The effects of an air-dried diet designed to use unutilized local resources found in Hokkaido on the growth, carcass characteristic and fatty acid composition of fat in fattening pigs were examined. The unutilized resources used in the diet in this study were unmarketable potatoes (potato), disposed tofu (tofu), lower stems cut from asparagus (asparagus) all processed by freezing−thawing dehydration, as well as unmarketable wheat flour (wheat flour), and vitamin and mineral preparations. The diet was designed with the crude protein content in commercial diets as the targeted value. The component rates of the diet were as follows:for potatoes, 30.0%;tofu, 16.0%;asparagus, 10.0%;wheat flour, 43.5%;and vitamin and mineral preparations, 0.5%. Although the predictive value of the crude protein content in this designed diet was 17.2%, the analysis value of crude protein content was the same value (Lysine content was 0.82%). In the feeding experiment, there was no significant difference in the growth and carcass characteristics for each group. The fatty acid composition in the perirenal fat and intramuscular fat for the C18:1 content experimental group was significantly lower than those in the control group (P<0.05), and the C18:2 and C18:3 content groups were significantly higher than those of the control group (P<0.01). Moreover, the rate of n-6/n-3 of the experimental group was significantly lower than that of the control group (P<0.01), and the rate of C18:2/C18:0 was significantly higher than that of the control group (P<0.01). The melting point of the intermuscular fat and back fat of the experimental group was significantly lower than that of control group (P<0.01). It has been suggested that the designed diet in this study resulted in growth and meat product ability equal to the commercial diet, and especially, more so for the C18:2 and C18:3 content group than that of the commercial diet. The melting point of fat for the designed diet was lower and its fat was softer than that of the commercial diet.

The effects of increasing digestible energy (DE) with sugar and chocolate supplementation on pig growth and pork quality under high crude protein conditions were investigated. Under the same nutritional condition (16.3% crude protein and 0.74% lysine), DE was adjusted to 4.2ME/kg in the control group, 4.6Mcal/kg (with supplementation of sugar) in the HDE-S group, and 4.6Mcal/kg (with supplementation of chocolate) in the HDE-C group. Eighteen Duroc pigs (average body weight of 68.8kg) were assigned to three groups by weight and sex (six pigs per pen, 3 barrows and 3 gilts) and fed until they reached a body weight of about 118kg. All groups showed normal growth. Average daily gain was not affected by increased DE. Carcass weight tended to be greater in the supplemental groups than in the control group. Dressing percentage increased with increased dietary DE (P<0.01). For pork characteristics, longissimus dorsi muscle (LM) had higher L* in the HDE-S group than in the control and the HDE-C groups, and higher b* in the HDE-C group than in the control and the HDE-S groups. Average intramuscular fat (IMF) content of LM in all groups was high- over 7%, but IMF content was not significantly affected by increased DE. For inner layer back fat and leaf fat, monounsaturated fatty acids increased and polyunsaturated fatty acids decreased or tended to decrease with dietary increases of DE in the HDE-S and HDE-C groups. These results indicate that increasing DE as sugar or chocolate supplementation to the diet does not necessarily increase IMF but can increase monounsaturated fatty acids content in subcutaneous fat under a high crude protein dietary content.