論文宣讀

熱緊迫會降低白肉雞之生長效益，因提高代謝產能用以降溫，並會使代謝副產物活性氧物質(Reactive oxygen species, ROS)增加。ROS會影響下視丘控制食慾之神經元，使促進食慾的神經胜肽Y(Neuropeptide Y；NPY)跟刺鼠相關蛋白(Agouti-related protein；AgRP)受抑制，並增加促進飽食的前腦啡黑色素激素(pro-opiomelanocortin；POMC)跟古柯鹼及安非他命調控之轉錄（cocaine- and amphetamine-regulated transcript；CART）的表現，而降低其採食量，進而影響生長表現。本試驗所用之添加劑為乳酸菌中的副乾酪乳桿菌(Lactobacillus paracasei)，此株菌具有產生大量抗氧化劑五甲氧基色氨酸(5-Methoxytryptophan；5-MTP)之特性。故本試驗之目的乃了解此菌是否能改善白肉雞於熱緊迫下之生長效益。試驗使用60隻白肉雞，逢機分配至五個不同組別，分別是常溫對照組(NC)、加熱對照組(HC)、0.25%乳酸菌組(HM)、0.025%乳酸菌組(MM)、0.0025%乳酸菌組(LM)。試驗期間HC組與其他乳酸菌組自15日齡開始至35日齡試驗結束，每日會做4小時34℃的加熱處理，其他時期溫度為28℃，NC組則是15日齡至35日齡全程都維持28度。結果顯示，35日齡的體重及全期的採食量，HM組皆高於其他加熱處理組(P<0.05)。食慾基因調控結果，HM組提高21日齡與35日齡之NPY與AgRP並降低21日齡與35日齡的POMC和21日齡之CART。呼吸速率增加，但彼此無顯著差異。體溫則是在15日齡與35日齡在加熱後有增加，但組別間無顯著差異。在35日齡的LM與MM組別加熱前體溫有低於HC組的狀況。綜上所述，此副乾酪乳桿菌可改善白肉雞在熱緊迫下的採食量與體增重，但對其他生理指標無影響。
 
關鍵字: 熱緊迫、採食量、白肉雞、副乾酪乳桿菌、抗氧化

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