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The objective of this experiment was to measure the influence of virginiamycin on the apparent ileal digestibility (AID) of AA by growing pigs. Fifteen barrows were surgically equipped with a T-cannula in the distal ileum and used in the experiment (initial BW = 35.0 [+ or -] 2.7 kg). Animals were randomly allotted to 3 dietary treatments with 5 pigs per treatment during a 6-wk experiment. Dietary treatments included 1) a basal corn-soybean meal diet, 2) the basal diet supplemerited with 11 mg/kg of virginiamycin, and 3) the basal diet supplemented with 22 mg/kg of virginiamycin. Pigs were fed their respective treatment diets during wk 2, 3, and 4, but during wk 1, 5, and 6, all pigs were fed the basal diet. Ileal samples were collected on d 6 and 7 of each week. Results showed that the AID of all indispensable AA, except Arg, His, and Ile, increased (P < 0.05) during wk 2, 3, and 4 compared with wk 1 in pigs fed the diet containing 11 mg/kg of virginiamycin. Pigs fed 22 mg/kg of virginiamycin during wk 2, 3, and 4 had increased (P < 0.05) AID of Trp and Val during these weeks compared with the AID in wk 1. However, the increased AID of AA did not carry over to wk 5 and 6, when virginiamycin was withdrawn from the diet, regardless of the inclusion rate. In pooled data from wk 2, 3, and 4, the AID of CP, the mean of all indispensable AA, and Ile, Leu, Met, Phe, Trp, and Val increased (linear, P < 0.05) as virginiamycin was added to the diets, whereas a tendency (P < 0.10) for a linear or quadratic increase was observed for His, Lys, and Thr. These results indicate that addition of virginiamycin to corn-soybean meal diets fed to growing pigs increases the AID of AA, but this effect is not maintained after the removal of virginiamycin from the diet. Key words: amino acid, ileal digestibility, pig, virginiamycin doi: 10.2527/jas.2009-2063

Three experiments were conducted to evaluate a novel source of high-protein distillers dried grains produced by Buhler Inc. ([HP-DDG.sub.Buhler]) and red to growing pigs. The standardized ileal digestibility (SID) of AA in [HP-DDG.sub.Buhler] and in soybean meal (SBM) was determined in Exp. 1. Nine pigs (109.8 [+ or -] 2.78 kg of BW) were fitted with a T-cannula in the distal ileum and allotted to a triplicated 3 x 3 Latin square design with 3 diets and 3 periods per square. Diets containing [HP-DDG.sub.Buhler] or SBM as the only source of AA and an N-free diet were formulated. The SID of indispensable AA was less (P < 0.01) in [HP-DDG.sub.Buhler] than in SBM (Arg, 87.5 vs. 93.9%; His, 76.7 vs. 88.7%; Ile, 76.4 vs. 87.5%; Leu, 77.8 vs. 86.8%; Lys, 75.4 vs. 88.4%; Met, 82.8 vs. 88.4%; Phe, 77.9 vs. 87.3%; Thr, 72.5 vs. 83.5%; Trp, 85.1 vs. 91.0%; Val, 73.3 vs. 84.3%). The DE and ME in [HP-DDG.sub.Buhler] and in corn were measured in Exp. 2 using 16 growing barrows (24.6 [+ or -] 1.66 kg of BW). A corn-based diet and a diet containing 50% com and 48.2% HP-DDGBul,ler were formulated. The total collection method and the difference procedures were used. The concentrations of DE and ME in [HP-DDG.sub.Buhler] were greater (P < 0.001) than in corn (5,043 vs. 4,002 kcal/kg of DM and 4,690 vs. 3,921 kcal/kg of DM, respectively). Experiment 3 was a 9-wk growth assay using 40 pigs (initial BW: 58.2 [+ or -] 2.28 kg) allotted to 5 dietary treatments, with 8 replicates of individually housed pigs per treatment. Treatments included a control diet based on corn and SBM and 4 diets in which [HP-DDG.sub.Buhler] replaced 33, 66, 66, or 100% of the SBM in the control diet. All HP[HP-DDG.sub.Buhler] diets contained supplemental Lys and Thr to provide similar concentrations of SID Lys and Thr in all diets; one of the diets in which [HP-DDG.sub.Buhler] replaced 66% of the SBM and the diet in which HP[HP-DDG.sub.Buhler]. replaced 100% of the SBM also contained crystalline Trp. Dietary treatments had no effect on ADG (1.15, 1.13, 1.16, 1.12, and 1.14 kg), ADFI (3.33,6 3.35, 3.39, 3.30, and 3.33 kg), or G:F (0.35, 0.34, 0.34, 0.34, and 0.34 kg/kg). Carcass traits of pigs fed the diet in which [HP-DDG.sub.Buhler] replaced 100% of the SBM were not different from those of pigs fed the control diet. In conclusion, [HP-DDG.sub.Buhler] contains more DE and ME than corn, but has decreased SID values for AA compared with SBM. Soybean meal can be replaeed by [HP-DDG.sub.Buhler] in diets fed to finishing pigs without any effect on growth performance or carcass characteristics, provided that diets are adequate in indispensable AA. Key words: amino acid digestibility, carcass characteristic, energy, growth performance, high-protein distillers dried grains, pig doi: 10.2527/jas.2009-2060

Semiconductor heterostructures provide an ideal platform for studying high-mobility, low-density electrons in reduced dimensions (1-4). The realization of superconductivity in heavily doped diamond (5), silicon (6), silicon carbide (7) and [...]

Three experiments were conducted to investigate the effects of thermal stress and dietary Cr on growth performance and physiological variables in weanling pigs. In Exp. 1, a total of 54 pigs (BW of 5.95 [+ or -] 0.84 kg) were allotted to a 2 x 3 factorial arrangement using 2 ambient temperatures (23.7 or 40.5[degrees]C during d 14 to 28 postweaning) and 3 dietary concentrations of Cr (0, 1,000, or 2,000 [micro]g/kg) as Cr(III) picolinate. In Exp. 2, a total of 54 pigs (BW of 5.94 [+ or -] 1.29 kg) were allotted in the same treatment arrangement but with different ambient temperatures (26.5 or 16.0[degrees]C during d 14 to 26 postweaning). In Exp. 3, a total of 36 pigs (BW of 6.40 [+ or -] 0.72 kg) were allotted in the same treatment arrangement with ambient temperatures of 25.9 or 13.8[degrees]C during d 14 to 28 postweaning. During d 0 to 14 of all experiments, a neutral ambient temperature (NT) was maintained. In Exp. 1, pigs in high ambient temperature (HT) gained less BW (575 vs. 663 g/d; P < 0.001) and consumed less feed (926 vs. 1,074 g/d; P = 0.001) than pigs in NT during d 14 to 28. However, G:F was not affected by ambient temperature (0.623 vs. 0.618 g/g; P = 0.702). Dietary Cr had no effect on growth performance. Pigs in HT had less plasma cortisol (42.0 vs. 53.7 ng/mL; P = 0.012) and glucose (6.68 vs. 6.96 ng/mL; P = 0.018). Respiratory rate of pigs in HT was greater compared with the pigs in NT (114.6 vs. 65.0 breaths/min; P < 0.001) on d 27. In Exp. 2 and 3 (pooled), pigs in low ambient temperature (LT) had decreased G:F (0.636 vs. 0.663 g/g; P < 0.01) associated with a tendency toward a greater ADFI (1,026 vs. 942 g; P = 0.079) during d 14 to 26 (28). Ambient temperature or dietary Cr supplementation had no effect on blood measurements. In Exp. 3, the respiratory rate measured on d 22 and 27 was less (43.2 vs. 54.2 breaths/min and 42.2 vs. 57.0 breaths/min, respectively; P < 0.001) in the pigs in LT than the pigs in NT with no effects of dietary Cr supplementation. These results indicate that growth performance is affected by thermal stress and plasma cortisol is decreased by heat stress, but these effects are not moderated by dietary Cr. Key words: chromium, pig, thermal stress

In most animal growth experiments, groups of animals are housed within a pen. Occasionally, an individual animal shows a very different growth rate than its pen mates or dies during the experiment. When this happens, if pen feed intake (PFI) cannot be reestimated for the calculation of ADFI and feed efficiency, an observation will be lost from the data set. Therefore, we propose a model to estimate individual feed intake (IFI) of pigs in group feeding, with subsequent validation of the model using group feeding simulation studies. In the proposed model, the feed intake (FI) of each affected pen is partitioned into FI for maintenance (FIm) and FI for growth (Fig) for each animal within that pen. First, individual pig FIm for the period is calculated using the 1998 National Research Council estimation of ME for maintenance. Then, Fire for all pigs in the pen is summed. The difference between the summed FIm and the total PFI is that which supported growth in the pen. Next, Fig is calculated by apportioning the remaining feed equally to each unit of gain within the pen. Finally, the estimated IFI for the pig being removed from the pen is the sum of Fire and Fig for that pig; this FI estimate is subtracted from the original PFI to leave the new PFI for the remaining pigs. The validity of the estimated IFI is dependent on the accuracy of the maintenance energy equation and the energy analysis of the feedstuffs. In simulation studies, we compared the accuracy of the proposed method with 2 other methods. In simulation study 1, the proposed model showed better accuracy than at least one of the other methods during all tested periods (P < 0.001). In simulation study 2, the greater accuracy of the proposed method compared with 2 other methods was demonstrated again. Because calculation of IFI is relatively cumbersome, we developed a feed intake correction spreadsheet (FICS), an Excel spreadsheet containing macros for FI correction. All of the calculation procedures in the proposed model are included within the feed intake correction spreadsheet. The Excel file and instructions are being made available via a Web site. Key words: Excel, feed intake, pig

Two experiments were conducted to evaluate the efficacy of dietary DL-methionine hydroxy analog-free acid (MHA-FA, 88%) compared with DL-methionine (DLM, 99%) as Met sources in pigs. In Exp. 1, a total of 245 crossbred pigs (initial BW of 6.4 kg [SD = 0.5]) were allotted to 7 treatments in 7 replicates for an experimental period of 28 d. The basal diet (BD)was formulated to contain 17.5% CP and 0.21% Met. Dietary treatments included 1) BD, 2) BD + 0.030% DLM, 3) BD + 0.060% DLM, 4) BD + 0.090% DLM, 5) BD + 0.034% MHA-FA, 6) BD + 0.068% MHA-FA, and 7) BD + 0.103% MHA-FA; the MHA-FA was supplemented on an equimolar basis to the DLM. Because of a nonlinear response, exponential regression analysis was used to evaluate the responses, and a comparison of the equations was then made to determine the relative effectiveness of the 2 Met sources. With increases in dietary Met, weight gain increased (P < 0.05). Compared with DLM on a product-to-product (wt/wt) basis, the relative effectiveness of MHA-FA was calculated to be 73% for increasing weight gain and 54% for decreasing the feed:gain. In Exp. 2, a total of 30 weanling barrows [initial BW of 16.8 kg(SD = 2.8)] were used in a metabolism study to evaluate the relative value of MHA-FA to DLM. The BD was formulated to contain 16.9% CP and 0.21% Met. Dietary treatments included 1) BD, 2) BD + 0.030% DLM, 3) BD + 0.060% DLM, 4) BD + 0.046% MHA-FA, and 5) BD + 0.092% MHA-FA; the MHA-FA levels were chosen based on a pre-experiment estimate of bioequivalence in an attempt to provide approximately equal pig responses. There was no difference in fecal N output among the treatments; however, urine N linearly decreased with increasing concentrations of both sources (P = 0.034 for DLM, and P = 0.007 for MHA-FA), which resulted in a linear increase in retained N for both DLM (P = 0.012) and MHA-FA (P = 0.005). In addition, N retention (% of intake) linearly increased with increasing level of DLM (P = 0.014) and MHA-FA (P = 0.007). Using a slope-ratio procedure for comparison of the responses from the 2 sources, the relative biological equivalence value of MHA-FA to DLM in this experiment was 64.2% based on percent N retention and 66.3% based on the grams of N retained per day. Based on the results from both experiments, these data indicated that the mean relative bioequivalence of MHA-FA to DLM was 64% on a product-to-product (wt/wt) basis or 73% on an equimolar basis. Key words: bioefficacy, methionine, methionine hydroxy analog, pig

The magnetic properties of an [Fe.sub.87.3][Zr.sub.5.9][B.sub.6.5][Ag.sub.0.3] (at. %) amorphous alloy have been investigated as a function of annealing temperatures in order to know its potential applicability as core material for high-frequency applications. A very excellent soft magnetic material was developed. The amorphous alloy, which was annealed at [T.sub.a] = 400 [degrees] C, exhibited very high initial permeability ([[Mu].sub.i]) of 287 000 at 1 kHz and 2 mOe, very low coercivity ([H.sub.c]) of 15 mOe, and low core loss ([W.sub.c]) of 50 W/kg at 100 kHz and 0.1 T, respectively. It is notable that the values obtained in the present study are the best magnetic properties among various kinds of Fe-based soft amorphous materials reported up to now. The reason for the achievement of good soft magnetic properties is presumably due to the homogeneous formation of very fine [Alpha]-Fe clusters of size 2-3 nm in an amorphous matrix, which can be deduced from an increase of resistivity and transmission electron microscopy (TEM) observation. The very fine [Alpha]-Fe clusters, embedded in an amorphous matrix, had a great influence on the reduction of magnetostriction and refinement of the magnetic domain.

A new type of focusing transducer for ultrasonic contact testing is introduced. It contains an acoustic contact lens whose geometry was designed for the generation and point-focusing of surface waves. Its design is employed to build a prototype for Rayleigh waves whose stress pattern on the transducer's symmetry axis may be described by a model. The modeling results, which show a good fit with experimental data, indicate that the new design can enhance the surface evaluation of thin laminated films.

The preparation condition of ultrafine Al and AlN particles by thenitrogen plasma-molten Al reaction method was studied by a combiend technique of nitrogen plasma-aluminum reaction and spray deposition as well as by metalorganic techniques. It was shown that ultrafine Al and AlN particles can be produced by the plasma-metal reaction method and that their volume ratio canbe controlled in the range below 25% by changing the mixing ratio of nitrogen to argon and the total pressure of nitrogen.

Reactive sputtering was used to fabricate compositionally gradientAl-AlN films. Different mixing gas ratios resulted in varying phase changes in the order of Al+AlN, AlN+Al and AlN. Al concentration level decreased from 100 to 50%, although the mixing ratio increased from 0 to 0.2. In the Al and AlN phases, the lattice parameters remained constant along the sample thickness. Inaddition, the Al-AlN film exhibited functionally gradient characteristics.