Beziehungen zwischen Bodenfruchtbarkeitskennziffern,Ertrag und Inhaltsstoffen von Zuckerrüben auf Löß-Schwarzerde

Relations between soil fertility parameters and sugar beet yield and quality characteristics respectively, on Haplic Chernozem soils In interpreting four “experiments without interference” (VoE) on a total of 435 plots the influence of soil fertility parameters (BFK_i) as organic matter, P, K, Mg, pH value, Cu, B and Mn on sugar beet yield and its nutrient contents on Haplic Chernozem sites under Ca immission has been analysed. “VoE” is a method applied to find specific field data by means of which relations within the multidimensional system soil - plant are ascertained by utilizing soil and yield parameter variations. With increasing pH value the nutrient contents in the soil decreased in the order the following sequence: Mn, Mg. Cu, B; and, resulting from that, the sugar beet yield decreased significantly. The coefficients of determination (B) of the triple linear regression between yield and BFK_i ranged from B = 0,21 to B = 0,33 and between nutrient contents and BFK_i from B = 0 to B = 0,41. Most of the regression functions contained “BFK_i boron” as a variable. It has been found that there were positive correlations between “BFK_i pH value” and “soluble ashes” and negative correlations between “BFK_i pH value” and P contents in sugar beet.     

Binding of ractopamine HCl to ocular tissues of cattle and turkeys in vivo and to melanin in vitro

Experiments were conducted to determine the total residues remaining in ocular tissues of cattle and turkeys after oral administration of [14C]ractopamine HCl. Twelve cattle were intraruminally dosed with 0.9 mg x kg(-1) x d(-1) of [14C]ractopamine HCl for 7 d. Four cattle each were slaughtered with withdrawal periods of 48,96, and 144 h. Radioactive residues were not detectable in whole-eye homogenates from the cattle. Eight male and eight female turkeys per treatment received either 7.5, 22.5, or 30 ppm dietary [14C]ractopamine HCl (0.33, 1.02, and 1.36 mg x kg(-1) x d(-1); treatment groups 1, 2, and 3, respectively) for 7 d, and the birds were slaughtered with a 0-d withdrawal period. Eyes were dissected into retina/choroid/schlera (RCS), cornea/iris (CI), and aqueous humor (AH) fractions. Residues in RCS, CI, and AH of treatment 1 turkeys were not detectable. Residues in AH were < 0.02 ppm in treatment groups 2 and 3. Mean residues in RCS ranged from 0.15 to 0.26 ppm, and mean CI residues ranged from <0.09 to 0.17 ppm for treatment groups 2 and 3, respectively. The propensities of ractopamine and synthetic ractopamine metabolites to bind to melanin were studied in vitro using radiolabeled ligands with centrifugal filtration to separate melanin from unbound ligand. In vitro studies showed that [14C]ractopamine HCl binds to melanin rapidly and was displaced from melanin by other beta-agonists. Glucuronidation of ractopamine, which produced the major biotransformation product of ractopamine in all species studied to date, prevented binding to melanin. These studies demonstrate that the propensity for the in vivo binding of ractopamine HCl to pigmented ocular tissues is less than that reported for clenbuterol.