acid (TAA) digestibilities did not differ between broilers and roosters for three of the 6 feed ingredients. 4. Broilers had higher apparent total amino acid (TAA) digestibility than laying hens and roosters when fed on the maize diet (canola meal, maize, and soybean meal). 5. The apparent TAA digestibilities were similar across bird types for the dark distillers' dried grain with solubles, but the apparent lysine digestibility was much lower in the caecectomised roosters (15%) than the broilers (49%) and laying hens (43%). 6. The standardised TAA digestibility values in roosters were higher than in broilers for three of the 6 feed ingredients (canola meal, soybean meal, or meat and bone meal). 7. There were no differences between broilers and roosters, however, in the standardised TAA digestibility values for maize, dark and light DDGS. 8. The standardised TAA digestibility values for laying hens were lower for maize, higher for meat and bone meal, but no different for the remaining ingredients when compared with broilers. 9. The results from this study showed that both the apparent and standardised amino acid digestibility values in caecectomised roosters, laying hens, and broilers ingredients are similar for some, but not all, feed ingredients. 10. Nutritionists should, therefore, be cautious about using digestibility coefficients obtained by different methodologies as values may differ.

Estimation of the metabolizable energy content of meat and bone meal for swine

Experiments were conducted to determine apparent ME (AME) and apparent nitrogen-corrected ME (AME(n)) of 21 meat and bone meal (MBM) samples and to develop regression equations for predicting energy value of MBM. One hundred ninety-eight 32-kg of BW barrows were used for the study. The 22 treatments consisted of 1 corn-soybean meal reference diet and 21 test diets in which 21 MBM samples replaced 100 g/kg of corn and soybean meal such that the ratio of corn and soybean meal was the same in the reference and test diets. The DE, AME, and AME(n) of the MBM samples were determined by the difference method in a metabolism study consisting of 5-d adjustment and 5 d of total collection of feces and urine. On a DM basis, GE of MBM ranged from 3,895 to 5,193 kcal/kg, CP ranged from 491 to 641 g/kg, and ash ranged from 142 to 338 g/kg. The AME of the MBM samples ranged from 2,320 to 3,872 kcal/kg, whereas AME(n) ranged from 2,212 to 3,767 kcal/kg. None of the proximate compositions explained >50% of the variation in energy content of the MBM. Fat was positively correlated with GE, DE, AME, and AME(n) (r < or = 0.44), but CP, ash, Ca, and P were negatively correlated with DE, AME, and AME(n). The ratios of the proximate compositions to each other were correlated with the energy contents of the MBM. Crude protein:fat and GE:fat were negatively correlated with DE, AME, and AME(n) of the MBM (r ranged from -0.17 to -0.39), but fat:ash had the greatest positive correlation with AME and AME(n) compared with other ratios tested. When the data from 1 MBM sample that was an outlier were removed from the analysis, R(2) was 0.42 for AME and AME(n). The 4 variables that produced the best prediction equation for AME and AME(n) were GE, CP, P, and ash. The prediction equation for AME using these variables was AME = 13,587 - (1.25 x GE, kcal/kg) - (3.51 x CP, g/kg) + (30.4 x P, g/kg) - (16.4 x Ash, g/kg), and for AME(n), the equation was AME(n) = 13,547 - (1.25 x GE, kcal/kg) - (3.59 x CP, g/kg) + (31.0 x P, g/kg) - (16.5 x Ash, g/kg). It was concluded from this study that MBM is a good energy source for pigs and that, although other extrinsic factors may contribute to the variations in energy content of MBM, proximate compositions should be sufficient to predict the energy value of MBM for pigs.