Abstract Background:The aim of this study was to estimate variance components and to identify genomic regions and pathways associated with resistance to gastrointestinal parasites, particularly Haemonchus contortus, in a breed of sheep adapted to tropical climate.

Abstract: . Soil erosion can be accelerated by agricultural intensification, and the soil loss can alter the quality of water bodies. Sustainable agricultural production therefore requires the management of erosion and potential water pollution. In Uruguay, where there is heavy use of soil for agriculture, there is a need to continually develop and update erosion management policies.

ABSTRACT. Cross-pollination increases the number of seedy fruit in a wide range of Citrus cultivars including self-incompatible cultivars such as ?Nadorcott' mandarin, thereby diminishing the commercial value of the crop. Isolated block planting and whole tree net-covering are some of the techniques applied to increase seedlessness of cross-pollinated varieties. However, in net-covered trees a reduction in yield has been reported.

ABSTRACT. This research was conducted during two irrigation seasons (2014?2015 and 2015?2016) in Salto, Uruguay. This growing region is characterized by high annual precipitation and periods of soil water deficit of different intensities. This characterization casts much doubt to soybean growers regarding whether supplementary crop irrigation is useful for maximizing soybean yield, maintaining stable productivity and increasing profit margins.

The objective of this study was to evaluate the effects of the energy restriction of gestation of adult ewes from day 45 to day 115 on lamb live performance parameters, carcass and meat traits. In experiment I, dietary energy was restricted at 70% of the metabolizable energy (ME) requirements, after which ewes were re-fed ad libitum until lambing. In experiment II, dietary energy was restricted at 60% of the ME requirements, and ewes were re-fed to ME requirements until lambing. All ewes grazed together from the end of the restriction periods to weaning.

ABSTRACT. The objective of this study was to estimate the genetic?quantitative relationships between the beef fatty acid profile with the carcass and meat traits of Nellore cattle. A total of 1826 bulls finished in feedlot conditions and slaughtered at 24 months of age on average were used. The following carcass and meat traits were analysed:subcutaneous fat thickness (BF), shear force (SF) and total intramuscular fat (IMF). The fatty acid (FA) profile of the Longissimus thoracis samples was determined.

RESUMEN. Valores crecientes de consanguinidad pueden reducir la fertilidad, salud y productividad de los bovinos lecheros. El objetivo fue estimar el coeficiente de consanguinidad de la población de bovinos Holando Argentino con registro genealógico en la base de datos de la Asociación Criadores de Holando Argentino. La población en estudio comprendió 422.563 animales con ancestros conocidos, origen argentino y nacidos entre los años 1990 y 2009, referente a la genealogía de hembras de Registro de Crías (grado) y Registro de Pedigrí del Sistema Nacional de Control Lechero Oficial.

ABSTRACT. Enhancing pasture persistence is crucial to achieve more sustainable grass-based animal production systems. Although it is known that persistence of perennial ryegrass is based on a high turnover of tillers during late spring and summer, little is known about other forage species, particularly in subtropical climates. To address this question, this study evaluated survival of grazed tall fescue tillers growing in a subtropical climate.

ABSTRACT. Enhancing pasture persistence is crucial to achieve more sustainable grass-based animal production systems. Although it is known that persistence of perennial ryegrass is based on a high turnover of tillers during late spring and summer, little is known about other forage species, particularly in subtropical climates. To address this question, this study evaluated survival of grazed tall fescue tillers growing in a subtropical climate.

ABSTRACT. The single most important decision in plant breeding programs is the selection of appropriate crosses. The ideal cross would provide superior predicted progeny performance and enough diversity to maintain genetic gain. The aim of this study was to compare the best crosses predicted using combinations of mid-parent value and variance prediction accounting for linkage disequilibrium (VLD) or assuming linkage equilibrium (VLE).