Evaluation of in vitro methods to estimate digestibility of amino acids in the rumen undegraded protein fraction of feedstuffs

Soybean meal, SoyPlusRTM, dried distillers grains with solubles (DDGS), and fish meal samples were used in the evaluation of the modified three-step, the immobilized digestive enzyme assay ( IDEA), the guanidination, and the furosine in vitro procedures to estimate intestinal digestibility of amino acids in rumen undegraded protein ( RUP-AA). Identifying an in vitro method to estimate RUP-AA digestibility will allow for routine analysis of feeds for this parameter, which can lead to more accurate formulation of dairy rations. To determine the adequacy of these procedures, in vivo RUP-AA digestibility estimates were obtained using the precision-fed cecectomized rooster assay. Rumen undegraded residues ( RUR) were generated, and intact feeds and RUR were analyzed for AA and crop-intubated to cecectomized roosters. Results of the rooster experiments indicate that AA digestibility differs from RUP-AA for DDGS samples, and RUP-AA digestibility differs within samples. For the modified three-step procedure, digestibility of all AA in all feedstuffs was highly correlated to in vivo data. For the IDEA analysis, IDEA values of intact feeds were highly correlated to RUP-AA digestibility, which indicates that the ruminal incubation step can be eliminated with this method. The guanidination and furosine methods can be used to predict lysine digestibility only, which is often a limiting AA in dairy rations. Blocked lysine was calculated from furosine concentrations, and the guanidination procedure was used to calculate reactive lysine. Blocked and reactive lysine estimates were highly correlated to in vivo lysine digestibility. Of these two methods, the guanidination procedure was a better approach for predicting lysine digestibility across feedstuffs. To increase the number and type of sample analyzed, 5 BM samples were later obtained. Blood meal was only analyzed via the rooster assay, the modified three-step procedure, and the guanidination method. Among the BM samples, digestibility of AA was similar to RUP-AA. For the modified three-step procedure, the use of intact BM provided more accurate estimates of RUP-AA digestibility than the RUR. The guanidination method was not a good approach to predict lysine digestibility in BM. In conclusion, the modified three-step procedure appears to be the best in vitro approach to estimate RUP-AA digestibility

Evaluation of heat-processed sorghum, high-oleic and low-trypsin inhibitor soybean cultivars as alternatives for corn and conventional soybeans for broilers

Dr. Marcia C. Shannon, Dissertation Supervisor.includes vitaFour 21-d experiments were conducted to compare soybean meal (SBM) from high oleic to parent soybean cultivars on growth performance, energy and ileal AA (IAA). Soybean meal was prepared by laboratory-scale mechanical extraction. Two replicate chick assays (Exp. 1 and 2) with similar treatments were conducted to evaluate the growth efficiency. In Exp. 1 and 2, 50 d-old male broilers (Ross 308) were randomly placed in battery cages and allocated to 2 dietary treatments with 5 replicates and 5 birds per replicate. The SBM sources consisted of cold-pressed conventional SBM (CON) and cold-pressed high oleic SBM (HO). All SBM sources were heated in a forced-air oven at 120 degrees C for 20 min. Diets were formulated to meet or exceed NRC (1994) and Aviagen nutrient requirements for Ross 308 in Exp. 1 and 2, respectively. Broilers were weighed and feed disappearance measured on d 7, 14, and 21 in Exp. 1, and on d 10 and 21 on Exp. 2. Two assays (Exp. 3 and 4) were conducted to determine IAA digestibility and apparent metabolizable energy (AME) in Exp. 3 or ileal digestible 24 energy (IDE) in Exp. 4. In Exp. 3 and 4, 100 d-old broilers randomly allotted to 2 dietary treatments with 10 replicates and 5 birds per replicate. Chicks were fed a corn-SBM based diet for 17 d, and a diet was developed by substituting the soybean cultivars in a corn starch-dextrose basal diet and fed from d 18 to 21. A nitrogen-free diet was fed to determine ileal endogenous AA losses. Titanium dioxide (0.5 percent) was included in all diets as a digesta flow marker. Excreta and ileal samples were collected on d 21. Statistical analyses were performed as a completely randomized design using PROC GLM of SAS with significance level set at P less than or equal to 0.05. In Exp. 1, chicks fed diets containing HO had decreased ADG (P less than 0.05; 25.3 vs. 29.4 g) and increased feed:gain ratio (P less than 0.05) from d 0 to 14 (1.71 vs. 1.56) and d 0 to 21 (1.54 vs. 1.47), compared with chicks fed CON diet. In Exp. 2, chicks fed HO had lower BW at d 10 (P = 0.028; 143 vs. 153 g), lower ADG from d 0 to 10 (P = 0.030; 10.90 vs. 11.90 g), and greater feed:gain ratio from d 0 to 10 (P = 0.043; 1.55 vs. 1.45) compared with chicks fed CON diet. In Exp. 3, AA digestibility did not differ among all essential AA. There were no differences in AME (kcal per kg) from SBM between CON and HO, with values of 2,921 and 2,901 (P = 0.73), respectively. In Exp. 4, the digestibility of glutamic acid (P = 0.026; 94.4 vs. 95.2 percent) and arginine (P = 0.008; 94.4 vs 95.4 percent) from HO were lower than CON; however, the IDE of CON and HO were similar (3,419 and 3,343 kcal/kg; P = 0.08), respectively. In conclusion, although there were no differences in nutrient digestibility, in conditions of this study, broilers fed HO had impaired growth performance, mainly from 1 to 14 d of age.Dr. Marcia C. Shannon, Dissertation Supervisor.|Includes vita.Includes bibliographical references (pages 113-126)

The role of the giant Canada goose (Branta canadensis maxima) cecum in nutrition

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (April 25, 2007)Vita.Thesis (Ph.D.) University of Missouri-Columbia 2006.Waterfowl are renowned for their ability to exploit a wide variety of food resources. They feed on fresh and marine water invertebrates, aquatic and terrestrial plants, and agricultural grains and crops. This nutritional flexibility has allowed them to exploit virtually every water environment and establish a world-wide distribution. Their nutritional flexibility can be attributed to the diversity of anatomical, behavioral, and physiological adaptations that exist within Anatidae. Of particular importance is the ability of intestinal organs to adjust to a changing diet. The intent of this research was to investigate the role of the Canada goose (Branta candensis maxima) cecum in facilitating nutritional flexibility. True metabolizable energy assays indicated that the cecum increases the ability of the digestive system to extract energy from nutritionally poor foods (i.e. high fiber foods). Carboxymethyl cellulose assays conducted on cecal contents, confirmed the presence of cellulose-splitting bacteria within the ceca. True amino acid digestibility assays failed to detect differences in amino acid digestibility between intact and cecectomized geese. The bioassay, however, might not have been the appropriate approach to use with Canada geese. With the exception of a decrease in pancreas weight, the removal of the cecum did not lead to compensatory growth in the remaining digestive organs. Post-mortem examination, however, led to the discovery that 8 out of the 9 cecectomized geese had one or both ceca in various stages of regeneration.Includes bibliographical reference

Metabolic aspects of oryzanol in rats

Using a rat model, this study compared the bioavailability of three forms of oryzanol, a compound extracted from rice bran oil that has been associated with improved cholesterol levels. Various methods of extracting lipids from serum and liver were explored to determine oryzanol absorption. Cholesterol levels were obtained via enzymatic colorimetric assay and GCMS. Sprague Dawley retired female breeder rats were sustained for 11 weeks on a cholesterol-free diet to which either no oryzanol was added (n = 19) or 2.8 g/kg of oryzanol was added as: 7% oryzanol rice bran oil (RO, n = 8), crystalline oryzanol (CO, n = 8), or crystalline oryzanol dissolved in tocopherol-stripped corn oil (DO, n = 9). The percentage of dietary oryzanol recovered in the feces of rats fed the CO diet (41.9 ± 2.21, mean ± SEM) was significantly higher compared to the RO (28.3 ± 3.54) and DO (27.8 ± 2.63) groups (P \u3c 0.05), suggesting that bioavailability of crystalline oryzanol is lower relative to the oil forms. Oryzanol was not detected during GCMS analysis of serum following hexane extraction. Similarly, hexane extractions of liver analyzed via HPLC and GCMS did not reveal oryzanol. Hexane may not be an appropriate solvent for extracting oryzanol, or perhaps the compound is metabolized prior to its entry into the liver or bloodstream. Although serum cholesterol levels determined by colorimetric enzymatic assay did not differ significantly among the groups, levels were highest in the RO group, followed in sequence by the DO, CO, and oryzanol-free controls. It is likely that a cholesterol-enriched diet is required for the hypolipidemic effect of oryzanol to be realized. Additionally, it is plausible that the cholesterol values from the oryzanol-fed animals were inflated by phytosterols in the serum. Hexane extractions of serum analyzed via GCMS resulted in unintelligible data, suggesting that hexane is not a suitable solvent for the extraction of cholesterol from serum. Although a 2:1 chloroform:methanol mixture (Folch et al., 1956) resulted in more uniform values, it appeared that the extraction of total cholesterol from lipoproteins was incomplete. (Supported by USDA IFAFS 2000-04222

Protein-quality evaluation of complementary foods in Indian children

Background: The types of food in complementary feeding of infants and young children are important for growth and development. Food protein quality, as measured by the Digestible Indispensable Amino Acid Score (DIAAS), requires the determination of true ileal digestibility of indispensable amino acids (IAAs) in children. Objectives: First, the aim of this study was to measure the true ileal IAA digestibility of 4 (rice, finger millet, mung bean, and hen egg) commonly consumed complementary foods in children aged <2 y using the dual-isotope tracer method. Second, we calculated the DIAAS of complementary feeding diets and their relation to stunting in a representative Indian rural population. Design: Rice, finger millet, and mung bean were intrinsically labeled with deuterium oxide (2H2O), whereas egg was labeled through oral dosing of hens with a uniformly 2H-labeled amino acid mixture. True ileal IAA digestibility was determined by the dual-isotope tracer technique. The DIAAS of complementary food protein was calculated in children aged 1–3 y from a nationally representative survey to evaluate its relation with stunting. Results: True ileal IAA digestibility was lowest in mung bean (65.2% ± 7.1%), followed by finger millet (68.4 %± 5.3%) and rice (78.5% ± 3.5%), and was highest for egg (87.4% ± 4.0%). There was a significant inverse correlation of complementary food DIAAS with stunting in survey data (r = −0.66, P = 0.044). The addition of egg or milk to nationally representative complementary diets theoretically improved the DIAAS from 80 to 100. Conclusions: The true ileal IAA digestibility of 4 foods commonly consumed in complementary diets showed that the DIAAS was associated with stunting and reinforces the importance of including animal source food (ASF) in diets to improve growth. This trial was registered at http://ctri.nic.in/clinicaltrials/login.php as CTRI/2017/02/007921

Impact of dietary glutamine on amino acid digestibility values and intestinal morphometric parameters in neonate chicks

Two experiments were conducted to investigate the effects of fortification of the pre-starter diet with glutamine in post-hatch broiler chicks. In the first experiment, male chicks were used to study the impact of glutamine supplementation at three levels (0%, 1% and 2%) on performance, apparent faecal digestibility (AFD) and ileal digestibility (AID) of amino acids (AAs), as well as intestinal morphometric parameters from 0 to 14 days old. The best performance was obtained at 1% supplementation. Average daily feed intake and feed conversion ratio (FCR) were affected by treatments. Supplementing diets with glutamine resulted in increase of digestibility values for arginine (Arg), lysine (Lys), isoleucine (Ile) and valine (Val). Glutamine-supplemented diets led to higher villus height (VH) and shallower crypt depth (CD) in the jejunum and ileum. A second experiment was performed to investigate whether the form of glutamine could affect performance and morphometric parameters in newly hatched chickens. A control diet was prepared, based on casein as the sole source of protein-bound AAs. Three diets based on synthetic AAs were used to obtain nutrient values of the control diet, which were supplemented with a synthetic form of glutamine, glutamic acid and a 50 : 50 ratio of glutamine : glutamic acid. Chickens fed the control diet presented higher average daily weight gain and better FCR. None of the AID coefficients of amino acids were influenced by the dietary treatments, except glutamic acid and aspartic acid, which were decreased in chicks fed synthetic AAs. In conclusion, 1% glutamine supplementation improved performance, morphometric parameters and AID and AFD values of cationic AAs. The form in which dietary glutamine was provided could affect performance.Keywords: Amino acid, broiler, digestibility, intestinal morpholog

Dietary fibre and the importance of the gut microbiota in feline nutrition : a review

Domestic cats are obligate carnivores and in this light hindgut fermentation has been considered unimportant in this species. However, a diverse microbiota has been found in the small and large intestines of domestic cats. Additionally, in vitro and in vivo studies support the hypothesis that microbial fermentation is significant in felines with potential benefits to the host. Results on microbiota composition and microbial counts in different regions of the feline gastrointestinal tract are compiled, including a description of modulating host and technical factors. Additionally, the effects of dietary fibre supplementation on the microbiota composition are described. In a second section, in vitro studies, using inocula from fresh feline faeces and focusing on the fermentation characteristics of diverse plant substrates, are described. In vivo studies have investigated the effects of dietary fibre on a broad range of physiological outcomes. Results of this research, together with studies on effects of plant fibre on colonic morphology and function, protein and carbohydrate metabolism, and the effects of plant fibre on disease conditions that require a decrease in dietary protein intake, are shown in a third section of the present review. Conclusively, for fructans and beet pulp, for example, diverse beneficial effects have been demonstrated in the domestic cat. Both dietary fibre sources are regularly used in the pet food industry. More research is warranted to reveal the potential benefits of other fibre sources that can be used on a large scale in feline diets for healthy and diseased cats

Improving the nutritive value and utilisation of non-conventional protein feed resources in smallholder village chicken production systems.

Ph. D. University of KwaZulu-Natal, Pietermaritzburg 2014.Poultry production is one of the most important activities for creating wealth in developing countries. This study was conducted to assess methods of improving the nutritive value and utilization of cowpeas, and ameliorating the negative effects of aflatoxins in chicken feeds. Farmer perceptions on feed resource availability and utilization of non-conventional feed resources for indigenous chickens were investigated in three Mozambican districts (n=240). Scavenging was the major source of feeds for chickens and two out of five of the respondents experienced feed shortages during the dry season (from May to October/November). Nearly 90 % of the respondents were willing to use novel protein sources (e.g. houseflies, earthworms and snails) as chicken feed. Household leftovers were identified as the major supplemental feed source, followed by kitchen waste, then crushed grain and maize bran, suggesting protein is deficient in chicken diets. Most often, the kitchen scraps include foods that are spoiled with mould or damaged by insects and are not used in human consumption. Farmers had no specific biases against the use of non-conventional feed ingredients for chickens. Households in mountain zones were more likely to use maize bran for feeding chickens than those near dams (odds ratio 8.26). Educated farmers were three times more likely to feed chickens with maize bran (odds ratio 3.01). Topography highly influenced household’s likelihood of experiencing feed shortage. Farmers in mountains zones were 2.3 times more likely to experience feed shortage than the farmers in dam areas. Households headed by females were 1.2 times more likely to experience feed shortage than households headed by men. Chemical composition, amino acid digestibility and the true metabolisable energy of cowpeas and pigeon peas- under various processing (heat and enzyme) treatments, as well as effects on growth performance, growth of internal organs, and gut health were investigated through feeding trials. The precision-fed cecectomized rooster assay was used to determine amino acid digestibility and true metabolizable energy of cowpeas. Crude protein (CP) content was higher (P0.05) amino acid concentrations compared with raw black-eyed beans. Heat treatment had no effect (P>0.05) on the levels of methionine, threonine, proline, alanine, valine or leucine. The amino acid content of nhemba was reduced (P0.05) on amino acid digestibility in black-eyed beans, but increased amino acid digestibility of nhemba by 3.4 %. True metabolizable energy (TMEn) was significantly increased (3535 versus 3164 kcal/kg) by extrusion. Body weight gains, feed conversion and gut morphology demonstrated that, despite the overall lower nutritional value of local legumes compared to soybeans, extruded cowpeas with enzymes, or roasted pigeon peas, could improve bird production and gut health. The effectiveness of diatomaceous earth (DE), bentonite clay (BC) and turmeric (TUM) in ameliorating the toxic effects of aflatoxin B1 (AFB1) was assessed in growing chickens. Addition of AFB1 to the BD depressed (P0.05) from those of control chicks. In contrast, chicks fed the 2.0 mg AFB1/kg diet alone had significantly depressed (P0.05) feed intake and growth rate of chickens fed the AFB1 diet. Chickens fed a control diet plus BC and either DE or TUM were as healthy as the control chicks. Bentonite clay gave a higher (P<0.05) body weight gain than the control chicks. Compared with chicks fed AFB1 alone, the addition of TUM into the AFB1 diet was not effective in preventing or reducing the increase in relative liver or kidney weight. Addition of a combination of both BC and TUM to the AFB1 diet prevented the increase in relative liver and kidney weights caused by AFB1. In contrast, the addition of a combination of DE and TUM to the AFB1 diet was not effective in reducing or preventing the increase in the weight of these organs caused by AFB1. Chickens fed the AFB1 diet supplemented with combinations of BC and TUM or DE and TUM had lower (P0.05) concentrations of Alanine aminotransferase (AST), Gamma-glutamyltransferase (GGT), and uric acid (UA) to that of chicks fed AFB1 only. In conclusion the addition of TUM alone into the AFB1 diet also did not demonstrate an ameliorating effect. The addition of the combination of BC and TUM to the AFB1 diet was not as effective in reversing the effect of AFB1 on BWG as the combination of DE and TUM. When BC and DE were fed in combination with TUM, the results showed a reversal in the comparative individual effectiveness of BE and DE in their ameliorating effect on BWG