Effect of heat treatment on protein quality of rapeseed protein isolate compared with non-heated rapeseed isolate, soy and whey protein isolates, and rice and pea protein concentrates.

BACKGROUND: Rapeseed protein isolate is used in the food industry, and heating is often used during rapeseed processing. However, the digestible indispensable amino acid score (DIAAS) for heat-treated rapeseed protein isolate is unknown. The present study aimed to test the hypothesis that heating rapeseed protein isolate improves protein quality resulting in DIAAS that is greater than for pea and rice protein concentrates, and comparable to that of soy and whey protein isolates. RESULTS: Standardized ileal digestibility (SID) of amino acids (AA), except leucine and methionine, was not different between heat-treated rapeseed protein isolate and soy protein isolate, but SID of most AA was greater (P < 0.001) for heat-treated rapeseed protein isolate than for brown rice protein concentrate, pea protein concentrate, rapeseed protein isolate and soy protein isolate, but not whey protein isolate. Non-heated rapeseed protein isolate had a reduced (P < 0.001) DIAAS for 6-month-old to 3-year-old children compared with soy protein isolate, but this was greater (P < 0.001) than for pea and brown rice protein concentrates. The DIAAS for heat-treated rapeseed protein isolate was greater (P < 0.001) than for non-heated rapeseed protein isolate for all age groups. Heat-treated rapeseed protein isolate and whey protein isolate had a DIAAS > 100 for individuals older than 3 years. CONCLUSION: Rapeseed protein isolate had a DIAAS comparable to soy protein isolate, but heat-treated rapeseed protein isolate and whey protein isolate had DIAAS ≥ 100, qualifying these proteins as 'excellent'. Rice and pea protein concentrates had DIAAS < 75. © 2023 Society of Chemical Industry.

Ferulic and coumaric acid in corn and soybean meal-based diets and in feces from pigs fed these diets.

BACKGROUND: Arabinoxylan is the main fiber component in corn and corn co-products that are commonly included in pig diets. However, this fiber fraction is resistant to enzymatic degradation in the gastrointestinal tract of pigs. Ferulic acid and p-coumaric acid are covalently linked to arabinoxylan, so it is likely that the majority of these hydroxycinnamic acids are excreted in feces. However, data to confirm this have not been reported. The objective of this research was therefore to quantify the ferulic and p-coumaric acids in a diet based on corn and soybean meal (SBM) and in a diet based on corn, SBM, and distillers' dried grains with solubles, as well as in feces from pigs fed these diets. RESULTS: The concentration of bound ferulic and coumaric acids in diets was greater in the corn-SBM-DDGS diet and in feces from pigs fed this diet than in the corn-SBM diet and feces from pigs fed that diet. The disappearance of free coumaric acids was greater (>85%) than that of bound phenolic acids (<50%) in both diets. The disappearance of free coumaric acid and bound ferulic acid in the intestinal tract of pigs was not different between the two diets. In contrast, disappearance of bound coumaric acid was greater (P < 0.05) in the corn-SBM diet than in the corn-SBM-DDGS diet. CONCLUSION: A diet based on corn and SBM contains less hydroxycinnamic acid than a corn-SBM-DDGS diet but bound phenolic acids are more resistant to digestion by pigs than free phenolic acids. © 2023 Society of Chemical Industry.

Comparison of True Ileal Amino Acid Digestibility between Adult Humans and Growing Pigs.

BACKGROUND: It is not feasible to determine the true ileal amino acid (AA) digestibility of protein sources in humans on a routine basis, and the growing pig has been recommended as an animal model for this purpose but requires further validation. OBJECTIVES: To determine and compare true ileal AA digestibility between adult human ileostomates and growing cannulated pigs for a range of food proteins. METHODS: Seven protein sources (black beans, bread, collagen, pigeon peas, wheat bran, whey protein isolate, and zein) that spanned the range of digestibilities typically seen in foods were evaluated. Six female growing pigs received each of the protein sources, as well as a protein-free diet, and digesta were collected via ileal T-cannula. Adult human ileostomates consumed the same protein sources (5-8 ileostomates, depending on the protein source), as well as a protein-free diet, and digesta were collected. Titanium dioxide and celite were included in the diets as indigestible markers. True ileal AA digestibility coefficients were determined. RESULTS: There was a significant effect of protein source (P ≤ 0.001) for all AAs. The effect of species was not significant (P > 0.05) except for total lysine (but not for available lysine). When analyzed within diets, the statistically significant species effect for true lysine digestibility was found for black beans only. Pig and human digestibility values were generally highly and significantly (P ≤ 0.05) correlated. A linear regression equation derived for true ileal AA digestibility (given as coefficients) determined in the human and pig for the overall mean of all AAs was (y = human, x = pig) y = 1.00x - 0.010, with the slope not statistically significant (P > 0.05) from unity and the intercept not different (P > 0.05) from zero. CONCLUSIONS: True ileal AA digestibility values determined in the growing pig can be directly used for predicting digestibility in adult humans.

Digestible indispensable amino acid score (DIAAS) is greater in animal-based burgers than in plant-based burgers if determined in pigs.

PURPOSE: Determine digestible indispensable amino acid score (DIAAS) for animal- and plant-based burgers and test the hypothesis that DIAAS calculated for a burger and a burger bun is additive in a combined meal. METHODS: Ten ileal cannulated gilts were fed experimental diets for six 9-d periods with ileal digesta being collected on d 8 and 9 of each period. Six diets contained a burger (i.e., 80% lean beef, 93% lean beef, 80% lean pork, Impossible Burger, or Beyond Burger) or a burger bun as the sole source of crude protein and amino acids. Three additional diets were based on a combination of the bun and 80% beef, pork, or Impossible Burger. A nitrogen-free diet was also used. The DIAAS for all ingredients and mixed meals was calculated for children from 6 months to 3 years and for individuals older than 3 years, and DIAAS for combined meals was predicted from individual ingredient DIAAS. RESULTS: The 93% lean beef and the pork burgers had greater (P < 0.05) DIAAS than the plant-based burgers for both age groups. The 80% lean beef burger had greater (P < 0.05) DIAAS than the plant burgers for children from 6 months to 3 years, and greater (P < 0.05) DIAAS than the Beyond Burger for individuals older than 3 years. There were no differences between the measured and predicted DIAAS. CONCLUSIONS: The protein quality of animal-based burgers is greater than that of plant-based burgers. However, for individuals older than 3 years, the Impossible Burger has comparable protein quality to the 80% lean beef burger. The DIAAS obtained from individual foods is additive in mixed meals.

Values for Digestible Indispensable Amino Acid Score (DIAAS) Determined in Pigs Are Greater for Milk Than for Breakfast Cereals, but DIAAS Values for Individual Ingredients Are Additive in Combined Meals.

BACKGROUND: Breakfast cereals contain low-quality proteins and are often consumed with milk. The digestible indispensable amino acid score (DIAAS) has been used to evaluate protein quality, but it is not known if DIAAS obtained in individual foods is additive in combined meals. OBJECTIVES: The following hypotheses were tested: amino acids (AAs) in milk complement AAs in breakfast cereals to provide a balanced meal, and DIAAS in individual foods is additive in combined meals. METHODS: Six ileal cannulated gilts [body weight mean: 55.6 ± 3.7 (SD) kg] were allotted to a 6 × 6 Latin square with six 7-d periods. Ileal digesta were collected for 9 h on days 6 and 7 of each period. Three diets contained a breakfast cereal (i.e., cornflakes or quick oats) or dry milk as the sole source of AAs. Two additional diets contained a combination of dry milk and cornflakes or quick oats. A nitrogen-free diet was also used, and DIAAS was calculated for cornflakes, quick oats, dry milk, and the 2 combined meals for children aged 6 to 36 mo and individuals older than 36 mo through adulthood. For the combined meals, DIAAS was also predicted from the individual ingredient DIAAS. RESULTS: Dry milk had greater (P < 0.05) DIAAS (123 and 144) than quick oats (57 and 67), but cornflakes had less (P < 0.05) DIAAS (16 and 19) than the other ingredients. Both breakfast cereal-dry milk meals had DIAAS close to or greater than 100 for children aged 6 mo to 3 y and for older children, adolescents, and adults, but there were no differences between measured and predicted DIAAS. CONCLUSIONS: The combination of milk and breakfast cereals results in a meal that is balanced in indispensable AAs for humans, and DIAAS obtained from individual ingredients is additive in mixed meals.

Pork Products Have Digestible Indispensable Amino Acid Scores (DIAAS) That Are Greater Than 100 When Determined in Pigs, but Processing Does Not Always Increase DIAAS.

BACKGROUND: Raw meat contains all indispensable amino acids (IAAs), but before human consumption, meat usually undergoes some degree of processing. Processing affects the 3-dimensional structure of proteins, which may affect amino acid (AA) digestibility and, therefore, overall protein quality. OBJECTIVES: The experiment aimed at determining digestible indispensable amino acid scores (DIAAS) for pork products, and to test the hypothesis that processing increases DIAAS. METHODS: Ten ileal cannulated gilts (body weight: 26.63 ± 1.62 kg) were randomly allotted to a 10 × 10 Latin square design with ten 7-d periods. Ileal digesta were collected for 9 h on days 6 and 7 of each period. Nine diets contained a single pork product (i.e., raw belly, smoked bacon, smoked-cooked bacon, non-cured ham, alternatively cured ham, conventionally cured ham, and loins heated to 63°C, 68°C, or 72°C) as the sole source of AAs. A nitrogen-free diet was formulated to determine basal endogenous losses of AAs, which enabled calculation of standardized ileal digestibility (SID) of AAs. DIAAS were subsequently calculated according to the FAO. RESULTS: All pork products had DIAAS >100 (as-is basis). Loin heated to 63°C had the greatest (P < 0.05) DIAAS for children 6 mo to 3 y and smoked-cooked bacon had the greatest (P < 0.05) DIAAS for children older than 3 y, adolescents, and adults. Raw belly, smoked bacon, and loins heated to 68°C and 72°C had a reduced (P < 0.05) DIAAS for both reference patterns compared with other proteins. Alternatively cured ham had greater (P < 0.05) DIAAS when compared with non-cured ham and conventionally cured ham. CONCLUSIONS: Bacon, ham, and loin are excellent proteins with DIAAS >100, and processing may sometimes, but not always, increase DIAAS.

Determination of True Ileal Amino Acid Digestibility in the Growing Pig for Calculation of Digestible Indispensable Amino Acid Score (DIAAS).

Digestible indispensable amino acid score (DIAAS) has been recommended by the FAO for the evaluation of protein quality in human foods, but the application of DIAAS is currently limited because of a lack of published data on the true ileal amino acid (AA) digestibility of AAs in foods. The importance of DIAAS is highlighted. To calculate DIAAS, it is necessary to determine the true ileal AA digestibility of human foods using the growing pig as an animal model for the human based on previous FAO recommendations. A method is described in detail in Supplemental Methods to determine the true ileal AA digestibility of foods for humans using the pig as a model for the adult human. Adoption of the method will enable consistency in the development of databases on predicted true ileal AA digestibility in human foods for the calculation of DIAAS.

Most meat products have digestible indispensable amino acid scores that are greater than 100, but processing may increase or reduce protein quality.

An experiment was conducted to test the hypothesis that meat products have digestible indispensable amino acid scores (DIAAS) >100 and that various processing methods will increase standardised ileal digestibility (SID) of amino acids (AA) and DIAAS. Nine ileal-cannulated gilts were randomly allotted to a 9 × 8 Youden square design with nine diets and eight 7-d periods. Values for SID of AA and DIAAS for two reference patterns were calculated for salami, bologna, beef jerky, raw ground beef, cooked ground beef and ribeye roast heated to 56, 64 or 72°C. The SID of most AA was not different among salami, bologna, beef jerky and cooked ground beef, but was less (P < 0·05) than the values for raw ground beef. The SID of AA for 56°C ribeye roast was not different from the values for raw ground beef and 72°C ribeye roast, but greater (P < 0·05) than those for 64°C ribeye roast. For older children, adolescents and adults, the DIAAS for all proteins, except cooked ground beef, were >100 and bologna and 64°C ribeye roast had the greatest (P < 0·05) DIAAS. The limiting AA for this age group were sulphur AA (beef jerky), leucine (bologna, raw ground beef and cooked ground beef) and valine (salami and the three ribeye roasts). In conclusion, meat products generally provide high-quality protein with DIAAS >100 regardless of processing. However, overcooking meat may reduce AA digestibility and DIAAS.

Raw and roasted pistachio nuts (Pistacia vera L.) are 'good' sources of protein based on their digestible indispensable amino acid score as determined in pigs.

BACKGROUND: Pistachio nuts may be consumed as raw nuts or as roasted nuts. However, there is limited information about the protein quality of the nuts, and amino acid (AA) digestibility and protein quality have not been reported. Therefore, the objective of this research was to test the hypothesis that raw and roasted pistachio nuts have a digestible indispensable AA score (DIAAS) and a protein digestibility corrected AA score (PDCAAS) greater than 75, thereby qualifying them as a good source of protein. RESULTS: The standardized ileal digestibility (SID) of all indispensable AAs, except arginine and phenylalanine, was less in roasted pistachio nuts than in raw pistachio nuts (P < 0.05). Raw pistachio nuts had a PDCAAS of 73, and roasted pistachio nuts had a PDCAAS of 81, calculated for children 2-5 years, and the limiting AA in the PDCAAS calculation was threonine. The DIAAS values calculated for children older than 3 years, adolescents, and adults was 86 and 83 for raw and roasted pistachio nuts respectively. The limiting AA in both raw and roasted pistachio nuts that determined the DIAAS for this age group was lysine. CONCLUSION: The results of this research illustrate that raw and roasted pistachio nuts can be considered a good quality protein source with DIAAS greater than 75; however, processing conditions associated with roasting may decrease the digestibility of AAs in pistachio nuts. © 2020 Society of Chemical Industry.

Digestible indispensable amino acid score (DIAAS) and protein digestibility corrected amino acid score (PDCAAS) in oat protein concentrate measured in 20- to 30-kilogram pigs.

BACKGROUND: Oat protein concentrate is often used in human food, but the quality of this protein has not been characterized. Therefore, the objectives of this experiment were to determine the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in oat protein concentrate and to determine differences in protein quality estimates between the protein digestibility-corrected AA score (PDCAAS) and the digestible indispensable AA score (DIAAS) when using growing pigs for both measurements. RESULTS: For infants, the most limiting AA in oat protein concentrate was the aromatic AA (Phe + Tyr), for which the DIAAS value was 41 and the PDCAAS was 43. For children (6 months to 3 years) and children older than 3 years, the most limiting AA in oat protein concentrate was Lys, for which the DIAAS was 56 and 67 and the PDCAAS was 58 and 69, respectively. CONCLUSION: The DIAAS value for oat protein concentrate was close to the calculated value for PDCAAS, but below the recommended intake for protein. Therefore, to satisfy the daily human AA requirement, oat protein needs to be complemented by other proteins of higher quality and specifically with greater lysine concentrations. © 2017 Society of Chemical Industry.

Additivity of values for phosphorus digestibility in corn, soybean meal, and canola meal in diets fed to growing pigs.

OBJECTIVE: This study was conducted to determine the apparent and standardized total tract digestibility (ATTD and STTD) of phosphorus (P) in corn, soybean meal (SBM), and canola meal (CM), and additivity of values for ATTD and STTD of P in corn, SBM, and CM in diets fed to growing pigs. METHODS: Thirty-six growing barrows (initial body weight of 21.6±1.7 kg) were placed in metabolism crates and allotted to a completely randomized design with 6 diets and 6 pigs per diet. Six diets were formulated using corn, SBM or CM as the sole source of P, or corn and SBM, or corn and CM, or corn, SBM, and CM as the P source in each diet, respectively. Fecal samples were collected for 5 d following a 7 d adaptation period to the diets. RESULTS: Values for ATTD and STTD of P in corn, SBM, and CM in growing pigs were 33.12% and 37.76%, 50.19% and 56.62%, 34.93% and 39.45%, respectively. The ATTD and STTD of P in SBM were greater (p<0.05) than those in corn and CM. However, there were no differences in the ATTD or STTD of P between corn and CM. The determined STTD of P in the mixture of corn and SBM, corn and CM, and corn, SBM, and CM is not different from the calculated STTD values. CONCLUSION: Values for STTD of P in corn, SBM, and CM are additive in their mixture fed to growing pigs.

Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS).

An experiment was conducted to compare values for digestible indispensable amino acid scores (DIAAS) for four animal proteins and four plant proteins with values calculated as recommended for protein digestibility-corrected amino acid scores (PDCAAS), but determined in pigs instead of in rats. Values for standardised total tract digestibility (STTD) of crude protein (CP) and standardised ileal digestibility (SID) of amino acids (AA) were calculated for whey protein isolate (WPI), whey protein concentrate (WPC), milk protein concentrate (MPC), skimmed milk powder (SMP), pea protein concentrate (PPC), soya protein isolate (SPI), soya flour and whole-grain wheat. The PDCAAS-like values were calculated using the STTD of CP to estimate AA digestibility and values for DIAAS were calculated from values for SID of AA. Results indicated that values for SID of most indispensable AA in WPI, WPC and MPC were greater (P<0·05) than for SMP, PPC, SPI, soya flour and wheat. With the exception of arginine and tryptophan, the SID of all indispensable AA in SPI was greater (P<0·05) than in soya flour, and with the exception of threonine, the SID of all indispensable AA in wheat was less (P<0·05) than in all other ingredients. If the same scoring pattern for children between 6 and 36 months was used to calculate PDCAAS-like values and DIAAS, PDCAAS-like values were greater (P<0·05) than DIAAS values for SMP, PPC, SPI, soya flour and wheat indicating that PDCAAS-like values estimated in pigs may overestimate the quality of these proteins.

Comparative digestibility of energy and nutrients in diets fed to sows and growing pigs.

The objective of this research was to compare values for digestible energy (DE) and metabolisable energy (ME) and apparent total tract digestibility (ATTD) of nutrients in 11 diets fed to both growing pigs and gestating sows. Three diets were based on corn, wheat or sorghum and eight diets were based on a combination of corn and soybean meal, canola meal, conventional distillers' dried grains with solubles, low-fat distillers' dried grains with solubles, corn germ meal, corn bran, wheat middlings or soybean hulls. A total of 88 gestating sows (252 ± 24.2 kg BW; parity two to six) and 88 growing barrows (40 ± 4.7 kg BW) were used and randomly allotted to the 11 diets with eight replicate sows or pigs per diet. Faecal and urine samples were collected for 4 d following a 19 d adaptation period. The DE, ME and ATTD of gross energy (GE), acid detergent fibre (ADF), neutral detergent fibre (NDF) and crude protein (CP) in the 11 diets were calculated. Gestating sows had greater (p < 0.05) ATTD of GE and CP and DE values for all diets compared with growing pigs. Gestating sows also had greater (p < 0.05) ME values than growing pigs for the three grain diets and the diets containing wheat middlings and soybean hulls. No differences were observed in ATTD of ADF and NDF between gestating sows and growing pigs for any of the diets, except that gestating sows had greater (p < 0.05) ATTD of NDF than growing pigs when they were fed the four protein diets. The ATTD of GE and CP and DE values in gestating sows may be predicted by using equations generated from the values of ATTD of GE and CP and DE values obtained in growing pigs. Results of this research indicate that ATTD values of CP and GE obtained in gestating sows are greater than the values obtained in growing pigs, but values for ATTD of ADF obtained in growing pigs are not different from values in gestating sows.

Prediction of digestible and metabolisable energy in soybean meals produced from soybeans of different origins fed to growing pigs.

The objective of this experiment was to determine the digestible energy (DE) and metabolisable energy (ME) in 22 sources of soybean meal (SBM) produced from soybeans from different countries and subsequently to establish equations for predicting the DE and ME in SBM based on their chemical composition. The 22 sources of SBM were all processed in Chinese crushing plants, but the soybeans used originated from China (n=6), the US (n=6), Brazil (n=7) or Argentina (n=3). The basal diet was a corn-based diet and 22 additional diets were formulated by mixing corn and 24.3% of each source of SBM. The average DE and ME in SBM from China, the US, Brazil and Argentina were 15.73, 15.93, 15.64 and 15.90 MJ/kg and 15.10, 15.31, 14.97 and 15.42 MJ/kg, respectively, and no differences among countries were observed. From a stepwise regression analysis, a series of DE and ME prediction equations were generated. The best-fit equations for SBM were DE=38.44-0.43 crude fibre -0.98 gross energy +0.11 acid detergent fibre (R2=0.67, p<0.01) and ME=2.74+0.97 DE -0.06 crude protein (R2=0.79, p<0.01). In conclusion, there were no differences in the DE and ME of SBM among the different soybean sources used in this experiment. The DE and ME of SBM of different origin can be predicted based on their chemical composition when fed to growing pigs.

Digestible indispensable amino acid score and digestible amino acids in eight cereal grains.

To determine values for the digestible indispensable amino acid score (DIAAS), it is recommended that ileal amino acid (AA) digestibility values obtained in growing pigs are used to characterise protein quality in different foods. Therefore, an experiment was conducted to determine the standardised ileal digestibility (SID) of AA in eight cereal grains (yellow dent maize, Nutridense maize, dehulled barley, dehulled oats, polished white rice, rye, sorghum and wheat) fed to pigs, where SID values in pigs can be used to calculate approximate DIAAS values in humans. In the present experiment, twenty-four barrows with a T-cannula inserted in the distal ileum were allotted to eight diets and fed for three periods to give a total of nine replicate pigs per diet. Each period lasted 14 d, and ileal digesta samples were collected on days 13 and 14. Among the SID values obtained for all cereal grains, values for total indispensable AA were greatest (P< 0·05) in rice and lowest (P< 0·05) in rye and sorghum. The concentrations of SID indispensable AA in rice were less (P< 0·05) than in dehulled oats, but greater (P< 0·05) than in the other cereal grains, and the concentrations of SID indispensable AA in Nutridense maize were greater (P< 0·05) than in yellow dent maize and sorghum, but less (P< 0·05) than in the other cereal grains, except rye. In conclusion, results indicate that to meet dietary requirements for AA in humans, diets based on yellow dent maize or sorghum require more AA supplementation than diets based on other cereal grains.

Comparative digestibility of energy and nutrients and fermentability of dietary fiber in eight cereal grains fed to pigs.

BACKGROUND: Cereal grains provide a large portion of caloric intake in diets for humans, but not all cereal grains provide the same amount of energy. Therefore, an experiment was conducted to determine and compare the metabolizable energy (ME), the apparent ileal digestibility (AID), and the apparent total tract digestibility (ATTD) of gross energy (GE) and nutrients in eight cereal grains when fed to pigs. RESULTS: Rice had greater (P < 0.05) AID of GE than other cereal grains, greater (P < 0.05) AID of starch than yellow dent corn, dehulled barley, rye, and wheat, and greater (P < 0.05) ATTD of GE than yellow dent corn, rye, sorghum, and wheat. Dehulled barley, rye, and sorghum had less (P < 0.05) AID of starch than other cereal grains. Dehulled barley had greater (P < 0.05) ATTD of GE than rye. Dehulled oats had the greatest (P < 0.05) ME compared with other cereal grains, whereas rye had the least (P < 0.05) ME. CONCLUSION: Dehulled oats provide more energy to diets and should be used if the goal is to increase caloric intake. In contrast, sorghum and rye may be more suitable to control diabetes and manage body weight of humans.

Effect of novel fiber ingredients on ileal and total tract digestibility of energy and nutrients in semi-purified diets fed to growing pigs.

BACKGROUND: Consumption of different dietary fibers may influence the digestibility of carbohydrates and other nutrients. Therefore the objectives of this experiment were to determine the effect of novel fiber ingredients on the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of gross energy (GE), dry matter (DM), crude protein (CP) and total dietary fiber (TDF) in pigs and to calculate the standardized digestibility of analyzed TDF in four novel fiber ingredients. RESULTS: The AID of DM and GE in diets containing novel fiber ingredients was less (P < 0.05) than in a maltodextrin diet. Addition of cellulose or pullulan, but not resistant starch (RS) 60, RS 75 or soluble corn fiber 70, reduced (P < 0.05) the AID of CP. The average ileal and total tract endogenous losses of analyzed TDF were calculated at 25.25 and 42.87 g kg⁻¹ DM intake, respectively. CONCLUSION: Addition of novel fiber ingredients to a maltodextrin-based diet had different effects on the AID of DM, CP, GE and TDF. Measurements of the standardized digestibility of analyzed TDF may be a better indicator of TDF fermentability than measurements of AID and ATTD of TDF, because some endogenous metabolites may be analyzed as TDF.

Effects of co-products from the corn-ethanol industry on body composition, retention of protein, lipids and energy, and on the net energy of diets fed to growing or finishing pigs.

BACKGROUND: Conventional distillers dried grains with solubles (DDGS-CV), uncooked distillers dried grains with solubles (DDGS-BPX) and high-protein distillers dried grains (HP-DDG) are used in diets for pigs to provide protein and energy. These ingredients may have different effects on body composition and energy retention. Therefore, an experiment was conducted to determine effects of DDGS-CV, DDGS-BPX and HP-DDG on body composition and on retention of protein, lipids, and energy when fed to growing or finishing pigs. RESULTS: The total organ weight was greater (P < 0.05) for finishing pigs fed the HP-DDG diet than for finishing pigs fed the basal diet or the DDGS-CV diet. Finishing pigs fed the DDGS-CV diet had greater (P < 0.05) lipid gain than pigs fed the other diets, and the net energy (NE) for DDGS-CV was greater (P < 0.05) than for DDGS-BPX, but the NE value of HP-DDG was not different from that of DDGS-CV or DDGS-BPX. CONCLUSION: Inclusion of up to 30% DDGS or HP-DDG in diets fed to growing or finishing pigs will not affect body composition or the retention of energy, protein and lipids, regardless of the stage of growth of pigs. The NE value of DDGS-BPX and HP-DDG is not affected by the stage of growth of pigs, but the NE value of DDGS-CV is greater in finishing than in growing pigs.

The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p < 0.05) than ileal endogenous fluxes and total tract endogenous losses of Ca, but ileal endogenous fluxes were less (p < 0.05) than total tract endogenous losses. Standardised digestibility of Ca was not affected by the level of phytic acid, but decreased (p < 0.05) as Ca level increased in L. calcareum Ca diets, but that was not the case if calcium carbonate was the source of Ca (interaction, p < 0.05). The standardised duodenal digestibility (SDD), standardised ileal digestibility (SID) and standardised total tract digestibility (STTD) of Ca were not different if calcium carbonate was the source of dietary Ca. However, the STTD of Ca in L. calcareum Ca was greater (p < 0.05) than the SID and SDD of Ca. The SDD, SID and STTD of Ca in calcium carbonate were greater (p < 0.05) than those of L. calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly absorbed before the duodenum, but Ca from L. calcareum Ca is mostly absorbed in the jejunum and ileum.

Pelleting and particle size reduction of corn increase net energy and digestibility of fiber, protein, and fat in corn-soybean meal diets fed to group-housed pigs.

BACKGROUND: Reduction of the particle size of corn increases energy digestibility and concentrations of digestible and metabolizable energy. Pelleting may also reduce particle size of grain, but it is not known if there are interactions between particle size reduction and pelleting. The objective of this experiment was to test the hypothesis that particle size reduction and pelleting, separately or in combination, increase N balance, apparent total tract digestibility (ATTD) of fiber and fat, and net energy (NE) in corn-soybean meal diets fed to group-housed pigs. METHODS: Six corn-soybean meal-based diets were used in a 3 × 2 factorial design with 3 particle sizes of corn (i.e., 700, 500, or 300 µm) and 2 diet forms (i.e., meal or pelleted). Pigs were allowed ad libitum access to feed and water. Twenty-four castrated male pigs (initial weight: 29.52 kg; standard diviation: 1.40) were allotted to the 6 diets using a 6 × 6 Latin square design with 6 calorimeter chambers (i.e., 4 pigs/chamber) and 6 periods. Oxygen consumption and CO2 and CH4 productions were measured during fed and fasting states and fecal and urine samples were collected. RESULTS: Regardless of particle size of corn, the ATTD of gross energy (GE), N, and acid-hydrolyzed ether extract (AEE), and the concentration of NE were greater (P < 0.05) in pelleted diets than in meal diets. Regardless of diet form, the ATTD of GE, N, and AEE, and the concentration of NE were increased (linear; P < 0.05) by reducing the particle size of corn, but the increase was greater in meal diets than in pelleted diets (interaction; P < 0.05). CONCLUSIONS: Both pelleting and reduction of corn particle size increased nutrient digestibility and NE, but increases were greater in meal diets than in pelleted diets.