Abstract: This experiment was conducted to investigate the effects of metabolizable lipogenic substances (MLS) on the growth performance,carcass quality and meat quality of growing pigs.Eighteen healthy Duroc×Landrace×Yorkshire hybrid pigs with similar body size and body weight range of 28.15 kg±4.51 kg were randomly divided into three groups.The diets with the same nutritional level but different MLS levels were fed for 28 days.MLS levels were 70.51 g/d (group Ⅰ),68.09 g/d (group Ⅱ) and 40.58 g/d (group Ⅲ).The growth performance,carcass quality and meat quality of the growing pigs were measured.The results showed that the effects of different MLS levels on average daily feed intake,average daily gain and feed and gain ratio of pigs were not significant (P>0.05).Among the three groups,feed and gain ratio of group Ⅱ was the lowest.There was no significant difference in carcass indexes such as slaughter rate,backfat thickness and eye muscle area among the three groups (P>0.05).The cooked meat rate of group Ⅲ was significantly lower than groups Ⅰ and Ⅱ (P<0.05),while other meat quality indexes such as brightness value,marble score and dripping loss had no significant difference (P>0.05).There was little difference in pH between 45 minutes and 24 hours after slaughter between groups (P>0.05).In conclusion,under the conditions of this experiment,most indexes of growth performance,carcass quality and meat quality of growing pigs were not significantly different among those of three metabolizable lipogenic substances level diets,but they were of guiding significance for optimizing the formula and future production.

Key words: metabolizable lipogenic substances; growing pigs; growth performance; carcass quality