Ileal Digestible Amino Acid Content Research Articles

Standardized ileal digestible amino acid contents in flaxseed and flaxseed meals fed to growing–finishing pigs

A total of 10 cannulated barrows with an average body weight of 55.99 ± 3.73 kg were assigned to test diets containing either full-fat flaxseed (FFS), expeller-pressed flaxseed meal (expeller-FM), or solvent-extracted flaxseed meal (solvent-FM). The standardized ileal digestibility (SID) of methionine and threonine was higher (P < 0.05) in FFS than in expeller-FM. Similarly, the SID of crude protein (CP) and threonine was higher (P < 0.05) in FFS than that in solvent-FM. However, expeller-FM and solvent-FM had greater (P < 0.05) contents of SID CP, arginine, leucine, phenylalanine, aspartic acid, glutamic acid, and serine than FFS.

Prediction of the total and standardized ileal digestible amino acid contents from the chemical composition of soybean meals of different origin in broilers

The objective of this experiment was to determine total amino acid (TAA) content, standardized ileal digestibility (SID) of crude protein, and standardized ileal amino acid digestibility in 9 sources of soybean meal (SBM) of different origin and to subsequently establish equations for predicting the TAA content and concentration of standardized ileal digestible amino acids (SIDAA) based on their protein content and other proximate components. Concentration of SIDAA of the samples was also predicted using TAA values. A total of 160 1-day-old male broiler chicks were randomly assigned to 10 dietary treatments consisted of 9 semipurified diets containing one SBM (200 g of crude protein/kg) as the only source of dietary amino acid (AA) and one N-free diet to determine endogenous ileal AA flow. The birds were fed with a standard diet from 0 to 18 D of age, and experimental diets were fed from 19 to 24 D of age. The fitness of the models of the study was tested using the adjusted coefficient of determination (R2) value, P-value regression and coefficients, and standard error of prediction (SEP). The coefficient of SID for Lys and Cys among SBM varied from 86.7 to 96.3 and 74.1 to 89.3, respectively, with significant difference (P < 0.05). In equations based on protein content, the adjusted R2 value ranged from 40.7 (Ile) to 99.6 (Met) and 37.2 (Met + Cys) to 99.6 (Met) for TAA content and concentration of SIDAA, respectively. Inclusion of other proximate components of test samples (e.g., crude fiber, neutral detergent fiber, acid detergent fiber, ash, gross energy, and so on) into the regression equation increased the adjusted R2 value and decreased the SEP. The results of linear regression revealed that it is possible to satisfactorily estimate the TAA content and concentration of SIDAA of SBM through its protein content and other proximate components, but the prediction equations based on other proximate components were more accurate in terms of reflecting the measured results; however, additional time and costs were associated with this approach. It is also possible to estimate the concentration of SIDAA through TAA values with reasonable accuracy and lower SEP.

Relationship between chemical composition and standardized ileal digestible amino acid contents of corn grain in broiler chickens

This experiment was conducted to evaluate the chemical composition and standardized ileal amino acid digestibility of corn grain and to use these data to develop prediction equations for estimating total amino acids (TAAs) and standardized ileal digestible amino acids (SIDAAs) for broiler chickens. Four types of corn grains were obtained from different origins (Brazil, Ukraine, Russia, and Iran). Eighty-day-old Ross 308 male broiler chicks were fed a standard diet until day 18, and experimental diets were fed from 19 to 24 D of age. Five dietary treatments consisted of 4 semi-purified diets containing corn from each origin as the only source of amino acid (AA) and a N-free diet for determination of basal endogenous AA losses. Assay diets contained 939 g of test corn/kg. The concentration of crude protein and gross energy ranged from 7.58 to 8.39% (coefficient of variation [CV] = 4.72%) and 4,121 to 4,621 kcal/kg (CV = 5.09%), respectively. There was significant variation among the 4 corn grains in standardized ileal digestibility (SID) for CP, Phe, Leu, Asp, Glu, Ser, Gly, Ala, and Tyr (P ≤ 0.05). The results of linear regression showed that linear prediction equations based on protein content can be used to predict the TAA and SIDAA contents (e.g., TLys = 0.041 × CP, adj R2 = 95.9, standard error of prediction [SEP] = 0.05; SIDLys = 0.0356 × CP, adj R2 = 96, SEP = 0.051). Inclusion of other proximate components of test samples into the regression equation increased the R2 value and decreased the SEP value (e.g., TLys = 0.329 × crude fiber [CF] ‒ 0.209 × Ash, adj R2 = 99.9, SEP = 0.005; SIDLys = ‒1.1591 + 0.836 × CF ‒ 0.055 × Ash, adj R2 = 99.9, SEP = 0.001). The concentration of TAA and SIDAA was highly correlated (adj R2 > 89%) for most AA and showed that the amount of SIDAA could be predicted from its total concentration with a high degree of accuracy (e.g., SIDLys = 0.0023 + 0.861 × TLys, adj R2 = 99.9, SEP = 0.0001). In conclusion, this in vitro assays and equations accurately predicted TAA and SIDAA corn grain samples for broiler chickens and can serve as a reference analysis to develop calibration equations for rapid feed quality evaluation methods such as near-infrared reflectance spectroscopy.

Evaluation of energy and amino acids of brown rice and its effects on laying performance and egg quality of layers.

Two experiments were conducted to determine apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and ileal digestible amino acid (AA) content of brown rice (BR) and to investigate the effect of dietary supplementation of BR on laying performance and egg quality of laying hens. In Exp. 1, 72 Hy-line Brown layers (49-week-old) were allocated to two treatments using a completely randomized block design, and each treatment included six cages per treatment and six hens per cage. A semi-purified diet was formulated to include BR as the sole source of AA and energy and an N-free diet was used to determine basal endogenous loss of AA. The hens were fed a commercial layer diet for adaptation to the experimental environment and diet for 7 days from d 0, and then fed experimental diets for 5 days from d 7. Excreta were collected from d 10 to 11 and ileal digesta were collected on d 12. On a dry matter (DM) basis, the AME and AMEn of BR was determined at 3,773 and 3,729 kcal/kg, respectively. The apparent ileal digestibility (AID) of BR ranged from 32.7% for Thr to 73.7% for Arg. The range of the standardized ileal digestibility (SID) value was between 79.4% for Met and 96.6% for Lys. In Exp. 2, 252 Hy-line Brown layers (44-week-old) were divided into four groups, comprising seven replicates of nine birds each and assigned to four experimental diets containing 0 (Control), 5%, 10%, or 15% BR for 5 weeks. The BR-containing diets were formulated to be equal in the content of AMEn and digestible AA to those of the diet without BR. No significant differences were observed in laying performances. Egg quality and blood profiles were not linearly or quadratically affected by dietary treatments. These results suggest that up to 15% BR can be included into layer feed without any adverse effects on laying performance and egg quality, if its energy and digestible AA values are well evaluated.

Effects of feeding high-protein corn distillers dried grains and a mycotoxin mitigation additive on growth performance, carcass characteristics, and pork fat quality of growing-finishing pigs.

Two experiments investigated the effects of feeding diets containing 30% of novel high-protein distillers dried grains (HP-DDG) sources to growing–finishing pigs on growth performance, carcass characteristics, and pork fat quality. A four-phase feeding program was used in both experiments, and diets within phases were formulated based on National Research Council (NRC; 2012) recommendations for metabolizable energy and standardized ileal digestible amino acid content of HP-DDG. In Exp. 1, a total of 144 pigs (body weight [BW] = 20.3 ± 1.6 kg) were fed either corn-soybean meal control diets (CON) or 30% HP-DDG diets (HP-DDG) containing 0.7 mg/kg deoxynivalenol (DON), 0.1 mg/kg fumonisins (FUM), and 56 μg/kg zearalenone (ZEA) for 8 wk. On week 9, a mycotoxin mitigation additive (MA) was added to CON and HP-DDG diets, resulting in a 2 × 2 factorial arrangement of treatments consisting of: CON, CON + MA, HP-DDG, and HP-DDG + MA. Pigs fed HP-DDG had lower (P < 0.01) average daily gain (ADG) and average daily feed intake (ADFI) compared with those fed CON during the first 8 wk. After MA was added to diets, pigs fed HP-DDG diets without MA had lower (P < 0.05) overall ADG than those fed HP-DDG + MA and less (P < 0.05) final BW than pigs fed CON or CON + MA. Adding MA to HP-DDG diets containing relatively low concentrations of mycotoxins was effective in restoring growth performance comparable to feeding CON. In Exp. 2, a different source of HP-DDG was used, and mycotoxin MAs were added to all diets at the beginning of the trial. A total of 144 pigs (BW = 22.7 ± 2.3 kg) were fed either a corn-soybean meal control diet or a 30% HP-DDG diet containing 0.5 mg/kg DON and 0.8 mg/kg FUM for 16 wk. Pigs fed HP-DDG diets had less (P < 0.01) final BW and ADG than pigs fed CON, but there were no differences in ADFI. Feeding the HP-DDG diets reduced (P < 0.01) hot carcass weight, carcass yield, longissimus muscle area (LMA), and percentage of carcass fat-free lean compared with pigs fed CON but did not affect backfat (BF) depth. Pigs fed HP-DDG had less (P < 0.01) saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) content and greater (P < 0.01) polyunsaturated fatty acid (PUFA) and iodine value in BF than pigs fed CON. These results suggest that feeding diets containing relatively low concentrations of co-occurring mycotoxins can be detrimental to growth performance, and the addition of MA alleviated the growth reduction. Feeding 30% HP-DDG reduced BW, ADG, carcass yield, LMA, and percentage of fat-free lean of growing–finishing pigs but yielded acceptable pork fat quality.

Standardized ileal digestible amino acid and metabolizable energy content of wheat from different origins and the effect of exogenous xylanase on their determination in broilers

This study was conducted to determine the standardized ileal digestible amino acids (SID AA) and nitrogen-corrected apparent metabolizable energy (AMEn) contents of 6 wheats from different origins in China and incidentally to investigate the effects of exogenous xylanase addition on SID AA and AMEn determination in broiler chicks. A total of 480 chicks were divided into 48 cages of 10 birds each balanced for body weight and fed 8 types of diets in a completely randomized design (6 replicated cages per diet) from 21 to 26 d of age. The individual wheat constituted the only source of crude protein in a semi-purified experimental diet. A nitrogen-free diet was designed to estimate basal endogenous AA loss and determine the SID AA. Titanium oxide (0.3%) was used as an indigestibility marker, and nutrient digestibility and retention were determined by the substitution method. From day 24 to 26, excreta samples were collected for AMEn determination. On day 26, the birds were euthanized, and ileum contents were obtained for AA digestibility determination. Wheat from Gansu had greater (P < 0.05) SID AA contents except Lys, Thr, Phe, and Cys, with a higher (P < 0.001) AMEn (11.83 MJ/kg) than the other wheats. The SID content of mean indispensable amino acids and dispensable amino acids were 87.35% and 88.17%, respectively, and the average AMEn value of 6 wheats was 11.14 MJ/kg. Compared with the diet without xylanase, the added xylanase resulted in higher (P < 0.05) SID contents of Met, Lys, Trp, Arg, Ile, Leu, Val, Gly, Asp, Glu, Pro, and Ala; the SID AA values were raised by 1.96% (mean of all AA); and the AMEn content was significantly increased (+0.87 MJ/kg) (P < 0.05). In conclusion, origins of wheats have significant effects on SID AA and AMEn values which were positively correlated with crude protein content of wheat; exogenous xylanase addition to a wheat-based poultry diet could significantly improve SID AA and AMEn contents for broilers.

Energy values and standardized ileal digestibility of amino acids in some feedstuffs for broilers

The objective of this study was to determine the energy values, standardized ileal digestibility coefficients and digestible amino acid contents of parboiled brown rice bran (PBRB), protein sorghum meal (PSM) and bread waste meal (BWM) in broiler diets. In the first trial, 144 broiler chicks at 14 days of age were evaluated in a completely randomized design involving three feedstuffs + a control diet, with six replicates and six birds per experimental unit. The total excreta collection method was adopted to determine the energy values of the feedstuffs. In the second trial, 144 broilers at 24 days of age were used in a completely randomized design involving three feedstuffs + a protein-free diet, with six replicates and six birds per experimental unit. Ileal digesta was harvested to determine the standardized ileal digestibility coefficients and digestible amino acid contents of the feedstuffs. The nitrogen-corrected apparent metabolizable energy (AMEn) values of PBRB, PSM and BWM were 2638, 2799 and 3399 kcal.kg-1, respectively. The metabolizability coefficients of AMEn (CAMEn) of PBRB, PSM and BWM were 54.13, 57.35 and 86.66%, respectively. Bread waste meal had the highest CAMEn (p &lt; 0.05) and standardized ileal digestibility of amino acids (p &lt; 0.01), followed by PBRB and PSM. The main limiting digestible amino acids in PBRB, PSM and BWM were found at the following respective levels: methionine - 0.19, 0.33 and 0.24%; lysine - 0.40, 0.46 and 0.40%; threonine - 0.25, 0.50 and 0.45%; and valine - 0.44, 0.73 and 0.48%.

Cooking Conditions Affect the True Ileal Digestible Amino Acid Content and Digestible Indispensable Amino Acid Score (DIAAS) of Bovine Meat as Determined in Pigs

Cooking processes affect the physical, chemical, and structural properties of meat proteins. Cooking may also affect the protein quality of meat, as indicated by the true ileal digestibility of individual amino acids, the content of each truly digestible amino acid, and the digestible indispensable amino acid score (DIAAS). The study aimed to determine the effect of the cooking process (raw, not cooked; boiled; grilled; pan-fried; roasted) of beef on true (standardized) ileal amino acid digestibility, true ileal digestible amino acid content, and DIAAS. Beef topside steak was subjected to one of the following conditions: raw, boiled, grilled, pan-fried, or roasted, followed by mincing. The growing pig was used as an animal model for the adult human. Diets containing the raw or cooked meats (10% crude protein content) were fed to growing pigs (n=6 per diet; mean±SEM bodyweight, 23.6±0.48 kg) and samples of terminal ileal digesta were collected under anesthesia. True ileal amino acid digestibility of the beef was determined and DIAAS values were calculated. There were only minor differences in true ileal amino acid digestibility across cooking conditions with all amino acids having true ileal amino acid digestibility in the range of 90-100%. In general, boiled meat had the highest true ileal digestible amino acid content (total of 724 g/kg dry matter), and roasted meat the lowest (total of 641 g/kg dry matter; P<0.001). The DIAAS was greater (P<0.001) for the raw, boiled, and pan-fried meat treatments (97-99%) than for roasted meat (91%) or grilled meat (80%). The high DIAAS (range 80-99%) across cooking conditions confirms that bovine meat is a high-quality protein source. Cooking conditions affect the true ileal digestible amino acid content and DIAAS of beef, as determined with the use of the pig model.

Metabolizable energy and standardized ileal digestible amino acid contents of a high-protein sunflower meal fed to broiler chicks

This study was conducted to determine the standardized ileal digestible amino acid (AA) and nitrogen-corrected apparent metabolizable energy (AMEn) contents of a high-protein sunflower meal (HiSFM) fed to broiler chicks. A total of 144 broiler chicks were randomly allotted to one of three dietary treatments with eight replicate cages of six birds. Birds were fed the experimental diets from day 14 to day 21 of age. The results showed that gross energy, crude protein, nonphytate phosphorus, lysine (Lys), methionine (Met), threonine (Thr), and total nonstarch polysaccharide contents of HiSFM were 4178 kcal kg−1, 48.7%, 0.86%, 1.59%, 0.75%, 1.45%, and 14.6%, as-fed basis, respectively. The standardized ileal digestible Lys, Met, and Thr of HiSFM were 12.6, 6.8, and 11.6 g kg−1(dry matter basis), respectively. In addition, the AMEncontent of HiSFM fed to broiler chicks was 1785 kcal kg−1. In conclusion, compared with literature values for sunflower meal, HiSFM had lower standardized ileal digestibility of indispensable AA and higher AMEncontent. The standardized ileal digestible AA and AMEnvalues of HiSFM obtained from the current study could be used when formulating poultry diets and to obtain predictable bird performance.

Influence of mild feed restriction and mild reduction in dietary amino acid content on feeding behaviour of group-housed growing pigs

This study investigates changes in the feeding behaviour of pigs as a result of a restriction in their feed allowance and a reduction in dietary indispensable amino acid (AA) content. Ninety-six Topig Talent×PIC barrows were housed in 8 pens and individually fed either ad libitum (AL) or a restricted diet (RF) from 47 to 145kg body weight (BW). The amount of feed given to RF pigs was close to their expected voluntary intake, but it was limited to proportions of 0.33, 0.66 and 1.00 of the estimated daily amount of feed in 3 time intervals, 00:01 to 8:00, 8:01 to 16:00 and 16:01 to 24:00h, respectively. From 86kg BW, the pigs in 4 of the pens were fed diets with conventional standardized ileal digestible AA content (CAA), while the pigs in the other pens received diets (LAA) in which the proportions of dietary indispensable AA were lowered with respect to CAA by 0.91 from 86 to 118kg BW and by 0.82 from 118 to 145kg BW. Automated feeders monitored individual feeding behaviour. Data were analysed by pig and feeding phase with a 2×2 factorial design. Over the whole experimental period, feed restriction resulted in a decrease in daily feed intake (7%, P <0.001), the number of visits (27%, P <0.001) and the time spent feeding (14%, P <0.001), but an increase in feed consumption per visit (20%, P=0.001) and feeding rate (10%, P=0.032). The reduction in AA increased daily feed intake (7%, P=0.031), tended to increase feeding rate (14%, P=0.07) and interacted with feeding regime with respect to the number and duration of feeding visits. During growing and finishing, we observed high, negative, non-linear relationships between feed consumption per visit and visit frequency (R2=0.989 to 0.876), between visit duration and visit frequency (R2=0.648 to 0.695), and between feeding rate and time spent feeding in a day (R2=0.802 to 0.707), and positive linear relationships between visit duration and feed consumption per visit (R2=0.614 to 0.570). The individual feeding rate during growing was positively correlated with that during finishing (R2=0.458). We conclude that pigs try to adapt their feeding pattern to compensate for a reduction in feed allowance or nutrient restriction by, for example, increasing their feeding rate, which may reflect increased feeding motivation.

Starter and subsequent grower response of Pekin ducks to low-protein diets in starter phase

A dose-response experiment was conducted to investigate the effects of feeding 6 starter diets containing the analyzed crude protein (CP) contents (168.6, 178.9, 184.2, 192.0, 195.8, and 203.3g/kg) from d 1–19 on growth performance and carcass traits of starter Pekin ducks and the subsequent growth performance and carcass traits of ducks fed a common grower diet from d 20–35. The 480 one-d-old male White Pekin ducks were divided to 6 experimental treatments and each treatment had 8 replicate pens of 10 ducks. All starter experimental diets were formulated to contain similar dietary energy concentration and standardized ileal digestible amino acid contents. At d 19 and 35, the growth performance of each pen were determined and 2 ducks were randomly selected from each pen and harvested to evaluate carcass traits. During the starter period, as dietary CP decreased from 203.3 to 168.6g/kg, the body weight, weight gain, and feed intake were not affected but feed/gain increased linearly (P = 0.017). According to broken-line regression, the 196.8g/kg was the minimum dietary CP requirement necessary to obtain the optimal feed/gain during the starter period. Moreover, the breast meat percentage of starter ducklings was not influenced by reducing dietary CP, but the leg meat percentage decreased linearly (P = 0.024) and abdominal fat percentage increased linearly (P = 0.018). During the grower period from d 20–35, the protein restriction during the starter phase had no negative effects on the subsequent growth performance from d 20–35 or carcass traits at d 35. It was concluded that reducing dietary CP had negative effects on the performance of starter ducks but the protein restriction during the starter phase had no adverse effects on the overall performance of grower Pekin ducks.

Standardized ileal digestible amino acid contents of canola meal from Canadian crushing plants for growing pigs.

Studies have shown that there are variations in the chemical and nutritive composition of canola meal (CM) produced in Canada, some of which may result from differences among the canola seed crushing plants. Therefore, it is necessary to determine the variability in the nutritive value of CM as its end users desire increased meal consistency and more information on any potential variability in AA digestibility. Thus, 18 ileal cannulated barrows (average initial BW = 23.3 kg) were used to determine the apparent (AID) and standardized (SID) ileal digestibility of N and AA and standardized ileal digestible N and AA contents in CM from 6 processing plants in Canada. Two processing plants provided CM in both mash and pellet forms, whereas the other 4 provided it only in mash form, giving a total of 8 CM samples. The barrows were fed 9 cornstarch-based diets. The first 8 diets were formulated to contain the CM samples as the only source of AA. The ninth diet was a casein-cornstarch diet to determine ileal endogenous AA losses. All diets contained 0.3% titanium dioxide as an indigestible marker. Pigs were housed individually in pens and were fed the 9 diets in a completely randomized design for 3 periods to give 6 pigs per diet. Each experimental period lasted for 7 d, consisting of 5 d of adaptation and 2 d of ileal digesta collection at 2-h intervals from 0800 to 2000 h on d 6 and 7. There was an effect ( < 0.05) of CM source on 1) the AID of N, Met, Cys, Thr, Val, Gly, and Ser; 2) the SID of N, Met, and Cys; and 3) the standardized ileal digestible content of all AA. Pelleting reduced ( < 0.05) the standardized ileal digestible content of Arg, Ile, Glu, and Gly in 1 of the CM samples tested and of all AA except His in the other CM sample. The SID values for Arg, Lys, Met, and Thr averaged 87.2%, 78.2%, 84.5%, and 74.1%, respectively. The standardized ileal digestible contents of Arg, Lys, Met, and Thr averaged 2.10%, 1.71%, 0.50%, and 1.01%, respectively. In conclusion, there were variations in the AID, SID, and standardized ileal digestible AA contents of CM among crushing plants in Canada.

Standardized ileal digestible amino acid contents of canola meal from Canadian crushing plants for growing pigs

Standardized ileal digestible amino acid contents of canola meal from Canadian crushing plants for growing pigs

Effects of Origins of Soybean Meal on Growth Performance, Nutrient Digestibility and Fecal Microflora of Growing Pigs

This experiment was conducted to investigate the effects of soybean meal (SBM) of different origin (Korea, India or Brazil) on performance, fecal microflora and economics of grower pigs. A total of 144 grower pigs (initial BW, 10.4 kg) were randomly allotted to six treatments on the basis of BW. Pig's diets containing SBM were formulated based on the total amino acid (TAA) or true ileal digestible amino acid (TIDAA) levels. Pigs fed domestic SBM diets had greater (p<0.05) overall ADG, ADFI and final body weight and apparent total tract digestibility (ATTD) of DM, GE and CP (phases I, II and III) than those fed diets containing SBM originated from India or Brazil. Moreover, greater (p<0.05) ADG, ADFI, feed /gain (F/G), and ATTD of DM, GE and CP were observed in response to diets formulated on a TIDDA basis when compared with those formulated on a TAA basis. The fecal microflora was not affected (p>0.05) by dietary treatments. The overall feed cost per kg body weight gain was less (p<0.05) for diets formulated using domestic SBM than for those containing SBM from India, while the feed cost per kg body weight gain was less (p<0.05) for diets formulated prepared on a TIDAA than a TAA basis. These results indicate that domestic SBM has better quality than SBM imported from Brazil or India and better performance was obtained when diets were formulated based on the true ileal digestible amino acid (TIDAA) content.

Gross and true ileal digestible amino acid contents of several animal body proteins and their hydrolysates

Amino acid compositions of ovine muscle, ovine myofibrillar protein, ovine spleen, ovine liver, bovine blood plasma, bovine blood globulins and bovine serum albumin and the amino acid compositions and in vivo (laboratory rat) true ileal amino acid digestibilities of hydrolysates (sequential hydrolysis with Neutrase, Alcalase and Flavourzyme) of these protein sources were determined. True ileal amino acid digestibility differed (P<0.05) among the seven protein hydrolysates. The ovine myofibrillar protein and liver hydrolysates were the most digestible, with a mean true ileal digestibility across all amino acids of 99%. The least digestible protein hydrolysate was bovine serum albumin with a comparable mean true ileal digestibility of 93%. When the digestible amino acid contents were expressed as proportions relative to lysine, considerable differences, across the diverse protein sources, were found in the pattern of predicted absorbed amino acids.

Prediction of digestible and metabolizable energy content and standardized ileal amino Acid digestibility in wheat shorts and red dog for growing pigs.

Two experiments were conducted to evaluate the effects of chemical composition of wheat shorts and red dog on energy and amino acid digestibility in growing pigs and to establish prediction models to estimate their digestible (DE) and metabolizable (ME) energy content and as well as their standardized ileal digestible (SID) amino acid content. For Exp. 1, sixteen diets were fed to thirty-two growing pigs according to a completely randomized design during three successive periods. The basal diet was based on corn and soybean meal while the other fifteen diets contained 28.8% wheat shorts (N = 7) or red dog (N = 8), added at the expense of corn and soybean meal. Over the three periods, each diet was fed to six pigs with each diet being fed to two pigs during each period. The apparent total tract digestibility (ATTD) of energy in wheat shorts and red dog averaged 75.1 and 87.9%. The DE values of wheat shorts and red dog averaged 13.8 MJ/kg (range 13.1 to 15.0 MJ/kg) and 15.1 MJ/kg (range 13.3 to 16.6 MJ/kg) of dry matter, respectively. For Exp. 2, twelve growing pigs were allotted to two 6×6 Latin Square Designs with six periods. Ten of the diets were formulated based on 60% wheat shorts or red dog and the remaining two diets were nitrogen-free diets based on cornstarch and sucrose. Chromic oxide (0.3%) was used as an indigestible marker in all diets. There were no differences (p>0.05) in SID values for the amino acids in wheat shorts and red dog except for lysine and methionine. Apparent ileal digestibility (AID) and SID values for lysine in different sources of wheat shorts or red dog, which averaged 78.1 and 87.8%, showed more variation than either methionine or tryptophan. A stepwise regression was performed to establish DE, ME and amino acid digestibility prediction models. Data indicated that fiber content and amino acid concentrations were good indicators to predict energy values and amino acid digestibility, respectively. The present study confirms the large variation in the energy content and amino acid digestibility in wheat shorts and red dog, and describes the factors that influence this variation and presents equations based on chemical composition that could probably be used to predict the DE and ME values as well as the amino acid digestibility of wheat shorts and red dog.

Metabolizable energy and standardized ileal digestible amino acid contents of expeller-extracted canola meal fed to broiler chicks

An experiment was conducted to determine the standardized ileal digestible amino acid (AA) and AMEn contents of expeller-extracted canola meal (EECM) fed to broiler chicks. One hundred forty-four broiler chicks were divided into 24 groups of 6 birds balanced for BW and fed 4 diets in a completely randomized design (6 groups per diet) from d 14 to 21 of age. The diets were a corn-soybean meal-based basal diet formulated to meet NRC nutrient requirements, the basal diet with energy- and AA-yielding ingredients replaced by 30% of either solvent-extracted canola meal (SECM) or EECM, and a low-protein casein-cornstarch-based diet. The SECM, which is commonly used in formulating poultry diets, was fed for comparison with EECM, whereas the casein-cornstarch-based diet was fed to estimate basal endogenous AA losses for determining standardized ileal digestibility of AA. All 4 diets contained titanium oxide (0.3%) as an indigestible marker, and nutrient digestibility and retention were determined by the substitution method. From d 19 to 21, excreta samples were collected for AMEn determination. On d 21, the birds were killed by cervical dislocation, and contents of the whole ileum were obtained for determination of AA digestibility. Expeller-extracted canola meal had greater (P<0.05) standardized ileal digestible contents of Gly, Leu, Ser, Thr, Asp, and Glu and tended to have greater (P<0.10) standardized ileal digestible contents of Ile, Lys, Phe, Ala, and Tyr than SECM. Compared with SECM, EECM had greater (P<0.001) AMEn (2,694 vs. 1,801 kcal/kg). The results show that the EECM evaluated in the current study had greater standardized ileal digestible AA and AMEn contents than SECM, and hence, it may be a better source of protein and energy for broiler chicks than SECM. The standardized ileal digestible AA and AMEn values of EECM used in the current study could be used when formulating broiler chicken diets using the same to minimize the N excretion and feeding cost.

Decreasing dietary particle size of lupins increases apparent ileal amino acid digestibility and alters fermentation characteristics in the gastrointestinal tract of pigs

Two experiments were conducted to examine the effects of lupin particle size on amino acid (AA) and energy digestibility and fermentation characteristics in pigs. Expt 1 examined the effects of lupin variety (cv. Tanjil and Mandelup) and lupin particle size (746, 888, 1099 and 1136 mum) on the total-tract apparent digestibility of dietary components in 63.5 (sd 7.28) kg pigs. While variety had no effect on total-tract apparent digestibility, decreasing particle size of lupins linearly increased total-tract apparent digestibility of crude protein of diets containing 350 g lupins per kg (P < 0.01). Expt 2 examined the effect of lupin particle size (567, 995, 1198, 1250 and 1304 mum) on digestion and fermentation characteristics in 29.8 (sd 2.9) kg pigs. Pigs were fed the respective diets ad libitum for the first 2 weeks and fed at three times maintenance energy level in the third week. Pigs were euthanised under sedation at 46.7 (sd 4.21) kg to collect digesta samples along the intestinal tract. Decreasing particle size increased apparent ileal and total-tract digestible N (P < 0.01) and the apparent and standardised ileal digestible AA content (P < 0.05- < 0.001) of lupins. Decreasing particle size of lupins linearly decreased the molar proportion of straight-chain volatile fatty acids (sum of acetic, propionic and butyric acids; VFAAPB), while branched-chain fatty acids (sum of valeric, caproic, isobutyric and isovaleric acids) were linearly increased (P < 0.001). The results demonstrated that particle size of lupins is a critical factor influencing nutrient, especially AA, utilisation efficiency and fermentation characteristics in the gastrointestinal tract of pigs.

Chemical composition and standardised ileal digestible amino acid contents of Lathyrus ( Lathyrus cicera) as an ingredient in pig diets

Lathyrus cicera is a grain legume that is well adapted to grow in low rainfall regions. However, it contains a neurotoxin, 3-(- N-oxalyl)- l-2,3-diaminopropionic acid (ODAP), which can cause paralysis of the lower limbs, known as “lathyrism”. An experiment was conducted to measure the nutrient content and ileal digestible amino acid content of a recently-released low ODAP Lathyrus variety chalus. Chemical analyses and total tract digestibility showed that the new Lathyrus variety chalus contained 0.9 g ODAP/kg, 265 g crude protein/kg and 13.5 MJ digestible energy/kg on an as-fed basis. The ileal digestible nutrient content of chalus was measured with six grower pigs (Large White×Landrace, 43 ± 0.3 kg) fitted with a simple T-piece cannula. The chalus contained 12.9, 1.4 and 5.4 g of apparent ileal digestible lysine, methionine and threonine, respectively/kg. Standardised ileal digestible amino acid content was calculated using published endogenous amino acid losses determined in 34-kg-growing pigs under a protein-free method. The chalus contained 14.3, 1.5 and 6.0 g of standardised ileal digestible lysine, methionine and threonine, respectively/kg.

Source of the Variation in Meat and Bone Meal Nutritional Quality

The gross composition, gross amino acid content, apparent ileal amino acid digestibility and apparent ileal digestible amino acid content from 64 commercially produced meat and bone meals were statistically analysed. The samples were produced by 22 plants over a 2.5 year period with eight plants using batch dry rendering and 14 plants using low temperature rendering. A linear model with method and time of year (period) as fixed effects, plant within method as a random effect and sheep percent as a covariate was fitted to the composition data. The majority of the variation in the gross composition, amino acid digestibility and digestible amino acid content was explained by differences between plants using the same method. Neither rendering season nor origin of the raw materials contributed significantly to the observed variation in meat and bone meal protein quality. Rendering method (low temperature or batch rendering) had a significant effect on the variation observed in gross fat content, gross energy content, pepsin nitrogen digestibility, protein solubility and total lanthionine content. The digestibility of a number of amino acids and the apparent digestible content of arginine, cysteine, aspartic acid, proline and hydroxyproline were also significantly affected by rendering method. On average, batch dry and low temperature rendering systems produce meat and bone meals of similar nutritional quality. The variation between plant and within plant, however, is large, indicating that purchasing meat and bone meal from the same plant does not guarantee a consistent quality.