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An N-balance experiment was conducted to test the hypothesis that d-Methionine (d-Met) has the same bioavailability and efficacy as l-Methionine (l-Met) when fed to weanling pigs. A Met-deficient basal diet containing 0.24% standardized ileal digestible (SID) Met was formulated. Six additional diets were formulated by adding 0.036%, 0.072%, or 0.108% d-Met or l-Met to the basal diet, and these diets, therefore, contained 77%, 87%, or 97% of the requirement for SID Met. Fifty-six barrows (10.53 ± 1.17 kg) were housed in metabolism crates and allotted to the seven diets with eight replicate pigs per diet. Feces and urine were collected quantitatively with 7-d adaptation and 5-d collection periods. Blood and tissue samples from pigs fed the basal diet and pigs fed diets containing 0.108% supplemental Met were collected on the last day. Results indicated that N retention (%) linearly increased (P < 0.01) as supplemental d-Met or l-Met increased in diets. Based on N retention (%) as a response, the linear slope-ratio regression estimated the bioavailability of d-Met relative to l-Met to be 101% (95% confidence interval: 57%-146%). The villus height and crypt depth in the jejunum were not affected by the Met level or Met source. Total antioxidant capacity or thiobarbituric acid reactive substance concentrations in plasma or tissue samples from pigs fed the control diet or diets containing 0.108% supplemental d-Met or l-Met were not different. Abundance of mRNA for some AA transporters analyzed in intestinal mucosa of pigs also did not differ. Therefore, it is concluded that d-Met and l-Met are equally bioavailable for weanling pigs.

A number of feed additives are marketed to assist in boosting the pigs' immune system, regulate gut microbiota, and reduce negative impacts of weaning and other environmental challenges. The most commonly used feed additives include acidifiers, zinc and copper, prebiotics, direct-fed microbials, yeast products, nucleotides, and plant extracts. Inclusion of pharmacological levels of zinc and copper, certain acidifiers, and several plant extracts have been reported to result in improved pig performance or improved immune function of pigs. It is also possible that use of prebiotics, direct-fed microbials, yeast, and nucleotides may have positive impacts on pig performance, but results have been less consistent and there is a need for more research in this area.

The hypothesis that exogenous xylanase added to diets for gestating and lactating sows will increase the apparent total tract digestibility (ATTD) of gross energy (GE) and total dietary fiber (TDF), and digestible energy (DE) and metabolizable energy (ME) was tested. Two diets for gestating and two diets for lactating sows containing corn, soybean meal, distillers dried grains with solubles, wheat middlings, and soybean hulls were formulated without or with 16,000 BXU per kg of exogenous xylanase (Econase XT; AB Vista, Marlborough, UK). Lactation diets contained an indigestible marker. Diets were fed to gestating and lactating sows in two reproductive cycles. A total of 106 gilts and sows were randomly allotted to the two gestation diets 7 d after breeding in a randomized complete block design with 4 blocks. On d 30 post-breeding, 8 non-pregnant animals were removed. From the remaining 98 animals, 48 sows (24 replicates per treatment, 12 sows per block) were placed in metabolism crates on d 35 (midgestation) for 10 d with feces and urine collected for 5 d. The same 48 sows were placed in metabolism crates again on d 95 (late-gestation). All sows were moved to the lactation unit on d 106 and lactation diet feeding was initiated. Fecal samples were collected (grab-sampling) for 5 d starting on d 10 post-farrowing. Sows were weaned on d 20 and 63 sows were rebred. Of these sows, 46 sows were placed in metabolism crates on d 35 and 95 as in the first cycle, and treatments in the farrowing unit were also as in the first cycle. Data were analyzed using the MIXED procedure of SAS with sow as the experimental unit, diet as fixed effect, and block and replicate as random effects. Results indicated that in the first cycle, the ME in mid-gestation, and the ATTD of TDF, and DE and ME in late-gestation were greater (P < 0.05) in sows fed the xylanase-diet compared with the control diet (Table 1). During the first lactation period, sows fed the xylanase-diet had greater (P < 0.05) ATTD of TDF and GE and greater (P < 0.05) DE than sows fed the control diet. During the second gestation period, sows fed the xylanase-diet had greater (P < 0.05) DE and ME in mid- and late-gestation, but no differences were observed in ATTD of TDF (Table 2). During the second lactation period, sows fed the xylanase-diet had greater (P < 0.05) ATTD of TDF and GE and greater (P < 0.05) DE than sows fed the control diet. In conclusion, DE was greater in the xylanase-diet than the control diets during two reproductive cycles, and sows fed lactation diets with xylanase had greater digestibility of fiber. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that there are no differences among sources of sunflower co-products on the apparent total tract digestibility (ATTD) of P and Ca and on the standardized total tract digestibility (STTD) of P regardless of where the ingredients were produced. Six sources of sunflower meal (SFM) were obtained from the U.S. (2 sources), Ukraine (2 sources), Hungary, and Italy. A source of sunflower expellers (SFE) from the U.S. was also used. Seven diets were formulated by mixing each source of sunflower co-product with cornstarch; therefore, the sunflower co-product was the only source of P in these diets. Seven additional diets that were similar to the previous seven diets with the exception that 300 units per kg of microbial phytase were added were also formulated. A total of 112 barrows (initial body weight = 17.95 kg ± 1.37 kg) were allotted to the 14 diets using 4 blocks, 2 pigs per diet in each block, and a total of 8 replicate pigs per diet. Pigs were placed in individual metabolism crates to allow for the total collection of fecal materials for 4 days after 7 days of adaptation to the diets. Diets and dried fecal samples were analyzed for dry matter, Ca, and P. Data for Ca and P digestibility were analyzed in a randomized complete block design in a 7 × 2 factorial arrangement using the PROC MIXED function in SAS. Results indicated that diets containing phytase had greater (P < 0.01) ATTD of Ca and P and greater (P < 0.01) STTD of P than diets without phytase (Table 1). Digestibility of P was also greater in one of the sources of SFM from Ukraine compared with the other sources except for the SFM from Hungary (Table 2). Pigs fed the diet containing one of the sources of SFM from the U.S. had greater (P < 0.05) ATTD of Ca compared with pigs fed diets containing the other source of SFM from the U.S. or one of the Ukraine SFM sources. In conclusion, some variability in the ATTD and STTD of P and the ATTD Ca was observed among SFM of different origins, but the ATTD and STTD of P and ATTD of Ca in SFM and SFE were greater if microbial phytase was used. [ABSTRACT FROM AUTHOR]

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 < 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 < 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 < 0.05) compared with soft 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, 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. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that dietary inclusion of either a conventional or a novel source of torula yeast in diets for weanling pigs improves growth performance and intestinal health. The novel torula yeast was produced using forestry byproducts (i.e., wood hydrolysate) as the carbon source, whereas the conventional torula yeast was produced using wheat dextrose as the carbon source. A total of 120 weanling pigs (6.53 ± 0.78 kg) were allotted to three treatments with four pigs per pen and ten replicate pens per diet. Pigs were fed one of three diets from d 1 to 14 post-weaning (phase 1), whereas all pigs were fed a common diet in phase 2 (d 15 to 28). The three dietary treatments included a control diet that contained 5% fishmeal, 3.5% plasma protein, and no torula yeast. The second diet contained 1.5% fishmeal, 14% of the novel torula yeast, and no plasma protein, whereas the third diet contained 1.5% fishmeal, 14% of the conventional torula yeast, and no plasma protein. Pig weights were recorded on d 1, d 14, and d 28. Feed allotments were recorded daily, and feed left in the feeders was recorded on d 14 and 28 to calculate average daily gain, average daily feed intake, and average gain to feed ratio. Fecal scores were visually assessed every other day. On d 7, one pig per pen was euthanized to collect ileal tissue for assessment of morphology. At the end of phases 1 and 2, blood samples were collected, and cytokines, plasma urea nitrogen, peptide YY, immunoglobulin G, total protein, and albumin were analyzed. Data were analyzed using an ANOVA in the Mixed Procedure of SAS with pen as the experimental unit. Diet was the fixed effect, whereas weaning weight was the random effect. Results indicated that both sources of torula yeast could replace fish meal and plasma protein without negatively affecting overall growth performance, intestinal morphology, or blood characteristics of pigs (Table 1). Pigs fed one of the diets containing torula yeast had reduced (P < 0.05) fecal scores during phase 1 compared with pigs fed the control diet. On d 14, pigs fed the conventional torula yeast diet had greater (P < 0.05) concentration of interleukin-2 in plasma compared with pigs fed the control diet. Greater (P < 0.05) concentrations of interleukin-4 and interleukin-10 were observed in plasma from pigs fed one of the diets containing torula yeast compared with pigs fed the control diet on d 14. In conclusion, inclusion of either a conventional or a novel source of torula yeast at the expense of animal proteins in diets for weanling pigs may improve intestinal health without influencing growth performance of weanling pigs. [ABSTRACT FROM AUTHOR]

The hypothesis that the nutritional value of corn protein (approximately 50% protein) is greater than in two sources of distillers dried grains with solubles (DDGS1 and DDGS2) was tested. In Exp. 1, eight ileal-cannulated barrows (37.1 ± 2.4 kg) were allotted to a Latin square and fed a N-free diet or diets based on corn protein, DDGS1, or DDGS2. Data were analyzed by ANOVA using SAS with treatment and replicate being fixed and random effects, respectively. Concentrations of standardized ileal digestible (SID) AA were greater (P < 0.05) in corn protein than in DDGS (Table 1). In Exp. 2, 32 barrows (16.5 ± 0.9 kg) in metabolism crates received diets based on, corn, corn protein, DDGS1, or DDGS2. Data were analyzed as in Exp. 1. Corn protein had greater (P < 0.01) ME compared with DDGS1 and DDGS2 (Table 1). In Exp. 3, 160 pigs (6.02 ± 0.84 kg) were allotted to 4 treatments with 8 pens per treatment. Phase 1 and 2 diets contained 0, 5, 5, or 10% and 0, 2.5, 7.5, or 10% corn protein, respectively, which replaced enzyme-treated soybean meal (HP300) or plasma in phase 1 or HP300 in phase 2. Diets were formulated using ME and SID AA values from Exp. 1 and 2. A common phase 3 diet was used. Data were analyzed as in Exp. 1. At the end of phase 1, BW was reduced (P < 0.05) for pigs fed the diet with the greatest inclusion of corn protein, but there was no difference at the end of the experiment (Table 2). Fecal score tended (P = 0.066) to be reduced in phase 2 for pigs fed the greatest inclusion of corn protein. In conclusion, corn protein has greater ME and digestible AA than DDGS and may reduce fecal scores of pigs. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that increasing levels of phytase increases mineral digestibility and bone ash by pigs fed diets containing 0.23%, 0.29%, or 0.35% phytate-P. Within each level of phytate, 5 diets were formulated based on corn, soybean meal, and canola meal to contain 0, 500, 1,000, 2,000, or 4,000 phytase units (FTU)/kg of a novel consensus bacterial 6-phytase variant (PhyG). In addition, 3 reference diets were formulated by adding a commercial Buttiauxella phytase (PhyB) at 1,000 FTU/kg to the 3 diets containing no PhyG. A randomized complete block design with 144 pigs (12.70 ± 4.01 kg), 18 diets, and 8 replicate pigs per diet was used. Pigs adapted to diets for 15 d followed by 4 d of fecal collection. Femurs were collected on the last day. Data were analyzed as a 3 × 5 factorial with 3 levels of phytate-P and 5 levels of phytase, and contrast statements were used to compare 1,000 FTU of PhyG with PhyB. Pig was the experimental unit. Diets containing 0.35% phytate-P had reduced (P < 0.01) apparent total tract digestibility (ATTD) of Ca, P, Mg, and K compared with diets containing 0.23% or 0.29% phytate-P, but inclusion of phytase increased (P < 0.01) ATTD of Ca, Na, and K (Table 1). Phytase increased ATTD of P and Mg, but to a greater extent in diets with 0.23 or 0.29% phytate-P than in diets with 0.35% phytate-P (interaction, P < 0.05). Phytase increased bone ash, but to a greater extent if there was 0.35 rather than 0.23 or 0.29% phytate-P in the diets (interaction, P < 0.05). PhyG increased ATTD of P more (P < 0.05) than PhyB. In conclusion, the novel consensus phytase is effective in increasing bone ash and ATTD of Ca, P, Na, Mg and K. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that increasing levels of phytase increases mineral digestibility and growth performance of pigs fed diets with 3,000 mg/kg of Zn. A positive control (PC) diet that met nutrient requirements and a negative control (NC) diet that was deficient in total Ca (-0.16%), digestible P (-0.14%), metabolizable energy (-50 kcal/kg), and digestible amino acids (-0.02%) were formulated. Eight additional diets were formulated by adding 500, 1,000, 1,500, or 2,000 phytase units/kg of a novel bacterial 6-phytase (PhyG) or a commercial Buttiauxella phytase (PhyB) to the NC diet. A randomized complete block design with 400 weanling pigs (5.82 ± 0.70 kg), 10 diets, 4 pigs per pen, and 10 replicate pens per diet was used. Pigs were fed the experimental diets for 28 d. Fecal samples were collected from 1 pig per pen on d 26 to 28. Linear and quadratic effects of PhyG and PhyB were determined using polynomial contrast statements. Contrast statements were used to compare effects of PC diet with NC diet, and to compare effects of PhyG diets with PhyB diets. Overall, pigs fed the NC diet had reduced growth performance (P < 0.05) compared with pigs fed the NC diet (Table 1). Linear (P < 0.01) and quadratic (P < 0.05) increases in overall average daily gain and average daily feed intake of pigs were observed as dietary concentrations of PhyG or PhyB increased. Increasing levels of PhyG or PhyB linearly increased (P < 0.01) the apparent total tract digestibility (ATTD) of P and Ca. PhyG increased ATTD of P more (P < 0.05) than PhyB. In conclusion, both phytases are effective in increasing mineral digestibility and growth performance in pigs fed diets with pharmacological levels of Zn; however, PhyG improved P digestibility more than PhyB. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to test the hypothesis that different combinations of conditioning and expansion of soybean expellers increases nutritional value. Non-heat-treated soybean expellers (L-1) and soybean expellers conditioned for 60 s at 90ºC followed by expansion at 110ºC (L-2) were used. Two additional sources of soybean expellers (L-3 and L-4) were processed as L-2 with the exception that the initial conditioning was followed by long-term conditioning for 12 or 48 min at 100ºC before expansion. Analyzed trypsin inhibitor activity in L-1, L-2, L-3, and L-4 was 34.0, 23.1, 4.2, and 2.4 mg/g, respectively. In experiment 1, 10 cannulated barrows (54.22 ± 4.54 kg) were allotted to a replicated 5 × 4 Youden square with 5 diets and 4 periods and 8 replicates per diet. Each source of soybean expellers was included in one diet, and a N-free diet was also used. Data were analyzed by ANOVA using the Mixed Procedure of SAS. The standardized ileal digestibility (SID) of all amino acids (AA) in L-1 was less (P < 0.01) compared with L-2, L-3, and L-4 (Table 1), and SID of all AA in L-2 was less (P < 0.01) than in L-3 or L-4. In experiment 2, 40 barrows (17.52 ± 1.63 kg) were housed in metabolism crates and fed a corn diet or 4 diets based on corn and each source of soybean expellers. Feces and urine were collected using the marker-to-marker approach with 5-d adaptation and 4-d collection periods. Data were analyzed as in Exp. 1. The metabolizable energy (ME) in L-1 was less (P < 0.01) than in L-2, L-3, and L-4 (Table 1). In conclusion, the SID of AA in soybean expellers was maximized if 12 or 48 min of conditioning at 100ºC was used before expansion, but long-term conditioning did not increase ME. [ABSTRACT FROM AUTHOR]