Effect of dietary organic and inorganic micromineral source and level on sow body, liver, colostrum, mature milk, and progeny mineral compositions over six parities.

A sow study evaluated the effects of 2 dietary micromineral sources (organic or inorganic) and 3 dietary mineral levels [NRC, industry (IND), and IND + Ca:P] with selected sows killed at parities 1, 2, 4, and 6. Three sows per treatment group were killed at weaning (total = 68), and their body and liver, 72 colostrum and milk samples (17 d), 69 full-term stillborn pigs and their livers, and 32 pigs at weaning were analyzed for minerals. Tissue and milk samples from the sows were analyzed as a 2 x 3 x 4 factorial arrangement of treatments in a completely randomized design (CRD) with 3 replicates per treatment. Full-term stillborn pig mineral compositions were determined at parities 1, 3, and 5 and evaluated as a 2 x 3 x 3 factorial arrangement of treatments in a CRD with 3 replicates per treatment. Weanling pigs from parity 6 sows were analyzed as a 2 x 3 factorial in a CRD. Sow and pig mineral compositions are reported on an equivalent empty BW and kilograms of liver weight basis. The results indicated that sow body macromineral contents were not affected by dietary micromineral source or level or when the diets contained added Ca and P. Sow body Se increased when dietary organic microminerals increased from the NRC to the IND level, resulting in a source x level interaction (P < 0.01), but there was no increase in those sows fed inorganic microminerals. There were increases in Cu (P < 0.05) and Se as levels increased from NRC to the IND, and there were increases (P < 0.05) in Cu and Zn when the IND + Ca:P diet was fed compared with feeding the IND diet. Increases (P < 0.01) in sow liver Cu, Se, and Zn occurred as microminerals increased from the NRC to the IND level. As parity advanced, there were cubic increases (P < 0.01) in sow body Cu, Fe, and Se, but a quadratic increase in Zn (P < 0.05). There was no clear effect of sow dietary treatments on full-term stillborn pig or liver micromineral contents, except Se (P < 0.01). There was a greater pig body Se content when sows were fed organic microminerals at the greater level, resulting in a source x level interaction (P < 0.01). Colostrum minerals were generally not affected by diet variables, except Se. Colostrum Se was greater when sows were fed the organic micromineral source than the inorganic source at the greater level, resulting in a source x level interaction (P < 0.05). Milk Cu (P < 0.01) and Zn (P < 0.01) increased as dietary level increased. Milk Se was increased when organic Se was fed (P < 0.05) and when the micromineral level was increased (P < 0.01). Weaned pig body Fe (P < 0.01) and Se (P < 0.01) were greater when organic microminerals were fed to the sow, whereas Mn (P < 0.01) and Zn (P < 0.05) increased when the IND level was fed. These results indicate that the dietary micromineral source and level had a minimal effect on sow body and liver mineral contents or in colostrum and pigs at birth, except Se, which was greater when the organic form was fed.

Dietary protein concentration affects intestinal microbiota of adult cats: a study using DGGE and qPCR to evaluate differences in microbial populations in the feline gastrointestinal tract.

The objective of this study was to identify qualitative and quantitative differences in microbial populations of adult cats fed diets containing different protein concentrations. Following a 4 week baseline period, eight healthy adult domestic short-hair queens (>1-year-old) were randomly allotted to a moderate-protein (MP; n = 4) or high-protein (HP; n = 4) diet for 8 weeks. Fresh faecal samples were collected after baseline and 8 weeks on treatment and stored at -80 degrees C. Following DNA extraction, samples were analyzed using denaturing gradient gel electrophoresis to distinguish qualitative changes between diets. Quantitative polymerase chain reaction was used to measure E. coli, Bifidobacterium, Clostridium perfringens, and Lactobacillus populations. Compared to baseline, cats fed MP had a bacterial similarity index of 66.7% as opposed to 40.6% similarity for those fed HP, exhibiting marked changes in intestinal bacteria of cats fed HP. Bifidobacterium populations were greater (p < 0.05) in cats fed MP versus HP (9.44 vs. 5.63 CFU/g). Clostridium perfringens populations were greater (p < 0.05) in cats fed HP than MP (12.39 vs. 10.83 CFU/g). In this experiment, a high-protein diet resulted in a dramatic shift in microbial populations. Decreased Bifidobacterium population in cats fed HP may justify prebiotic supplementation for such diets.

Fish protein substrates can substitute effectively for poultry by-product meal when incorporated in high-quality senior dog diets.

An experiment was conducted to analytically define several novel fish substrates and determine the effects of feeding diets containing these substrates on total tract nutrient digestibilities and on immune status of senior dogs. The control diet contained poultry by-product meal while test diets contained 20% milt meal (MM), pink salmon hydrolysate (PSH) and white fish meal (WFM) added at the expense of poultry by-product meal. Concentrations of lymphocytes positive for CD3, CD4, CD8 and CD21 cell-surface markers and immunoglobulin concentrations were measured. Gene expression of cytokines tumour necrosis factor (TNF)-, interleukin (IL)-6, interferon (IFN)-, IL-10 and transforming growth factor (TGF)-ß was determined by quantitative real-time polymerase chain reaction. Major compositional differences were noted among fish substrates but apparent nutrient digestibility coefficients and immune indices were not affected by treatment. Fish protein substrates were found to be effective substitutes for poultry by-product meal, providing diets of high nutritive value for senior dogs.

The impact of commercial human infant formula on fecal attributes in a weanling pig model.

An experiment to assess the influence of commercially available infant formulas on characteristics of feces in a weanling piglet model was conducted. Seven commercial infant formulas [whey, whey+alpha-lactalbumin, whey+alpha-lactalbumin+oligofructose, whey+GOS+polyfructose, whey protein concentrate 1 (with 27.3% acid hydrolyzed fat), whey protein concentrate 2 (with 29.4% acid hydrolyzed fat), and enzymatically hydrolyzed whey protein concentrate] were offered to weanling piglets ad libitum for 14d. Fecal attributes that were assessed include: consistency, color, odor, dry matter, organic matter, pH, biogenic amines, short- and branched-chain fatty acids, phenols, indoles, and ammonia. Overall, there were very few differences among treatment groups in fecal attributes assessed. Minor differences in the concentrations of fecal acetate, valerate, putrescine, and cadaverine were observed in piglets fed GOS+polyfructose-containing formula. However, stool consistency, score, odor, pH, ammonia, phenols, and indoles were similar among treatment groups. Diet had an effect on fecal dry matter percentage, organic matter percentage, color, and 4 week body weights of the piglets. The results obtained in this experiment demonstrate that healthy gut function is prevalent in weanling piglets consuming the experimental treatments.

Evaluation of fermentable oligosaccharides in diets fed to dogs in comparison to fiber standards.

Blends of fermentable oligosaccharides in combination with nonfermentable fiber, cellulose, were evaluated for their ability to serve as dietary fibers in dog foods. Using a 6 x 6 Latin square design, 6 diets were evaluated that contained either no supplemental fiber, beet pulp, cellulose, or blends of cellulose, fructooligosaccharides, and yeast cell wall added at 2.5% of the diet. Six ileal-cannulated dogs were fed 175 g of their assigned diet twice daily. Chromic oxide served as a digestibility marker. Nutrient digestibility, fecal microbial populations, fermentative end products, and immunological indices were measured. Total tract DM and OM digestibilities were lowest (P < 0.05) for the cellulose treatment. Crude protein digestibility was lower (P < 0.05) for the treatments containing carbohydrate blends. The cellulose treatment had the lowest (P < 0.05) concentration of bacteria, and all diets containing fermentable fiber had greater (P < 0.05) fecal bifidobacteria concentrations compared with the diets without supplemental fermentable fiber. Lactobacilli concentrations tended to be greater (P < 0.08) in treatments containing fermentable fiber compared with the cellulose treatment. Bifidobacteria and lactobacilli concentrations were similar for the beet pulp treatment compared with the fermentable oligosaccharide blends. Total fecal short-chain fatty acid concentration was greater for the beet pulp treatment (P < 0.05) compared with the control and cellulose treatments. The treatments containing fermentable fiber had greater (P < 0.05) fecal butyrate concentrations compared with cellulose and control treatments. Immune indices were not affected by treatment. Our results suggest that dog foods containing blends of fermentable and nonfermentable carbohydrates produce similar physiological results as dog food containing beet pulp as a fiber source. Therefore, blends of these carbohydrates could be useful substitutes for beet pulp in dog foods.

A dose-response evaluation of spray-dried yeast cell wall supplementation of diets fed to adult dogs: effects on nutrient digestibility, immune indices, and fecal microbial populations.

The yeast cell wall (YCW) preparation, Safmannan, was evaluated as a dietary supplement for adult dogs. Using a 5 x 5 Latin square design with 14-d periods, adult dogs cannulated in the terminal ileum were supplemented with 0, 0.05, 0.25, 0.45, or 0.65% YCW based on daily food allowance. Apparent ileal nutrient digestibility responded cubically (P = 0.07 to 0.10) to YCW supplementation. Ileal nutrient digestibility tended (P = 0.09) to be greater with YCW supplementation compared with control. Apparent total tract digestibility responded cubically (P < 0.05) to YCW supplementation. Total white blood cell and eosinophil counts tended (P < 0.09) to decrease quadratically with YCW supplementation, with the lowest counts at the 0.25% supplementation level, whereas monocyte counts decreased (P < 0.05) linearly with YCW supplementation. Serum immunoglobulin A (IgA) concentrations tended (P = 0.09) to respond cubically to YCW, with the lowest value at the 0.25% supplementation level. Ileal IgA tended (P < 0.09) to respond quadratically, with the greatest ileal IgA concentration at 0.25% YCW. Using serial dilution and plating enumeration techniques, fecal Escherichia coli concentrations decreased linearly (P = 0.01) with YCW supplementation, whereas Clostridium perfringens responded cubically (P = 0.09). Cubic trends were noted for E. coli (P = 0.10) and lactobacilli (P = 0.08) concentrations, as evaluated by quantitative PCR analysis. Total fecal DNA was most similar to the control treatment at 0.25% YCW. Although the effects on immunological indices appear limited, our results suggest that YCW supplementation in dogs at less than 1% may affect ileal and total tract nutrient digestibility, and the colonization of the gut by E. coli may be decreased.

Tissue weights and body composition of two genetic lines of barrows and gilts from twenty to one hundred twenty-five kilograms of body weight.

Barrows and gilts of 2 genetic lines with differing lean gain potentials (high-lean = 375 g of fat-free lean/d; low-lean = 280 g of fat-free lean/d) were used to determine tissue and organ weights and compositions from 20 to 125 kg of BW. The experiment was a 2 (genetic line) x 2 (sex) x 5 (BW) factorial arrangement of treatments in a completely randomized design conducted with 2 groups of pigs in 6 replicates (n = 120 pigs). Six pigs from each sex and genetic line were slaughtered at 20 kg of BW and at 25 kg of BW intervals to 125 kg of BW. At slaughter, the internal tissues and organs were weighed. Loin and ham muscles were dissected from the carcass and trimmed of skin and external fat, and the ham was deboned. Residuals from the loin and ham were combined with the remaining carcass. Body components were ground, and their compositions were determined. The results demonstrated that tissue weights increased (P < 0.01) as BW increased. Loin and ham muscle weights increased but at a greater rate in the high-lean line and in gilts resulting in genetic line x BW and sex x BW interactions (P < 0.01). Liver and heart expressed on a BW or a percentage of empty BW basis increased at a greater rate in the high-lean line resulting in a genetic line x BW interaction (P < 0.01). Liver and intestinal tract weights were heavier in barrows than in gilts, significant only at 45 (P < 0.05), 75 (P < 0.01), and 100 (P < 0.05) kg of BW. Loin and ham muscles from the high-lean genetic line and gilts had greater (P < 0.01) water, protein, and ash contents compared with the low-lean genetic line and barrows resulting in genetic line x BW and sex x BW interactions (P < 0.01). The remaining carcass (minus loin and ham muscles) had greater (P < 0.01) amounts of water and protein, and less (P < 0.01) fat in the high-lean genetic line and gilts. The high-lean genetic line and gilts had more total body water, protein, and ash, but less body fat, with these differences diverging as BW increased, resulting in a genetic line x BW interaction (P < 0.01). The results indicated that liver and heart weights were greater in high-lean pigs, reflecting the greater amino acid metabolism, whereas the liver and intestinal tract weights were greater in barrow than gilts, reflecting their greater feed intakes and metabolism of total nutrients consumed.

Phenotypic measurements and various indices of lean and fat tissue development in barrows and gilts of two genetic lines from twenty to one hundred twenty-five kilograms of body weight.

Two genetic lines with different lean gains were evaluated for various body measurements and indices of lean tissue in barrows and gilts from 20 to 125 kg of BW. One genetic line was identified as the low-lean line [280 g of fat-free lean (FFL)/d], and the second line was the high-lean line (375 FFL gained/d). The experiment was conducted as a completely randomized design using a 2 x 2 x 5 factorial arrangement of treatments in 6 replicates (n = 120 pigs). The 2 genetic lines and sexes were provided ad libitum access to cornsoybean mixtures that met or exceeded their required amino acid requirements for their respective lean gain potentials. Six pigs of each sex and genetic line were slaughtered initially and at 25-kg of BW intervals to 125 kg of BW. Pigs slaughtered were measured for height, width, and length using metal calipers. Backfat and LM area were measured using real-time ultrasound, with backfat depth also measured using A-mode ultrasound technology. Longissimus muscle area and back-fat thickness at the 10th rib were measured on the chilled carcass. Data was analyzed using the MIXED procedure of SAS, with the animal as the experimental unit. Shoulders (P < 0.05) and lumbars (P < 0.05) were wider in the low-lean genetic line and in barrows. Gilts and the high-lean genetic line had less backfat and greater LM areas than the low-lean genetic line. As BW increased, there was a greater increase in FFL tissue and lower backfat depths in the high-lean vs. the low-lean genetic line. This resulted in a greater divergence of measurement values as BW increased. Femur weight, length, and cortical wall thickness were greater in the high-lean genetic line, but the differences were not significant. The high-lean genetic line had a greater (P < 0.01) organic matrix content in the femur and less ash, resulting in a lower percentage of bone ash (P < 0.01). The results indicate that differences occurred phenotypically between pigs having more muscle (wider hams) or more fat (wider shoulder and lumbar). As BW increased, the high-lean pigs had an increase in lean tissue, particularly after 75 kg of BW, and less backfat and less bone mineralization, whereas the low-lean line pigs had increased backfat and greater bone mineralization. Real-time ultrasound measurements using various formulas to estimate lean tissue produced values close to those determined from carcass measurements at 100 and 125 kg of BW.

Amino acid availability and true metabolizable energy content of corn distillers dried grains with solubles in adult cecectomized roosters.

Five sources of corn distillers dried grains with solubles (DDGS), which varied in darkness of color, were collected from several processing plants in the Midwestern United States. Sources of DDGS were analyzed for their amino acid and energy contents, measured for color score, and evaluated for TMEn, apparent amino acid digestibility, and true amino acid digestibility. A precision-fed rooster assay was used, in which each DDGS sample was tube fed (25 g) to adult cecectomized roosters, and the excreta were collected for 48 h. The experiment was conducted as a randomized complete block design with 8 replicates. Seven adult roosters (averaging 75 wk of age) were used in each period, with 5 fed the DDGS sources and 2 fasted to estimate basal endogenous amino acid losses. One source (no. 5) was the darkest, 2 sources (no. 2 and 4) were light, whereas 2 other sources (no. 1 and 3) were intermediate in color as measured by a colorimeter. Total lysine content of the DDGS sources ranged from 0.48 to 0.76%, with the lowest lysine content in the darkest DDGS source. Apparent and true lysine digestibility was approximately 30 and 15 percentage units lower (P < 0.05), respectively, in the dark-colored source (no. 5) than in the other 4 sources. Average apparent and true digestibility of the essential amino acids were 10 and 8 percentage units lower (P < 0.05), respectively, in source 5 than the other 4 sources. The TMEn content of the 5 DDGS sources was also lower (P < 0.05) in the darkest DDGS (no. 5). Our results suggest that when the color score of a DDGS source, as measured by a colorimeter, reached a certain threshold (lightness between 28 and 34), amino acid availability and true metabolizable energy content may be reduced. This reduction was particularly evident for lysine, which had the lowest digestibility in the darkest DDGS source. These results suggest that dark-colored DDGS may have been overheated during drying, causing Maillard reactions to be more extensive and resulting in a lowered total lysine content, lysine digestibility, and TMEn content.

Determination of the ileal amino acid and energy digestibilities of corn distillers dried grains with solubles using grower-finisher pigs.

An experiment evaluated the ileal apparent and standardized AA and apparent energy digestibilities in grower-finisher pigs of 5 sources of distillers dried grains with solubles (DDGS) from corn. The 5 DDGS sources were analyzed for AA, GE, NDF, ADF, and color score. Diets were formulated to contain 15% CP from the test DDGS sources (approximately 60% of the diet). A low-protein (5% casein) diet was used to estimate basal endogenous AA losses. The experiment was conducted in 2 replicates of a 6 x 6 Latin Square design, with 6 treatments and six 1-wk periods. The experiment used 12 crossbred barrows [(Yorkshire x Landrace) x Duroc], averaging 28 kg of BW and 60 d of age, and surgically fitted with a T-cannula in the distal ileum. After a 10-d recovery period, treatment diets were fed in meal form, initially at 0.09 kg . BW(0.75). Feed intake was equalized between pigs within each period and increased for each subsequent period. Periods included 5 d of diet acclimation followed by two 12-h ileal digesta collections, one on d 6 and one on d 7. Apparent and standardized digestibility of AA was calculated using chromic oxide (0.4%) as an indigestible marker. The results demonstrated that apparent and standardized lysine digestibilities ranged from 24.6 to 52.3% and 38.2 to 61.5%, respectively. Average apparent essential AA digestibility was lower (P < 0.05) in sources 1 and 5, the 2 sources that were darkest in color. Apparent and standardized digestibility of the averaged nonessential AA were lower (P < 0.05) in source 5 than in all other sources. Source 5, the darkest colored DDGS, had a 10% lower (P < 0.05) average apparent and standardized essential AA digestibility and was more than 15% lower (P < 0.05) in lysine digestibility than the 3 lightest colored sources. Apparent ileal energy digestibility did not differ among the 5 sources. Lysine content and digestibility seemed to be reduced to a greater extent by the darker colored DDGS than the other essential AA, suggesting that the Maillard reaction reduced total lysine content and lowered its digestibility. These results, therefore, imply that darker colored DDGS sources may have lower (P < 0.05) analyzed lysine contents, as well as lower (P < 0.05) lysine and essential AA digestibilities, than lighter colored DDGS sources.

Evaluation of the inclusion of soybean oil and soybean processing by-products to soybean meal on nutrient composition and digestibility in swine and poultry.

This experiment was designed to evaluate the effects of selected soybean (SB) processing byproducts (gums, oil, soapstock, weeds/trash) when added back to soybean meal (SBM) during processing on the resulting nutrient composition, protein quality, nutrient digestibility by swine, and true metabolizable energy (TMEn) content and standardized AA digestibility by poultry. To measure ileal DM and nutrient digestibility, pigs were surgically fitted with a T-cannula in the distal ileum. The concentration of TMEn and the standardized AA digestibility by poultry were determined using the precision fed cecectomized rooster assay. Treatments in the swine experiment included SBM with no by-products; SBM with 1% gum; SBM with 3% gum; SBM with 0.5% soapstock; SBM with 1.5% soapstock; SBM with 2% weeds/trash; SBM with a combination of 3% gum, 1.5% soapstock, and 2% weeds/trash; SBM with 5.4% soybean oil; and roasted SB. A 10 x 10 Latin square design was utilized. The experiment was conducted at the University of Illinois, Urbana-Champaign, and at The Ohio State University, Columbus. In the swine experiment, apparent ileal DM, OM, CP, and AA digestibilities were reduced (P < 0.05) when pigs consumed the combination by-product diet compared with the diet containing no by-products. Apparent ileal digestibilities of DM, CP, and total essential, total nonessential, and total AA were lower (P < 0.05) for any diet containing by-products compared with the diet with no by-products. Apparent ileal digestibilities of DM, OM, CP, and AA were lower (P < 0.05) for the roasted SB-compared with the SB oil-containing diet. In the rooster experiment, TMEn values were greater (P < 0.05) for roasted SB compared with SBM with no by-products and increased linearly as the addition of soapstock increased. Individual, total essential, total nonessential, and total AA digestibilities were lower (P < 0.05) for roosters fed roasted SB versus SBM devoid of by-products. Gums, soapstock, and weeds/trash reduce the nutritive value of the resultant meal when they are added back during processing.

Ileal amino acid digestibilities by pigs fed soybean meals from five major soybean-producing countries.

Growing conditions and processing technologies to which soybeans (SB) are exposed have an effect on digestibilities of AA found in the resultant soybean meals (SBM). This study evaluated SBM from five major SB-producing countries (Argentina, Brazil, China, India, and the United States). An industry representative in each country collected samples of unprocessed SB and SBM subjectively determined to be of high, intermediate, or low quality. The SB from each country were processed into SBM under uniform conditions in the United States. Five experiments (each examining the three SBM and the SB processed in the United States from a single country) were conducted to determine true ileal AAd digestibilities. In addition, a standard SBM purchased on the open market in the United States was used in all experiments as a control. Data from pigs fed a low-protein casein diet in each study were used to calculate true AA digestibilities. Pigs were fitted with simple T-cannulas at the terminal ileum and allotted to treatments in Latin square design experiments. Duplicate experiments were conducted at the University of Illinois and at The Ohio State University. Within each country comparison, pigs fed the SBM processed in the U.S. from SB grown in the five countries had lower (P < 0.05) true total amino acid (TAA) digestibilities than did pigs fed any of the SBM prepared within the country of origin, except the United States. This indicates that processing conditions used at the U.S. pilot plant were not ideal when using SB from other countries. True TAA digestibilities of the diets containing the high-, intermediate-, and low-quality SBM did not differ, except for China, where the low-quality SBM (83.5%) had a lower (P < 0.05) digestibility than the intermediate- (89.6%) or high- (89.0%) quality meals. Soybean meal produced in Argentina (average, 87%) and Brazil (average, 82%) had lower (P < 0.05) true TAA digestibilities than did the standard SBM (91%), indicating that the processing plants in those countries may produce a less digestible SBM than that available on the open market in the United States.

Effects of diet complexity and dietary lactose levels during three starter phases on postweaning pig performance.

Four experiments involving 1,005 crossbred pigs weaned at 19 +/- 2 d of age evaluated the effect of diet complexity and lactose level on starter pig performances. Experiment 1 was a randomized complete block (RCB) conducted in nine replicates with 135 pigs. A complex diet using several protein sources, a semicomplex diet with fewer protein sources, and a simple diet of corn and soybean meal comprised the three treatment groups. All diets contained 25% lactose (as-fed basis) with lysine (total) constant from d 0 to 14 (1.55%) and d 14 to 28 (1.45%), respectively. Gain, feed intake, and feed efficiency (P < 0.05) improved as diet complexity increased during both periods. In Exp. 2, 240 pigs in eight replicates in a RCB design were fed complex diets, but dietary lactose (total; as-fed basis) levels ranged from 10 to 35% in 5% increments from 0 to 14 d after weaning. From 14 to 30 d, a common 17% lactose diet was fed to evaluate the effects of early lactose level on subsequent responses. Gains (P < 0.05) increased for the 0- to 7- and 0- to 14-d periods as lactose increased to 30%. Similar gains resulted for all treatment groups from 14 to 30 d after weaning, with no evidence of compensatory responses to early lactose levels. In Exp. 3, 330 pigs were fed complex diets. From 0 to 7 d after weaning, the diets contained 25% lactose (as-fed basis), and from 7 to 21 d postweaning, the lactose levels ranged from 7 to 31% in 5% increments. Gain (P < 0.01) and feed efficiency (P < 0.05) increased from 7 to 21 d to the 17% lactose level. In Exp. 4, 300 pigs were fed 25 and 17% (as-fed basis) lactose diets from 0 to 7 and 7 to 21 d postweaning, respectively. From 21 to 35 d postweaning, lactose levels of 0 to 20% in 5% increments were added to a corn-soybean meal diet. The experiment was conducted as a RCB design in 12 replicates. Gain (P < 0.05) and feed intake (P < 0.05) increased to 10 to 15% lactose. When the data from Exp. 4 were partitioned into lighter (15.0 kg) and heavier (17.7 kg) pig weight replicates, only the lighter replicates had significant improvements in gain, feed intake, and feed efficiency (P < 0.05) in response to dietary lactose. These results demonstrated that starter pigs performed better when fed complex diets, that dietary lactose levels of 25 to 30% (to 7 kg BW) during the initial week postweaning, 15 to 20% lactose during d 7 to 21 (to 12.5 kg BW), and 10 to 15% lactose during d 21 to 35 postweaning (to 25 kg BW) resulted in maximum performance.

Effect of soybean meal particle size on amino acid and energy digestibility in grower-finisher swine.

A study was conducted using the ileal digestibility technique with grower-finisher pigs to evaluate the effects of particle size reduction of soybean meal (SBM) on amino acid and energy digestibility. Soybean meal was processed through a hammer mill to achieve average particle sizes of 900, 600, 300, and 150 microm. The treatments included the use of two soybean meal sources and soy protein concentrate. One source of SBM was ground to four different particle sizes (i.e., 949, 600, 389, 185); a second source was a common SBM source used in other trials (i.e., 800 microm). The soy protein concentrate had an average particle size of 385 microm. A low-protein (5% casein) diet was fed to determine endogenous amino acid losses. This experiment was conducted in a 7 x 7 Latin Square design in two replicates using 14 crossbred barrows ([Landrace x Yorkshire] x Duroc) that averaged 28 kg BW and 60 d of age. Animals were surgically fitted with a T-cannula at the distal ileum. Treatment diets were fed in meal form, initially at 0.09 kg BW(0.75) and at graded increases at each subsequent period. Pigs within replicate were fed a constant quantity of their treatment diet for a 5-d adjustment period followed by a 2-d collection of ileal digesta samples. Apparent and true digestibility of amino acids was calculated by use of chromic oxide (0.5%) as an indigestible marker. Apparent digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. True digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. When the essential amino acids were averaged, apparent digestibility increased (P < 0.10) from 83.5% to 84.9% as particle size decreased, whereas, nonessential amino acid digestibility increased only slightly (P > 0.15). Essential amino acid true digestibility increased numerically from 91.0% to 92.4% as particle size decreased. Energy digestibility was not affected by particle size (P > 0.15). These results suggest that a reduction in particle size of soybean meal resulted in a small increase in the digestibility of its amino acids with the essential amino acids being affected more than the nonessential amino acids. The largest improvement in digestibility, however, was obtained when the particle size was reduced to 600 microm.

Evaluating the antioxidant status of weanling pigs fed dietary vitamins A and E.

Two experiments evaluated the relationship of vitamin E (source and level) and vitamin A (level) on the apparent absorption and retention of both vitamins in weaned pigs. Both experiments used a combined total of 460 crossbred pigs ([Yorkshire x Landrace] x Duroc), housed in elevated 1.2- x 1.2-m crates containing five pigs per pen. Experiment 1 was a 2 x 2 x 2 factorial arrangement of treatments in a randomized complete block design conducted in seven replicates. Levels of vitamin A (2,200 or 13,200 IU/kg), vitamin E (15 or 90 IU/kg), and two vitamin E sources (D-alpha-tocopheryl acetate [D-TAc] or DL-alpha-tocopheryl acetate [DL-TAc]) were evaluated over a 35-d period. Vitamin A or E levels and the two vitamin E sources did not affect pig performances to 20 kg BW. Serum retinol and alpha-tocopherol concentrations increased (P < 0.01) as the dietary level of each vitamin increased. Serum alpha-tocopherol declined as dietary vitamin E level increased when vitamin A level increased resulting in an interaction (P < 0.05). Serum alpha-tocopherol concentrations were higher (P < 0.05) at 35-d postweaning when D-TAc was the vitamin E source. Experiment 2 was a 3 x 2 factorial arrangement of treatments conducted in six replicates. Three levels of vitamin A (2,200, 13,200, or 26,400 IU/ kg) and two sources of vitamin E (D-TAc or DL-TAc) each provided at 40 IU/kg diet were evaluated over a 35-d period. Pig performances to 35-d postweaning were not affected by the dietary variables. Serum alpha-tocopherol (P < 0.01) and retinol (P < 0.05) concentrations increased as their respective vitamin level increased. Serum (P < 0.05) and liver (P < 0.01) alpha-tocopherol concentrations both declined as dietary vitamin A levels increased resulting in interaction responses. Serum alpha-tocopherol concentration was higher (P < 0.05) at 35-d postweaning when d-TAc was the vitamin E source. Dietary vitamin E sources had no effect on serum or liver retinol concentrations. These results demonstrated that both supplemental vitamin A and vitamin E increased in the blood as their dietary levels increased. However, as dietary vitamin A level increased, serum and liver alpha-tocopherol concentrations declined, suggesting a reduced absorption and retention of alpha-tocopherol when weaned pigs were fed high dietary vitamin A levels.