Supplementing growing cattle grazing native subtropical Campos grasslands during winter improves the low, even negative, average daily weight gain (ADG) typical of extensive animal production systems in Uruguay. Nonetheless, to render the practice profitable, it is crucial to control supplement feed efficiency (SFE), that is, the difference in ADG between supplemented and control animals (ADGchng) per unit of supplement dry matter (DM) intake. Little has been studied specifically on how SFE varies in these systems.

ABSTRACT.- AbstractThe results of the first evaluation of the Prolific Sheep Project of INIA (2008-2011) demonstrated that the crossbred biotypes Corriedale by East Friesian or Corriedale by Finnish Landrace weaned 60 % more lambs than pure Corriedale and, on the other hand, the crossbred East Friesian by Finnish Landrace weaned 85 % more than pure Corriedale. However, and under the same productive conditions, the behavior at lambing and colostrum production of these new biotypes are unknown.

ABSTRACT.- Irrigated rice fields are major sources of two important greenhouse gases (GHG), methane and nitrous oxide. As an initial step towards obtaining local information, emissions of CH4 and N2O from rice paddy soil were measured by the static chamber technique in greenhouse and field experiments conducted in eastern Uruguay. In the greenhouse experiment, the effect of two flooding moments (21 and 45 days after emergence) and nitrogen fertilization (0 and 50 kg N ha-1) on gas emissions was studied. Early flooding and nitrogen fertilization tended to increase N2O emissions.

ABSTRACT.- Irrigated rice fields are major sources of two important greenhouse gases (GHG), methane and nitrous oxide. As an initial step towards obtaining local information, emissions of CH4 and N2O from rice paddy soil were measured by the static chamber technique in greenhouse and field experiments conducted in eastern Uruguay. In the greenhouse experiment, the effect of two flooding moments (21 and 45 days after emergence) and nitrogen fertilization (0 and 50 kg N ha-1) on gas emissions was studied. Early flooding and nitrogen fertilization tended to increase N2O emissions.

Las cianobacterias pueden producir cianotoxinas altamente tóxicas para la salud humana y animal. Si bien éstas se asocian al período estival, en los últimos años en Uruguay se han registrado durante todo el año, especialmente en cuerpos de agua lénticos como lagunas, tajamares y embalses.