鍾秀枝(1) 連一洋(2) 張秀鑾(1) 黃祥吉(1) 林德育(1)
雛白痢(PD)是白痢沙氏桿菌引起之家禽介卵傳染病，受感染之幼雛會出現腸炎和白痢等症狀，並造成高死亡率。然受感染之成雞則成為無症狀之帶菌者，其會經由種蛋傳染至雛雞。因此，雛白痢清除為養雞產業重要課題之一。本試驗應用行政院農業委員會畜產試驗所2001年繁衍之四個近親品系土雞(L7公雞185隻、母雞435隻，L9公雞220隻、母雞543隻，L11公雞141隻、母雞821隻，L12公雞182隻、母雞408隻)種雞群，計2207隻，於選種前進行雛白痢全面篩檢。檢測方法以血清學檢查方法進行之，雞隻經採血分離血清後，應用行政院農業委員會家畜衛生試驗所雛白痢診斷液作平板凝集試驗；分別以25 ul血清加入25 ul抗原攪均後，於1分鐘內呈紫色顆粒狀凝集者為陽性反應，1分鐘後未呈現凝集現象者為陰性反應。檢測結果顯示：四個近親品系土雞之陽性率分別為L7公雞11.4 %、母雞16.6 %，L9公雞8.2 %、母雞8.5 %，L11公雞9.2 %、母雞15.0 %，L12公雞2.2 %、母雞11.8 %。四個近親品系土雞之陽性率無論公母皆以L7較高，而公雞最低者為L12，母雞最低者為L9。進一步評估母雞40週齡產蛋數發現，雛白痢陰性反應母雞之產蛋數顯著高於陽性反應者(62.7 vs. 59.6個，P<0.01)。
PULLORUM DISEASE SCREEN FOR TLRI NATIVE CHICKEN
H. C. Chung(1), Y. Y. Lien, H. L. Chang(1), H. C. Huang(1) and D.Y. Lin(1)
(1)Taiwan Livestock Research Institution of COA
(2) Department of Veterinary Medicine, National
Pingtung University of Science and Technology
Salmonella pullorum is known as the cause of pullorum disease (PD), which can be contagious through egg and is characterized by enteritis and white diarrhea symptoms with high mortality in chicks. However, infected adult chicken becomes no symptomatic carrier and infects the chicks via eggs. Thus, PD elimination becomes one of the important issues in poultry industry. A total of 2207 chickens propagated from Chicken Farm/TLRI/COA in 2001 were screen for PD free prior to selection, which including four inbred lines (185 and 435 birds of L7, 220 and 543 birds of L9, 141 and 821 birds of L11, and 812 and 408 birds of L12 for cocks and hens, respectively). The diagnostic test used was serum agglutination test to eliminate the reactors from the breeding flocks. After serum separated whole blood sample, 25 ul diagnostic antigen obtained from National Veterinary Research Institute/Council of Agriculture was added and mixed thoroughly with 25 ul bird serum by use of the tip of the serum pipette. The bird was classified as positive reactor if agglutination occurred within one minute and negative otherwise. Frequencies of positive were 11.4% and 16.6% (L7), 8.2% and 8.5% (L9), 9.2% and 15.0% (L11), 2.2% and 11.8% (L12) for cocks and hens, respectively. Results indicated that the L7 had the highest infection rate in both cocks and hens among lines considered in this study; L12 and L9 showed the lowest contagious rates in cocks and hens, respectively. Also, negative hens had better laying performance than those of positive ones in terms of egg number produced up to 40 weeks of age (62.7 vs. 59.6 eggs, P<0.01).
Key Words: Pullorum disease (PD), Positive frequency, Egg number.