Ghanaatparast-Rashti M, Mottaghitalab M, Ahmadi H
Faculty of Agriculture Science, Department of Animal Science, University of Guilan, Rasht, Iran.
Faculty of Agriculture Science, Department of Poultry Science, Tarbiat Modares University, Tehran, Iran.
J Anim Physiol Anim Nutr (Berl). 2018 Apr;102(2):e806-e817. doi: 10.1111/jpn.12838. Epub 2017 Nov 13.
A Box-Behnken design (BBD) in a response surface methodology (RSM) was used to investigate the response of broiler chicks to in ovo feeding (IOF) of beta-hydroxy beta-methylbutyrate (HMB), dextrin and the timing of the first water and feed deprivation. On day 18th of incubation, 1,500 eggs were randomly assigned to 15 experimental runs of BBD, each with 4 replicates, as 3 levels IOF of HMB (0%, 0.5% and 1%) and dextrin (0%, 20% and 40%), and 3 levels of the first water and feed deprivation (6, 27 and 48 hr). Day-old chicks from each replicate were then used to assess the effect of IOF and time first water and feed access on chick's responses. The IOF of dextrin leads to respectively 9.7%-15.5% lower hatchability for 20% and 40% inclusion (p < .05), whereas HMB inclusion appeared with no effect on hatchability (p > .05). Administration of dextrin or HMB into the amnion of embryos elevated length, width and surface area of villus, and increased glycogen content of liver and breast (p < .05). In all parameter models, the linear terms showed highest contribution (R = 0.81-0.97) to explain existing variation in chick's responses. The first water and feed deprivation had largest effect on BW2 and glycogen content of liver and breast. It is concluded that if possible, place chicks before 7 hr of hatch to preserve BW loss and have maximum response from IOF. If not possible, use IOF with 40% dextrin + 0.5% HMB to preserve gut integrity and energy status up to 48 hr. This should give advantage to chicks to recover fast after feeding, but that would have to be confirmed by trials growing birds to slaughter age.
采用响应面法（RSM）中的Box-Behnken设计（BBD），研究肉仔鸡对β-羟基-β-甲基丁酸（HMB）、糊精的胚内注射（IOF）以及首次水和饲料剥夺时间的反应。在孵化第18天，将1500枚鸡蛋随机分配到BBD的15个实验批次中，每个批次有4个重复，设置HMB（0%、0.5%和1%）和糊精（0%、20%和40%）的3个IOF水平，以及首次水和饲料剥夺的3个水平（6、27和48小时）。然后，每个重复的一日龄雏鸡用于评估IOF和首次水和饲料获取时间对雏鸡反应的影响。糊精的IOF导致20%和40%添加量时孵化率分别降低9.7%-15.5%（p<0.05），而添加HMB对孵化率无影响（p>0.05）。向胚胎羊膜内注射糊精或HMB可增加绒毛长度、宽度和表面积，并增加肝脏和胸肌的糖原含量（p<0.05）。在所有参数模型中，线性项对解释雏鸡反应的现有变异贡献最大（R=0.81-0.97）。首次水和饲料剥夺对2日龄体重以及肝脏和胸肌的糖原含量影响最大。得出的结论是，如果可能，在孵化7小时前放置雏鸡，以减少体重损失并使IOF产生最大反应。如果不可能，则使用含40%糊精+0.5%HMB的IOF，以在48小时内维持肠道完整性和能量状态。这应该有利于雏鸡在喂食后快速恢复，但这必须通过将鸡饲养至屠宰年龄的试验来证实。
