A total of 300 male broilers (Ross 308) were exposed to cool conditions at high altitudes to study the effects of dietary Arg supplementation on performance and physiological and zootechnical variables. A corn-soybean meal (SBM) and a corn-canola meal (CM) diet were formulated for the starting (1 to 3 wk of age) and growing (3 to 6 wk of age) stages according to NRC recommendations. Two additional diets were prepared by supplementing 0.2 and 0.4% l-Arg to the corn-CM diet. Substitution of CM for SBM caused a significant (P < 0.05) reduction in weight gain and feed intake and resulted in impaired feed:gain. Supplementing Arg in the CM diet restored the feed and weight losses to a significant extent so that a significant difference was found between CM diet and CM + 0.4% Arg in terms of weight gain for the growing (3 to 6 wk) stage and the entire study (1 to 6 wk; P < 0.05). Total plasma nitric oxide (NO) concentration analyzed by nitrate plus nitrite assay was measured in the treatment groups. A significant (P < 0.05) decrease in plasma NO level was observed by substituting CM for SBM in the diet. Supplementing the CM diet with Arg increased the plasma NO level above that of SBM group. Carcass and breast yields were significantly decreased (P < 0.05) as a result of substituting CM for SBM. The substitution of CM for SBM, however, significantly (P < 0.05) increased the proportions of thighs and heart. The right ventricular weight:total ventricular weight ratio and ascites mortality showed a significant (P < 0.05) increase when SBM was replaced by CM in the diet. Fortification of the CM diet with Arg eliminated the significant difference in the right-to-total ventricular weight ratios when compared with the SBM diet. In conclusion, feeding CM to broiler chickens raised at high altitude caused reduced growth performance and predisposed the birds to pulmonary hypertension and ascites, which were partly restored by Arg supplementation.

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This study presents the high-velocity impact performance of a composite material composed of woven Kevlar fabric impregnated with a colloidal shear thickening fluids (STFs). Although the precise role of the STF in the high-velocity defeat, process is not exactly known but it is suspected to be due to the increased frictional interaction between yarns in impregnated fabrics. In order to explore the mechanism of this enhanced energy absorption, high-velocity impact test was conducted on neat, impregnated fabric and also on pure STF without fabric. A finite element model has been carried out to consider the effect of STF impregnation on the ballistic performance. For this purpose, fabric was modeled using LS-DYNA by employing the experimental results of yarn pull-out tests to characterize the frictional behavior of the STF impregnated fabric. The simulation result is a proof that the increased performance for STF impregnated Kevlar fabric is due to the increased friction.

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