Shi Hanyi, Wang Jinquan, White Dima, Martinez Oscar Jonathan Tejeda, Kim Woo Kyun
Department of Poultry Science, University of Georgia, Athens, GA 30602, USA.
Department of Agriculture, Southern Arkansas University, Magnolia, AR 71753, USA.
Poult Sci. 2023 Nov;102(11):103062. doi: 10.1016/j.psj.2023.103062. Epub 2023 Aug 23.
An experiment was conducted to evaluate effects of phytase and coccidial vaccine on growth performance, bone ash, bone 3-D microstructure, nutrient digestibility, and gene expression of intestinal biomarkers in broilers fed a regular or nutrient-reduced diet. The experiment was conducted in a 2 × 4 factorial arrangement with 6 replicates per treatment and 10 birds per replicate. Two main factors were coccidial vaccine and dietary treatments. The dietary treatments included: 1) a positive control (PC; normal nutrient levels); 2) a negative control (NC; with a reduction of 0.15% of Ca and avP and 5% of essential amino acid (EAA) and crude protein relative to PC); 3) NC + 500 FTU/kg of phytase; and 4) NC + 1,500 FTU/kg of phytase. No interaction effect of phytase and coccidial vaccine on growth performance, bone ash, and apparent ileal digestibility (AID) was observed. For the main effect, birds fed the NC diet showed lower (P = 0.007) BWG during d 0 to 21 compared to PC birds, whereas supplementing 500 or 1,500 FTU/kg phytase increased BWG to the similar level to the PC. During d 0 to 21, vaccinated birds had a lower (P < 0.001) FI and better (P = 0.045) FCR compared to unvaccinated birds. Birds fed the NC diet resulted a decrease in tibia fat-free dry bone weight (P = 0.012), ash weight (P = 0.005), ash percentage (P < 0.001), and ash concentration (P = 0.019) compared to the PC group at d 21, whereas supplementing phytase at 500 or 1,500 FTU/kg in NC diet was able to improve these bone parameters to the similar level to the PC; however, vaccination did not have any effect on bone ash. Similarly, birds fed with the NC diet showed had significant lower bone microstructure levels including bone volume, bone mineral density, and bone mineral content (P < 0.001), and supplementing phytase at 1,500 FTU/kg improved these parameters. Vaccination improved AID of nitrogen (P < 0.001). Birds from the NC and both phytase supplementation groups had a higher (P = 0.001) AID of Ca compared to the PC. Supplementing phytase at 500 FTU/kg or 1,500 FTU/kg improved (P < 0.001) AID of P compared to the NC. Additionally, the NC had a lower AID of DM than the PC, whereas supplementing phytase at 500 FTU/kg or 1,500 FTU/kg improved DM digestibility (P = 0.0299). In conclusion, supplementation of phytase at 500 or 1,500 FTU/kg improved growth performance, bone mineralization, and nutrient digestibility regardless of vaccination, with a more pronounced effect when supplementing phytase at 1,500 FTU/kg.
进行了一项试验，以评估植酸酶和球虫疫苗对饲喂常规日粮或低营养日粮的肉鸡生长性能、骨灰分、骨骼三维微观结构、养分消化率及肠道生物标志物基因表达的影响。试验采用2×4析因设计，每个处理6个重复，每个重复10只鸡。两个主要因素为球虫疫苗和日粮处理。日粮处理包括：1）正对照（PC；正常营养水平）；2）负对照（NC；相对于PC，钙、有效磷降低0.15%，必需氨基酸和粗蛋白降低5%）；3）NC+500 FTU/kg植酸酶；4）NC+1500 FTU/kg植酸酶。未观察到植酸酶和球虫疫苗对生长性能、骨灰分及回肠表观消化率（AID）的交互作用。对于主效应，在0至21日龄期间，饲喂NC日粮的鸡与PC组相比，体重增长（BWG）较低（P=0.007），而添加500或1500 FTU/kg植酸酶可使BWG提高至与PC组相似的水平。在0至21日龄期间，与未接种疫苗的鸡相比，接种疫苗的鸡采食量（FI）较低（P<0.001），饲料转化率（FCR）较好（P=0.045）。在21日龄时，与PC组相比，饲喂NC日粮的鸡胫骨无脂干骨重（P=0.012）、灰分重（P=0.005）、灰分百分比（P<0.001）和灰分浓度（P=0.019）均降低，而在NC日粮中添加500或1500 FTU/kg植酸酶能够使这些骨骼参数提高至与PC组相似的水平；然而，接种疫苗对骨灰分无影响。同样，饲喂NC日粮的鸡骨骼微观结构水平显著较低，包括骨体积、骨矿物质密度和骨矿物质含量（P<0.001），添加1500 FTU/kg植酸酶可改善这些参数。接种疫苗可提高氮的AID（P<0.001）。与PC组相比，NC组及两个植酸酶添加组的鸡钙AID较高（P=0.001）。与NC组相比，添加500 FTU/kg或1500 FTU/kg植酸酶可提高磷的AID（P<0.001）。此外，NC组的干物质AID低于PC组，而添加500 FTU/kg或1500 FTU/kg植酸酶可提高干物质消化率（P=0.0299）。总之，无论是否接种疫苗，添加500或1500 FTU/kg植酸酶均可提高生长性能、骨矿化及养分消化率，添加1500 FTU/kg植酸酶时效果更显著。
