ABSTRACT

1. A vaccination regime is a schedule for the administration of vaccines which may vary according to country or even by farm. This study aimed to measure the production and health performance of broilers treated with different vaccination regimes.

2. A total of 108 Cobb 500 broiler birds were randomly divided into three treatment groups, with six replicates consisting of six birds per replicate. Each treatment group was administered with different vaccination regimes against Newcastle Disease (ND), Infectious Bronchitis (IB) and Infectious Bursal Disease (IBD). Treatment 1 (T1) broilers were vaccinated against ND+IB and IBD on days 7 and 14 of age, respectively (control); Treatment 2 (T2) broilers were vaccinated against ND+IB on days 3 and 7 of age, and IBD on day 14; and Treatment 3 (T3) broilers were vaccinated against ND+IB on days 7 and 21 and IBD on day 14. Throughout the 42-day study period, data and samples were collected to determine the growth performance, immune status, carcase characteristics and meat quality.

3. There were significant differences (P < 0.05) on growth performance (body weight, body weight gain, feed intake and cumulative feed conversion ratio), white blood cell count (heterophils percentage, lymphocytes percentage and heterophils to lymphocytes ratio), carcase characteristics (kill-out weight, de-feathered weight, dressing percentage, drumsticks and gastrointestinal tract weight) and meat quality (cooking loss and drip loss) between treatments. T1 broilers showed better growth, white blood cell count, carcase characteristics and meat quality compared to T2 and T3 broilers.

4. Based on findings from the current work, vaccination against ND+IB and IBD on days 7 and 14 proved to be the best vaccination regime for broiler production, due to the better production performance and health status of broilers.

摘要

1. 疫苗接种制度是接种疫苗的时间表，可能因国家甚至农场而异。本研究旨在测量用不同疫苗接种方案处理的肉鸡的生产和健康表现。

2. 总共 108 只 Cobb 500 肉鸡被随机分为三个处理组，六个重复，每个重复六只鸡。每个治疗组都接受了针对新城疫 (ND)、传染性支气管炎 (IB) 和传染性法氏囊病 (IBD) 的不同疫苗接种方案。处理 1 (T1) 肉鸡分别在第 7 天和第 14 天接种了 ND+IB 和 IBD 疫苗（对照）；处理 2 (T2) 肉鸡在第 3 天和第 7 天接种 ND+IB，在第 14 天接种 IBD；处理 3 (T3) 肉鸡在第 7 天和第 21 天接种 ND+IB，在第 14 天接种 IBD。在 42 天的研究期间，收集数据和样品以确定生长性能、免疫状态、胴体特征和肉质量。

3. 生长性能（体重、体重增加、采食量和累积饲料转化率）、白细胞计数（嗜血细胞百分比、淋巴细胞百分比和嗜血淋巴细胞比）、胴体特征有显着差异（P < 0.05）处理之间的（杀灭重量、去毛重量、屠宰率、鸡腿和胃肠道重量）和肉质（蒸煮损失和滴落损失）。与 T2 和 T3 肉鸡相比，T1 肉鸡表现出更好的生长、白细胞计数、胴体特征和肉质。

4. 根据目前工作的结果，证明在第 7 天和第 14 天接种 ND+IB 和 IBD 是肉鸡生产的最佳疫苗接种方案，因为肉鸡的生产性能和健康状况更好。