Effect of illumination color on growth, carcass characteristics, and fatty acid composition of lipid and muscle tissues in pigs

摘要

We studied the effect of illumination color on the growth, meat production and fatty acid composition in lipid and muscle tissues of pigs. Twenty-four three-way crossbred pigs (Landrace X Large White X Duroc) were used. The pigs were divided into 4groups of 6; red lamp, blue lamp, incandescent lamp, and no lamp (control) groups. Initially, all of them were fed the food for growing stage of fattening pig approximately 30 to 65 kg of body weight, and then they were fed the food for finishing stage of fattening pig until about 105 kg of body weight under the specified illumination which came from in two lamp heads. There were not significant difference in daily weight gain and the amount of feed convertion ratio among the four groups. Result of dressed carcass percentage and back fat thickness showed no significant difference among the four groups. As for the fatty acid composition of back fat, the blue lamp group showed the lowest value in C18 : 0 content, and a significant difference was seen between that group and the control (P<0.05). In C18 : 2 concentration, the lowest value of the control group was significantly different from that of red lamp group (P<0.05). There were no significant differences in loin lipid content among any group. However, when the fatty acid composition of intramuscular fat was examined, the control group showed the highest C14 : 0 concentration value, and which was significantly different from that of the incandescent lamp group (P<0.05). In the concentration of C18: 0, the red lamp group showed the highest value, and sig-nificant differences between the four groups were seen as follows : between red lamp group and control group (P<0.05), between red lamp group and blue lamp group (P<0.05), and between red lamp group and incandescent lamp group (P< 0.05). In comparison of saturated fatty acid content, red lamp group showed the highest value, and significant differences between the four groups were seen as follows : between red lamp group and blue lamp group (P<0.05), between red lamp group and incandescent lamp group (P<0.05), and between blue lamp group and incandescent lamp group (P<0.05). Moreover the red lamp group demonstrated lower levels of unsaturated fatty acid concentration, and significant differenceswere seen among that group and the blue and incandescent lamp groups (P<0.05). The red lamp group also showed the highest proportion of saturated fatty acid to unsaturated fatty acid concentrations, indicating blue lamp group and incandescent lamp groupdifferent significantly from each other (P<0.05). Significant differences were not seen in triglyceride. total cholesterol, and HDL-cholesterol quantity among any of the groups. However, the blue lamp group had the lowest value for the proportion of HDL-cholesterol to total cholesterol, and a significant difference was seen when compared to the red lamp group (P<0.05).