Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Agriculture
Root Growth Of Two Perennial Grass Types And Musk Thistle (Carduus Nutans) In Temperate Grasslands Of North America, Chengchou Han, Stephen L. Young
Root Growth Of Two Perennial Grass Types And Musk Thistle (Carduus Nutans) In Temperate Grasslands Of North America, Chengchou Han, Stephen L. Young
West Central Research and Extension Center, North Platte
Root architecture of prairie grasslands, which depends on plant phenology and edaphic conditions, strongly influences susceptibility to invasion by nonindigenous plant species. Field studies were conducted to compare in situ root growth patterns of warm-season (WS) and cool-season (CS) perennial grasses and musk thistle during a 2-yr period that included a drought in the second year. In 2 yr, CS grasses had the highest amount of roots (1,296 m roots m–2 [395 ft roots ft–2]) across shallow (0 to 28 cm [0 to 11 in.]), medium (28 to 56 cm), and deep (56 to 98 cm) depths …
Bioeconomic Factors Of Beef Heifer Maturity To Consider When Establishing Criteria To Optimally Select And/Or Retain Herd Replacements, M. C. Stockton, R. K. Wilson, D. M. Feuz, L. A. Stalker, R. N. Funston
Bioeconomic Factors Of Beef Heifer Maturity To Consider When Establishing Criteria To Optimally Select And/Or Retain Herd Replacements, M. C. Stockton, R. K. Wilson, D. M. Feuz, L. A. Stalker, R. N. Funston
West Central Research and Extension Center, North Platte
Understanding the biology of heifer maturity and its relationship to calving difficulty and subsequent breeding success is a vital step in building a bioeconomic model to identify optimal production and profitability. A limited dependent variable probit model is used to quantify the responses among heifer maturities, measured by a maturity index (MI), on dystocia and second pregnancy. The MI account for heifer age, birth BW, prebreeding BW, nutrition level, and dam size and age and is found to be inversely related to dystocia occurrence. On average there is a 2.2% increase in the probability of dystocia with every 1 point …