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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.

Two studies were conducted to determine the effects of a novel Escherichia coli phytase expressed in Pseudomonas fluorescens on growth performance, bone mineralization, and nutrient digestibility in pigs fed corn-soybean meal diets. In experiment 1, 160 nursery pigs (9.79 ± 1.22 kg) were randomly allotted to one of four treatments with 10 pens per treatment and four pigs per pen. Phase I and phase II diets were provided from d 0 to d 14 and d 14 to d 28, respectively. Treatments included: positive control (PC) with all nutrients meeting requirements; negative control (NC) with standardized total tract digestible (STTD) P reduced by 0.15% and 0.14% compared with PC in phase I and phase II, respectively; and NC diets containing 250 or 500 units of phytase (FTU) per kilogram. Results demonstrated that pigs fed PC had greater (P < 0.01) ADG and G:F for the overall experimental period, and greater (P < 0.01) bone ash and P concentrations, compared with pigs fed NC or diets with phytase supplementation. Pigs fed diets containing phytase had greater (P < 0.01) ADG and G:F for the overall experimental period compared with pigs fed the NC diet without phytase, and bone ash and P weights were increased (P < 0.01) as well. In experiment 2, 63 growing barrows (56.25 ± 2.54 kg) were blocked by BW and randomly allotted to one of seven treatments with nine pens per treatment and one pig per pen. A basal corn-soybean meal diet was formulated to meet nutrient requirements for growing pigs with the exception that STTD P was reduced by 0.18% compared with the requirement, and Ca was included to achieve a Ca:STTD P ratio of 2.15. Six additional diets were formulated by adding 250, 500, 750, 1,000, 1,500, or 2,000 FTU/kg of phytase to the basal diet. Pigs were fed experimental diets for 12 d with 7 d of adaptation and 5 d of fecal sample collection. Results indicated that there was a linear (P < 0.01) increase in apparent total tract digestibility of ash and ether extract, and STTD of Ca and P also increased (linear, P < 0.05) in response to increasing doses of phytase. Increasing phytase levels in the diets resulted in increase (quadratic, P < 0.05) in apparent ileal digestibility of Arg, His, Ile, Lys, Trp, Asp, and Glu. In conclusion, the novel E. coli phytase was effective in increasing growth performance, bone mineralization, and Ca and P digestibility in pigs fed corn-soybean meal-based diets. Results also indicated that this phytase had the potential to enhance the digestibility of fat and certain AA.

An experiment was conducted to test the hypothesis that productivity of sows fed diets containing canola meal produced from high-protein or conventional varieties of canola seeds is not different from that of sows fed corn-soybean meal (SBM) diets. A total of 180 sows (initial BW: 207.8 ± 29.11 kg) were randomly allotted to 1 of 5 diets with 36 to 40 sows per diet. A 2-phase feeding program was used with gestation diets fed from day 7 of gestation to farrowing and lactation diets fed during the lactation period and from weaning to first estrus. The 5 diets within each phase consisted of a control diet based on corn and SBM, 2 diets were based on corn and high-protein canola meal (CM-HP) that was included to replace 50 or 100% of the SBM in the control diet, and 2 diets contained conventional canola meal (CM-CV) included to replace 50 or 100% of the SBM in the control diet. Soybean hulls were included in diets fed during gestation to standardize the concentration of NDF to approximately 13% in all diets. However, no soybean hulls were used in lactation diets resulting in increased concentrations of NDF as the dietary concentration of CM-HP or CM-CV increased. Results of the experiment indicated that there were no differences in sow BW changes during gestation, in sow BW on day 1 post-farrowing, or at weaning due to dietary treatments. No differences were observed among diets in ADFI during gestation or lactation or in the number of total pigs born, pigs born alive, still-born pigs, or weaned pigs per litter. Likewise, no differences were observed among diets in litter birth weight, live litter birth weight, litter BW at weaning, or litter ADG. As the inclusion level of CM-HP or CM-CV increased, the percentage of pigs surviving during the lactation period increased (linear, P < 0.05), but the wean to first estrus interval also increased as the dietary concentration of CM-CV increased (linear, P < 0.05). Average pig BW at weaning and pig ADG decreased (linear, P < 0.05) as the inclusion level of CM-HP increased. No differences were observed between CM-HP and CM-CV with the exception that pigs born from sows fed CM-CV during gestation had greater (P < 0.05) average live pig birth weight compared with pigs born from sows fed CM-HP during gestation. Results of this experiment indicate that CM-HP or CM-CV may replace all SBM in diets fed to sows during gestation and lactation.

Work was conducted to test the hypothesis that the nutritional composition of bakery meal varies depending on where in the United States the meal is produced due to different raw materials being used in the production of the meals. Forty-six samples of bakery meal were collected from feed mills located in the swine producing states in the United States. Based on the state where samples were collected, they were grouped into 5 regions: 1) AL, DE, GA, NC, PA, and VA (10 samples); 2) CO, MO, OK, and TX (10 samples); 3) IN, KY, OH, and TN (8 samples); 4) IA (11 samples); and 5) MN (7 samples). All samples were analyzed for proximate components, GE, AA, carbohydrates, and minerals, and IVDMD and in vitro energy digestibility (IVGED) were also determined. Results indicated that the average concentration of DM was (91.84 ± 1.29%) and there was no difference among regions. The concentration of ash in bakery meal from MN was greater (P < 0.05) than in meals from other regions, but for all other proximate components, no differences among sources were observed. The average concentration (DM basis) of CP (12.20 ± 2.16%), acid hydrolyzed ether extract (AEE, 9.38 ± 1.95%), starch (44.61 ± 5.47%), and NDF (13.77 ± 4.23%) indicated that bakery meal consists of a mixture of food ingredients originating from flour or whole cereal grains and with some high-fiber ingredients such as brans or canola coproducts also included. It also appears that oil or fats were added during production. With the exception of His, no differences among regions were observed for indispensable AA and the average concentrations (DM basis) of Lys, Met, Thr, and Trp were 0.35 ± 0.08%, 0.19 ± 0.03%, 0.38 ± 0.06%, and 0.13 ± 0.03%, respectively. The bakery meals from MN contained more (P < 0.05) Ca than bakery meals from other regions, indicating that limestone may have been added to bakery meal from MN to improve flowability. However, bakery meals from MN and IA contained less (P < 0.05) total P, phytate, and phytate-bound P than bakery meals produced in the states east of the Mississippi River. There were, however, no differences in IVDMD (79.06 ± 6.62%) or of IVGED (74.84 ± 8.20%) of bakery meals among regions. The present results indicate that variations in the chemical composition of bakery meal obtained from different regions in the United States are relatively small and likely without great impact on the nutritional value of the meals, but in vivo digestibility experiments are needed to confirm this hypothesis.

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.