[Influence of season of the year and sugar cane molasses as energy source, on number of piglets born in gilts] | Efecto del clima y de la inclusion de melaza sobre el numero de lechones nacidos en cerdas nuliparas

English. The objetive of present study was to determine the effects of season of the year and source of energy in diet offered to gilts during an estrus cycle on gilt performance. Sixty three gilts were used in a randomized 2x2 factorial experiment. Dietas differing in energy sources: 70.4 % grain corn (CORN) or 51.7 % cane molasses (MOL), and season: dry (DRY) or rainfall and winds (RAI) season were the main effects. Treatments were randomly assigned from second to third estrus. During the second estrus cycle, experimental diets were offered in restricted amounts providing equal levels of other, to result in identical nutrients (differing with energy density). Gilts were allowed to be bred by a boar 2.8+-0.1 times. Number of piglets born and born alive were greater (p0.05) for the MOL than COR gilts (p0.01). Number of piglets born and born alive (p0.05) was greater for gilts bred in dry than RAI. Gilts fed MOL during an estrucs cycle prior to breeding delivered more piglets born and born alive than COR, independently of season of year.

Spanish; Castilian. Se determino el efecto de una fuente de energia variada, suministrada a las cerdas nuliparas durante un ciclo estral previo a la monta y de la estacion climatica del ano, en el numero de lechones nacidos al partos subsecuente. Se utilizaron 63 cerdas nuliparas, en un diseno completamente al azar, con un arreglo factorial 2x2. Los factores fueron: la fuente variada de energia en la racion (70.4 % de maiz o 52 % de melaza de cana) y la estacion en que fueron apareadas las cerdas (nortes y secas). Los tratamientos fueron asignados a partir del segundo estro y la confirmacion del tercero (asignacion de la monta). Durante el segundo ciclo estral, las dietas experimentales fueron ofrecidas en cantidades restringidas para resultar en un consumo similar de energia metabolizable y proteina cruda. Las cerdas que recibieron la dieta con melaza tuvieron un mayor (p0.05) numero de lechones nacidos y nacidos vivos con respecto al grupo maiz. Durante secas, se incremento (p0.01) el numero de lechones nacidos (p0.05) nacidos vivos con relacion a nortes. La inclusion de melaza en la racion de las cerdas nuliparas, durante un ciclo estral previo a la monta, incrementa el numero de lechones nacidos de manera independiente a la estacion. El numero de lechones nacidos disminuyo en las cerdas apareadas en nortes con respecto a secas.