ABSTRACT.- In Uruguay, the mortality of dairy calves due to infectious diseases is high. Escherichia coli is a natural inhabitant of the intestinal microbiota, but can cause several infections. The aim of the work was to characterize E. coli isolates from intestinal and extraintestinal origin of dead newborn calves. Using PCR, virulence gene characteristics of pathogenic E. coli were searched. The pathogenic E. coli were molecularly characterized and the phylogroup, serogroup and the Stx subtype were determined.

ABSTRACT.- Previous studies on winter supplementation of growing cattle grazing stockpiled native Campos grasslands suggest that forage allowance (FA), herbage mass, and weather conditions before and during the supplementation period could all affect supplement feed efficiency (SFE)-that is, the difference or change in average daily gain (ADG) between supplemented (S) and control (C) animals (ADGchng, kg) per unit (kg) of supplement dry matter (DM) intake. In this study, we analyse data from fifteen collated winter supplementation trials carried out in Uruguay between 2004 and 2018.

Breeding sheep for increased feed efficiency (FE) and decreased methane emissions (ME) is an alternative for developing more sustainable sheep production systems. With the aim of generating genetic and genomic tools, we added in 2018 the evaluation of FE and greenhouse gases emissions to the usual phenotyping as part of the national genetic evaluation per breed, for wool, meat, growth, health and reproduction traits. This initiative provides the information to characterize FE and ME and estimate genetic parameters for Uruguayan sheep.

The anti-meat consumption trend is installed globally, where different organized and influencer collectives propose a transformation of agri-food systems and a diet practically free of red meat. The narrative is mainly based on the negative effects of meat consumption on human health, the environment, and cruelty to animals. However, evidence based on scientific information is counteracting these visions. At least 500 million people around the world are totally dependent on livestock for their livelihood and food security.

The anti-meat consumption trend is installed globally, where different organized and influencer collectives propose a transformation of agri-food systems and a diet practically free of red meat. The narrative is mainly based on the negative effects of meat consumption on human health, the environment, and cruelty to animals. However, evidence based on scientific information is counteracting these visions. At least 500 million people around the world are totally dependent on livestock for their livelihood and food security.

Breeding sheep for increased feed efficiency (FE) and decreased methane emissions (ME) is an alternative for developing more sustainable sheep production systems. With the aim of generating genetic and genomic tools, we added in 2018 the evaluation of FE and greenhouse gas emissions to the usual phenotyping as part of the national genetic evaluation per breed, for wool, meat, growth, health and reproduction traits. This initiative provides the information to characterize FE and ME and estimate genetic parameters for Uruguayan sheep.

Intensified pasture-based systems have proven to be the most profitable option for the Uruguayan dairy industry. However, it is unknown if their biophysical performance is attainable with voluntary milking systems (VMS), an alternative recently explored to make dairy more attractive to future generations. The aim of this study was to compare milk production (MP) of two pasture-based production systems:a conventional milking system (CMS), where cow flow is forced, and a VMS, where cow flow is voluntary.

Intensified pasture-based systems have proven to be the most profitable option for the Uruguayan dairy industry. However, it is unknown if their biophysical performance is attainable with voluntary milking systems (VMS), an alternative recently explored to make dairy more attractive to future generations. The aim of this study was to compare milk production (MP) of two pasture-based production systems: a conventional milking system (CMS), where cow flow is forced, and a VMS, where cow flow is voluntary.

Residual feed intake (RFI) has become in a widely spread index of feed efficiency, however, although most of beef cattle systems in the world are pasture-based, RFI evaluation and research is usually performed in confinement conditions. Currently, selection in favor of feed efficiency has an unclear effect on reproductive performance of grazing beef heifers.

Cow-calf grazing systems are the main economic and social activity at Campos grassland, a biodiversity hotspot and ecosystem service provider. However, low reproductive, productive and economic results have triggered these systems sustainability for decades. Low results have been explained mainly by lack of grazing management (overgrazing) and low cow energy intake for calf production.