가소화에너지 및 라이신 수준이 제주재래돼지 교잡종의 성장 및 육질 특성에 미치는 영향

Abstract

The goal of this study was to establish the proper level of feed for establish the proper level of feed for digestible energy, finishing digestible energy, and finishing lysine, in order to establish a suitable specification system for hybrids of Jeju native pig and Landrace. I assessed the effects of the different diets on growth performance (weight gain, daily weight gain, daily feed intake, feed requirement), carcass characteristics (carcass weight, carcass rate, backfat thickness), and meat quality (general ingredients of sirloin, flesh color, pH, shear force, cooking loss, water holding capacity).

In the first experiment, in which i was assessed the diets given to growing pigs, a total of 36 pigs with an average initial body weight of 26.62±3.07 kg were allocated to four treatment groups given diets of different digestible energy levels. The treatments were: 3,000 kcal DE/kg, 3,200 kcal DE/kg, 3,400 kcal DE/kg and 3,600 kcal DE/kg. The compound feeds were given ad libitum for 50 days, and the nutrient components (except the plasticizing energy level) were set to the same conditions. During the growing period, the weight gains in the four treatment groups were 19.7±0.99 kg, 18.64±0.40 kg, 24.32±0.40 kg and 22.81±0.36 kg, respectively. The treatments of 3,400 kcal/kg and 50.33±7.15 kg, 3,600 kcal/kg produced significant differences in growth performance without any significant difference in carcass characteristics: percentage, back fat thickness, cooking loss, water holding capacity, and pH in the loin. The most significant result was obtained for the shear force (as one measure of meat quality) in the group fed at 3,200 kcal/kg. Collagen, moisture, and protein contents were highest in this group. Feeding a low-energy diet appeared to have no significant effect on carcass characteristics; however, phase feeding of alow-energy diet had negative effects on growth performance and meat quality. The results suggest that diets of digestible energy levels of 3,400 kcal/kg and 3,600 kcal/kg are suitable for growing Jeju native black pig hybrids.

The second experiment was conducted in a similar fashion as the first but with Jeju native black pig hybrids at the finishing stage. A total of 48 pigs, with an average initial body weight of 55.94±7.43 kg, were allocated to four treatments of different digestible energy levels. The treatments were: 3,200 kcal DE/kg, 3,300 kcal DE/kg, 3,400 kcal DE/kg and 3,500 kcal DE/kg. The compound feeds were given ad libitum for 90 days, and the nutrient components (except the digestible energy level) were set to the same conditions. During the finishing period, the weight gain values in the four treatment groups were 43.33±6.17 kg, 39.18±4.93 kg, 42.92±7.25 kg and 50.33±7.15 kg, respectively. Daily weight gain values in the four treatment groups were 0.46±0.04 kg, 0.42±0.04 kg, 0.45±0.05 kg and 50.33±7.15 kg. Treatment group 4, which received the diet of 3,500 kcal/kg, showed significantly higher growth (p<0.05) than animals in the other treatment groups. Carcass characteristics were also tested at 210 days of age, and the carcass weight was also significantly higher(p<0.05) for the fourth treatment group, at 74.17±9.86 kg. Backfat thickness in each of the treatment groups was 13.0±3.34 mm, 13.08±3.33 mm, 15.58±3.04 mm and 14.83±4.18 mm. There was no significant difference between treatments, but the lower the digestible energy level, the thinner was the fat. There was no significant difference in proximate, carcass percentage, or cooking loss in the loin. However, the highest water-holding capacity was observed for the 3,300 kcal/kg treatment group. The results of the second experiment suggest that treatments at digestible energy levels of 3,500 kcal/kg are suitable for finishing Jeju native black pig hybrids.

In the third experiment we investigated growth rates and meat quality in response to lysine levels. I selected thirty-six155-day-old hybrid pigs(Jeju native black pig x Landrace) with an average body weight of 85 kg and carried out the feeding trial for 45 days until the pigs were 200 days old. The pigs were separated into three treatment groups (12 heads per group) and given a blended feed that contained 1.0%, 0.8%, or 0.6% lysine. The plasticization energy was 3,200 kcal/kg, and the crude protein level was 15%. The feed method was autonomous, and unlimited feed and water were provided during the trial. In terms of growth characteristics, the treatment group given 0.8% lysine had an average total weight gain of 24.06±3.92 kg, with a daily weight gain of 0.53±0.08 kg, but there was no significant difference among the treatments. There was also no significant difference in the cooking loss. The lowest lysine level (0.6%) tended to thicken the back fat. In terms of meat quality, when the lysine level was lowered to 1%, 0.8%, and 0.6%, the fat content in the sirloin was 5.21±0.84%, 6.05±0.79%, and 7.23±0.79%, respectively. As for physical properties, there was a significant decrease in cooking loss and shear force when the content of lysine was decreased from 1% to 0.6%. This decrease is thought to be influenced by muscle fat content. The results of our study indicate that a diet with 0.6% lysine is suitable for finishing Jeju native black pig hybrids.