安定化處理對米糠保存及飼糧添加安定化米糠對離乳豬生長表現之影響

Abstract

本研究旨在探討加熱方式對米糠保存及飼糧中添加安定化米糠對離乳仔豬生長及抗氧化性狀的影響。 本試驗分成兩個部分：試驗一，利用三種不同的加熱方式處理米糠，並進行為期八週的儲存性試驗，測定其營養成分及抗氧化特性之變化。試驗二，將安定化米糠添加於離乳豬飼糧中，探究其生長表現及抗氧化性狀的影響。結果顯示，使用加熱處理可有效抑制游離脂肪酸的產生，其中又以乾式擠壓處理組的效果最佳。隨著加熱溫度的上升，總多酚的含量會隨之減少。米糠醇則會隨著儲藏時間拉長，含量也隨之上升。米糠之油脂氧化(硫巴比妥酸值)狀況，則會隨著加熱溫度的上升而上升。添加米糠於飼糧中對於離乳仔豬生長表現，並無顯著的影響，但在第一週時，各處理皆出現糞便評分偏低的情形。各處理之肝臟中的超氧化物歧化酶及硫巴比妥酸值，並無顯著的差異，就盲腸內容物的揮發性脂肪酸而言，0%米糠處理組之丙酸含量顯著的高於其它兩處理組。 綜觀上述，加熱處理可有效抑制解脂酶的活性，離乳豬餵飼含有米糠的飼糧28日後，對其生長表現及抗氧化酵素不會有顯著的影響，但高纖餵飼可能導致仔豬下痢，建議在離乳兩週後再開始添加。

The objective of this study was conducted to understand the effect of thermal process on preservation of rice bran and dietary supplement of stabilized rice bran on growth performance of weanling pigs. This experiment was divided into two parts. Firstly we stabilized rice bran by different thermal process, including dry-extrusion, moist-extrusion, and pelleting. Processed rice bran samples were put into bags for storage stability evaluation at room temperature for 8 weeks. The free fatty acid content of rice bran did not increase because lipase activity was suppressed by thermal process with dry-extrusion having the biggest impact on the enzyme. However, the lipid oxidation (thiobarbituric acid value) of rice bran would increase with the raised thermal temperature. The total phenol content and DPPH scavenging ability decreased with increase of thermal temperature. Furthermore, the γ-oryzanol contents increased with longer storage time. Secondly, 48 weanling pigs were divided randomly into 3 treatments. There were three treatments which contained 0%, 4% and 8% of dry-extrusion stabilized rice bran in the diet. After 4 weeks of feeding, there were no significant differences in growth performance, triglyceride content and thiobarbituric acid value in blood among all treatments. Cecal digesta propionic acid concentrations decreased with stabilized rice bran supplementation. In conclusion, thermal stabilized process could prolong the shelf-life of rice bran. Diet contains up to 8% of stabilized rice bran did not seem to affect the growth performance of weanling pigs. Nevertheless, high fiber diet might cause diarrheal during first week after weanling, thus we suggest that rice bran can be added in the diet 2 weeks after weanling