The effect of a high monounsaturated fat diet on body weight, backfat and loin muscle growth in high and medium-lean pig genotypes

Abstract

The objective of this study was to evaluate whether the use of a diet rich in oleic acid could have an effect on daily weight gain, backfat and loin muscle (Longissimus thoracis) depth. One hundred and ninety-two barrows and gilts, from two genotypes were fed a grain and soy diet (CONTROL with 28% C18:1) or a similar diet enriched with oleic acid (HO with 43% C18:1, Greedy-Grass OLIVA ® ). The pigs were housed in 16 pens in groups of 12 according to their sex, diet and genotype. From 75 days of age every three weeks, the pigs were weighed and the backfat and loin muscle depth were ultrasonically recorded (PIGLOG ® ). The inclusion of the dietary fat had no significant effect on the growth variables nor on the backfat and loin muscle depth measurements taken. However, the barrows resulted in higher live weight and backfat compared to the gilts at the end of the trial. Conversely, the gilts showed higher loin depth. Moreover, York-sired pigs were heavier than Pietrain-sired pigs during the whole trial and showed higher backfat at the last two measurements. Pietrain-sired pigs had higher loin muscle depth at the last measurements. The results of the present study suggest that the addition of a dietary fat into diets aiming at modifying the meat fatty acid profile has no detrimental effects on performance variables, or on backfat and loin muscle growth and thus, no negative economic impact for producers.Additional key words: backfat depth; loin muscle depth; monounsaturated fatty acids; sex. ResumenEfecto de una dieta rica en ácidos grasos monoinsaturados sobre el peso vivo, el espesor de grasa dorsal y la profundidad de lomo en cerdos de alto y medio crecimiento magro El objetivo de este estudio consistió en evaluar si administrar una dieta rica en ácido oleico en cerdos de engorde ejercía algún efecto sobre la ganancia de peso, el espesor de grasa dorsal y la profundidad del músculo Longissimus thoracis. Ciento noventa y dos machos castrados y hembras de los genotipos (Landrace*Large White)*Pietrain y (Landrace*Large White)*York recibieron una dieta de cereales y soja (CONTROL con 28% C18:1) o una dieta similar rica en ácido oleico (HO con 43% C18:1, Greedy-Grass OLIVA ® ). Los cerdos se alojaron en 16 corrales en grupos de 12, según su dieta, sexo y genotipo. A partir de los 75 días de vida, y a continuación cada tres semanas, los animales se pesaron y se midió mediante ultrasonidos (PIGLOG ® ) el espesor de grasa dorsal y la profundidad de lomo. No se detectaron diferencias en la ganancia media diaria ni en el espesor de grasa dorsal y lomo entre los cerdos alimentados con dieta HO y dieta CONTROL. En cambio, los machos castrados presentaron un mayor peso vivo y un mayor espesor de grasa dorsal que las hembras. Estas, en cambio presentaron una mayor profundidad de lomo. Los cerdos cruzados con York fueron más pesados durante toda la prueba y presentaron un mayor espesor de grasa dorsal que los cruzados con Pietrain. Los animales del genotipo Pietrain presentaron una mayor profundidad de lomo durante las ...