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

Standardized Ileal Digestibility of Amino Acids in Hybrid Rye Ground to Two Particle Sizes and Fed With or Without Multienzyme Supplement to Young Growing Pigs

A newly developed hybrid rye with enhanced ergot resistance has potential as an alternative energy source for pigs. An experiment was conducted to evaluate the effects of particle size (PS) and multienzyme supplement (MES) on the apparent total tract digestibility (ATTD) of energy and nutrients and the standardized ileal digestibility (SID) of amino acids (AA) in hybrid rye fed to growing pigs. Bono and Gatano, two hybrid rye varieties, were ground to either a coarse (1111 and 1210 μm) or a fine (594 and 717 μm) PS using a hammer mill. Eighteen ileal-cannulated barrows (initial BW = 18.2 ± 1.0 kg) were randomly assigned to 1 of 9 dietary treatments in a replicated 9 × 3 incomplete Latin square design to give six observations per treatment. Among the nine experimental diets, eight featured two hybrid rye varieties (Bono or Gatano), either coarsely or finely ground, as the only source of AA with or without MES, while an N-free diet was used to estimate the endogenous losses of AA at the distal ileum. All diets contained titanium dioxide as an indigestible marker. Each period lasted 9 days, with the first 5 days being for adaptation followed by 2 days each for faecal and ileal digesta collection. Data were analysed using the MIXED procedure of SAS, with the final model having variety, PS, MES, their two-way interactions, and a three-way interaction. No interactions were noted except that the apparent ileal digestibility and SID of crude protein (CP) and most AA in Gatano had greater effects of MES than Bono (Variety × MES; p < 0.05). The ATTD of dry matter (DM), gross energy (GE) and CP were greater (p < 0.05) in Bono diets than in Gatano diets. Finely ground hybrid rye diets had higher (p < 0.05) ATTD of neutral detergent fibre assayed with a heat stable amylase and expressed inclusive of residual ash (NDF) and ether extract compared to coarsely ground hybrid rye diets. Dietary MES supplementation increased (p < 0.05) the ATTD of DM, GE, CP, NDF, acid detergent fibre expressed inclusive of residual ash, and ash in hybrid rye diets. In conclusion, the nutrients digestibility of hybrid rye can be affected by its variety. PS reduction improved the nutrient digestibility in hybrid rye, and MES supplementation improved the energy and AA digestibility in hybrid rye fed to growing pigs.

Reduction of particle size of field peas (Pisum sativum L.) increases net energy and digestibility of starch when fed to growing pigs, but there is no difference in nutritional value between peas from the United States and peas from Canada

Two experiments were conducted to test the hypotheses that particle size of field peas and location where peas are grown do not affect apparent total tract digestibility of nutrients and gross energy, digestible energy (DE), metabolizable energy (ME), and net energy (NE), apparent ileal digestibility (AID) of starch, or standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA). In both experiments, 3 sources of field peas were used. One source was obtained from the United States and 2 sources were obtained from Canada (i.e., Canada 1 and Canada 2). The U.S. field peas were ground to 678, 457, or 265 µm, whereas the 2 sources of Canadian peas were ground to 411 and 415 µm, respectively. Therefore, 5 batches of field peas were used in both experiments. A basal diet contained corn and soybean meal as the only source of energy, starch, and AA, and 5 diets containing corn and soybean meal and 50% of each source of field peas were also formulated. The ratio between corn and soybean meal was 1.92:1 in all diets. In experiment 1, an N-free diet was also used to calculate basal endogenous losses of AA and CP, but in experiment 2, no N-free diet was used. In experiment 1, 7 barrows (initial body weight = 60.6 ± 2.1 kg) that had a T-cannula installed in the distal ileum were allotted to a 7 × 7 Latin square design with 7 diets and 7 periods. In experiment 2, 24 pigs (initial body weight = 30.8 ± 1.0 kg) were housed in 6 calorimeter chambers with 4 pigs per chamber. The 6 chambers were allotted to one of the 6 diets using a 6 × 6 Latin square design with 6 consecutive periods of 15 d. Results of experiment 1 demonstrated that the SID of CP and AA was not influenced by the origin of the peas or by the particle size, but the AID of starch increased (linear, P < 0.001) as particle size was reduced from 678 to 457 or 265 µm. Results of experiment 2 indicated that growing location did not affect concentrations of DE, ME, or NE of field peas, but concentrations of DE, ME, and NE increased (linear, P < 0.05) when particle size was reduced from 678 to 457 or 265 µm. In conclusion, field peas grown in Canada or the United States have the same nutritional value, but starch digestibility and NE increase if the particle size of field peas is reduced.

Prediction of available energy and amino acid digestibility of Chinese sorghum fed to growing-finishing pigs

Two experiments were conducted to determine digestible energy (DE), metabolizable energy (ME), as well as the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in 10 sorghum samples fed to pigs. In experiment 1, 22 crossbred barrows (Duroc × Yorkshire × Landrace, Initial body weight [BW]: 70.0 ± 1.8 kg) were selected and allotted to a replicated 11 × 3 incomplete Latin square design, including a basal diet and 10 sorghum energy diets and three consecutive periods. Each period had 7 d adaptation and 5 d total feces and urine collection. The DE and ME were determined by the total collection and the difference method. In experiment 2, 22 crossbred barrows (Duroc × Yorkshire × Landrace, Initial BW: 41.3 ± 1.2 kg) that had a T-cannula installed in the distal ileum were assigned to a replicated 11 × 3 incomplete Latin square design, including an N-free diet and 10 sorghum diets. Each period had 5 d adaptation and 2 d ileal digesta collection. The basal endogenous N losses were measured by the N-free diet method. All diets in experiment 2 were added 0.30% titanium dioxide as an indigestible marker for calculating the ileal CP and AA digestibility. On an as-fed basis, the DE and ME contents in sorghum were 3,410 kcal/kg (2,826 to 3,794 kcal/kg) and 3,379 kcal/kg (2,785 to 3,709 kcal/kg), respectively. The best-fit prediction equation for DE and ME were DE = 6,267.945 - (1,271.154 × % tannin) - (1,109.720 × % ash) (R2 = 0.803) and ME = 51.263 + (0.976 × DE) (R2 = 0.994), respectively. The SID of CP, Lys, Met, Thr, and Trp (SIDCP, SIDLys, SIDMet, SIDThr, and SIDTrp) in 10 sorghum samples were 78.48% (69.56% to 84.23%), 74.27% (61.11% to 90.60%), 92.07% (85.16% to 95.40%), 75.46% (66.39% to 80.80%) and 87.99% (84.21% to 92.37%), respectively. The best prediction equations for SID of CP and the first four limiting AAs were as following: SIDCP = 93.404 - (21.026 × % tannin) (R2 = 0.593), SIDCP = 42.922 - (4.011 × % EE) + (151.774 × % Met) (R2 = 0.696), SIDLys = 129.947 - (670.760 × % Trp) (R2 = 0.821), SIDMet = 111.347 - (232.298 × % Trp) (R2 = 0.647), SIDThr = 55.187 + (3.851 × % ADF) (R2 = 0.609) and SIDTrp = 95.676 - (10.824 × % tannin) (R2 = 0.523), respectively. Overall, tannin and ash are the first and second predictors of DE and ME values of sorghum, respectively, and the tannin, EE, Trp, ash, CF, and ADF can be used as the key predictors for SID of CP and first four limiting AAs.

Protein Quality in Perspective: A Review of Protein Quality Metrics and Their Applications

For design of healthy and sustainable diets and food systems, it is important to consider not only the quantity but also the quality of nutrients. This is particularly important for proteins, given the large variability in amino acid composition and digestibility between dietary proteins. This article reviews measurements and metrics in relation to protein quality, but also their application. Protein quality methods based on concentrations and digestibility of individual amino acids are preferred, because they do not only allow ranking of proteins, but also assessment of complementarity of protein sources, although this should be considered only at a meal level and not a diet level. Measurements based on ileal digestibility are preferred over those on faecal digestibility to overcome the risk of overestimation of protein quality. Integration of protein quality on a dietary level should also be done based on measurements on an individual amino acid basis. Effects of processing, which is applied to all foods, should be considered as it can also affect protein quality through effects on digestibility and amino acid modification. Overall, protein quality data are crucial for integration into healthy and sustainable diets, but care is needed in data selection, interpretation and integration.

Available energy and amino acid digestibility of yellow dent corn fed to growing pigs1

Two experiments were conducted to determine the DE and ME as well as the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA in corn fed to growing pigs. All corn was yellow dent corn collected from different areas in China. In Exp. 1, 60 crossbred barrows (Duroc × Landrace × Yorkshire; 40.7 ± 3.5 kg BW) were randomly allotted to 1 of 10 diets to determine the DE and ME of corns. Diets were formulated to contain 96.8% of 1 of the 10 corn samples and 3.2% of other microingredients. In Exp. 2, 11 crossbred barrows (Duroc × Landrace × Yorkshire; 30.5 ± 2.3 kg) fitted with a T-cannula at the distal ileum were assigned to a 6 × 11 Youden square design with 6 periods and 11 diets. Diets included a N-free diet based on cornstarch and sucrose and 10 test diets formulated with 96.6% 1 of the 10 corns as the sole source of AA. Chromic oxide (0.3%) was added to each diet as an indigestible marker for calculating the AA digestibility. On a DM basis, the starch, ether extract (EE), CP, NDF, and ADF contents of corns averaged 74.05% (69.98 to 78.59%), 3.83% (2.04 to 4.73%), 9.63% (7.74 to 10.43%), 10.80% (10.27 to 11.46%), and 2.27% (2.03 to 2.57%), respectively. The CV of EE, CP, and ADF was 22.59, 8.22, and 8.21%, respectively. The DE and ME of corns averaged 4,087 and 3,981 kcal/kg, respectively, and ranged from 3,999 to 4,161 kcal/kg and from 3,898 to 4,067 kcal/kg, respectively. The DE and ME values were positively correlated (P < 0.05) with the EE content. Optimal prediction equations of ME were ME = 940.35 + (0.72 × DE) + (21.88 × EE) (R2 = 0.94) or ME = 1,051.50 + (0.82 × DE) - (282.05 × ash) (R2 = 0.99). In Exp. 2, significant differences (P < 0.05) were observed in the SID of Arg, His, Phe, Ala, Pro, Cys, and Tyr. The SID of Lys (average 73.79%), Met (average 87.32%), and Thr (average 80.06%) ranged from 61.45 to 78.47%, from 74.09 to 90.91%, and from 79.19 to 85.79%, respectively. The standardized ileal digestible Met was positively correlated (P < 0.01) with the Met and CP contents. The obtained prediction equations were standardized ileal digestible Met = 31.34 + (3.43 × CP) + (116.04 × Met) and standardized ileal digestible Met = 104.92 + (294.71 × Met) - (7.03 × NDF). In conclusion, sources had an effect on the energy values and ileal digestibility of most AA in corn. The ME can be predicted by the DE combined with either the EE or ash content. The AA concentrations and SID of AA in corn varied largely.

An integrated look at the effect of structure on nutrient bioavailability in plant foods

The true bioavailability of a nutrient being intrinsically coupled to the specific food matrix in which it occurs remains poorly considered in nutrition science. During digestion, the food matrix and, in particular, the structure of food modulate the extent and kinetics to which nutrients and bioactive compounds make themselves available for absorption. In this perspective, we describe an integrated look at the effect of structure on nutrient bioavailability in plant foods. Based on this integrated look, cell wall integrity and the particle size of the plant material during its transit in the small intestine determine the bioavailability of plant nutrients; in turn, cell wall integrity and particle size are determined by the level of oral processing and, accordingly, what subsequently escapes digestion in the upper intestine and is utilized by colon microbiota. Ultimately, the effect on nutrient digestion is linked to food structure through each step of digestion. A consideration of the structure rather than just the composition of foods opens up possibilities for the design of healthier foods. © 2018 Society of Chemical Industry.

Processing of ingredients and diets and effects on nutritional value for pigs

A conventional diet based on corn and soybean meal fed to pigs is usually provided in a mash form and in most cases, processing other than grinding and mixing is not used. However, due to the high cost of energy in pig diets, use of high fiber ingredients such as soybean hulls, distillers dried grains with solubles, and wheat middlings has increased. High fiber concentrations in the diet usually results in reduced energy and nutrient digestibility due to the low capacity of pigs to digest fiber, which negatively impacts growth performance and carcass composition of the pigs. Feed processing technologies such as changes in grinding procedures, expansion, extrusion, pelleting, use of enzymes or chemical treatments may, however, be used to solubilize some of the cellulose and hemicellulose fractions that form the cell wall of plants in the ingredients, and therefore, increase nutrient availability. This may have a positive effect on energy digestibility, and therefore, also on pig growth performance and carcass composition, but effects of different feed technologies on the nutritional value of feed ingredients and diets fed to pigs are not fully understood. It has however, been demonstrated that reduced particle size of cereal grains usually results in increased digestibility of energy, primarily due to increased digestibility of starch. Extrusion or expansion of ingredients or diets may also increase energy digestibility and it appears that the increase is greater in high fiber diets than in diets with lower concentrations of fiber. Chemical treatments have not consistently improved energy or nutrient digestibility, but a number of different enzymes may be used to increase the digestibility of phosphorus, calcium, or energy. Thus, there are several opportunities for using feed technology to improve the nutritional value of diets fed to pigs.

A Comparison of Diets Supplemented with a Feed Additive Containing Organic Acids, Cinnamaldehyde and a Permeabilizing Complex, or Zinc Oxide, on Post-Weaning Diarrhoea, Selected Bacterial Populations, Blood Measures and Performance in Weaned Pigs Experimentally Infected with Enterotoxigenic E. coli

The effects of feeding a diet supplemented with zinc oxide (ZnO) or a blend of organic acids, cinnamaldehyde and a permeabilizing complex (OACP) on post-weaning diarrhoea (PWD) and performance in pigs infected with enterotoxigenic E. coli (ETEC) were examined. Additionally, changes in selected bacterial populations and blood measures were assessed. A total of 72 pigs weaned at 22 d of age and weighing 7.2 ± 1.02 kg (mean ± SEM) was used. Treatments were: base diet (no antimicrobial compounds); base diet + 3 g ZnO/kg; base diet + 1.5 g OACP/kg. Dietary treatments started on the day of weaning and were fed ad libitum for 3 weeks. All pigs were infected with an F4 ETEC on d 4, 5 and 6 after weaning. The incidence of PWD was lower in pigs fed ZnO ( p = 0.026). Overall, pigs fed ZnO grew faster ( p = 0.013) and ate more ( p = 0.004) than the base diet-fed pigs, with OACP-fed pigs performing the same ( p > 0.05) as both the ZnO- and base diet-fed pigs. Feed conversion ratio was similar for all diets ( p > 0.05). The percentage of E. coli with F4 fimbriae was affected a day by treatment interaction ( p = 0.037), with more E. coli with F4 fimbriae found in pigs fed ZnO on d 11 ( p = 0.011) compared to base diet-fed pigs. Only significant time effects ( p < 0.05) occurred for blood measures. Under the conditions of this study, inclusion of OACP gave statistically similar production responses to pigs fed ZnO, however pigs fed ZnO had less PWD compared to OACP- and the base diet-fed pigs.

Forage plants as an alternative feed resource for sustainable pig production in the tropics: a review

Globally, pressure on concentrate feed resources is increasing, especially in the tropics where many countries are net importers of food. Forage plants are a possible alternative, but their use as feed ingredients for pigs raises several issues related to their higher fibre and plant secondary metabolites contents as well as their lower nutritive value. In this paper, the nutritive value of several forage species and the parameters that influence this nutritive value in relationship to the plant family, the physiological stage, the plant part and the preservation method (fresh, hay and silage) are reviewed. The influence of the breed and the physiological status of the animal on animal voluntary intake of fibre-rich ingredients, digestibility as related to gastrointestinal volume and transit time and growth performances are also discussed. The final section highlights the advantages and drawbacks of forage plants in pig diets and stresses the need for proper economic evaluation to conclude on the benefits of the use of forage plants in pig feed.

Whole body protein deposition and plasma amino acid profiles in growing and/or finishing pigs fed increasing levels of sulfur amino acids with and without Escherichia coli lipopolysaccharide challenge

A split plot experiment with 72 male pigs weighing 52.9 ± 0.39 kg (mean ± SEM) was conducted to examine AA partitioning and body protein deposition (PD) in response to increasing dietary sulfur amino acids (SAA) with or without immune system (IS) activation. The main plot was with and without IS activation, and 4 diets containing different amounts of standardized ileal digestible (SID) SAA (SAA to Lys ratios of 0.45, 0.55, 0.65 and 0.75) were the subplots. Activation of IS was achieved by intramuscular injection of Escherichia coli lipopolysaccharides (LPS; serotype 055:B5, Sigma; 30 μg/kg BW) every Monday and Thursday, with control pigs injected with sterile saline. Maximum body PD, measured by dual-energy X-ray absorptiometry (DXA), and minimum plasma urea content were achieved at SID SAA:Lys ratio of 0.55 in saline-injected pigs but were achieved at a SID SAA:Lys ratio of 0.75 in IS-activated pigs. Immune system activation increased rectal temperature (P < 0.05), plasma haptoglobin (1.1 vs. 2.0 mg/mL; P < 0.001), and the proportion of neutrophils (0.39 vs. 0.42; P < 0.05) and decreased serum albumin content (38.4 vs. 36.8 g/L; P < 0.01). Increasing dietary SAA had no effects on these variables. Immune system-activated pigs had lower levels of homocysteine (Hcy; P < 0.001) and a lower Ser content (P < 0.05). Results showed that increasing dietary SAA as DL-methionine in growing and/or finishing pigs altered plasma AA contents, and that use efficiency of the AA was improved when greater levels of SAA were supplemented in IS-activated pigs.

Prediction of apparent, standardized, and true ileal digestible total and reactive lysine contents in heat-damaged soybean meal samples

Forty-two individually housed entire male pigs weighing 37.5 ± 0.15 kg (mean ± SEM) were used in a randomized block design having 7 dietary treatments (n = 6). The dietary treatments were 5 semisynthetic diets containing 350 g/kg of soybean (Glycine max) meal (SBM) with variable heat treatments (0, 7, 14, 21, and 28 min autoclaved at 135°C), a protein free (N-free) diet, and an enzymatically hydrolyzed casein (EHC) diet. Heat treatment linearly decreased (P < 0.001) total Lys content from 27.5 to 19.2 g/kg and reactive Lys content from 23.4 to 11.7 g/kg. Apparent, standardized, and true ileal digestible total and reactive Lys contents linearly decreased (P < 0.001) with increasing severity of heat treatment and were accurately predictable (P < 0.001) from total and reactive Lys content in heat-damaged SBM. These data indicate that excessive heat processing of SBM reduced both the content (P < 0.001) and digestibility (P < 0.001) of total and reactive Lys in SBM.

Morphometric features and glycoconjugate pattern of rabbit intestine are affected by particle size of pelleted diets

Feed particle size effects on morphology and glycoconjugate pattern was investigated in the rabbit intestine. Rabbits fed with fine particles (2 mm) displayed more irregularly shaped, higher duodenal villi and deeper crypts in distal colon as well as higher number of goblet cells than coarse (8 mm) fed ones. Brush border expressed: (i) in duodenum, neutral/sulfated glycoconjugates and glycans binding MAL II, SNA, Con A than KOH-sialidase-PNA and DBA reactivity in fine and coarse fed rabbits, respectively, (ii) in cecum, mainly sulfoglycans in coarse fed rabbits, MAL II and PNA staining in all samples, and (iii) in distal colon few sulfoglycans and MAL II reactivity. Enterocytes bound MAL II in duodenum, Con A in cecum, DBA, and Con A in distal colon of all rabbits, SNA in distal colon of coarse fed ones. Brunner's glands displayed high presence of acidic/sulfated mucins in fine fed rabbits, neutral glycoconjugates and reactivity with MAL II, SNA, PNA, KOH-sialidase-PNA, and Con A in all rabbits. Goblet cells exhibited: (i) in duodenum neutral and sulfomucins as well as MAL II and KOH-sialidase-PNA staining, than SNA and DBA in fine and coarse fed rabbits, respectively, (ii) in cecum sulfated glycans, MAL II, SNA, KOH-sialidase-PNA, DBA reactivity, and (iii) in distal colon acidic/sulfomucins, MAL II and SNA staining, and DBA reactivity in fine fed specimens. Crypt cells exhibited neutral and PNA reactive glycoconjugates in the cecum. In the distal colon also acidic/sulfated glycans, and MAL II, KOH-sialidase-PNA, DBA; SNA staining showed weaker reactivity in fine fed rabbits, which bound Con A.