Evaluation of recently developed techniques for estimating diet composition in browsing herbivores.

Accuracy of estimates of botanical composition of herbivore diet may be improved through the use of recently developed techniques (alkane analysis, remote controlled oesophageal fistula valve). Three Boer goats allowed free choice of five forage species were used to compare seven methods of estimating diet composition with observed diet composition. The evaluated techniques either monitored intake [bite-count (IT1), bite mass corrected bite-count (IT2), relative bite mass corrected bite-count (IT3), micro-histological analysis of oesophageal extrusa collected at hourly intervals (IT4)] or faeces [alkane analysis (FT1), micro-histological faecal analysis (FT2), and in vitro corrected, micro-histological faecal analysis (FT3)]. Intake techniques had higher Kulczynski's similarity coefficients with measured values (70.7, 70.2, 65.5, and 78.6 respectively for IT1, IT2, IT3 and IT4) than did faecal techniques (58.9, 58.0 and 51.2 respectively for FT1, FT2 and FT3). Compared to IT2 and IT3, IT4 provided estimates of diet composition that was more similar to measured diet composition in terms of Kulczynski's similarity coefficients. However, estimates of diet composition were significantly different from measured values in 60% of cases for IT4 but only 40% of cases for IT2 and IT3. It is concluded that bite-count techniques (IT1 - IT3) can give as accurate estimate of diet composition as the more costly and technically demanding micro-histological analysis of oesophageal extrusa (IT4)

Dielectric and magnetic properties of high porous Gd+3 substituted nickel zinc ferrite nanoparticles

We report on the synthesis and characterization of Gd+3 substituted Ni-Zn nano ferrites (Ni0.6Zn0.4 GdyFe2-yO4; y = 0, 0.1, 0.15, and 0.2) via low-temperature citrate gel auto-combustion method. The structural studies carried out by PXRD revealed a decrease in the lattice constant and crystallite sizes upon Gd+3 substitution with low concentration but increases with further increase in the concentration. We found the porosity of the samples decreases linearly as a function of Gd+3 concentrations. Well defined spherical grains with a higher porosity of the samples are confirmed by FESEM analysis. With an increase in the Gd+3 concentrations, the dielectric constant increased up to five folds in the magnitude. The contribution of grain boundary and other factors on the electrical properties was revealed by impedance spectroscopy. The reduced remanence ratios showed in the magnetic hysteresis imply the charge in change in the magnetic properties upon the substitution of Gd+3 in the prepared ferrite