ABSTRACT- In fluvial dynamics studies, there are instances where it becomes necessary to estimate the daily discharge of a river in locations where only one instantaneous level record is available per day. In such cases, there may be no rating curve, or one that is unreliable, making it difficult to make accurate discharge estimates. A daily rating curve would be an estimate of the daily discharge of a river, from a single instantaneous stage level. This work proposes to estimate synthetic (non-gauged) daily rating curves from nearby gauged locations using a rainfall-runoff model.

ABSTRACT.- The Río de la Plata Grasslands (RPG) are one of the largest areas of open ecosystems (grasslands, shrublands and savannas) in the world. Historically, these systems have experienced, and continue to experience, an enormous loss of natural habitats. Moreover, their importance has been largely invisible in comparison to forested systems. The remaining area of open ecosystems in the RPG region varies according to the source from 38 to 58% of the original area.

ABSTRACT.- Brazilian livestock breeding programmes strive to enhance the genetics of beef cattle, with a strong emphasis on the Nellore breed, which has an extensive database and has achieved significant genetic progress in the last years. There are other indicine breeds that are economically important in Brazil; however, these breeds have more modest sets of phenotypes, pedigree and genotypes, slowing down their genetic progress as their predictions are less accurate.

ABSTRACT.- We reported thirteen cases of bilateral stringhalt associated with Hypochaeris radicata that occurred in horses in Uruguay during a severe drought in the summer of 2023. All horses were affected chronically and progressively by bilateral hyperflexion of hindlimbs. In two severely affected horses, the main histological lesions included neuronal chromatolysis and axonal spheroids in the ventral gray horn in the lumbar and sacral spinal cord and axonal degeneration and digestion chambers in ventral roots fibers and long peripheral nerves.

ABSTRACT.- This study identified the relationship between energy balance and some blood metabolites in primiparous dairy cows with different calving conception interval. Twenty primiparous Holstein-Friesian dairy cows were grouped according to the interval (days) from calving to conception into early-conception (early-c; 150 days) group; and evaluated on day-7 prior to parturition, and days 28, 56 and 90 postpartum. All groups presented positive energy balance, serum concentrations of HDL, urea-N and progesterone with no difference on days 28 and 56 of lactation.

ABSTRACT.- Reproduction is crucial in the efficiency of grazing-based beef production systems. There are different ways to improve reproductive indices in cattle, such as through herd management, nutrition and/or genetics. It was shown that different levels of herbage allowance and the use of crossbred cows could improve the follicular and uterine characteristics that translate into higher cow fertility.

ABSTRACT.- CONTEXT: The Latin America-Caribbean (LAC) region has the potential to pursue a sustainable expansion of livestock production and capitalise on the growing global demand for dairy and beef products. However, it is necessary to understand the predominant production systems and their biophysical, economic, social, and environmental performances. OBJECTIVE: This study aimed to compare the milk production systems of nine countries of the region according to their major biophysical, socio-economic, and environmental performance indicators.

ABSTRACT.- Dairy systems in South America's humid subtropics include grass-legume pastures in rotation with winter-summer double-cropping for silage, thus combining direct grazing with periods of effective confinement for concentrate and silage supplementation. The environmental impacts of these so-called hybrid systems remain unclear. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.

ABSTRACT.- Management practices during the rearing of dairy heifers should allow an adequate body growth and reproductive development to attain puberty several months before the first conception. Proposed target age and body weight (BW) at first calving for Holstein heifers are between 22-24 months and 82% of mature BW, respectively, for which heifers must conceive at around 15 months of age with 60% of their mature BW.

ABSTRACT.- The process of intensification of the dairy sector has been characterized in recent decades by the increase in milk production per hectare, the increase in livestock density, the inclusion of more concentrates in the diet, and the improvement of the genetic merit of dairy cows. The use of models has productive, environmental, and economic advantages. The objectives of the study were to describe a new model, "OLE!