Abstract
The present study was conducted to analyze the mechanism to produce high quality pork by using eco-feed mainly composed of breadcrumb. Forty cross bred fattening pigs (LWD) (average body weight, 70 kg) were allotted to control and four types of eco-feed groups : combination of high (16.3%) and low (12.9%) protein contents and middle (0.55%) and low (0.43%) lysine content. The pigs were slaughtered at over 105 kg live weight and carcass characteristics and meat quality were evaluated. Fattening periods were more prolonged in the low protein×low lysine groups than in the control group. The average daily gain was lower in the eco-feed groups than in the control group. There was no significant difference in meat color and fat color. The L* value, degree of marbling and content of intramuscular fat of the longissimus muscle were higher in the eco-feed groups than in the control group. The dietary protein level did not significantly affect the intramuscular fat content of the longissimus muscle. However, a significant effect of dietary lysine level was apparent. The interaction of dietary protein level with dietary lysine level of intramuscular fat content was significant. By lowering lysine/protein ratio in the diet, the production of marbling pork was possible even in the high protein and middle lysine. No significant differences existed in refractive index and melting point of backfat between the control group and eco-feed group. In the eco-feed group, oleic acid content increased and linoleic acid content decreased. In conclusion, the present study shows that the mechanism of marbling pork fed on bread was affected more by the lysine content rather than by the low protein content, suggesting that lysine/protein ratio is particularly important.
