- 期刊
- OpenAccess
分期餵飼靈芝固態發酵物對肉雞生長性能與免疫反應之時間效應
Time effects of phase feeding supplemental lingzhi culture on growth performance and immune responses of broilers
摘要
先前肉雞研究發現，飼糧添加靈芝固態發酵物（lingzhi culture, LZC）會改變育成期（0 － 21天）和生長期（22 － 35天）之免疫反應，但分期添加LZC之時間效應，尚未明瞭，故研究目的為探討分期餵飼LZC之飼糧時間組合對肉雞生長性能和免疫反應之影響。試驗採用640隻白肉雞逢機分配至2種飼糧於2階段飼養期所組合而成之4個處理組，包括（A）全期不添加LZC組（對照組）；（B）育成期添加LZC組；（C）生長期添加LZC組；及（D）全期添加LZC組。飼糧區分成基礎飼糧組和於基礎飼糧添加1 g/kg LZC之LZC組。育成期區分成基礎飼糧組和LZC組，每處理組各有16欄，各處理於生長期再區分成基礎飼糧和LZC二組，使生長期每處理組各有8欄。雞隻採用平飼飼養，每欄飼養20隻。每欄於試驗第21和35天分別逢機選取公母雞各1隻，分析脾臟、盲腸扁桃腺（cecal tonsil）及血清新城雞病（newcastle disease, ND）之免疫反應。結果發現，育成期添加LZC不影響肉雞當期之生長性能，但可較對照組提高生長期之體增重和飼料效率以及改善飼養全期之飼料效率（P < 0.05）。育成期添加LZC降低第21天脾臟細胞增生反應，但提高脾臟CD1^+以及盲腸扁桃腺CD3^+與CD8^+之T淋巴細胞比率，並且使脾臟之CD4^+ T淋巴細胞比率下降。育成期添加LZC降低第21天血清IgG-和IgM-特異性之ND抗體力價（P < 0.05），但生長期添加LZC可以提高第35天脾臟細胞分泌IFN-γ濃度，而僅於生長期添加LZC組可較全期添加LZC組增加血清IgA-特異性之ND抗體力價（P < 0.05）。綜合上述結果顯示，肉雞飼糧添加LZC處理組合不僅會影響育成期與生長期之免疫反應，且於生長期停止添加後仍然可以改善生長期之體增重和飼料效率，但對免疫反應之影響依賴分析項目呈現反向增加或逐漸消失，但未能持續至生長期結束。
並列摘要
Lingzhi culture (LZC) possessing the potential of enhancing growth performance and immune responses of broilers have been reported in several previous studies. But in different phase feeding regimen, i.e., starter phase (day 0 to 21) or grower phase (day 22 to 35) of LZC supplementation in diet on the responses in broilers is not well-known yet. A total of 640 chickens were randomly allocated into 2 diet treatments and 2 phase feeding regimens. Four treatments were designed as follows: (1) control group-without LZC in the whole phase, (2) LZC was added only in the starter phase, (3) LZC was added only in the grower phase, and (4) LZC was added in the whole period. The control diet was a corn-soybean meal formulated and supplemental LZC was added at 1 g/kg as treatment diet. Day-old chicks were randomly allocated for floor feeding with 16 pens per treatment in the starter phase and 8 pens per treatment in grower phase and 20 chicks in each pen for feeding 35 days. Two birds (one male and 1 female) per pen were randomly sacrificed for analyzing immune responses of spleen, cecal tonsil, and newcastle disease (ND) antibody titer on day 21 and 35, respectively. Results showed that starter diet with supplemental LZC did not affect growth performance from day 0 to 21, but could increase the BW gain and FE of broilers from day 22 to 35 and FE of broilers from day 0 to 35 (P < 0.05). Starter diet with supplemental LZC decreased the splenocytes proliferation and CD4^+ T lymphocytes of spleen on day 21. However, increased CD1^+ lymphocytes of spleen and CD3^+ and CD8^+ lymphocytes of cecal tonsil in LZC group were observed (P < 0.05). Supplemental LZC in starter diet decreased the serum specific-IgG and -IgM ND titers on day 21 (P < 0.05), but increased the IFN-γ secretion of splenocytes on day 35 in grower diet (P < 0.05). Moreover, the serum ND-specific IgA titer was enhanced when LZC was supplemented only in growth phase as compared to the whole phase supplementation. In conclusion, diet added with LZC had an evident effect on immune responses during the starter and growth phases, respectively. Furthermore, after starter phase supplemental LZC and grower phase was withdrawn, the growth performance in broilers was still enhanced during the grower phase and overall phases, but the immune effect did not last.