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Illinois is one the major corn producing states in the nation, and much of the corn produced in Illinois is used to produce ethanol. In recent years, ethanol plants have been centrifuging solubles, and the resulting distillers dried grains with solubles (DDGS) contains less fat than conventional DDGS. Therefore, the purpose of this experiment was to determine if the concentration of DE and ME in DDGS produced in and around Illinois varies among plants. Twenty-four barrows (average initial BW: 28.1 ± 1.8 kg) were randomly allotted to 1 of 24 dietary treatments in a 24 × 8 Youden square design with 24 diets and 8 periods. Approximately 250 kg of DDGS was procured from 23 ethanol plants, and a corn diet and 23 corn–DDGS diets were formulated. Results indicated that only 3 of the 23 sources of DDGS could be categorized as conventional DDGS with more than 10% acid hydrolyzed ether extract, whereas the remaining 20 sources of DDGS contained between 5 and 10% acid hydrolyzed ether extract, thus categorizing these sources as low-oil DDGS. The concentration of DE in conventional DDGS was greater (P

An experiment was conducted to test the hypothesis that concentrations of digestible energy (DE) and metabolizable energy (ME) in threonine and valine biomass products are not different from those in fish meal. Two threonine biomass products (i.e., Thr-BM1 and Thr-BM2) and 1 valine biomass product (Val-BM) were obtained from the production of crystalline l -threonine and l -valine. The biomass products consist of the fermentation biomass that is left after the crystalline amino acids have been harvested at the end of fermentation. Forty weanling barrows (11.25 ± 0.65 kg) were placed individually in metabolism crates and allotted to a completely randomized design with 5 diets and 8 replicate pigs per diet. A bakery meal-based diet consisting of 973.5 g/kg bakery meal was formulated. Four additional diets containing a mixture of bakery meal and Thr-BM1, Thr-BM2, Val-BM, or fish meal were also formulated. Feces and urine samples were collected for 5 days after a 5-day adaptation period. Results indicated that the apparent total tract digestibility of gross energy was less (P

Two experiments were conducted to determine digestible energy (DE) and metabolizable energy (ME) and the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein and amino acids in high protein canola meal (CM-HP), conventional canola meal (CM-CV), and soybean meal fed to growing pigs. In Exp. 1, 32 barrows (initial body weight: 47.3 ± 6.2 kg) were housed in metabolism cages and randomly allotted to one of four diets with eight replicate pigs per diet. A corn-based diet (973 g/kg corn) and three diets that contained both corn and each of the two sources of canola meal or soybean meal were formulated. Feces and urine were collected for 5 days after a 5-day adaptation period. The DE and ME values were 14.40 and 13.84 MJ/kg in corn, 12.43 and 10.34 MJ/kg in CM-HP, 11.02 and 9.65 MJ/kg in CM-CV, and 15.63 and 14.13 MJ/kg in soybean meal, respectively. The DE and ME were greater (P < 0.05) in corn and soybean meal than in CM-HP and CM-CV, but the DE and ME were not different between CM-HP and CM-CV. In Exp. 2, eight barrows (initial body weight: 46.4 ± 5.6 kg) were equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 4 × 4 Latin square design with 4 diets and 4 periods in each square. A N-free diet and three cornstarch based diets that contained CM-HP, CM-CV, or soybean meal as the sole source of amino acids were formulated. Each period lasted 7 days and ileal digesta were collected on day 6 and 7 of each period. The AID and SID of crude protein and most amino acids in CM-HP and CM-CV were less (P < 0.05) than in soybean meal. The AID and SID of crude protein in CM-HP was greater (P < 0.05) than in CM-CV. However, no differences were observed in AID and SID of any amino acids between CM-HP and CM-CV. The concentration of standardized ileal digestible crude protein and almost all amino acids was greater (P < 0.05) in soybean meal than in CM-HP and CM-CV, and CM-HP contained more (P < 0.05) standardized ileal digestible crude protein and amino acids than CM-CV. In conclusion, increased concentration of crude protein in canola meal does not compromise the concentration of DE and ME, and does not compromise AID or SID of amino acids. As a consequence, the novel CM-HP supplies the same amount of DE and more digestible amino acids for growing pigs compared with CM-CV.

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 339 µm). In Experiment 1, 10 growing barrows (initial body weight: 29.2±1.4 kg) 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 965.5 g/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

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.

Lemna protein concentrate (LPC; 68.0% CP) is produced by extracting protein from de-oiled and dehydrated biomaterials from plants of the Lemnaceae family and may be used as a protein source for animals. There are, however, no published data on the nutritional value of LPC fed to pigs. Three experiments were, therefore, conducted to determine the concentration of ME, the standardized total tract digestibility (STTD) of P, and the standardized ileal digestibility (SID) of AA in LPC and to compare these values to values for fish meal and soybean meal (SBM). Experiment 1 was conducted to determine the ME of LPC, fish meal, SBM, and corn. Thirty-two barrows (initial BW: 16.8 ± 2.8 kg) were placed in metabolism cages and allotted to a randomized complete block design with 4 diets and 8 replicate pigs per diet. A corn-based diet and 3 diets that contained corn and LPC, fish meal, or SBM were formulated. Feces and urine were collected for 5 d after a 5-d adaptation period, and all samples were analyzed for GE. Results indicated that the concentration of ME was not different among corn, fish meal, and SBM (3,855, 3,904, and 4,184 kcal/kg DM, respectively), but there was a tendency (P = 0.08) for a reduced ME in LPC (3,804 kcal/kg DM) compared with SBM. In Exp. 2, 24 barrows (initial BW: 12.5 ± 2.5 kg) were allotted to a randomized complete block design with 3 diets and 8 replicate pigs per diet and used to determine the STTD of P in LPC, fish meal, and SBM. Three diets that each contained 1 of the 3 test ingredients as the sole source of P were formulated. Pigs were placed in metabolism cages, and feces were collected for 5 d after a 5-d adaptation period. The STTD of P in LPC (72.8%) was not different from the STTD of P in fish meal (65.6%), but tended (P = 0.07) to be greater than in SBM (62.8%). The SID of AA in LPC, SBM, and fish meal was determined in Exp. 3. Eight barrows (initial BW: 21.4 ± 4.0 kg) were equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 4 × 4 Latin square design. A N-free diet and 3 cornstarch-based diets in which SBM, SBM and LPC or SBM and fish meal were the only sources of AA were formulated. The SID of most indispensable AA was greater (P < 0.05) in fish meal than in LPC, but the overall SID of AA was not different between fish meal and LPC. In conclusion, the ME and the STTD of P are not different between LPC and fish meal, but there is a tendency for greater ME in SBM than in LPC, whereas the STTD of P tends to be greater in LPC than in SBM. The SID of the most indispensable AA is greater in fish meal than in LPC.

Two experiments were conducted to determine the concentration of DE and ME and the standardized ileal digestibility (SID) of AA in chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, a spent hen-soybean meal (SBM) mixture, and conventional SBM fed to weanling pigs. In Exp. 1, 48 barrows (initial BW: 14.6 ± 2.2 kg) were placed in metabolism cages and allotted to 6 diets with 8 replicate pigs per diet in a randomized complete block design. Six corn-based diets were formulated. The basal diet contained 98.1% corn (as-fed basis) and 5 diets contained corn and 11 to 16% chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, spent hen-SBM mixture, or SBM. All test ingredients were included in their respective diets at levels that were expected to result in similar concentrations of CP among diets. Feces and urine were collected for 5 d. The ME was 3,957, 3,816, 4,586, 4,298, 4,255, and 4,091 kcal/kg DM for corn, chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, the spent hen-SBM mixture, and SBM, respectively. The ME in poultry byproduct meal was greater (P < 0.01) than in corn, chicken meal, the spent hen-SBM mixture, and SBM, and the ME in hydrolyzed porcine intestines and the spent hen-SBM mixture was greater (P < 0.01) than in corn and chicken meal, but there was no difference among hydrolyzed porcine intestines, the spent hen-SBM mixture, and SBM. In Exp. 2, 12 barrows (initial BW: 12.2 ± 1.5 kg) were equipped with a T-cannula in the ileum and allotted to a replicated 6 × 6 Latin square design. A N-free diet and a cornstarch-SBM based diet were formulated. Four additional diets were formulated by mixing cornstarch, sucrose, and SBM with chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, or the spent hen-SBM mixture. The SID of CP and all AA, except Trp and Pro, was greater (P < 0.01) in SBM than in all other ingredients. The SID of CP and all indispensable AA in the spent hen-SBM mixture was also greater (P < 0.01) than in chicken meal and hydrolyzed porcine intestines, and with the exception of Arg and Val, SID values of all indispensable AA in the spent hen-SBM mixture were greater than in poultry byproduct meal. However, with the exception of Val and Lys, there were no differences between chicken meal and poultry byproduct meal. In conclusion, the ME in hydrolyzed porcine intestines and the spent hen-SBM mixture is greater than in chicken meal, but not different from the ME of SBM. Poultry by product meal provides more ME than SBM, chicken meal, and the spent hen-SBM mixture, and the SID of most indispensable AA is greater in the spent hen-SBM mixture than in chicken meal, poultry byproduct meal, and hydrolyzed porcine intestines, but less than in SBM.

An experiment was conducted to test the hypothesis that the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P in fermented soybean meal (FSBM) are greater than in conventional soybean meal (SBM-CV) when fed to growing pigs. Four diets were formulated to contain FSBM or SBM-CV and either 0 or 800 units/kg of microbial phytase. The only sources of P in these diets were FSBM and SBM-CV. A P-free diet to estimate basal endogenous losses of P was also formulated. Thirty barrows (initial BW: 14.0 ± 2.3 kg) were placed in metabolism cages and allotted to 5 diets in a randomized complete block design with 6 pigs per diet. Feces were collected for 5 d after a 5-d adaptation period. All samples of ingredients, diets, and feces were analyzed for P, and values for ATTD and STTD of P were calculated. Results indicated that the basal endogenous P losses were 187 mg/kg of DMI. As phytase was added to the diet, the ATTD and STTD of P increased (P < 0.01) from 60.9 to 67.5% and from 65.5 to 71.9%, respectively, in pigs fed FSMB. Likewise, addition of phytase to SBM-CV increased (P < 0.01) the ATTD and STTD of P from 41.6 to 66.2% and from 46.1 to 71.4%, respectively. The ATTD and STTD of P were greater (P < 0.01) in FSBM than in SBM-CV when no phytase was used, but that was not observed when phytase was added to the diet (soybean meal × phytase interaction, P < 0.01). In conclusion, the ATTD and STTD of P in FSBM was greater than SBM-CV when no microbial phytase was added, but when phytase was added to the diets, no differences between FSBM and SBM-CV were observed in the ATTD and STTD of P.

Two experiments were conducted to determine DE and ME and the standardized ileal digestibility (SID) of CP and AA in 2 sources of high-protein canola meal (CM-HP1 and CM-HP2), conventional canola meal (CM-CV), and soybean meal (SBM) fed to growing pigs. In Exp. 1, 40 barrows (51.5 ± 4.0 kg initial BW) were housed in metabolism cages and randomly allotted to 1 of 5 diets with 8 replicate pigs per diet. A corn-based diet (97.4% corn) and 4 diets that contained both corn and each of the 3 sources of canola meal or SBM were formulated. Feces and urine were collected for 5 d after a 5-d adaptation period. The DE and ME were 3,347 and 3,268 kcal/kg in corn, 3,312 and 2,893 kcal/kg in CM-HP1, 3,627 and 3,346 kcal/kg in CM-HP2, 2,798 and 2,492 kcal/kg in CM-CV, and 4,000 and 3,796 kcal/kg in SBM, respectively. Values for DE and ME were greater (P< 0.05) in SBM than in all other ingredients, but DE and ME were greater (P < 0.05) in corn and the 2 high-protein canola meals than in CM-CV. The DE and ME were also greater (P< 0.05) in CM-HP2 than in CM-HP1. In Exp. 2, 10 barrows (65.3 ± 10.4 kg initial BW) were 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. A N-free diet and 4 corn starch-based diets that contained CM-HP1, CM-HP2, CM-CV, or SBM as the sole source of AA were formulated. Each period lasted 7 d and ileal digesta were collected on d 6 and 7 of each period. The SID of CP and all AA except Pro were greater (P < 0.05) in SBM than in the 3 sources of canola meal. With the exception of His and Lys, no differences in SID of indispensable AA were observed among the 3 sources of canola meal. The SID of His and Lys were greater (P < 0.05) in CM-HP1 and CM-HP2 than in CM-CV and the SID of CP was greater (P < 0.05) in CM-HP2 than in CM-CV, but no differences in the SID of indispensable AA were observed between CM-HP1 and CM-HP2. In conclusion, the 2 high-protein canola meals used in this experiment have ME values that are not different from corn but greater than in CM-CV. The SID of most AA is greater in SBM than in canola meals, but SID of His and Lys are greater in high-protein canola meals than in CM-CV. As a consequence, high-protein canola meals supply more ME and SID of AA for growing pigs than CM-CV.

Two experiments were conducted to determine the standardized total tract digestibility (STTD) of P and the concentration of DE and ME in corn, hominy feed, bakery meal, distillers dried grains with solubles (DDGS), corn gluten meal, corn gluten feed, and corn germ meal fed to growing pigs. In Exp. 1, 84 barrows (initial BW: 13.7±2.3 kg) were placed in metabolism cages and allotted to 14 diets with 6 replicate pigs per diet in a randomized complete block design. Seven diets were formulated to contain corn, hominy feed, bakery meal, DDGS, corn gluten meal, corn gluten feed, or corn germ meal as the sole source of P. Seven additional diets were similar to the initial 7 diets with the exception that 600 units of microbial phytase was included in each diet. The STTD of P was greater (P0.05) in DDGS, corn gluten meal, and corn gluten feed than in corn, hominy feed, bakery meal, and corn germ meal, and the STTD of P was also greater (P0.05) in bakery meal than in corn and hominy feed. Addition of phytase increased (P0.05) the STTD of P in corn, hominy feed, bakery meal, and corn germ meal but not in corn gluten meal, corn gluten feed, or DDGS. In Exp. 2, 56 barrows (initial BW: 14.6±2.2 kg) were placed in metabolism cages and allotted to 7 diets with 8 replicate pigs per diet in a randomized complete block design. A corn-based diet consisting of 97.5% corn and vitamins and minerals was formulated. Four additional diets were formulated by mixing corn and DDGS, corn gluten feed, corn gluten meal, or corn germ meal, and 2 diets were based on hominy feed or bakery meal. The concentration of ME was 3,891, 3,675, 3,655, 3,694, 4,400, 3,169, and 3,150 kcal/kg DM in corn, hominy feed, bakery meal, DDGS, corn gluten meal, corn gluten feed, and corn germ meal, respectively. The ME (DM basis) in corn was greater (P0.05) than in hominy feed, bakery meal, corn gluten feed, and corn germ meal, but less (P0.05) than in corn gluten meal, and the ME in hominy feed, bakery meal, and DDGS was greater (P0.05) than in corn gluten feed and corn germ meal. In conclusion, DDGS, corn gluten meal, and corn gluten feed have a greater STTD of P than corn, hominy feed, bakery meal, and corn germ meal, but phytase can be included in diets containing corn, hominy feed, bakery meal, and corn germ meal to improve P digestibility. The ME in corn gluten meal is greater than in bakery meal, corn, and other corn coproducts.

Two experiments were conducted to determine the digestibility of energy and nutrients and the concentration of DE, ME, and NE in fermented soybean meal (FSBM), conventional soybean meal (SBM-CV), and fish meal fed to weanling pigs. In Exp. 1, 36 barrows (initial BW: 22.0 ± 3.85 kg) were placed in metabolism cages and allotted to a randomized complete block design with 4 diets and 9 pigs per diet. Feces and urine were collected for 5 d after a 5 d adaptation period. Four diets including a corn-based diet and 3 diets consisting of corn and each of the experimental ingredients (FSBM, SBM-CV, and fish meal) were formulated. Results indicated that the apparent total tract digestibility (ATTD) of GE in corn, FSBM, and SBM-CV was 88.6, 88.2, and 90.3%, respectively, but the ATTD of GE in fish meal (84.0%) was less (P < 0.01) than in the other ingredients. The concentrations of DE, ME, and NE in SBM-CV were 4,553, 4,137, and 2,972 kcal/kg DM. These values were greater (P < 0.01) than the DE, ME, and NE in FSBM (4,296, 3,781, and 2,710 kcal/kg DM), corn (3,951, 3,819, and 2,791 kcal/kg DM), and fish meal (3,827, 3,412, and 2,450 kcal/kg DM). However, FSBM contained more (P < 0.01) DE, ME, and NE than fish meal and more (P < 0.01) DE than corn. The biological value of the protein in fish meal (75.4%) was greater (P < 0.05) than in corn (34.8%) and FSBM (62.8%), and the biological value of protein in SBM-CV (67.1%) was greater (P < 0.05) than in corn but not different from FSBM and fish meal. In Exp. 2, 8 barrows (initial BW: 10.4 ± 0.47 kg) were equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 4 × 4 Latin square design with 4 diets and 4 periods per square. Three diets containing FSBM, SBM-CV, or fish meal as the sole source of AA and a N-free diet were formulated. The standardized ileal digestibility (SID) of all indispensable AA except Lys, Thr, and Trp was greater (P < 0.01) in FSBM than in fish meal. The SID of Met and Val was also greater (P < 0.05) in FSBM than in SBM-CV, but for the remaining indispensable AA, no difference between FSBM and SBM-CV was observed. In conclusion, the concentration of DE, ME, and NE is less in FSBM than in SBM-CV. However, DE, ME, and NE are greater in FSBM than in fish meal, but the SID of most AA is not different between FSBM and SBM-CV although they are greater than in fish meal.

Background The association between use of oral contraceptives (OCs) and cerebral infarction was established in studies from northern Europe and the USA during the 1960s and 1970s. Since then, the constituents of hormonal OCs have changed and now contain lower doses of oestrogen and progestagen. Current recommendations restrict OC use to younger women who do not have other risk factors for cardiovascular disease, in this international study we assessed the risk of CC-associated first stroke in women from Europe and other countries throughout Vie world.Methods In this hospital-based, case-control study, we assessed the risk of ischaemic stroke in association with current use of combined OCs in 697 cases, aged 20-44 years, and 1962 age-matched hospital controls in 21 centres in Africa, Asia, Europe, and Latin America. The diagnosis of ischaemic stroke was almost exclusively based on computed tomography (CT), magnetic resonance imaging (MRI), or cerebral angiography carried out within 3 weeks of the clinical event. Ail cases and controls were interviewed while in hospital with the same questionnaire, which included information on medical and personal history, details of lifetime contraceptive use, and blood-pressure measurements before the most recent episode of OC use.Findings The overall odds ratio of ischaemic stroke was 2 . 99 (95% CI 1 . 65-5 . 40) in Europe and 2 . 93 (2 . 15-4 . 00) in the non-European (developing) countries, Odds ratios were lower in younger women and those who did not smoke, and less than 2 in women who did not have hypertension and who reported that their blood pressure had been checked before the current episode of OC use. By contrast, among current OC users with a history of hypertension, the odds ratio was 10 . 7 (2 . 04-56 . 6) in Europe and 14 . 5 (5 . 36-39 . 0) in the developing countries. In Europe, the odds ratio associated with current use of low-dose OCs (

An experiment was conducted to test the hypothesis that the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P in fermented soybean meal (FSBM) are greater than in conventional soybean meal (SBM-CV) when fed to growing pigs. Four diets were formulated to contain FSBM or SBM-CV and either 0 or 800 units/kg of microbial phytase. The only sources of P in these diets were FSBM and SBM-CV. A P-free diet to estimate basal endogenous losses of P was also formulated. Thirty barrows (initial BW: 14.0 ± 2.3 kg) were placed in metabolism cages and allotted to 5 diets in a randomized complete block design with 6 pigs per diet. Feces were collected for 5 d after a 5-d adaptation period. All samples of ingredients, diets, and feces were analyzed for P, and values for ATTD and STTD of P were calculated. Results indicated that the basal endogenous P losses were 187 mg/kg of DMI. As phytase was added to the diet, the ATTD and STTD of P increased (P0.01) from 60.9 to 67.5% and from 65.5 to 71.9%, respectively, in pigs fed FSMB. Likewise, addition of phytase to SBM-CV increased (P0.01) the ATTD and STTD of P from 41.6 to 66.2% and from 46.1 to 71.4%, respectively. The ATTD and STTD of P were greater (P0.01) in FSBM than in SBM-CV when no phytase was used, but that was not observed when phytase was added to the diet (soybean meal × phytase interaction, P0.01). In conclusion, the ATTD and STTD of P in FSBM was greater than SBM-CV when no microbial phytase was added, but when phytase was added to the diets, no differences between FSBM and SBM-CV were observed in the ATTD and STTD of P.

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.

The objectives of this experiment were to determine effects of reducing particle size on growth performance, carcass characteristics, stomach morphology, and VFA concentration in the hindgut of growing-finishing pigs if diets were formulated to a constant ME. Thirty-six gilts and 36 barrows (32.00 ± 1.58 kg initial BW) were individually penned and randomly allotted to 4 dietary treatments in a 2 × 4 factorial design with sex (gilts and barrows) and corn particle size (i.e., 865, 677, 485, and 339 μm) as factors. The ME was determined in the same 4 batches of corn in a previous experiment to be 3,826, 3,868, 3,895, and 3,964 kcal/kg DM, respectively. Pigs were fed a 3-phase program from 32 to 129 kg. Within each phase, 4 corn-soybean meal diets were formulated, and the only difference among diets was that the corn used was ground to the 4 specified particle sizes and soybean oil was added to the diets in decreasing amounts as the corn particle size was reduced to reflect the increased ME in corn with reduced particle size. Results of the experiment indicated that initial BW, final BW, overall ADFI, and overall ADG were not different among treatments, but final G:F for gilts decreased from 0.38 to 0.35 (linear, < 0.05) as the particle size decreased from 865 to 339 μm, but no difference was observed for barrows (interaction, < 0.05). However, G:F did not change if calculated based on HCW because dressing percentage increased (linear, < 0.01) from 79.30 to 80.29% as the particle size decreased, which was partly due to a reduction (linear, < 0.01) from 3.01 to 2.52 kg in empty intestinal weight. Back fat depth, HCW, loin eye area, and carcass fat-free lean percentage were not different among treatments. There were no incidences of ulcers in the esophageal region of the stomach regardless of the particle size of corn, but parakeratosis in the esophageal region increased ( < 0.05) as the particle size of corn decreased. The concentration of acetate, proprionate, and butyrate in the cecal contents decreased (linear, < 0.01) from 2,537 to 1,846, from 872 to 617, and from 702 to 226 μg/mL, respectively, and the pH in the cecal and colon contents increased (linear, < 0.01) from 6.04 to 6.64 and from 5.85 to 6.25, respectively, as the particle size decreased. In conclusion, by using corn ground to a smaller particle size, the amount of added fat may be reduced in the diets without affecting growth performance of barrows or carcass composition of barrows and gilts.