Apparent Amino Acid Digestibility Research Articles

Comparison of Corn Ethanol Co-products from Brazil and USA Apparent and Standardized Ileal Digestibility of Amino Acids in Pigs

Abstract The objective of this study was to determine the apparent and standardized ileal digestibility (AID and SID) of crude protein (CP) and amino acids (AA) of a corn distillers dried grains with solubles (DDGS) from USA (UDG), a corn bran with solubles from Brazil (CBS) and high protein corn distillers dried grains from USA and Brazil (UHP and BHP), in growing pigs. Fifty crossbred barrows (46.2±5.3kg) were fed a semi-purified N-free diet, used to determine endogenous N losses, or four diets composed of 40% of each ingredient, as the only source of N, substituting for cornstarch in N-free diet. Animals were fed at 2.8 x maintenance (110 kcal of DE per kg of BW0.75) for 9 d and on the 10th d were euthanized for ileal digesta collection. TiO2 was used as an indigestible marker (0.3%) for digestibility calculations. A randomized block design was used, with 10 replicates, using the pig as the experimental unit, and results submitted to orthogonal contrast test. The CBS, UDG, BHP and UHP contained (as-fed basis) 13.9, 25.8, 42.9 and 34.9% CP; 9.0, 6.4, 10.3 and 7.3% EE; 40.8, 40.2, 32.7 and 47.5% NDF; 4.51, 4.53, 5.30 and 4.90 Mcal/kg GE; and 0.40, 0.73, 1.37 and 1.00% Lys, respectively. The AID of CP, Arg, His, Ile, Leu, Lys, Thr and Val; and the SID of His, Leu, Lys, and Val of BHP were 8 to 36% greater (P < 0.05) than those from UHP. The AID of CP, Arg, Ileu, Leu, Phe, Thr, and Trp; and SID of CP, Arg, Phe, and Thr of UDG were 9 to 45% greater (P < 0.05) than those of CBS. In conclusion, BHP had a greater digestibility of most AA than UHP, while the CBS evaluated had lower nutritional value than the UDG source.

Nutrient digestibility of extruded canola meal in ileal-cannulated growing pigs and effects of its feeding on diet nutrient digestibility and growth performance in weaned pigs

Canola meal (CM) contains less crude protein (CP) and more fiber and anti-nutritional factors such as glucosinolates than soybean meal (SBM) and consequently has a lower nutrient digestibility. Therefore, processing strategies that may increase the feeding value of CM warrant study. In two experiments, the effects of extrusion of Brassica napus CM on apparent (AID) and standardized ileal digestibility (SID) of amino acids (AA), apparent total tract digestibility (ATTD) of gross energy (GE) in growing pigs, and growth performance and diet digestibility in weaned pigs were assessed. Solvent-extracted CM was extruded using a single-screw extruder at three screw speeds: 250 (CM-250), 350 (CM-350), or 450 (CM-450) rpm. In exp. 1, in a double 4 × 4 Latin square, eight ileal-cannulated barrows (initial body weight [BW], 68.1 kg) were fed corn starch-based diets containing 50% CM or extruded CM. The CM sample contained 43.2% CP, 33.2% total dietary fiber (TDF), and 8.9 µmol of total glucosinolates/g on a dry matter (DM) basis. Extrusion increased (P < 0.05) the AID of CP, reduced (P < 0.05) apparent hindgut fermentation of CP, and decreased (P < 0.05) predicted net energy (NE) value of diets. Extrusion increased diet AID and CM SID of most indispensable AA by 3.1 to 5.3%-units. In exp. 2, 200 weaned pigs (initial BW, 8.3 kg) were fed diets containing 20% SBM, CM, or extruded CM starting 2 wk postweaning for 3 wk. The CM sample contained 42.7% CP, 28.3% TDF, and 5.3 µmol total glucosinolates/g DM. Wheat-based diets provided 2.3 Mcal NE/kg and 5.1 g SID Lys/Mcal NE. Dietary inclusion of extruded CM replacing SBM decreased (P < 0.05) diet ATTD of DM, GE and CP, and DE value. Average daily feed intake, average daily gain (ADG), and gain:feed (G:F) of pigs did not differ between extruded CM and SBM diets and were not affected by extrusion, but increasing extruder screw speed linearly increased (P < 0.05) ADG for day 1 to 7 and G:F for the entire trial. In conclusion, extrusion increased diet AID and CM SID of AA but not DE and predicted NE values of CM. However, increasing extruder speed did not further increase the SID of most of the AA of CM in growing pigs. Dietary inclusion of 20% CM or extruded CM did not affect the growth performance in weaned pigs.

Effects of spray dried yeast (Saccharomyces cerevisiae) on growth performance and carcass characteristics, gut health, cecal microbiota profile and apparent ileal digestibility of protein, amino acids and energy in broilers.

The aim of present study was to determine the effects of supplementation of either synbiotic or probiotic on growth performance and carcass characteristics, gut health, cecal microbiota prolife and apparent ileal digestibility of protein, amino acids, and energy in broilers. Two hundred and forty-day-old straight-run broilers (Ross 308) were allotted randomly to 1 of 5 dietary treatments including basal diet (control), supplemented with either synbiotic (Nutromax P) or probiotic (Actera), each at 0.5 and 1 g/kg of the diet for 5 weeks. The overall findings of the study indicated better (p < 0.05) growth performance of broilers by synbiotic supplementation (1 g/kg) compared with those fed probiotic (1 g/kg) supplemented and control diets. The broilers consuming diet supplemented with 1 g/kg synbiotic has an increased carcass yield in comparison with those fed control diet. The findings of gut health indicated significantly increased villus height and goblet cells, by synbiotic supplementation (1 g/kg), compared with control diet in broilers. The broilers fed 1 g/kg synbiotic supplemented diets had 18% increased protein, 9 to 31% higher amino acid, and 34% better energy digestibility, whereas 8.4% decreased protein digestibility in broilers fed probiotic (1 g/kg) supplemented compared with control diet in broilers. The broilers fed synbiotic (1 g/kg) supplemented diets had increased cecal Lactobacillus and decreased Salmonella, E. coli, and Clostridium count compared with those fed control diet. In conclusion, synbiotic supplementation (1 g/kg) resulted in improved production performance, balanced cecal microbial composition, and better digestibility of nutrients in broilers compared with those fed control and diets supplemented with probiotics.

Investigating the effect of available phosphorus and calcium level on the potential of a multi-carbohydrase and phytase complex on growth performance, amino acids and phosphorus digestibility in broilers from 1 to 21 days of age

An experiment was carried out to investigate the influence of dietary available phosphorus (avP) and calcium (Ca) levels on the nutritional potential of a multi-carbohydrase and phytase complex (MCPC) on the apparent ileal digestibility (AID) of amino acids (AA) and phosphorus (P) and performance of broilers fed with corn-soybean meal based-diets from 1 to 21 day of age. A total of 400 one-day-old male Cobb 500 chicks were allocated to 4 treatments in a randomized complete block design with 2 × 2 factorial arrangements of treatments. The two factors were levels of avP and Ca (adequate =4.5 g avP and 9. 0 g Ca per kg or suboptimal =3.5 g av and 7.5 g Ca per kg) and levels of MCPC supplementation (0 or 200 mL per ton feed). Growth performance, feed intake (FI) and feed conversion ratio (FCR) were measured on day 21. Excreta samples were collected on days 19–21 and ileal digesta were collected from all birds on day 21. There was an interaction between avP and Ca levels and MCPC on the final body weight (P < 0.001), body weight gain (BWG, P < 0.001) and FI (P = 0.002) from 1 to 21 days of age. Regardless of the dietary level of avP and Ca, supplementation with MCPC improved (P < 0.001) the BWG and the FCR. An interaction (P < 0.05) was also observed between level of avP and Ca and MCPC on AID of Cys, Gly, His, Lys, Met, Ser, Thr, Tyr, and Val. The addition of MCPC also improved (P < 0.001) apparent ileal digestibility of overall amino acids (AA) by (4.0% and 5.9%) and P (39% and 37%) for adequate and suboptimal levels of avP and Ca, respectively. This study demonstrated that MCPC is an effective solution to improve the availability of AA and P for broilers and consequently the performance. It also highlighted the need to consider interactions with dietary avP and Ca levels to optimize the nutritional benefits of an enzyme solution combining multi-carbohydrase and phytase activities in poultry nutrition.

Do Growing Rabbits with a High Growth Rate Require Diets with High Levels of Essential Amino Acids? A Choice-Feeding Trial.

Simple SummaryTwo diets were designed to investigate the effect of the growth rate on amino acid requirements in growing rabbits: M diet (with medium levels of amino acids, following current nutritional recommendations for growing rabbits) and H diet (with high levels of lysine, sulphur amino acids and threonine compared with current nutritional recommendations). Performance, nutrient retention and digestibility (faecal and ileal) trials, as well as a choice-feeding test were conducted. We found no differences in animal performance, nutrient retention and digestibility parameters between diets, but the animals showed a preference for the M diet, expressed by a high intra-individual repeatability in preference. Our results provide useful information and nutrition tools to move towards precision protein nutrition in growing rabbits.As a consequence of the genetic selection process in growing rabbits, there are currently fast-growing animals exhibiting an average daily gain that may exceed 45 g/d. The protein requirements of these animals, namely amino acid requirements, may differ from animals with low growth rates. The objective of this work was to evaluate growth performance, the coefficient of total tract apparent digestibility (CTTAD), the apparent ileal digestibility (AID) of amino acids and nutrient retention of fast-growing rabbits when they had access to a diet with high levels of amino acids and/or a diet formulated with current nutritional recommendations in a choice-feeding trial. To this end, two diets were formulated: the M diet following current nutritional recommendations for growing rabbits (including 8.1, 5.8 and 6.9 g/kg dry matter (DM) of total lysine, sulphur amino acids and threonine, respectively) and the H diet with higher levels of total lysine, sulphur amino acids and threonine (9.4, 6.6 and 7.8 g/kg DM, respectively). A total of 220 weaned rabbits, from a paternal line selected for the growth rate, had free access to the M diet, the H diet or both (MH) diets from 28 to 63 days of age. The CTTAD of DM, crude protein and gross energy from 49 to 53 days of age as well as the AID of amino acids of the diets at 63 days of age were determined. Protein, amino acids and energy retained in the empty body from 28 to 63 days of age were also registered. No significant differences in growth performance, CTTAD, AID and nutrient retention between dietary treatments were observed. However, animals fed the H diet showed a higher AID of cysteine (p < 0.05) and higher threonine retention (p < 0.05) compared to the M diet. As regards the choice-feeding trial, MH animals showed a higher feed intake of the M diet compared to the H diet (+8.61%; p < 0.001), and furthermore, more than 50% of the animals preferred the M diet throughout the experimental period (p < 0.05). Our results suggest that animals with high growth rates do not show significantly higher productive traits when fed the H diet compared to the M diet. As regards choice feeding, MH animals were capable of choosing their preferred diet, showing high intra-individual repeatability in preference for the M diet. It would be interesting to continue studying this behaviour of choice based on amino acid levels.

Protein value and health aspects of the seaweeds Saccharina latissima and Palmaria palmata evaluated with mink as model for monogastric animals

The aim of the present work was to evaluate the protein value of products from the two seaweeds Saccharina latissima and Palmaria palmata grown in Norwegian waters and to characterize possible beneficial or detrimental effects in the intestine and other organs. Mink, a well-established model for comparison of nutrient digestibility in monogastric animals was used. Two products from each of the seaweeds, a dried whole biomass and a protein concentrate, were evaluated. Five diets were made; a reference diet based on fish meal, and one for each of the four seaweed products. In the latter four, seaweed supplied 200 g/kg of crude protein. Each diet was fed to four male mink for two weeks. The results showed that diets with seaweed were less palatable than the fish meal diet. The animals fed the whole Saccharina diet had a significantly higher water intake and urine production than the other animals, supposedly due to the very high ash content of this seaweed product. This diet also stood out regarding urine concentration of iodine, which was 300 times higher than for the fishmeal-based diet. Apparent digestibility coefficient (ADC) for total amino acids, estimated by difference, showed low values for all the seaweed products; 0.574 and 0.734 for the whole and protein concentrated Saccharina products, and 0.588 and 0.700 for the two Palmaria products, respectively. The apparent amino acid digestibility coefficients (ADC) showed greater variation and were particularly low for histidine, <0.000 and 0.271 for the whole Saccharina and Palmaria products, respectively. Also, the ADC of methionine was low for these products, and cysteine ADC showed negative values for both Saccharina products. The estimated chemical score of the proteins, based on the digestible amino acids profile, was 0 and 520 g/kg for the whole product and protein concentrate of Saccharina, 260 and 520 g/kg for the whole product and the protein concentrate of Palmaria palmata, respectively. Expression of genes associated with digestive and immune functions showed minor effects in the jejunum, somewhat more pronounced effects in the colon. The latter effects were related to immune functions and lipid metabolism. No diet-related alterations in the histology of the jejunum and colon were observed. The histological investigation of liver and kidney structure showed some alterations in the seaweed fed animals. Regarding microbiota assemblage in mucosa of jejunum and colon, no clear diet effects were observed either in richness or diversity. In conclusion: the biological value of the seaweed proteins was low. Only one of the products, the Palmaria protein concentrate, might be considered of any use as a protein source. No clear beneficial or detrimental effects of the seaweed products were observed on gut health and function. The results regarding kidney structure and function, as well as the high iodine in the urine, indicating that further investigations are required to secure that animal health is not challenged by use of these seaweed ingredients in animal diets.

Performance and ileal amino acid digestibility in broilers fed diets containing solid-state fermented and enzyme-supplemented canola meals

Two experiments were conducted to determine the performance and ileal amino acid digestibility in growing male broilers fed diets containing solid-state fermented canola meal (SSFCM) and enzyme-supplemented canola meal (CM). In experiment 1 (performance trial), a total of 300-day-old Ross 308 male broiler chicks were allotted to six dietary treatments with five replicate pens of 10 birds each. Diet 1 was based on corn-soybean meal (SBM) as reference, diets 2 and 3 contained 300 g/kg CM and 300 g/kg SSFCM, respectively. Diet 4 contained 300 g/kg CM + phytase (PHY). Diet 5 contained 300 g/kg CM + xylanase (XYL). Diet 6 contained 300 g/kg CM + PHY + XYL. PHY at 500 FTU/kg and XYL at 1000 U/kg were added to the respective diets. During the experimental period (1–21 d), birds fed SBM and SSFCM diets recorded improved FI (p < 0.05). Broilers fed CM diet with enzyme supplementation had improved FCR compared to SSFCM diet. In experiment 2 (digestibility trial), a total of 240-twenty-one-day-old Ross 308 male broiler chicks were assigned to six dietary treatments with five replicate cages of eight birds each. Diet 1 was based on SBM, diets 2 and 3 contained 400 g/kg CM and 400 g/kg SSFCM, respectively. Diet 4 contained 400 g/kg CM + PHY. Diet 5 contained 400 g/kg CM + XYL. Diet 6 contained 400 g/kg CM + PHY + XYL. The inclusion of SSFCM and enzyme-supplemented CM in diets did not improve the apparent ileal digestibility (AID) of amino acids. The AID of calcium (Ca) was highest (p < 0.05) in SBM, CM and SSFCM. The AID of phosphorus (P) was increased (p < 0.05) in SBM and CM + PHY. Ca retention was higher (p < 0.05) in SSFCM and CM + PHY + XYL. Feeding SBM, SSFCM, CM + PHY and CM + PHY + XYL diets enhanced P retention. Further studies are required to establish the practical and nutritional implication of SSFCM on performance and ileal amino acid digestibility in broilers.

Effects of dietary iron level on growth performance, hematological status, and intestinal function in growing-finishing pigs.

This study investigated the different addition levels of iron (Fe) in growing-finishing pigs and the effect of different Fe levels on growth performance, hematological status, intestinal barrier function, and intestinal digestion. A total of 1,200 barrows and gilts ([Large White × Landrace] × Duroc) with average initial body weight (BW; 27.74 ± 0.28 kg) were housed in 40 pens of 30 pigs per pen (gilts and barrows in half), blocked by BW and gender, and fed five experimental diets (eight replicate pens per diet). The five experimental diets were control diet (basal diet with no FeSO4 supplementation), and the basal diet being supplemented with 150, 300, 450, or 600 mg/kg Fe as FeSO4 diets. The trial lasted for 100 d and was divided into the growing phase (27 to 60 kg of BW) for the first 50 d and the finishing phase (61 to 100 kg of BW) for the last 50 d. The basal diet was formulated with an Fe-free trace mineral premix and contained 203.36 mg/kg total dietary Fe in the growing phase and 216.71 mg/kg in the finishing phase based on ingredient contributions. And at the end of the experiment, eight pigs (four barrows and four gilts) were randomly selected from each treatment (selected one pig per pen) for digesta, blood, and intestinal samples collection. The results showed that the average daily feed intake (P = 0.025), average daily gain (P = 0.020), and BW (P = 0.019) increased linearly in the finishing phase of pigs fed with the diets containing Fe. On the other hand, supplementation with different Fe levels in the diet significantly increased serum iron and transferrin saturation concentrations (P < 0.05), goblet cell numbers of duodenal villous (P < 0.001), and MUC4 mRNA expression (P < 0.05). The apparent ileal digestibility (AID) of amino acids (AA) for pigs in the 450 and 600 mg/kg Fe groups was greater (P < 0.05) than for pigs in the control group. In conclusion, dietary supplementation with 450 to 600 mg/kg Fe improved the growth performance of pigs by changing hematological status and by enhancing intestinal goblet cell differentiation and AID of AA.

Effect of Dietary Lysine and Energy Levels on Apparent Nutrient, Nitrogen, and Amino Acids Digestibility of Local Muscovy Ducks

Effect of Dietary Lysine and Energy Levels on Apparent Nutrient, Nitrogen, and Amino Acids Digestibility of Local Muscovy Ducks

СТАНДАРТИЗИРОВАННАЯ ИЛЕАЛЬНАЯ УСВОЯЕМОСТЬ АМИНОКИСЛОТ БЕЛКОВОГО КОНЦЕНТРАТА НА ОСНОВЕ ЛИЧИНОК МУХ Lucilia spp. (Diptera: Сalliphoridae) И ЕГО ВЛИЯНИЕ НА ПОКАЗАТЕЛИ КРОВИ У ЦЫПЛЯТ-БРОЙЛЕРОВ(Gallus gallus L.)

Bioconversion is an ecologically friendly and effective way of the utilization of organic wastes; it involves the use of these wastes as a substrate in the biotechnologies of different products. The larvae of the black soldier fly (Hermeia illucens L.) grown on the organic wastes have been earlier studied as a raw material for feed ingredients for poultry; recently the larvae of common green bottle fly (Lucilia spp.) draw the attention as a potential source of feed-grade protein for animals and poultry. The dried defatted biomass of the larvae contains crude protein (no less than 62 %), fat (10 %), lysine (no less than 4 %), methionine + cystine (2.0 %) and hence could be a promising protein source in diets for poultry. However, despite the apparent advantages of the bioconversion of organic wastes by insects into the dietary protein sources for poultry there is a scarcity of the data on the quality of these products and on their effects on poultry. Earlier research evidenced the efficiency of the supplementation of diets for growing turkeys with 5.0-7.5 % of dried full-fat Lucilia larvae; however, the ileal digestibility of amino acids in turkeys (necessary for the balancing of dietary amino acids) was not assessed. The study presented is a first attempt of the in vivo assessment of ileal digestibility of amino acids from Lucilia larvae protein concentrate (LLPC) in broilers (Gallus gallus L.). The aim of the study was the determination of apparent (AID) and standardized ileal digestibility (SID) of amino acids from LLPC within the experimental diet and its effects on the morphological and biochemical blood indices in broilers. AID and SID were determined in the vivarium of the All-Russian Research and Technological Institute of Poultry in 2019 on broilers (cross Smena 8, 18-42 days of age) with chronic ileal fistulae fed mono-protein diet contained LLPC, dextrose, fiber, and a premix of vitamins and minerals. SID was calculated with the endogenous losses of amino acids taken into account. SID of potentially limiting amino acids were as follows: lysine 82.9 %, methionine 86.6 %; threonine 80.4 %; arginine 89.5 %; isoleucine 80.0 %; leucine 81.9 %; valine 79.9 %; histidine 82.9 %, and phenylalanine 85.7 %. The beneficial effects of LLPC on the blood indices were found: the activity of alanine transaminase was significantly higher by 23.5 % in broilers fed LLPC in compare to control while the activity of aspartate transaminase was lower by 24.6 % (p < 0.05) indicating the prevalence of the anabolic processes over the catabolic. The significant increase in total protein concentration in serum (by 20.0 %, p < 0.05) and increase in hemoglobin concentration by 4.2 % in compare to control evidenced the activation of the metabolism. The use of SID (instead of AID) allows for more accurate balancing of dietary contents of available amino acids, more adequate amino acid supply to poultry, and for the reduction of nitrogen emissions into the environment due to the optimization of dietary protein content.

183 Isoquinoline alkaloids increase apparent ileal digestibility of amino acids and crude protein and apparent total tract digestibility of crude protein by finishing pigs fed corn-soybean meal diets

Abstract An experiment was conducted to determine if the inclusion of a preparation of isoquinoline alkaloids (IQ) in corn-soybean meal diets fed to finishing pigs increases the apparent ileal digestibility (AID) of amino acids (AA) and crude protein (CP) and the apparent total tract digestibility (ATTD) of CP and gross energy. Twelve ileal cannulated barrows (BW: 77.2 ± 6.23 kg) were allotted to a triplicated 4 x 3 incomplete Latin square design with 4 diets and 9 replicates per diet. Diets were supplemented with either 0, 40, 80, or 160 mg/kg IQ and with 0.40% titanium dioxide as an indigestible marker. Each collection period lasted 14 d with d 1 through 10 as an adaptation to the diets, fecal samples were taken using the grab sampling technique on d 11 and 12, and ileal digesta were collected for 8 h on d 13 and 14. Data were analyzed using the Proc MIXED procedure of SAS. Contrast statements were used to determine linear and quadratic effects of including IQ in the diets. Results were considered significant at P ≤ 0.05 and considered a trend at 0.05 &amp;lt; P ≤ 0.10. Inclusion of IQ resulted in a quadratic increase (P &amp;lt; 0.05) in the AID of CP and AA in corn-soybean meal diets fed to finishing pigs, with the greatest digestibility values generally observed in the 40 mg/kg IQ treatment. Additionally, IQ resulted in a quadratic increase (P = 0.009) in the ATTD of CP, with the greatest digestibility observed in the 80 mg/kg IQ treatment. Therefore, it was concluded that supplementing corn-soybean meal diets with 40 or 80 mg/kg IQ may increase the AID of CP and AA and ATTD of CP by finishing pigs.

Amino acid digestibility coefficient values of animal protein meals with dietary protease for broiler chickens.

A digestibility experiment was conducted to evaluate the effects of dietary exogenous monocomponent protease on the coefficient of apparent total tract digestibility (ATTD) and coefficient apparent ileal digestibility (AID) of amino acids in meat and bones meal (MBM), poultry byproducts meal (PBPM), and feather meal (FM). A total of 512 Cobb-500 male broiler chickens (aged 14 d) were randomly placed into 64 metabolism cages (8 birds per pen) and were allocated to eight treatments with eight replicates in a semi-controlled environmental room. The experimental diets consisted of the basal diet (corn/SBM) and the replacement of 300 g/kg on a weight basis with MBM, PBPM, or FM. The excreta were collected during 3 d (19 to 21 d), and the ileal digesta (using Celite as an indigestible marker) only 1 d (21 d). The protease contained 75,000 PROT units/g. The use of the enzyme increased (P < 0.05) ATTD for alanine, cysteine, glycine, and threonine in the basal diet and AID for the amino acids alanine, cysteine, glycine, lysine, threonine, and valine for the basal diet (vegetable). Regarding meals, there was an increase (P < 0.05) in the amino acid digestibility in large part due to the amino acids of MBM (14) and PBPM (9), with only five amino acids for FM. The amino acids glycine and threonine showed increases (P < 0.05) in both total and ileal digestibility for all animal meals and for the diet based on corn and soybean meal, which indicates a high specificity of the enzyme for these amino acids. The overall results obtained in this study found satisfactory effectiveness of this exogenous protease. The total collection method was lower by 1.83% of amino acids digestibility than the ileal method.

Initial assessment of protein and amino acid digestive dynamics in protein-rich feedstuffs for broiler chickens.

A study evaluating apparent digestibilities of protein and amino acids and their corresponding digestion rates in four small intestinal sites in broiler chickens was completed to further investigate dietary optimisation via synchronised nutrient digestion and absorption. A total of 288 male Ross 308 broiler chickens were offered semi-purified diets with eight protein-rich feedstuffs, including; blood meal (BM), plasma protein meal (PPM), cold pressed (CCM) and expeller-pressed (ECM) canola meal, high (SBM HCP) and low (SBM LCP) crude protein soybean meals, lupins and peas. Diets were iso-caloric, iso-nitrogenous and the test ingredient was the sole source of dietary nitrogen. Each diet was offered to 6 bioassay cages with 6 birds per cage from day 21 to 28 post hatch. On day 28, all birds were euthanized and digesta samples were collected from the proximal jejunum, distal jejunum, proximal ileum and distal ileum to determine apparent protein and amino acids digestibility coefficients, digestion rates and potential digestible protein and amino acids. Dietary protein source significantly influenced energy utilisation, nitrogen retention, apparent protein (N) digestibilities, digestion rates and potential digestible protein along the small intestine. Diets containing BM and SBM LCP exhibited the highest protein digestion rate and potential digestible protein, respectively. Digestibility coefficients and disappearance rates of the majority of amino acids in four sections of the small intestine were influenced by dietary protein source (P < 0.01) and blood meal had the fastest protein digestion rate. In general, jejunal amino acid and protein digestibilities were more variable in comparison to ileal digestibilities, and the differences in protein and amino acid disappearance rates were more pronounced between types of feedstuffs than sources of similar feedstuffs.

Standardized Ileal Digestibility of Amino Acids in Feed Ingredients for Broiler Chickens

The objective of this experiment was to determine the apparent (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in five feed ingredients for male broiler chickens (Ross 308). The test feed ingredients consisted of corn, wheat, soybean meal (SBM), canola meal (CM), and corn distillers dried grains with solubles (DDGS). The birds were fed a standard starter diet for the first 19 d. On day 19, nine hundred sixty birds were assigned to six dietary treatments with eight replicate cages (20 birds/cage) in a randomized complete block design. All experimental diets contained chromic oxide (0.5% in the diet) as an indigestible index. The diets were offered <i>ad libitum</i> for 4 d. At the end of the experiment, all birds were euthanized and ileal digesta samples were collected immediately. The indispensable AA with the least AID and SID were Thr for all the ingredients used in the present study, except for DDGS, in which Lys had the lowest digestibility. For indispensable AA, the AID and SID of Leu, Phe, Arg, and Met were the greatest in corn, DDGS, wheat, SBM, and CM, respectively. The results from the present study showed that there are variations in both the AID and SID of CP and AA among feed ingredients.

Protein digestive dynamics of meat and bone meals in broiler chickens

This study determined the variations in protein digestibilities and digestion rates in broiler chickens offered diets containing 7 different meat and bone meals (MBM). A total of 252 male Ross 308 broiler chickens were offered 7 atypical diets largely based on maize and MBM from 24 to 28 d post-hatch. Each experimental diet was offered to 6 replicates with 6 birds per replicate cage. Excreta were collected in their entirety from 25 to 27 d post-hatch and on 28 d post-hatch. Digesta samples were collected from the proximal jejunum, distal jejunum, proximal ileum and distal ileum. Apparent digestibilities of protein were determined in each segment and apparent digestibilities of amino acids were measured in the distal ileum. There were significant differences in apparent protein digestibility coefficients in the proximal jejunum (P = 0.006), where broiler chickens offered the high ash beef meal (diet 7) generated the lowest protein digestibility in the proximal jejunum (0.318). Similarly, there were significant differences in apparent digestibility coefficients in the distal jejunum (P < 0.001) and distal ileum (P < 0.001) but not in the proximal ileum. More pronounced differences were found in the disappearance rate of protein and there were significant differences in all 4 segments of the small intestine (P < 0.001). Broiler chickens offered the high ash beef meal had the lowest protein disappearance rate (P < 0.001). No difference was observed in the predicted protein digestion rate (P = 0.486) but chickens offered the high ash beef meal had the lowest potential digestible protein (0.662, P = 0.034) whereas the highest potential digestible protein (0.739) was detected in diet 5 (containing a beef meal). This study contributed to the establishment of a preliminary database to include digestion rates of starch and protein into practical diet formulation.

Arginine addition in a diet for weaning pigs can improve the growth performance under heat stress.

The effects of arginine (Arg) and methionine (Met) supplementation on nutrient use in pigs were determined under hot season conditions. A total of five experimental diets including basal diet (CON) were supplemented with two types of amino acids (Arg and Met) and two different amounts of amino acids (0.2% and 0.4%). Under hot season condition, pigs fed with additional Arg were significantly higher in average daily gain (ADG) than the CON group and the ADG increased linearly (p < 0.05) with increasing Arg supplementation. But there was no significant difference with Met supplementation (p > 0.05). The apparent ileal digestibility (AID) of amino acids had no significant difference among treatments (p > 0.05), while d-reactive oxygen metabolites (d-ROMs) concentration in treatments with Arg supplementation, were significantly higher (p < 0.05) than other treatments. In conclusion, exposure of pigs to heat stress does not affect the AID of amino acid, whereas pig fed with additional Arg improved ADG and feed efficiency under heat stress condition.

Effects of feed intake level on the additivity of apparent and standardized ileal digestibility of amino acids in diets for growing pigs

The present study was conducted to evaluate the additivity of apparent (AID) and standardized (SID) ileal digestibility of AA in diets at two feed intake (FI) levels. A total of 28 growing barrows were used in this study with 7 treatments and two 10-d experimental periods (7 d adaptation and 3 d ileal digesta collection). The seven treatments contained 3 experimental diets (Corn, SBM, and Corn + SBM mixed diet) at 2 feeding levels (low and high, represented 3% of BW per day and ad libitum, respectively) in a 3 × 2 factorial arrangement and a nitrogen-free diet (NFD) fed at low feeding level. There were 8 replicates for each of the 7 treatments. The AID of AA determined in low FI was greater than the AID determined in high FI levels for nitrogen and all AA except for Leu, Met, Cys, and Tyr in corn, SBM, and the mixed diet (P < 0.05). The SID of AA determined in low FI was greater than the SID determined in high FI levels for nitrogen, Phe, Thr, Trp, Ala, Asp, Glu, and Ser in corn, SBM, and the mixed diet (P < 0.05). When using AID of AA in corn and SBM determined at low FI level to predict the AID in the mixed diets at low FI level, the predicted AID underestimate the actual determined values of His, Phe, Trp, Vale, Asp, Glu, and Pro (P < 0.05). In low FI level, the predicted SID underestimated the determined values of Asp (P < 0.05) and overestimated Leu, and Cys (P < 0.05). When the digestibility derived at low FI level were used to predict the AID of AA in the mixed diets fed at high FI level, the predicted AID overestimated the determined values in nitrogen, Leu, Thr, and all non-essential AA except for Gly and Tyr (P < 0.05). Using the values derived from low FI level condition to estimate the SID of the mixed diet in high FI level condition, the determined SID of AA in the mixed diets was overestimated in His, Leu, Met, Thr, Val, Ala, Cys, Ser, and Tyr (P < 0.05). The determined AID of the mixed diet in high FI level were underestimated for His, Lys, Phe, Thr, and all dispensable AA except for Pro, Ser, and Tyr (P < 0.05), when AID of AA in corn and SBM derived from high FI level was used in the calculation. The predicted SID in the same calculation underestimated the SID of Asp and Glu in the mixed diet (P < 0.05). In conclusion, low FI level may increase the determined AID and SID of protein and AA in diets, which leads to the lack of additivity and overestimation of the actual AID and SID of AA in the complete diet when using the digestibility were derived from low FI level animals to predict the digestibility in high FI conditions.

A moderate protein diet does not cover the requirements of growing rabbits with high growth rate

Genetic selection for feed efficiency has increased the growth rate and requirements of growing rabbits, while the protein content of commercial feeds has been adjusted to avoid digestive disorders. The aim of this work was to evaluate how a diet with moderate levels of protein content [146 g crude protein (CP)/kg] could be affecting protein and amino acids acquisition depending on the growth rate of the animals. From 189 weaned rabbits (28 days old), only 41 animals were selected at 42 days, in order to ensure the greatest variability for growth rate during fattening. To achieve this goal, animals came from three genetic lines: H and LP (maternal lines selected by litter size) and R (paternal line selected for growth rate), characterised by normal, moderate and high growth rate during the fattening period, respectively. Apparent faecal digestibility of dry matter (DM), CP and gross energy (GE) of the diet from 49–53 days of age, as well as the ileal apparent digestibility of DM, CP and amino acids at 63 days of age, was determined in all the selected animals. Protein, energy and amino acids retained in the empty body during the fattening period were also determined by slaughtering 15 weaning rabbits at 28 days, and the 41 selected animals at 63 days of age. Animals from the R line showed higher feed intake than those from maternal lines, as well as lower feed conversion ratio, even below that expected from their growth rate. Apparent faecal digestibility of GE and apparent ileal digestibility of DM, CP and cystine of the diet were higher in LP than in H rabbits (P < 0.05), showing intermediate values in R rabbits. However, apparent ileal digestibility of glutamic acid and glycine was significantly higher in R than in H rabbits (P < 0.05), showing intermediate values in LP rabbits. As expected, both daily protein and energy retained in the empty body increased as growth increased. However, R growing rabbits seem to have lower protein retained and higher energy retained in the empty body than that expected from their growth. In fact, protein to energy retained ratio was clearly lower for R growing rabbits. These results seem to show the possible existence of some limiting amino acid when current moderate protein diets are used in growing rabbits with high growth rates, recommending a review of the amino acid requirements for the growing rabbits from paternal lines.

Effects of isoquinoline alkaloids on apparent ileal digestibility of amino acids, acid hydrolyzed ether extract, and starch by young growing pigs fed corn-soybean meal diets.

An experiment was conducted to test the hypothesis that a preparation of isoquinoline alkaloids (IQ) obtained from Macleaya cordata and added to corn-soybean meal diets increases the apparent ileal digestibility (AID) of amino acids (AA), crude protein (CP), starch, and acid hydrolyzed ether extract (AEE) when fed to young growing pigs. Thirty-two ileal cannulated barrows (initial body weight = 12.19 ± 1.38 kg) were allotted to a randomized complete block design with four diets and eight replicate pigs per diet. Diets were supplemented with 0, 90, 180, or 360 mg/kg IQ and with 0.40% chromic oxide. Diets were fed for 27 d and ileal digesta were collected on days 13 and 14 (period 1) and on days 26 and 27 (period 2). Effects of IQ inclusions were analyzed using contrast statements, and differences between periods were analyzed using a repeated measures statement. A quadratic increase (P < 0.05) in the AID of Thr, Trp, Val, Pro, and Tyr was observed in period 1 as IQ was included in the diets, and AID of CP, Arg, His, Ile, Leu, Met, Phe, Thr, Trp, Val, Pro, and Tyr was greater in period 2 than in period 1 (P < 0.05). In period 1, a quadratic increase (P < 0.05) was observed for the AID of starch as IQ increased in the diet, but the AID of starch was less (P < 0.05) in period 2 than in period 1. No differences among treatments or periods were observed for AID of AEE. Results indicate that inclusion of approximately 90 mg/kg of IQ in diets for weanling pigs may increase the AID of starch and some AA.

Toward standardized amino acid matrices for exogenous phytase and protease in corn–soybean meal–based diets for broilers

A total of 468 male Ross 308 broilers were used in a digestibility study to determine the additivity of apparent or standardized amino acid (AA) digestibility values for corn, soybean meal (SBM), or a mixture of corn and SBM that were supplemented, or not, with either phytase, protease, or a combination of phytase and protease. These treatments generated a total of 12 experimental diets that were arranged in a 3 × 4 design. A nitrogen-free diet was also fed to estimate endogenous AA loss. Apparent and standardized AA digestibility values were assessed on day 28 posthatch. The apparent digestibility of AA in the complete diet was higher (P < 0.05) than expected based on the digestibility of the corn and SBM individually. However, this overestimation was corrected by the adjustment to standardized values. Importantly, addition of protease or the combination of protease and phytase increased (P < 0.05) the digestibility of AA in corn and SBM. Furthermore, these effects were arithmetically coherent with respect to the measured effects of the enzymes in the mixture of corn and SBM, even improving the additivity of AA digestibility values when assessed on an apparent basis. This study demonstrates that the effect of exogenous protease and phytase on AA digestibility in complete diets is predictable based on measurements made in individual ingredients. In addition to improving digestibility values per se, exogenous protease and phytase may enhance precision in least cost formulation systems.