RESUMEN. El estudio analiza la realidad de los productores ganaderos de basalto (Uruguay), una de las regiones del país que concentra mayor número de productores y que, además, debido a sus características agroecológicas, tiene especial consideración dentro de las políticas públicas. El objetivo del trabajo consistió en evaluar los distintos aspectos que inciden en la adopción y apropiación tecnológica, incluyendo los criterios que se siguen para la toma de decisiones. Para su concreción se utilizaron métodos cualitativos y cuantitativos.

ABSTRACT. The apple production area in Uruguay is of approximately 4000 ha, with an average fruit production of 62,000 t per year. Apple is the most important crop within deciduous fruits, and has behaved as the most demanding, in crop technology, during the last years. Local climate and soil conditions in the south of the country, where the major apple producing area is located, can generate sanitary problems to apple trees.

ABSTRACT. Potential of production of pecan under Uruguayan agroecological conditions was estimated. In a pecan orchard representative of the south of the country, with 11-year-old trees, phenology stages were determined and setting was measured, as well as harvest. Determinations were done on two representative branches per tree of a sample of 22 trees. Climatic conditions of Uruguay, even though highly irregular, vary within a range suitable for pecan production.

ABSTRACT. Potential of production of pecan under Uruguayan agroecological conditions was estimated. In a pecan orchard representative of the south of the country, with 11-year-old trees, phenology stages were determined and setting was measured, as well as harvest. Determinations were done on two representative branches per tree of a sample of 22 trees. Climatic conditions of Uruguay, even though highly irregular, vary within a range suitable for pecan production.

ABSTRACT. ?Williams B.C.? pear was grafted on two pear rootstocks:?Farold®40? and ?Farold®69?, and on three clonal quince rootstocks:?BA 29?, ?Adams? and ?EMC? with and without ?Beurré Hardy? as an interstem. To evaluate the performance of these combinations in the south of Uruguay, grafted trees were planted in 2003 at INIA Las Brujas, ?Wilson Ferreira Aldunate? Experimental Station (34°40 S-56°20 W). Rows were 4.5 m apart and variable distance was used between plants according to rootstock:1.70 m (?BA29?, ?Farold®40? and ?Farold®69?), 1.50 m (?Adams?), and 1.30 m (?EMC?).

ABSTRACT. The objective of this study was to remove bottlenecks generally found in a computer program for average-information REML. The refinements included improvements to setting-up mixed-model equations on a hash table with a faster hash function as sparse matrix storage, changing sparse structures in calculation of traces, and replacing a sparse matrix package using traditional methods (FSPAK) with a new package using supernodal methods (YAMS); the latter package quickly processed sparse matrices containing large, dense blocks.

ABSTRACT. The objective of this study was to remove bottlenecks generally found in a computer program for average-information REML. The refinements included improvements to setting-up mixed-model equations on a hash table with a faster hash function as sparse matrix storage, changing sparse structures in calculation of traces, and replacing a sparse matrix package using traditional methods (FSPAK) with a new package using supernodal methods (YAMS); the latter package quickly processed sparse matrices containing large, dense blocks.

ABSTRACT. Predictive ability of genomic EBV when using single-step genomic BLUP (ssGBLUP) in Angus cattle was investigated. Over 6 million records were available on birth weight (BiW) and weaning weight (WW), almost 3.4 million on postweaning gain (PWG), and over 1.3 million on calving ease (CE). Genomic information was available on, at most, 51,883 animals, which included high and low EBV accuracy animals.

ABSTRACT Quality control filtering of single-nucleotide polymorphisms (SNPs) is a key step when analyzing genomic data. Here we present a practical method to identify low-quality SNPs, meaning markers whose genotypes are wrongly assigned for a large proportion of individuals, by estimating the heritability of gene content at each marker, where gene content is the number of copies of a particular reference allele in a genotype of an animal (0, 1, or 2). If there is no mutation at the marker, gene content has an additive heritability of 1 by construction.

ABSTRACT. One of the main animal health problems in tropical and subtropical cattle production is the bovine tick, which causes decreased performance, hide devaluation, increased production costs with acaricide treatments, and transmission of infectious diseases. This study investigated the utility of genomic prediction as a tool to select Braford (BO) and Hereford (HH) cattle resistant to ticks.