the aim of this research was to compare the amounts of existing mineral elements in plant aerial parts, litter and soil ofthree range species (bromus tomentellus, psathyrostachys fragilis, agropyron tauri) in order to investigate the litter effectof species on soil properties of taleghan rangeland. the measured mineral elements include carbon, nitrogen,phosphorous and potassium. after selection...

Variance ratios were estimated for random within-herd effects of age at test day and lactation stage, on test-day yield and somatic cell score to determine whether including these effects would improve the accuracy of estimation. Test-day data starting with 1990 calvings for the entire US Jersey population and Holsteins from California, Pennsylvania, Wisconsin, and Texas were analyzed. Test-day...

Methods of identification of quantitative trait loci (QTL) using a half-sib design are generally based on least-squares or maximum likelihood approaches. These methods differ in the genetical model considered and in the information used. Despite these differences, the power of the two methods in a daughter design in very similar. Using an analogy with a one-way analysis of variance, we propose ...