Apparent Ileal Digestibility Of Starch Research Articles

154 Reduction of particle size of field peas increases net energy and digestibility of starch when fed to growing pigs

Abstract Two experiments were conducted to test the hypothesis that particle size of field peas and location of production may affect the apparent ileal digestibility (AID) of starch, the standardized ileal digestibility (SID) of amino acids (AA), and net energy (NE). One source of peas from the U.S., and two sources from Canada were procured. The U.S. peas were ground to 265, 457, or 678 µm, whereas the two Canadian peas were ground to 411 and 415 µm, respectively. A basal diet containing corn and soybean meal as the sources of energy, starch, and AA, and five diets containing corn and soybean meal and 50% of each source of peas were formulated. Pigs were fed the same diets in Exp. 1 and 2, but an N-free diet was also used in Exp. 1. In Exp. 1, barrows [n = 7; initial body weight (BW) = 60.6 kg; SD = 2.1] that had a T-cannula installed in the distal ileum were allotted to a 7 × 7 Latin square design with seven diets and seven periods. Ileal digesta were collected and analyzed for Cr and AA. In Exp. 2, pigs (n = 24; initial BW = 30.8 kg; SD = 1.0) were used in a 6 × 6 Latin square design with six calorimetry chambers and six periods. To determine NE, feces and urine were quantitatively collected and O2 consumption and CO2 and CH4 productions were measured. In both Exp. 1 and 2, the statistical model included diet as the main effect and pairwise comparisons were used to separate the means. Contrast coefficients were also used to determine linear effects of particle size within the U.S. peas. Results from Exp. 1 indicated that the SID of AA was not influenced by the origin of the peas or by particle size, except that the SID of Arg was linearly (P = 0.042) increased (Table 1) as particle size of U.S. field peas was reduced. The AID of starch in the U.S. peas ground to 265 µm was greater (P < 0.05) than in the two Canadian sources, and the AID of starch and NE in diets were linearly (P < 0.001) increased as particle size was reduced. The NE in U.S. peas ground to 678 µm was less (P < 0.05) than in all other pea samples. In conclusion, AID of starch, SID of AA, and NE did not differ between field peas grown in Canada and peas grown in the U.S., but reducing the particle size of field peas resulted in improved digestibility of starch and energy by pigs.

168 Effects of feeding barley-based diets differing in fermentable starch and fiber on nutrient digestion and body composition in weaned pigs

Abstract Hulled and hull-less barley grains containing low insoluble fiber are alternative energy sources in weaning diets but are typically not part of weaned pig diets. The range in fermentable starch and fiber content among barley cultivars presents opportunities to investigate whether these fermentable carbohydrates of barley grain do influence nutrient digestion, gut short chain fatty acid (SCFA) profile and body composition. To explore, pigs [n = 40; body weight (BW) = 8.6 kg; 1-wk post-weaning] were housed individually and fed 1 of 4 diets containing 600 to 705 g of cereal grain/kg: 1) low-fermentable wheat (LFW); 2) high β-glucan, hull-less barley (HFBB); 3) high amylose, hull-less barley (HFAB); or 4) low-fermentable hulled barley (LFB). Diets provided 10.2 and 9.8 MJ NE/kg, and 1.32 and 1.21 g standardized ileal digestible (SID) lysine/MJ NE for phase 1 (d 0–14) and phase 2 (d 15–28), respectively. At the end of the trial, feces were collected, and pigs were slaughtered to collect digesta and the carcass that was subsequently ground. Subsamples of feces, digesta, and carcasses were freeze-dried and analyzed. The apparent ileal digestibility (AID) of crude protein (CP) and gross energy (GE) did not differ among diets. The AID of β-glucan was 3 times greater (P < 0.05) for LFW than HFBB and HFAB, while AID of starch was 12% less (P < 0.05) for HFAB than the other diets. Apparent total tract digestibility (ATTD) of GE and CP was 4.2 and 8.9% less (P < 0.05), respectively, for the 3 barley diets than the wheat diet. The apparent hindgut fermentation (AHF) of β-glucan was 2.6 times greater (P < 0.05) for HFAB and HFBB than LFW, while AHF of starch was 7.5 times greater for HFAB than LFW. The calculated NE value was greatest (P < 0.05) for LFW, intermediate for HFBB and HFAB, and least for LFB. Among diets, HFAB increased (P < 0.05) the concentration of butyrate (indicator of gut health) and propionate in cecal and colonic digesta, with butyrate up to 50% more (P < 0.05) than that of LFW. Carcass protein and lipid concentration did not differ among pigs fed the 4 diets. In conclusion, feeding barley instead of wheat grain to weaned pigs reduced diet nutrient digestibility but did not affect carcass protein and lipid concentration. Feeding high amylose barley increased gut SCFA concentration. Barley grain with increasing fermentable carbohydrates can thus be included as alternative ingredient in diets of young pigs.

Influence of particle size and origin of field peas on apparent ileal digestibility of starch and amino acids and standardized ileal digestibility of amino acids when fed to growing pigs.

The objective was to test the hypothesis that particle size and origin of field peas influence the apparent ileal digestibility (AID) of starch, crude protein (CP), and amino acids (AA) and the standardized ileal digestibility (SID) of AA. Three sources of field peas were procured. One source was from the United States and two sources were from Canada. The U.S. source and one of the sources from Canada (i.e., Canada 1) were each divided into two batches and ground to achieve a target particle size of 250 or 450µm, whereas the other source from Canada (i.e., Canada 2) was only ground to a target particle size of 250µm. Each batch of field peas was included in one diet as the only source of AA. An N-free diet was used to determine the basal endogenous losses of CP and AA. Six barrows (initial weight: 50.5kg; SD = 3.7) that had a T-cannula installed in the distal ileum were randomly allotted to a 6 × 6 Latin square design with six diets and six 7-d periods. Ileal digesta from pigs were collected for 2d after 5d of adaptation. Data were analyzed using a statistical model that included batch of field peas as the fixed effect and animal and period as the random effects. Contrast statements were used to analyze the effects of particle size, origin, and the interaction between particle size and origin. Results indicated that the AID of starch was increased by reducing the particle size in the U.S. source of field peas, but that was not the case for the Canada 1 source (interaction; P < 0.001). Particle size did not influence the AID of CP or AA, but the Canada 2 source of field peas had greater (P < 0.05) AID of Trp, Ala, Cys, Gly, and Tyr than the field peas from the United States. The SID of CP and AA was also not affected by the particle size of field peas. The SID of CP and Trp was greater (P < 0.05), and the SID of His, Ile, and Thr tended (P < 0.10) to be greater in the Canada 2 source compared with the U.S. source, but no differences between the two Canada sources were observed. In conclusion, a few differences in SID of AA between field peas produced in the United States and peas produced in Canada were observed, but there was no effect on SID of AA of reducing the particle size of field peas from 450 to 250µm, whereas the AID of starch increased by reducing the particle size only in the field peas from the United States.

303 Interactive Effects of Pelleting and Particle Size Reduction of Corn on Ileal Digestibility of Starch and Amino Acids in Corn-Soybean Meal Diets Fed to Pigs

Abstract The objective was to determine the interactive effects of particle size reduction and pelleting on the apparent ileal digestibility (AID) of starch and the standardized ileal digestibility (SID) of amino acids (AA) in corn-soybean meal diets fed to pigs. Six corn-soybean meal based diets were arranged in a 3 × 2 factorial with 3 particle sizes of corn (i.e., 700, 500, or 300 μm) and 2 diet forms (i.e., meal or pelleted). An N-free diet was also used and there were, therefore, a total of 7 diets. Pigs were allowed ad libitum access to feed and water. Pigs (n = 7; initial body weight = 59.30 kg; SD = 2.77) that were equipped with a T-cannula in the distal ileum were allotted to the 7 diets using a 7 × 7 Latin square design with 7 periods. Ileal digesta were collected for 2 days after 5 days of adaptation. The statistical model included diet as fixed effect and pig and period as random effects. Contrast coefficients were used to determine effects of diet form, linear effects of particle size, and the interaction. Results indicated that the AID of starch was linearly increased (P = 0.001) with reduced particle size of corn and pelleted diets had greater (P = 0.029) AID of starch than meal diets (Table 1). The SID of Leu, Lys, Met, Phe, Thr, and Val linearly increased with reducing particle size, but the increase was greater in pelleted diets than in meal diets (interaction, P &amp;lt; 0.05). The SID of Arg, His, Ile, and Val also linearly increased (P &amp;lt; 0.05) as the particle size of corn was reduced, and the SID of all indispensable AA except Trp was greater (P &amp;lt; 0.05) in pelleted diets than in meal diets. In conclusion, reducing the particle size of corn from 700 to 300 μm increased the AID of starch and the SID of AA, but the AID of starch and the SID of most indispensable AA was greater in pelleted diets than in meal diets. If there were interactions, the effects of reducing particle size were greater when corn particle size was reduced from 500 to 300 μm in meal diets and from 700 to 500 μm in pelleted diets.

301 Effects of Different Sources and Particle Sizes of Field Peas on Ileal Digestibility of Amino Acids and Starch by Growing Pigs

Abstract The objective was to test the hypothesis that particle size and origin influence the apparent ileal digestibility (AID) of starch and the standardized ileal digestibility (SID) of amino acids (AA) in field peas. Three sources of field peas were procured. One source was from the U.S. and 2 sources were from Canada. The U.S. source and 1 of the sources from Canada (i.e., Canada 1) were each divided into 2 batches and ground at 200 or 400 µm, whereas the other source from Canada (i.e., Canada 2) was only ground at 200 µm. Each source of field peas was included in one diet as the only source of AA. An N-free diet was used to determine the basal endogenous losses of crude protein (CP) and AA. Barrows (n = 6; initial body weight: 50.5 kg; SD = 3.7) that had a T-cannula installed in the distal ileum were randomly allotted to a 6 × 6 Latin square design with 6 diets and six 7-d periods. Ileal digesta from pigs were collected for 2 days after 5 days of adaptation. The statistical model included source as the fixed effect and animal and period as the random effects. Contrast statements were used to analyze effects of particle size, origin, and the interaction between particle size and origin. Results indicated that the AID of starch was increased by reducing the particle size of the U.S. source, but that was not the case for the Canada 1 source (interaction; P &amp;lt; 0.001; Table 1). No interactions were observed for the SID of CP or AA. The SID of CP and AA was not affected by particle size of field peas. The SID of CP and Trp was greater (P &amp;lt; 0.05) and the SID of His, Ile, and Thr tended to be greater in the Canada 2 source (P &amp;lt; 0.10) than in the U.S. source. In conclusion, a few differences in the SID of AA in field peas produced in the U.S. or Canada were observed, but there was no effect on SID of AA of reducing the particle size of field peas from 400 to 200 µm. However, the effect of particle size on the AID of starch was greater in field peas from the U.S. compared with field peas from Canada.

PSIII-5 Endosperm Hardness in Corn Affects the Digestibility of Energy and Fiber, and Increased Drying Temperature Reduces Amino Acid Digestibility

Abstract Two experiments were conducted to test the hypothesis that corn source and drying temperature influence the ileal digestibility of starch and amino acids (AA), as well as apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF) in diets for growing pigs. Two corn sources (i.e., soft or hard endosperm) were procured, and sources were divided into two drying batches (i.e., 35 or 120 oC). Therefore, four corn sources were used. In experiment 1, ten pigs (67.00 ± 2.98 kg) with a T-cannula installed in the distal ileum were allotted to a replicated 5 × 5 Latin square design with five diets and five periods giving ten replicates per diet. A nitrogen-free diet and four diets containing each source of corn as the only AA source were formulated. Data were analyzed in a 2 × 2 factorial arrangement of treatments using the MIXED procedure of SAS. The model included corn source, drying temperature, and the interaction between corn source and drying temperature. Results indicated that neither source nor drying temperature influenced the apparent ileal digestibility of starch in corn (Table 1), but the standardized ileal digestibility of most AA was less (P &amp;lt; 0.05) in corn dried at 120 oC compared with corn dried at 35 oC. In experiment 2, 40 pigs (20.82 ± 1.74 kg) were housed in metabolism crates and allotted to four diets with ten replicate pigs per diet. The four corn-based diets used in experiment 1 were also used in experiment 2. Feces and urine were collected using the marker-to-marker approach with 5-day adaptation and 4-day collection periods. Data were analyzed as explained for experiment 1. Results indicated that diets containing hard endosperm corn had greater (P &amp;lt; 0.05) ATTD of TDF compared with diets containing soft endosperm corn. The ATTD of GE and the concentration of metabolizable energy (ME) in hard endosperm corn were also greater (P &amp;lt; 0.05) compared with soft endosperm corn. Diets containing corn dried at 120 oC had greater (P &amp;lt; 0.05) ATTD of TDF compared with diets containing corn dried at 35 oC, but drying temperature did not influence ATTD of GE or ME. In conclusion, endosperm hardness did not influence the digestibility of AA and starch; however, drying corn at 120 oC resulted in reduced digestibility of AA. Hard endosperm corn had greater ATTD of GE and TDF, but drying temperature did not influence energy digestibility.

Effects of corn hardness and drying temperature on digestibility of energy and nutrients in diets fed to growing pigs.

Two experiments were conducted to test the hypothesis that corn kernel hardness and drying temperature influence the ileal digestibility of starch and amino acids (AA), as well as apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF) in diets for growing pigs. Two corn varieties with average or hard endosperm were grown and harvested under similar conditions, and after harvest each variety was divided into 2 batches that were dried at 35 oC and 120 oC, respectively. Therefore, four batches of corn were used. In experiment 1, ten pigs (67.00 ± 2.98kg) with a T-cannula installed in the distal ileum were allotted to a replicated 5 × 5 Latin square design with five diets and five periods giving ten replicates per diet. A nitrogen-free diet and four diets containing each source of corn as the only AA source were formulated. Results indicated that neither variety of corn nor drying temperature influenced apparent ileal digestibility of starch in the grain. The standardized ileal digestibility of most AA was less (P < 0.05) in corn dried at 120 oC compared with corn dried at 35 oC resulting in concentrations of most standardized ileal digestible AA being less (P < 0.05) in corn dried at 120 oC than in corn dried at 35 oC. In experiment 2, 40 pigs (20.82 ± 1.74kg) were housed in metabolism crates and allotted to four diets with ten replicate pigs per diet. The four corn-based diets used in experiment 1 were also used in experiment 2. Feces and urine were collected using the marker-to-marker approach with 5-day adaptation and 4-day collection periods. Results indicated that diets containing hard endosperm corn had greater (P < 0.05) ATTD of TDF than diets containing average endosperm corn. The ATTD of GE in hard endosperm corn was also greater (P < 0.05), and concentrations of digestible energy and metabolizable energy in hard endosperm corn were greater (P < 0.01) than in average endosperm corn. Diets containing corn dried at 120 oC had greater (P < 0.05) ATTD of TDF compared with diets containing corn dried at 35 oC; however, drying temperature did not influence the ATTD of GE. In conclusion, endosperm hardness did not influence the digestibility of AA and starch; however, drying corn at 120 oC reduced digestible AA concentrations. Hard endosperm corn had greater ATTD of GE and TDF, but drying temperature did not influence energy digestibility.

Energy, protein, and amino acid digestibility of mid- and zero-tannin faba bean differing in vicine and covicine content fed to growing pigs

Novel faba bean cultivars vary in nutrient content, digestibility and antinutritional factors that must be characterized to realize predictable growth performance in growing pigs. Therefore, four diets including 950 g faba bean/kg of either one of two zero-tannin cultivars (Snowbird, Snowdrop; both with vicine and covicine) or one of two mid-tannin cultivars (Fabelle, low vicine and covicine; Florent, high vicine and covicine) were fed to eight ileal-cannulated barrows (37.5 kg) for four 9-day periods to establish energy and nutrient digestibility. A nitrogen-free diet was fed to correct for basal endogenous losses of protein and amino acids. Mid-tannin cultivars had double the tannin content of zero-tannin cultivars (14.0 vs. 6.9 g/kg as is). Fabelle had the least vicine (0.6 g/kg) and covicine (0.4 g/kg) whereas zero-tannin cultivars contained the most vicine (6.8 g/kg) and covicine (3.4 g/kg). Starch ranged from 329 to 356 g/kg in faba bean cultivars. Resistant starch ranged from 124 to 150 g/kg. Crude protein (CP) ranged from 247 to 293 g/kg. Total dietary fibre ranged from 157 to 163 g/kg and was 96 % insoluble. The coefficient of apparent total tract digestibility of dry matter and gross energy were greatest (P < 0.05) for Snowbird and Snowdrop, intermediate for Fabelle and lowest for Florent. The coefficient of apparent ileal digestibility of starch was greater (P < 0.05) for zero- than mid-tannin cultivars. Diet and cultivar digestible energy values were greatest (P < 0.05) for Snowbird, intermediate for Fabelle and lowest for Florent; Snowdrop was not different from the latter two. Diet and cultivar net energy values were greater (P < 0.05) for Snowbird but not different among Snowdrop, Fabelle or Florent. The coefficients of standardised ileal digestibility (CSID) of CP, lysine, threonine, and methionine were generally greater (P < 0.05) for Snowbird, Snowdrop or Fabelle than Florent. The CSID of tryptophan was greater (P < 0.05) for Fabelle than Snowbird, Snowdrop or Florent. In conclusion, Florent with mid-tannin and vicine and covicine content, had lower energy, protein and amino acid digestibility than zero-tannin cultivars. Fabelle with mid-tannin but least vicine and convicine content, was intermediate in energy but not different in protein or amino acid digestibility than zero-tannin cultivars. Cultivar variation in content of macronutrients including total and resistant starch, protein and dietary fibre contributed to differences in energy, protein and amino acid digestibility that should be considered in diet formulation.

Effect of xylanase supplementation on nutrient and energy digestibility at three time periods in growing pigs fed diets based on corn or corn distillers dried grains with solubles

A digestibility trial was conducted to better understand how xylanase impacts diet utilization in pigs by measuring its impact on the digestibility of energy, nitrogen, fat, fiber, and starch in the small and large intestine and across the total tract at three collection periods. Thirty-two 16-week-old gilts (DNA 600 [DNA Genetics, Columbus, NE, USA] × C22 [PIC Inc., Hendersonville, TN, USA]) were surgically fitted with T-cannulae at the terminal ileum, housed individually, and assigned to 1 of 4 dietary treatments in a completely randomized design, providing 24 observations per treatment Diets were arranged in a 2 × 2 factorial:0 vs 165 mg xylanase/kg (27,225 birch xylan units (BXU)/kg) of finished feed to corn-soybean meal diets and 0 g/kg (lower fiber: LF) vs 300 g/kg (higher fiber: HF) corn distillers’ dried grains with solubles (DDGS). Prior to surgery, the body weight (BW) of the pigs averaged 37.3 ± 0.8 kg. Three collection periods consisting of a 2-day fecal collection followed by a 3-day ileal collection occurred at day 9–13, 19–23 and 39–43 when pigs averaged 46.0 ± 0.4, 54.1 ± 0.4, and 70.3 ± 0.5 kg, respectively. Ileal and fecal samples were analyzed to determine the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of gross energy (GE), dry matter (DM), neutral detergent fiber assayed with heat stable amylase (aNDF), acid detergent fiber (ADF), and nitrogen (N), and the AID of starch and amino acids (AA). Apparent fat digestibility values were corrected for endogenous losses and reported as true ileal digestibility (TID) and true total tract digestibility (TTTD). Xylanase inclusion tended to decrease AID of aNDF and decreased ADF in LF diets, but had no impact in HF diets, resulting in a fiber level (FL) × xylanase interaction (P ≤ 0.100). The AID of nitrogen increased with xylanase in LF diets, but decreased in HF diets, resulting in a FL × xylanase interaction (P = 0.025). Xylanase inclusion tended to increase the hindgut disappearance of aNDF and ADF (P ≤ 0.100). In LF diets, xylanase decreased ATTD of ADF, but increased ATTD of ADF in HF diets resulting in a FL × xylanase interaction (P = 0.010). Xylanase inclusion changed the pattern of hindgut disappearance and ATTD of nitrogen over the three collection periods, resulting in a xylanase × collection period interaction. Overall, xylanase supplementation slightly increased digestibility in pigs fed lower fiber diets, and had no impact on digestibility in higher fiber diets.

261 Increasing dietary amylose reduces rate of starch digestion and increases microbial fermentation in weaned pigs

Abstract Beneficial effects of SCFA in modulating gut health stimulated interest on dietary strategies to increase intestinal microbial activity and digesta SCFA. Amylose has lower apparent ileal digestibility (AID) than amylopectin. In the large intestine, undigested starch is fermented by microbes producing SCFA. The objective was to determine effects of increasing dietary amylose on starch flow and metabolite profile along the intestinal tract in weaned pigs. Weaned pigs (n=32; initial BW, 8.4 kg) were randomly allocated to 4 diets containing 67% starch with 0, 20, 35, or 70% amylose in a randomized complete block design. On day 21, pigs were euthanized to collect digesta and feces for evaluating starch digestion and metabolite profiles. Apparent hindgut fermentation (AHF) was calculated as apparent total tract digestibility minus AID. Feed intake was 12% lower (P &amp;lt; 0.05) and growth rate was 18% lower (P &amp;lt; 0.05) for pigs fed 70% amylose than pigs fed 0, 20, or 35% amylose. Feed efficiency was greatest (P &amp;lt; 0.05) for pigs fed with 35% amylose. The AID of starch was 44% lower (P &amp;lt; 0.05) in pigs fed 70% amylose. Starch was completely digested by the proximal colon in pigs fed 0, 20, or 35% amylose, but AHF of starch was 14% greater (P &amp;lt; 0.05) in pigs fed 70% amylose. Increasing dietary amylose did not alter digesta SCFA in the small intestine, but increased (P &amp;lt; 0.05) digesta SCFA in the cecum, specifically acetate and total SCFA, and increased (P &amp;lt; 0.05) propionate and valerate in all sections of the colon. In conclusion, increasing dietary amylose in weaned pigs stimulated hindgut fermentation of starch with a corresponding increase in digesta total SCFA in the cecum and colon. Optimizing dietary amylose may exert its effect as dietary prebiotic while promoting an optimal growth rate in young pigs.

Exogenous α-amylase supplementation reduces the variability of ileal digestible energy in broiler chickens fed complete diets with maize batches of variable protein solubility

This study evaluated the relationship between salt-soluble protein (SSP) of maize and the apparent ileal digestibility (AID) of complete diets in response to exogenous α-amylase supplementation in broiler chickens. Samples of 12 maize batches originating from the mid-north and northeast of China were analyzed for SSP. Six of the 12 sources of maize with a wide variation of SSP (from 21.1 % to >50 %) were selected. Six maize-soybean meal basal diets were formulated, including each source of maize with or without the addition of α-amylase (Ronozyme® HiStarch; DSM Nutritional Products). A total of 960 day-old male Arbor Acres Plus broiler chickens were randomly allocated to 12 treatments with 8 replicates per treatment in wired cages and fed experimental diets in 2 phases (d 1−14; d 15−28). At d 28, 4 birds selected from each cage were euthanized for evaluation of apparent ileal digestibility (AID) of starch and energy. The addition of α-amylase reduced the feed conversion ratio (FCR) of chickens from 1 to 28 d (1.407 vs. 1.426) compared to the basal diets across maize batches, particularly from 1 to 7 d (1.049 vs. 1.078). An interaction between maize batch and α-amylase supplementation on FCR was detected only at 7 d, when the batch with the lowest SSP exhibited the greatest response to α-amylase. Neither a main effect of α-amylase nor an interaction with maize batch on AID of starch were detected (P > 0.05). Nonetheless, α-amylase supplementation increased ileal digestible energy (IDE) from 12.21 to 12.50 MJ/kg dry matter across maize batches. These increments were mainly driven by the maize batch with the lowest SSP. α-amylase supplementation reduced the variability of IDE from a coefficient variance (CV)=5.2 % to a CV=0.7 % across maize batches. Interestingly, there was a strong negative correlation (r<-0.95; P < 0.001) between the initial IDE of maize and the IDE response to α-amylase, and a less strong correlation between SSP and the IDE response to α-amylase (r=-0.78, P = 0.07). SSP was not a predictor of starch digestibility at this age. Dietary α-amylase supplementation has the potential to significantly reduce the variability in the energy value of maize-based diets in commercial poultry production by improving the nutritional value of poorly digestible maize.

The apparent ileal digestibility and the apparent total tract digestibility of carbohydrates and energy in hybrid rye are different from some other cereal grains when fed to growing pigs.

An experiment was conducted to determine the apparent ileal digestibility (AID) and the apparent total tract digestibility (ATTD) of energy, starch, and total dietary fiber (TDF) in two varieties of hybrid rye and compare these values with values obtained for barley, wheat, corn, and sorghum. It was hypothesized that there are no differences in AID and ATTD of energy and nutrients among hybrid rye, barley, wheat, and sorghum. Twenty-four ileal cannulated barrows (initial body weight = 28.1 ± 3.0 kg) were randomly allotted to a two-period experimental design with six diets and four replicate pigs in each period for a total of eight replicate pigs per diet. Diets consisted of 97% of each grain, and each pig received a different diet in each period. The initial 5 d of each period were considered the adaptation period, whereas urine and fecal materials were collected from the feed provided from day 6 to 10, and ileal digesta were collected on days 12 and 13 of each period. Results indicated that the metabolizable energy (ME) on a dry matter (DM) basis was greatest (P < 0.05) in corn and wheat (3,732 and 3,641 kcal/kg DM), and least (P < 0.05) in barley (3,342 kcal/kg DM), whereas the two hybrid ryes contained 3,499 and 3,459 kcal/kg DM, respectively. The ME values in hybrid rye were not different from values determined for barley and sorghum (3,573 kcal/kg DM). In all grains, the AID of starch was greater than 90%, and the ATTD of starch was nearly 100%. Barley contained more TDF than the other cereal grains, and the two hybrid ryes had concentrations of soluble dietary fiber that were close to the concentration in barley but greater than in wheat, corn, and sorghum. The AID of TDF was less than 35% for all cereal grains, but the ATTD of TDF was greater (P < 0.05) in the two hybrid ryes (68% and 70%) than in the other ingredients (56% to 58%). In conclusion, feeding hybrid rye to pigs resulted in reduced pre-cecal absorption of energy compared with wheat, corn, and sorghum, but because hindgut fermentation of fiber was greater in hybrid rye than in other cereal grains, the content of ME in hybrid rye was not different from barley and sorghum but less than in corn and wheat.

PSIV-1 Apparent ileal and total tract digestibility of energy and carbohydrates in hybrid rye and other cereal grains fed to growing pigs

Abstract An experiment was conducted to test the hypothesis that apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of energy, starch, and total dietary fiber (TDF), and the concentration of ME in 2 hybrids of rye (Bono and Brasetto) are not different from values for barley, wheat, corn, and sorghum. Twenty-four ileal cannulated barrows (28.1 ± 3.0 kg) were placed in metabolism crates and randomly allotted to a 2-period experimental design with 6 diets and 4 replicate pigs in each 13-d period. Diets consisted of 97% of each grain, and no pig received the same diet twice. Urine and feces were collected for 4 d after 5 d of diet adaptation, and ileal digesta were collected on d 12 and 13 of each period. Data were analyzed using the Mixed procedure of SAS with the fixed effect of diet and the random effects of pig and period. The ME (DM basis) was greatest (P &lt; 0.05) in corn and wheat, and least (P &lt; 0.05) in barley, and the ME in Bono and Brasetto rye was 3,499 and 3,459 kcal/kg DM, respectively (Table 1). In all grains, the AID of starch was greater than 90%, and the ATTD of starch was nearly 100%. The AID of TDF was reduced (P &lt; 0.05) in Bono rye compared with all other cereal grains, but the ATTD of TDF was greater (P &lt; 0.05) in Bono and Brasetto rye than in the other grains. In conclusion, the current data indicate that rye results in reduced pre-cecal absorption of energy compared with wheat, corn, and sorghum, but hindgut fermentation of fiber is greater for pigs fed rye. The ME in hybrid rye is not different from values for barley and sorghum, but less than in wheat and corn.

Influence of graded levels of meals from three lupin species on growth performance and nutrient digestibility in broiler chickens

ABSTRACT 1. This study investigated the effect of different levels of seeds of lupin species (Lupinus angustifolius, Lupinus luteus and Lupinus albus) on broiler growth performance, nutrient digestibility and apparent metabolisable energy of poultry diets. 2. A control diet containing corn–soybean meal and test diets containing 50, 100, 150, 200 and 250 g/kg of three lupin species were fed to broiler chickens during a 35-day study period. There were 10 replicate cages of 8 broiler chickens per treatment. 3. Growth performance of the birds fed with yellow and white lupin diets was found to be similar to that of the birds in the control group. The use of narrow-leaved lupin seeds in the diet quadratically decreased the body weight gain of birds and increased feed conversion ratio during all the experimental periods (0–14, 15–35 and overall 0–35 days of age). 4. A significant interaction between lupin species and their inclusion levels for apparent metabolisable energy and apparent ileal digestibility of starch was observed, showing a negative effect of increasing levels of narrow-leaved lupin. Pearson correlation coefficients demonstrated that the presence of raffinose and non-starch polysaccharides is a key factor affecting the nutritive value of lupin, 5. Yellow and white lupins could be utilised as an alternative ingredient for soybean meal in the diet of broiler chickens without any adverse effects on growth performance. The narrow-leaved counterpart diet reduced broiler performance, and hence did not provide a satisfactory outcome.

Apparent and standardized ileal digestibility of AA and starch in hybrid rye, barley, wheat, and corn fed to growing pigs1

An experiment was conducted to determine the apparent ileal digestibility (AID) of AA and starch and the standardized ileal digestibility (SID) of AA in three varieties of hybrid rye and in one source of barley, wheat, and corn. Seven growing barrows (initial BW = 26.1 ± 2.4 kg) were randomly allotted to a 7 × 7 Latin square design with seven periods and seven experimental diets. Six diets included one of the grains as the sole source of AA, and an N-free diet was used to determine basal endogenous losses of CP and AA. In each period, ileal digesta were collected for 8 h on days 6 and 7 following a 5-d adaptation period. At the conclusion of the experiment, all ingredients, diets, and ileal digesta samples were analyzed for starch, CP, and AA. The AID of starch was greater (P < 0.05) in wheat and corn than in barley or hybrid rye, but all grains had AID values for starch that were above 95%. Wheat and barley contained more CP and indispensable AA than hybrid rye, but hybrid rye contained more indispensable AA compared with corn. The SID of CP and all indispensable AA was greater (P < 0.05) in barley, wheat, and corn than in the three varieties of rye. However, because of the greater concentration of AA in hybrid rye than in corn, the quantities of standardized ileal digestible CP and AA were not different between corn and hybrid rye. In conclusion, hybrid rye has greater concentrations of most AA than corn, but the digestibility of AA in rye is less than in other cereal grains. It is likely that the reason for the reduced SID of AA in rye is that rye contains more fructans and soluble dietary fiber than other cereal grains, which may increase viscosity and reduce the efficiency of endogenous peptidases.

In vitro and in vivo assessment of the effect of initial moisture content and drying temperature on the feeding value of maize grain

ABSTRACT1. This study assessed the impact of drying temperature (54, 90, and 130°C) and maize grain moisture content at harvest (36% and 29%) on in vitro digestibility, the growth performance and ileal digestibility of broiler chickens.2. In contrast to the results from the in vitro digestibility, apparent ileal digestibility of starch and energy decreased when the drying temperature was raised from 54 to 130°C, and this effect was more pronounced in maize grain harvested at high initial moisture content (36%). Ileal protein digestibility of maize grain decreased significantly when dried at the intermediate temperature (90°C) and with a high harvest moisture content (36%). Drying temperature and initial moisture content did not significantly affect AMEn.3. When maize was dried at 130°C, the particle sizes of flour recovered after standard milling procedures decreased significantly, which would influence animal growth performance and in vivo digestibility through animal feed selection.

Methodological impact of starch determination on starch content and ileal digestibility of starch in grain legumes for growing pigs

BackgroundGrain legumes represent a valuable energy source in pig diets due to their high starch content. The present study was conducted to determine the content and apparent ileal digestibility (AID) of starch in different grain legume cultivars for pigs by means of both a polarimetric and enzymatic method for starch determination.MethodsThree experiments were conducted with six barrows each which were fitted with ileal T-cannulas. In total, 18 diets including six different cultivars of faba beans (Vicia faba L.) and peas (Pisum sativum L.), five different cultivars of lupins (Lupinus luteus L., Lupinus angustifolius L.), and one diet with a soybean meal (SBM) were fed.ResultsThe starch content of faba beans and peas was greater (P < 0.05) when determined polarimetrically than enzymatically (438 vs. 345 g/kg dry matter (DM) in faba beans and 509 vs. 390 g/kg DM in peas, respectively). Considerable lower starch contents were obtained in lupins and SBM, with 82 and 48 g/kg DM (analyzed polarimetrically) and <1.1 and 3 g/kg DM (analyzed enzymatically), respectively. Mean values for contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in grain legumes ranged from 111 and 79 g/kg DM in peas to 248 and 207 g/kg DM in lupins, respectively. Contents of condensed tannins in the colored flowered faba bean cultivars ranged from 2.1 to 7.4 g/kg DM. The AID of starch was greater (P < 0.05) in pea than in faba bean cultivars, and using the polarimetric starch determination method resulted in greater (P < 0.05) digestibility values than using enzymatic starch analysis (84 vs. 80% in faba beans and 86 vs. 83% in peas). Moreover, AID of starch differed (P < 0.05) within pea cultivars and starch digestibility in faba beans decreased linearly (P < 0.05) as the content of condensed tannins increased. However, there was no relationship between contents of NDF and ADF and AID of starch in pea and faba bean cultivars.ConclusionBoth contents and AID of starch in grain legumes can vary as influenced by the analytical method used for starch determination. Generally, starch digestibility is greater when measured by polarimetric rather than enzymatic methods.

Effects of pelleting, extrusion, or extrusion and pelleting on energy and nutrient digestibility in diets containing different levels of fiber and fed to growing pigs

An experiment was conducted to determine effects of pelleting, extrusion, and extrusion and pelleting on energy and nutrient digestibility in diets containing low, medium, or high concentrations of fiber. Three diets were formulated: 1) the low-fiber diet contained corn and soybean meal; 2) the medium-fiber diet contained corn, soybean meal, and 25% distillers dried grains with solubles (DDGS); and 3) the high-fiber diet contained corn, soybean meal, 25% DDGS, and 20% soybean hulls. Each diet was divided into 4 batches after mixing. One batch was not further processed and was fed in a meal form, one batch was pelleted at 85°C, one batch was extruded at 115°C using a single-screw extruder, and one batch was extruded at 115°C and then pelleted at 85°C. Thus, 12 different diets were produced. Twenty-four growing pigs (26.5 ± 1.5 kg initial BW) had a T-cannula installed in the distal ileum and were allotted to the 12 diets in a split-plot design with 8 pigs allotted to the low-fiber diets, the medium-fiber diets, and the high-fiber diets, respectively. Diets were fed to the pigs during four 14-d periods. Within each type of diet, the 8 pigs were fed the diets produced using the 4 processing technologies. Therefore, there were 8 replicate pigs per diet. Pigs were adjusted to their diets for 14 d before the experiment was initiated. Each of the four 14-d periods consisted of 5 d for adaptation, 5 d of fecal collection according to the marker to marker approach, and ileal digesta were collected on d 13 and 14. Results indicated that pelleting, extrusion, or extrusion and pelleting improved ( < 0.05) the apparent ileal digestibility of starch and most indispensable AA. In most cases, there were no differences between the pelleted, the extruded, and the extruded and pelleted diets. The apparent total tract digestibility of GE was also improved ( < 0.05) by pelleting and by the combination of extrusion and pelleting. The ME of pelleted diets was greater ( < 0.05) than that of meal diets for the low- and medium-fiber diets, but this was not the case for high-fiber diets (interaction, < 0.05). Medium- and high-fiber diets that were extruded had greater ME ( < 0.05) than meal diets, but that was not the case for low-fiber diets. These data indicate that energy utilization may be improved by pelleting or extrusion or by a combination of the 2 technologies, but the response seems to be greater for extrusion in diets that are relatively high in fiber.

Effects of reducing the particle size of corn grain on the concentration of digestible and metabolizable energy and on the digestibility of energy and nutrients in corn grain fed to growing pigs

Two experiments were conducted to determine the apparent ileal digestibility (AID) of starch and gross energy (GE), the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA), the concentration of digestible energy (DE) and metabolizable energy (ME), and the standardized total tract digestibility (STTD) of P in corn ground to 4 different particle sizes (i.e., 865, 677, 485, and 339µm). In Experiment 1, 10 growing barrows (initial body weight: 29.2±1.4kg) were surgically equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 5×5 Latin square design with 5 diets and 5 periods in each square. One lot of corn was divided into 4 batches that were ground to the specified particle sizes and each batch was used in one diet that contained 965.5g/kg corn (as-fed basis) as the only source of starch, GE, and AA. Results indicated that the AID of starch and GE was increased (linear, P<0.05) as the particle size decreased from 865 to 339μm. With the exception of Trp, there was no impact of corn particle size on the SID of CP or any indispensable AA. In Experiment 2, 40 growing barrows (initial body weight: 22.8±2.1kg) were placed in metabolism crates and allotted to a randomized complete block design with 4 diets and 10 replicate pigs per diet. Each diet contained one of the 4 batches of corn used in Experiment 1 (977.0g/kg, as-fed basis) as the only source of GE and P. Results indicated that the concentration of ME was 16.02, 16.19, 16.31, and 16.60MJ/kg dry matter for corn ground to a mean particle size of 865, 677, 485, and 339µm, respectively. The ME concentration increased (linear and quadratic, P<0.01) as the particle size decreased. The average STTD of P in the 4 batches of corn was 37.4% and no differences among treatments were observed. In conclusion, decreasing the particle size of corn from 865 to 339µm linearly increased the concentration of DE and ME and the AID of starch and GE in corn, but the particle size of corn did not affect the STTD of P or the SID of indispensable AA and CP.

Raw vs extruded coloured-flower pea as an ingredient in broiler diets: effects on performance, ileal digestibility, gut morphology, and intestinal microbiota activity

ABSTRACT: Raw or extruded peas ( Pisum sativum, pink-flowered cv. Milwa) were used. Extrusion reduced the trypsin inhibitor activity (TIA) from 2.35 to 0.35 mg · g –1 , but did not affect tannins content, which was about 1 g · kg . A growth trial was conducted on 200 Ross 308 female broilers from day 1 to 35 of age. There were 3 treatment groups from day 1 to 14 including control without peas, 10% raw (RP) and extruded (EP) pea. From day 15 birds were kept individually, in groups of 18, and fed diets containing 15%, 20%, 25%, or 30% RP and EP. Chickens fed EP ate more feed ( P ≤ 0.05) but had similar body weight gains and worse feed conversion ratio ( P ≤ 0.05) than chickens fed RP. The apparent ileal digestibility (AID) of dry matter was lower in chickens fed EP than RP ( P ≤ 0.01), whereas AID of protein did not differ. The AID of starch was 0.835 in the control group, in chickens fed both RP and EP it was, on average, 2 percentage points higher ( P ≤ 0.01). In birds fed RP the short-chain fatty acid concentration in ileal digesta was lower (