The optimum starch content of diets fed to lactating cows is not well defined, but 24% to 26% starch (DM basis) has been suggested (Staples, 2007). Kaiser and Shaver (2006) and Bucholtz (2006), from surveys of high producing (>13,650 kg RHA) dairy farms in Wisconsin (n = 9) and Michigan (n = 18), respectively, reported starch concentrations of diets fed to lactating cow groups ranging from 25% ...

Introduction Ionophores have been used extensively in the beef industry in Canada since 1977. Until recently, there has been no label indication for use of ionophores in lactating dairy cattle. Ionophores are feed additives that alter rumen microbial populations through ion transfer across cell membranes. In Canada, the label warning prohibiting the use of Rumensin premix in lactating dairy ca...

The concept of extended lactation should improve cow health and productivity while reducing greenhouse gas emissions per kg milk produced in high-yield organic dairy herds. This is achieved through fewer calvings per year and hence production of fewer replacement heifers. Combined with fewer days dry per cow per year, this will reduce the annual herd requirement for feed while maintaining milk ...

Environmental temperature affects water turnover and isotope fractionation by causing water evaporation from the body in mammals. This may lead to rearrangement of the water stable isotope equilibrium in body fluids. We propose an approach to detect possible variations in the isotope ratio in different body fluids on the basis of different homoeothermic adaptations in varying reproductive stage...