True Digestibility Values Research Articles

Ticktrefoil (Desmodium) species as a nutraceutical forage resource for animals

AbstractTicktrefoil (Desmodium) species from the USDA, ARS, Plant Genetic Resources Conservation Unit (PGRCU) germplasm collection in Griffin, GA, were evaluated for their potential livestock nutraceutical (nutritional + pharmaceutical) value in a field small plot study at the Fort Valley State University (FVSU) Agricultural Research Station, Fort Valley, GA. Horse marmalade (Desmodium discolor Vogel), greenleaf ticktrefoil (Desmodium intortum [Mill.] Urb.), panicledleaf ticktrefoil (Desmodium paniculatum [L.] DC.), Hawaii ticktrefoil (Desmodium sandwicense E. May) and twisted ticktrefoil (Desmodium tortuosum [Sw.] DC.) were established in a greenhouse and transplanted to field plots, with plant material from each species harvested, freeze‐dried, ground and analyzed for nutrient content and bioactivity. Crude protein (CP) levels in D. discolor and D. tortuosum averaged 233 g/kg, whereas CP in D. intortum, D. paniculatum and D. sandwicense ranged from 99 to 157 g/kg. The Desmodium species had in vitro true digestibility values of 755 to 878 g/kg. There were no detectable condensed tannins in D. discolor and D. tortuosum, whereas D. intortum, D. paniculatum and D. sandwicense averaged 88, 89 and 73 g/kg total condensed tannin, respectively. There were species differences in flavonoid content (p < .01), with the highest delphinidin and cyanidin concentrations in D. sandwicense and D. paniculatum, respectively. There were no detectable levels of delphinidin or cyanidin for D. discolor or D. tortuosum. Quercitin and kaempferol concentrations were highest in D. intortum and D. paniculatum, respectively, whereas D. discolor and D. tortuosum had the lowest values. The highest protein precipitable phenolics and total phenolic concentrations were for D. paniculatum. Desmodium species have potential as nutraceutical forage for livestock and warrant further investigation.

Moderate adiposity levels counteract protein metabolism modifications associated with aging in rats

Physiological parameters such as adiposity and age are likely to influence protein digestion and utilization. The aim of this study was to evaluate the combined effects of age and adiposity on casein protein and amino acid true digestibility and its postprandial utilization in rats. Four groups were included (n = 7/8): 2months/normal adiposity, 2months/high adiposity, 11months/normal adiposity and 11months/high adiposity. Rats were given a calibrated meal containing 15N-labeled casein (Ingredia, Arras, France) and were euthanized 6h later. Digestive contents were collected to assess protein and amino acid digestibilities. 15N enrichments were measured in plasma and urine to determine total body deamination. Fractional protein synthesis rate (FSR) was determined in different organs using a flooding dose of 13C valine. Nitrogen and amino acid true digestibility of casein was around 95-96% depending on the group and was increased by 1% in high adiposity rats (P = 0.04). Higher adiposity levels counteracted the increase in total body deamination (P = 0.03) that was associated with older age. Significant effects of age (P = 0.006) and adiposity (P = 0.002) were observed in the muscle FSR, with age decreasing it and adiposity increasing it. This study revealed that a higher level of adiposity resulted in a slight increase in protein and individual amino acid true digestibility values and seemed to compensate for the metabolic postprandial protein alterations observed at older age.

Digestible Indispensable Amino Acid Scores (DIAAS) of Six Cooked Chinese Pulses.

Values for the digestible indispensable amino acid score (DIAAS) of a protein are based on true ileal amino acid (AA) digestibility values obtained in adult humans or in the growing pig as an animal model. An experiment was conducted using growing pigs to determine the true ileal digestibility (TID) values of AA in six cooked Chinese pulses (kidney bean, mung bean, adzuki bean, broad beans, peas and chickpeas). Each pulse was included in a diet as the only source of crude protein (CP). An N-free diet was given to allow determination of gut endogenous AA losses. Seven growing pigs each fitted with a T-cannula at the terminal ileum were allotted to a 7 by 6 incomplete Latin square with seven diets and six 7-d periods. The true digestibility values % for the total indispensable AA were higher (p < 0.001) for broad beans (87.3 ± 2.98) and lower (p < 0.001) for kidney bean (73.3 ± 4.84) than for the other pulses. For the older child (over 3 years), adolescent and adult, the DIAAS (%) was 88 for kidney bean, 86 for mung bean, 76 for chickpeas, 68 for peas, 64 for adzuki bean and 60 for broad beans.

The effects of fumaric and malic acids on the in vitro true digestibility of some alternative feedstuffs for ruminants

The aim of this study was to determine the effects of the addition of different amounts of fumaric acid (FA) and malic acid (MA) to the leaves of Robinia pseudoacacia (Black locust, acacia), Prunus laurocerasus (cherry laurel), Quercus cerris (oak), and Camellia sinensis (tea factory wastes, TFW), to improve their value as alternative feeds for ruminants. The parameters examined were the in vitro true digestibility of feed (IVTDAs fed), dry matter (IVTDDM), organic matter (IVTDOM), neutral detergent fiber (IVTDNDF) and count of protozoans. The digestibility experiments were performed with a DAISY incubator system. Organic acids were not added in the control group and 0.1%, 0.2% or 0.3% FA or MA were added to the experimental groups. Each treatment was replicated 6 times. Samples were incubated for 48 hours. Fumaric acid significantly reduced (P&amp;lt;0.01) all digestibility values of R. pseudoacacia leaves. When FA was applied at 0.1% to C. sinensis factory wastes, the IVTDOM increased significantly (P &amp;lt;0.05), with the same effect observed for Q. cerris (P&amp;lt;0.01). However, for the addition of 0.1% FA, IVTDAs Fed, IVTDDM and IVTDNDF values decreased significantly (P&amp;lt;0.01). Separately, malic acid did not have a significant effect on the in vitro true digestibility values determined in this study (P&amp;gt;0.05). Rumen protozoan counts decreased for both organic acid applications compared to counts in the fresh rumen contents. Because 0.1% fumaric acid increased the IVTDOM values of both C. sinensis factory wastes and Q. cerris leaves they can be considered potential alternative feed sources for ruminants.

Chemical composition, nutrient digestibility and metabolizable energy of germinated paddy rice

Germinated paddy rice (GPR) was examined for its potential as a feed ingredient in comparison with paddy rice (PR) without germination. The attributes related to the chemical composition, phytochemicals, thermal property, nutrient digestibility and ME value were evaluated. It was found that GPR samples contained 7.48% CP, 1.96% EE, 67.58% NFE and 12.55% crude fibre on an air-dry basis. The gross energy, 3.77 kcal/g, was found to be close to that of corn. Germinated paddy rice showed slightly lower ash, NFE and GE but higher CP, EE and CF than those of PR. The GPR exhibited high content of phytonutrients especially gamma-aminobutyric acid (GABA) and this enhanced its antioxidant activities. Germination was found to alter gelatinization temperature as evidenced by the thermal property. The true digestibility and ME values were evaluated using eight 1-year old male White Tail Yellow chickens housed in individual cages. The results revealed the true digestibility values of CP, EE and CF as 35.41, 61.35 and 46.26 per cent, respectively. Apparent ME (AME) and true ME values were 3.20 and 3.28 kcal/g on an air-dry basis, respectively. It is concluded that GPR could be a good alternative source of feed ingredient for poultry.

Digestibility of calcium and digestible calcium from inorganic sources evaluated in swine by two methods

SUMMARY The objective of the study was to determine the digestible calcium from different sources by direct and indirect methods. Thirty castrated male pigs were used, distributed in randomized blocks, in six treatments: 1- Calcitic limestone; 2-Dicalcium phosphate powder 18%; 3- Dicalcium phosphate powder 20%; 4- Dicalcium microgranulated phosphate 18%; 5- Monodicalcium microgranulated phosphate 20%; 6- Monodicalcium microgranulated phosphate 21%, with six replicates and one animal per experimental unit. A basal diet was formulated to meet the nutritional requirements of the animals, except for calcium (0.06%) and the evaluated sources replaced the basal diet in order to provide 0.45% of total Ca. At the same time, two stool collection methods were evaluated: total collection and fecal indicator. The animals were housed in metabolism cages for 12 days to collect feces and urine to determine the calcium values used to estimate digestibility coefficients and digestible calcium. The total collection method and the faecal indicator method did not affect the true digestibility coefficient of calcium. The calcium digestibility of the microgranulated dicalcium phosphate 21% (MM21) was superior in comparison with the other calcium sources evaluated by the indirect method in the present study. The average values of true digestibility of the calcium sources, in percentage, were: calcitic limestone: 82.47; dicalcium phosphate powder 18%: 80.87; dicalcium phosphate powder 20%: 85.65; dicalcium microgranulated phosphate 18%: 81.65; monodicalcium microgranulated phosphate 20%: 84.15; and monodicalcium microgranulated phosphate 21%: 88.35. The two methodologies can be used to determine the digestibility of calcium.

Chia Seed Shows Good Protein Quality, Hypoglycemic Effect and Improves the Lipid Profile and Liver and Intestinal Morphology of Wistar Rats.

Chia has been consumed by the world population due to its high fiber, lipids and proteins content. The objective was to evaluate the protein quality of chia untreated (seed and flour) and heat treated (90°C/20min), their influence on glucose and lipid homeostasis and integrity of liver and intestinal morphology of Wistar rats. 36 male rats, weanling, divided into six groups which received control diet (casein), free protein diet (aproteic) and four diet tests (chia seed; chia seed with heat treatment; chia flour and chia flour with heat treatment) for 14days were used. The protein efficiency ratio (PER), net protein ratio (NPR) and true digestibility (TD) were evaluated. The biochemical variables and liver and intestinal morphologies of animals were determined. The values of PER, NPR and TD did not differ among the animals that were fed with chia and were lower than the control group. The animals that were fed with chia showed lower concentrations of glucose; triacylglycerides, low-density lipoprotein cholesterol and very low-density lipoprotein and higher high-density lipoprotein cholesterol than the control group. The liver weight of animals that were fed with chia was lower than the control group. Crypt depth and thickness of intestinal muscle layers were higher in groups that were fed with chia. The consumption of chia has shown good digestibility, hypoglycemic effect, improved lipid and glycemic profiles and reduced fat deposition in liver of animals, and also promoted changes in intestinal tissue that enhanced its functionality.

Proteins of Bacuri almonds: nutritional value and in vivo digestibility

Bacuri (Scheelea phalerata Mart.) is a type of palm fruit tree widely distributed in the Brazilian Cerrado. The objective of this paper was to study the almonds of bacuri, in their form in natura and processed, focusing on their nutritional value through the profile of amino acids, anti-nutritional factors and in vivo digestibility. Raw and toasted samples of the almond presented a high level of proteins and fiber. Proteins of raw bacuri almond showed no limiting amino acid when compared to the ones recommended by FAO/WHO, and histidine was the most limiting essential amino acid in the toasted almonds. The almond of bacuri does not present anti- nutritional factors. In an assay with rats fed with control (casein), tests (bacuri almond flours) and aproteic diets, we verified the quantity of ration ingested and body weight gain, determining the urinary and metabolic nitrogen. Rats treated with the test diets presented inferior values of True Digestibility (DV), (82.9 and 72.3%, respectively for the raw and toasted almonds) when compared to the control group (92.3%). The raw bacuri almond presented a superior nutritional value to the one found in the toasted almond.

A multienzyme preparation enhances the utilization of nutrients and energy from pure corn and wheat diets in broilers

SUMMARY A metabolic experiment was conducted to investigate the effects of 2 different types of exogenous multienzyme preparations, one used to supplement a pure corn-based broiler diet (ME-C; mainly consisting of mannase, xylanase, cellulase, pectase, prolease, and glucoamylase) and the other added to a pure wheat-based broiler diet (ME-W; mainly containing xylanase, cellulase, glucanase, pectase, amylase, and glucoamylase), on the energy efficiency and nutrient utilization of broilers. Ninety 36-d-old Arbor Acres commercial male broilers were randomly allocated to 90 cages, and 72 of them were assigned to 8 treatment groups with 3 replicates of 3 broilers each. Four treatment groups were force-fed corn with different levels of ME-C (0, 50, 100, and 150 mg/ kg), and the other 4 treatment groups were force-fed wheat with different levels of ME-W (0, 50, 100, and 150 mg/kg). The remaining 18 birds were taken as 1 group, with 3 replicates of 6 birds for each, and used for endogenous excreta collection. Digestibility values of DM, NDF, starch, gross energy, and ME were measured by “true” methods. The ME-C and ME-W added to pure corn- and wheat-based diets, respectively, enhanced (P < 0.05) the apparent and true digestibility values of NDF, starch, DM, and gross energy and the AME and TME values of broilers. The nutrient digestibility and energy efficiency of corn responded quadratically (P < 0.05) to increasing amounts of ME-C. However, the digestibility of nutrients in corn did not change significantly at 100 and 150 mg/kg of ME-C, indicating a saturation effect. Thus, supplementation of 100 mg/kg of ME-C is sufficient to maximize the nutrient utilization and energy conversion of corn. However, linear (P < 0.001) and quadratic responses (P < 0.01) were observed for the nutrient digestibility and ME values in wheat-based diets with increasing amounts of ME-W added.

Evaluation of an expeller-extruded soybean meal for broilers

SUMMARY Any variation in processing soybeans for inclusion in poultry diets requires validation of the ability of the soybean meal to sustain growth performance similar to what is achieved with solvent-extracted soybean meal. Three experiments were conducted to investigate the effect of feeding an expeller-extruded soybean meal vs. a commercial solvent-extracted soybean meal. Growth performance attributable to the source of soybean meal did not differ for 0- to 18-d-old broilers fed 2 levels of Lys (1.0 or 1.3%) and 2 levels of ME (3,000 or 3,300 kcal/kg). Similar growth performance was obtained for broilers fed solvent-extracted soybean meal vs. expellerextruded soybean meal for 0 to 49 d. However, broilers fed the expeller-extruded soybean meal had lower breast meat yield (24.95 vs. 26.30%). True digestibility values determined with adult cecectomized roosters for the expeller-extruded soybean meal indicated digestibility values of 86.6, 83.5, 87.4, 85.5, 86.5, and 86.7 for Lys, Thr, Met, Val, Ile, and Leu, respectively, which are lower than those reported by the NRC for solvent-extracted soybean meal. The feeding value of expeller-extruded soybean meal used in these experiments was similar to that of solventextracted soybean meal; however, consideration must be given to amino acid digestibility to achieve optimal breast meat yield.

Prediction of the true digestible amino acid contents from the chemical composition of sorghum grain for poultry

Accurate knowledge of true digestible amino acid (TDAA) contents of feedstuffs is necessary to accurately formulate poultry diets for profitable production. Several experimental approaches that are highly expensive and time consuming have been used to determine available amino acids. Prediction of the nutritive value of a feed ingredient from its chemical composition via regression methodology has been attempted for many years. The artificial neural network (ANN) model is a powerful method that may describe the relationship between digestible amino acid contents and chemical composition. Therefore, multiple linear regressions (MLR) and ANN models were developed for predicting the TDAA contents of sorghum grain based on chemical composition. A precision-fed assay trial using cecectomized roosters was performed to determine the TDAA contents in 48 sorghum samples from 12 sorghum varieties differing in chemical composition. The input variables for both MLR and ANN models were CP, ash, crude fiber, ether extract, and total phenols whereas the output variable was each individual TDAA for every sample. The results of this study revealed that it is possible to satisfactorily estimate the TDAA of sorghum grain through its chemical composition. The chemical composition of sorghum grain seems to highly influence the TDAA contents when considering components such as CP, crude fiber, ether extract, ash and total phenols. It is also possible to estimate the TDAA contents through multiple regression equations with reasonable accuracy depending on composition. However, a more satisfactory prediction may be achieved via ANN for all amino acids. The R(2) values for the ANN model corresponding to testing and training parameters showed a higher accuracy of prediction than equations established by the MLR method. In addition, the current data confirmed that chemical composition, often considered in total amino acid prediction, could be also a useful predictor of true digestible values of selected amino acids for poultry.

Composição química, valores energéticos e digestibilidade verdadeira dos aminoácidos de farinhas de carne e ossos e de peixe para aves

Foram determinados a composição química, os valores energéticos, os coeficientes de digestibilidade e aminoácidos digestíveis verdadeiros de subprodutos de abatedouros, pelo método da "alimentação forçada" com galos cecectomizados. O delineamento experimental utilizado foi o inteiramente casualizado, com duas farinhas de peixe (FP1 e FP2), duas farinhas de carne e ossos (FCO1 e FCO2) e uma dieta jejum, tendo seis repetições e um galo por unidade experimental. Os valores de energia metabolizável aparente (EMA), EMA corrigida pelo balanço de nitrogênio (EMAn), energia metabolizável verdadeira (EMV) e EMV corrigida pelo balanço de nitrogênio (EMVn), valores expressos em kcal/kg de matéria natural, foram de 3.060, 3.188, 2.347 e 2.191 para a FP1, 3.238, 3.181, 2.603 e 2.377 para a FP2, 3.932, 4.057, 3.182 e 3.026 para a FCO1 e de 3.399, 3.710, 2.587 e 2.501 para a FCO2. Os coeficientes de metabolizabilidade da EMA, EMAn, EMV e EMVn, em porcentagem da energia bruta (EB), foram de 61,42; 64,99; 78,94 e 68,23 para a FP1, 63,58; 63,45; 80,94 e 74,00 para a FP2, 52,67; 58,40; 71,40 e 58,05 para a FCO1 e 49,04; 53,20; 67,73 e 55,97 para a FCO2. Os coeficientes médios de digestibilidade verdadeira dos aminoácidos essenciais e não-essenciais, em porcentagem, para a FP1, FP2, FCO1 e FCO2 foram, respectivamente, 94,32 e 92,87; 92,95 e 90,47; 83,24 e 76,94 e 83,83 e 76,96.

Estimation of true intestinal digestibility of dry matter, nitrogen and amino acids of cowpea and silverleaf desmodium forage legumes and Brachystegia spiciformis (musasa) browse legume

True intestinal digestibility of dry matter (DM), rumen-undegraded dietary protein (UDP) and amino acids of cowpea, silverleaf desmodium and Brachystegia spiciformis (musasa) were estimated. The true intestinal digestibility was calculated as the difference between the content of a bag that was preincubated in the rumen for 12, 24 and 48 h and was recovered in the faeces. Significantly higher DM and nitrogen disappearance rate in the rumen, postruminally and throughout the whole tract were found for cowpea than for silverleaf desmodium and musasa. Total amino acids or true nitrogen digestibility values of silverleaf desmodium and musasa tended to be higher than in cowpea. The true digestibilities for the individual amino acids in the different undegraded protein sources showed significant differences. The true intestinal digestibility of DM, nitrogen and amino acids in the mobile bags after 24 h and 48 h of preincubation in the rumen were higher for silverleaf desmodium and musasa, than in cowpea. Musasa and silverleaf desmodium provided little rumen-degradable nitrogen and supplied UDP to the intestines. The UDP supplied postruminally would be used for productive processes such as milk production and growth.

Apparent and true amino acid digestibility of artemia meal in broiler chicks (Short communication)

In order to determine the amino acid digestibility of artemia meal, five-week old male broiler chicks were given a semi-purified diet in which artemia meal was the sole source of protein. Apparent amino acid digestibility values of the assay diet, using ileal and excreta contents, were calculated using chromic oxide as indigestible marker. True digestibility values were calculated using endogenous output determined by feeding a nitrogen-free diet. The results showed that in determination of apparent amino acid digestibility of excreta, serine had the lowest (0.80) and methionine the highest (0.92) digestibility, while glycine had the lowest (0.88) and arginine and leucine the highest (0.95) apparent ileal digestibility. In measuring true excreta and ileal amino acid digestibility, alanine and glycine had the lowest (0.90 and 0.93) and methionine the highest (0.96 and 0.99) digestibility, respectively. In general, the site of measurement had no effect on apparent or true amino acid digestibility of artemia meal.

Coeficiente de digestibilidade verdadeira dos aminoácidos e valores de aminoácidos digestíveis do milho submetido a diferentes temperaturas de secagem e períodos de armazenamento

Determinou-se o coeficiente de digestibilidade verdadeira dos aminoácidos de amostras de milho submetidas a diferentes temperaturas de secagem (temperatura ambiente e secagem artificial a 80, 100 e 120°C) e períodos de armazenamento (0, 60, 120 e 180 dias). A digestibilidade verdadeira dos aminoácidos foi determinada pelo método de "alimentação forçada" utilizando-se galos Leghorn adultos cecectomizados, alojados individualmente em baterias metálicas. Utilizou-se delineamento inteiramente casualizado em esquema fatorial 4 × 4 (quatro temperaturas de secagem e quatro períodos de armazenamento) com um galo por unidade experimental e oito repetições por temperatura de secagem e período de armazenamento. As perdas endógenas foram determinadas com galos em jejum. O aumento da temperatura de secagem ocasionou redução linear da digestibilidade de metionina + cistina e isoleucina e efeito quadrático sobre a digestibilidade de metionina, treonina, lisina, triptofano e fenilalanina. Os maiores coeficientes de digestibilidade de metionina, treonina, lisina, triptofano e fenilalanina foram observados nas temperaturas 40, 25, 27, 32 e 40°C, respectivamente, obtidas por equação de regressão. Observou-se redução linear da digestibilidade de metionina e treonina com o tempo de armazenamento. A temperatura de secagem e o tempo de armazenamento dos grãos de milho reduzem a digestibilidade da maioria dos aminoácidos.

Ostrich (Strutio camelus) meat protein quality and digestibility

The purpose of the study was to evaluate ostrich meat protein quality, as its consumption has significantly increased in the last few years in Brazil. Male Wistar rats were distributed in groupe of six elements. The standard group received a casein-based diet, the control group received a protein-free diet, and the experimental group received ostrich meat diet as protein source. The evaluated biological parameters were protein efficiency ratio (PER), net protein ratio (NPR), net protein utilization (NPU), and true digestibility (TD). There were differences (p<0.05) among treatment groups for all evaluated biological parameters. Mean true digestibility values were 92.12% and 75.77% for casein and ostrich meat, respectively.

Comparison of ileal apparent, standardized and true digestibilities of amino acids in pigs fed wheat and lupine seeds

The aims of the investigation were to compare calculation methods for ileal apparent digestibility (AD) of amino acids (AA) and to demonstrate the calculation of ileal true digestibility (TD) using the regression approach and additionally, to compare the TD with the standardized digestibility (SD). Eight Goettingen minipigs, average 52 kg initial BW, were fitted with ileo-rectal anastomoses and fed consecutively with assay diets in four experiments according to a Latin rectangle design. To determine AD by using the ‘direct method’, diets contained wheat, lupine, or casein as the sole sources of protein. Furthermore, the ‘difference method’ was used by applying diets with wheat plus casein or wheat plus lupine. To determine AD using the regression (‘Reg2’) method, three graded levels of lupine mixed with wheat were fed. The TD and the basal ileal endogenous losses of AA (EL bAA) were determined using the regression approach (‘Reg1’) by feeding both 5 graded levels of lupine and 5 graded levels of wheat, each added with N-free mixture at 1000 g. In each experiment, one repetition comprised 10 days for adaptation and 4 days for quantitative collection of ileal effluents. Pigs were fed twice a day and the target dietary allowance was 35 g DM kg − 0.75 BW d − 1 in all experiments. There were no differences in the AD of any AA in lupine or in wheat when those were determined with the direct, difference or Reg2 method. The TD values of the most indispensable AA were higher than the AD (in lupine 8 to 20%-units for lysine and methionine and in wheat 6 to 11%-units for tryptophan and lysine, respectively). These differences reflected the EL bAA derived from the intercept ( a) of the Reg1. The EL bAA were higher in lupine than in wheat for arginine, histidine, leucine, methionine, phenylalanine, tryptophan, cysteine, glutamine, and serine ( P < 0.007 to 0.047). In conclusion, the TD of AA should be determined by Reg1 regression rather than calculation of SD, i.e. AD values corrected with means of EL bAA, because the latter cannot be assumed as constant.

Evaluation of Traditional Sorghum (Sorghum bicolor) Beer Residue, Shea-Nut (Vitellaria paradoxa) Cake and Cottonseed (Gossypium Spp) Cake for Poultry in Burkina Faso: Availability and Amino Acid Digestibility

The present study aimed to evaluate the nutritive value for chickens of some local by-products in Burkina Faso and to estimate their true amino acid digestibility in cockerels. Sun-dried sorghum (Sorghum bicolor) beer residue (n = 144) and shea-nut (Vitellaria paradoxa) cake (n = 36) samples were collected in two different locations during six months, while cottonseed (Gossypium spp) cake samples were purchased monthly in a local market for the same period (n = 24). Mean Dry Matter (DM) content of beer residue was 94.7% and Crude Protein (CP), Ether Extract (EE), Crude Fibre (CF), Calcium (Ca), Phosphorus (P) and Metabolizable Energy (ME) contents were 23.4, 5.6, 8.5, 0.14 and 0.25% of DM and 13.4 MJ/kg, respectively. Mean lysine, methionine, cystine and threonine contents were 0.87, 0.44, 0.41 and 0.63%, respectively and the corresponding true excreta digestibility values were 92, 98, 95 and 97%. Mean DM content of shea-nut cake was 95.6% and CP, EE, CF, Ca, P and ME contents were 6.7, 7.3, 10.9, 0.40 and 0.19% and 13.1 MJ/kg, respectively. Lysine, methionine, cystine and threonine contents were 0.27, 0.14, 0.09 and 0.23% and the true digestibility values were 96, 78, 88 and 77%, respectively. Mean DM, CP, EE, CF, Ca, P and ME contents of cottonseed cake were 94.8, 44.3, 5.9, 9.9, 0.34 and 1.3% and 12.7 MJ/kg. Lysine, methionine, cystine and threonine contents were 1.6, 0.80, 0.82 and 1.9% and the true digestibility values were 89, 97, 98 and 94%. Overall, higher nutritive values were found for samples collected between October and December and no difference was found between locations.

Digestibilidade ileal e perdas endógenas de aminoácidos de dietas com óleo de soja para suínos em crescimento

Este trabalho foi conduzido para avaliar o efeito de diferentes níveis de óleo de soja sobre as perdas endógenas e a digestibilidade ileal aparente e verdadeira dos aminoácidos em dietas para suínos em crescimento. Foram testadas quatro dietas isoprotéicas, à base de milho e farelo de soja, formuladas segundo as exigências para essa fase e suplementadas com níveis crescentes de óleo de soja (0,0; 1,5; 3,0; 4,5%) e 0,25% de óxido crômico como indicador de indigestibilidade. Dezesseis suínos canulados (cânula T simples), com 48,0 ± 6,0 kg, foram distribuídos em um delineamento em blocos casualizados, com base no peso dos animais. Não houve efeito dos níveis óleo de soja sobre os coeficientes de digestibilidade ileal aparente de glutamato, glicina, arginina, alanina, prolina, tirosina, histidina e lisina. Observaram-se efeito linear da suplementação com níveis de óleo de soja nos coeficientes de digestibilidade ileal aparente e verdadeira de serina e treonina e efeito quadrático da suplementação de óleo de soja sobre os coeficientes de digestibilidade ileal aparente e verdadeira de valina, fenilalanina, total de aminoácidos não-essenciais e total de aminoácidos essenciais. Os coeficientes de digestibilidade ileal verdadeira de arginina e tirosina também apresentaram efeito quadrático da suplementação de óleo de soja. Melhores valores de digestibilidade ileal aparente e verdadeira dos aminoácidos não-essenciais e essenciais são obtidos com adição de 2,8 a 3,0% de óleo de soja à dieta de suínos em crescimento.

Aminoácidos digestíveis verdadeiros de alimentos protéicos determinados em galos cecectomizados

Objetivou-se determinar os coeficientes de digestibilidade e os valores de aminoácidos digestíveis verdadeiros de 12 alimentos protéicos para aves. Utilizou-se o método de alimentação forçada, com galos Leghorne adultos cecectomizados, em um delineamento experimental inteiramente casualizado, com 12 tratamentos, seis repetições e um galo por unidade experimental. Os alimentos estudados foram: farelo de glúten de milho 22%, farelo de glúten de milho 60%, concentrado protéico de soja, soja integral extrusada parcialmente desengordurada, farinha de carne e ossos 36%, farinha de carne e ossos 45%, farinha de peixe, farinha de vísceras de aves de alto teor de gordura, farinha de penas, plasma sangüíneo 70%, plasma sangüíneo 78% e hemácias. Os valores médios dos coeficientes de digestibilidade verdadeira dos aminoácidos essenciais e não-essenciais, em porcentagem, foram, respectivamente, 83,32 e 87,20 para o farelo de glúten de milho 22%; 92,90 e 94,86 para o farelo de glúten de milho 60%; 91,10 e 90,19 para o concentrado protéico de soja; 88,90 e 88,91 para a soja integral extrusada parcialmente desengordurada; 88,63 e 85,94 para a farinha de carne e ossos 36%; 87,80 e 85,00 para a farinha de carne e ossos 45%; 89,39 e 87,32 para a farinha de peixe; 79,22 e 74,36 para a farinha de vísceras de aves de alto teor de gordura; 85,89 e 82,32 para a farinha de penas; 87,22 e 87,78 para o plasma sangüíneo 70%; 90,42 e 91,40 para o plasma sangüíneo 78%; e 95,25 e 94,31 para as hemácias.