INFLUENCE OF BACKFAT ON THE REPRODUCTIVE PERFORMANCE OF YORKSHIRE X LANDRACE SOWS | INFLUENCIA DE LA GRASA DORSAL EN EL COMPORTAMIENTO REPRODUCTIVO DE CERDAS YORKSHIRE X LANDRACE

Spanish; Castilian. Se utilizaron un total de 2065 registros de partos de 906 cerdas del cruce Yorkshire x Landrace, obtenidos entre los aos 2016 y 2019, ambos inclusive. Se eliminaron 37 registros procedentes de 11 cerdas que se encontraban en la base inicial y que se correspondan con el ao 2016. Finalmente, la muestra qued formada por 1998 partos de 895 hembras. Se estimaron las correlaciones entre el espesor de grasa dorsal al parto y al destete con los rasgos bajo estudio a partir de un Prog REG, mientras que con las variables independientes o de efectos fijos (paridad y grupo, segn rangos medidos de grasa dorsal al parto y al destete), se evalu la influencia sobre los rasgos bajo estudio, y en el caso de la paridad se evalu las prdidas de grasa a travs de un Proc GLM del SAS v.9.4. Hubo un mejor comportamiento de la grasa dorsal al parto en los grupos del 3 al 5 en los rasgos reproductivos con un rango superior a los 18 mm. Se alarg el intervalo destete-cubricin en cerdas que alcanzaron valores de 11.9 mm de grasa dorsal, y se apreciaron prdidas de grasa dorsal entre parto y destete en cerdas de primera paridad. Se observaron valores ms altos en los coeficientes de correlacin de la grasa dorsal al parto con respecto al destete en relacin a los rasgos reproductivos. Se concluye que la grasa dorsal al parto y al destete influyeron positivamente en los rasgos reproductivos, as como en el intervalo destete-cubricin de cerdas Yorkshire x Landrace. Se recomienda, establecer como requisito, que las cerdas al parto lleguen con 19 mm de espesor de grasa dorsal y 17 mm como mnimo para el destete de sus cras. Adems, realizar una evaluacin en otras entidades de la Unin Agropecuaria Militar que permita incrementar la eficiencia reproductiva en estas unidades.

English. A total of 2065 farrowing records of 906 sows from the Yorkshire x Landrace cross, obtained between the years 2016 and 2019, both inclusive, were used. 37 records from 11 sows that were in the initial base and that corresponded to the year 2016 were eliminated. Finally, the sample was made up of 1998 farrowings of 895 sows. The correlations between farrowing and weaning backfat thickness with the traits under study were estimated from a REG Prog, while with the independent variables or fixed effects (parity and group, according to measured ranges of backfat at farrowing and weaning), the influence on the traits under study were evaluated, and in the case of parity, fat losses were evaluated through a Proc GLM of SAS v.9.4. There was a better performance of backfat at farrowing in groups 3 to 5 in reproductive traits with a range greater than 18 mm. The weaning-mating interval was lengthened in sows that reached values of 11.9 mm of backfat, and losses of backfat were observed between farrowing and weaning in sows of first parity. Higher values were observed in the correlation coefficients of backfat at farrowing with respect to weaning in relation to reproductive traits. It is concluded that back fat at farrowing and weaning had a positive influence on reproductive traits, as well as on the weaning-mating interval of Yorkshire x Landrace sows. It is recommended, as a requirement, that sows arrive at birth with 19 mm of backfat thickness and at least 17 mm for the weaning of their offspring. In addition, carry out an evaluation in other entities of the Military Agricultural Union that allows increasing reproductive efficiency in these units.