Abstract
Effects of supplementary soybean oil and of kapok meal containing cyclopropenoid fatty acids on the characteristics of porcine fat were investigated in the present study using 12 piglets at age of 4 months.
The test was conducted with a 3×2 factorial design of dietary treatment with 3 different supplementary levels of soybean oil (0, 5 and 10%) and with 2 different levels of kapok meal (0 and 3%).
Dietary supplement of soybean oil affected the porcine fat at each of fat deposit sites (outer and inner layers of back fat and leaf fat) examined. The melting point of the fat was significantly lowered and both the iodine number and the refractive index rose up significantly by supplementing the oil. In the fatty acid composition, saturated fatty acids such as C16:0 and C18:0 tended to decrease as the supplementing of the oil increased, while the saturated fatty acids such as C18:2 tended to increase in the composition.
The supplementing of kapok meal significantly elevated the melting point of the fat at 3 different fat deposit sites, whereas hardly any appreciable influences were noted for the refractive index and iodine number. In the fatty acid composition, the content of C18:0 and the ratio of C18:0/C18:1 significantly increased at all the sites by supplementing kapok meal, whereas no influence was seen by it upon the content of C18:2.
There were interactions noted between the supplementing of the oil and that of kapok meal upon both the melting point and the level of C18:1. Specifically, the higher the amount of the supplementary oil, the less was the influence of kapok meal supplemented. The effects of the supplements varied with the deposit sites.
These results suggested that the effect of supplemented kapok meal for preventing soft fat would be affected by the increase in the content of oils and fats in the feed and that this effect would vary with the sites of deposit of fats in the body. More specifically, it was noted that the effect of supplementing the kapok meal could be appreciably noted in the leaf fat if the level of oil in the feed was low and that as the content of oil in the feed became larger, the effect was found to be less, especially showing hardly any traces of effect in the back fat.
