Department of Poultry Science, Mississippi State University, Mississippi State, MS 39762.
Zoetis, 1040 Swabia Court, Research Triangle Park, NC 27709.
Poult Sci. 2017 Sep 1;96(11):3944-3948. doi: 10.3382/ps/pex201.
Effects of the in ovo (i.o.) or subcutaneous (s.c.) method of administration (moa) of the Marek's disease (MD) vaccine and 4 or 18 h pre-placement holding time (pht) on the processing yield of male broilers through 49 d of age (doa) were investigated. Ross 708 broiler hatching eggs (3,900) were either i.o.-vaccinated at 18 d of incubation or chicks from eggs that were not i.o.-vaccinated were s.c.-vaccinated at hatch. The i.o. injections (50 μL) were delivered by a commercial multi-egg injector and s.c. injections (200 μL) were delivered by an automatic pneumatic s.c. injector. The pht was imposed on chicks after vaccination. Sixteen birds were initially assigned to each of 15 replicate floor pens belonging to each of the moa and pht combination groups and were grown out through 48 doa. At 48 doa, 6 birds were randomly selected from each replicate pen and were weighed and fasted for 16 h before being processed. At 49 doa, whole carcass, fat pad, breast muscle, and tenders muscles weights were recorded. Whole carcass weight as a percentage of live BW, and fat pad, breast muscle, and tenders muscles weights as percentages of both live and whole carcass weights were calculated. Upon subjection of the data to a 2 × 2 factorial analysis, only a main effect due to moa was observed for tenders muscles weight as a percentage of live and whole carcass weights. Tenders muscles weight as a percentage of both live (P ≤ 0.010) and whole carcass (P ≤ 0.004) weight was higher in birds hatched from eggs that received i.o. rather than s.c. vaccinations. In conclusion, in comparison to s.c. vaccination, i.o. vaccination increased relative tenders weight yield, whether or not broilers were held for 4 or 18 h prior to placement. Therefore, with regard to broiler processing yield, i.o. and s.c. vaccinations were safe for the administration of the MD vaccine, with i.o. vaccination displaying a slight potential advantage.
本研究旨在探讨马立克氏病（MD）疫苗的胚内（i.o.）或皮下（s.c.）给药方式（moa）以及放置前 4 或 18 小时（pht）对雄性肉鸡 49 日龄（doa）加工产量的影响。选用罗斯 708 肉鸡种蛋（3900 枚），孵化 18 日龄时进行胚内接种，或对未进行胚内接种的种蛋孵化出的雏鸡进行皮下接种。采用商业多蛋注射器进行胚内注射（50 μL），使用自动气动皮下注射器进行皮下注射（200 μL）。接种后对雏鸡实施 pht。将 18 只雏鸡最初分配到每个 moa 和 pht 组合组的 15 个重复地板笼中，并通过 48 doa 进行生长。在 48 doa 时，从每个重复笼中随机选择 6 只鸡进行称重，禁食 16 小时后进行加工。在 49 doa 时，记录全胴体、脂肪垫、胸肌和腿肌重量。计算全胴体重量占活重的百分比，以及脂肪垫、胸肌和腿肌重量占活重和全胴体重量的百分比。对数据进行 2×2 析因分析后，仅观察到 moa 对腿肌重量占活重和全胴体重量的百分比有主要影响。与皮下接种相比，接受胚内接种的鸡的腿肌重量占活重（P≤0.010）和全胴体（P≤0.004）的百分比更高。总之，与皮下接种相比，在放置前是否对肉鸡进行 4 或 18 小时的饲养，胚内接种均能提高相对腿肌重量的产率。因此，就肉鸡加工产量而言，胚内和皮下接种均可安全地接种 MD 疫苗，胚内接种具有轻微的潜在优势。
