Effect of dietary protein levels on productive performance and carcass traits of Thai native pigs from different geometric regions

Abstract

Southern native pigs (ST) group had significantly higher final weight (P < 0.05). Northern native pigs (NT) had the highest average daily gain (ADG) during the first 21 days of the rearing period (P < 0.05). Feed conversion ratio (FCR) and feed cost per gain (FCG) of NT and ST were lower than those of northeastern native pigs (NE) (P < 0.05). The lowest FCG were obtained with 12% and 14% protein diets, and the highest FCG were obtained with 18% protein diet (P < 0.05). For carcass traits, ST had higher slaughter weight, while NT had lower carcass weight, lower percentage of carcass, thinner backfat thickness, lower tenderloin weight, lower fat and skin weight, and lower belly weight, but had higher offal weight, higher percentage of offal and better marbling (P < 0.05). Dietary protein content did not affect carcass traits except for percent belly, because at 18% protein content, percent belly was lower than other groups (P < 0.05). For commercial production, NT could be of greater use because it had lower FCR and FCG without differing significantly in lean content. In addition, NT had higher marbling but lower backfat thickness.