Gao Mairui, Ren Yuying, Amalaradjou Mary Anne
Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
Poult Sci. 2025 Jun 12;104(9):105442. doi: 10.1016/j.psj.2025.105442.
As opposed to mammals, nutrient and energy availability for the embryo is limited to the nutrients deposited in the egg. This can create an energy imbalance in the perinatal period resulting in impaired perinatal embryo development, reduced hatchability, suboptimal hatchling quality and decreased post-hatch performance. Hence, it is critical to improve the energy status of the developing embryo to support the hatchling and immediate post-hatch development. Towards this, we observed that in ovo probiotic application to broiler eggs improved hatchability and hatchling quality. To understand the underlying mechanism, we investigated the effect of in ovo probiotic supplementation on glycogen reserves and embryo development in broilers. A total of 900 eggs (Ross 308) were either sprayed with phosphate buffered saline (PBS; control) or probiotics [∼9 log CFU/egg of Lactobacillus rhamnosus NRRL B-442(LR) or Lactobacillus paracasei DUP 13076 (LP)] during incubation. On day 18, eggs were transferred to the hatcher and set up for hatching. Embryos were sacrificed for morphometric measurements on day 10, 12, 14, 16, 18, 19, 20 and 21 of incubation. In addition, yolk sac membrane (YSM), yolk sac content (YSC), breast, and liver samples were collected for glycogen analysis and gene expression assays. Overall, in ovo probiotic spray significantly increased relative embryo weight, relative breast muscle and hatching muscle (P < 0.05). Additionally, glycogen content was significantly elevated in YSM, YS, liver and breast muscle throughout incubation and in the hatchling (P < 0.05). Further, we observed a significant downregulation of genes associated with the gluconeogenic pathways including PYGL, FBP1, PEPCK-C, PEPCK-M, and GK in the YSM, liver and breast muscle at day 21 (P < 0.05), thereby sparing the need for muscle protein breakdown. This in turn indicates the availability of sufficient glycogen reserves in the perinatal embryo to fuel the hatching process. In summary, in ovo spray application of probiotics improved glycogen reserves in the embryo thereby supporting optimum embryo development and improving hatchability and hatchling quality.
与哺乳动物不同，胚胎可获得的营养物质和能量仅限于卵中储存的营养物质。这可能在围产期造成能量失衡，导致围产期胚胎发育受损、孵化率降低、雏鸡质量欠佳以及出壳后性能下降。因此，改善发育中胚胎的能量状态对于支持雏鸡及出壳后的早期发育至关重要。为此，我们观察到对肉鸡种蛋进行胚内益生菌处理可提高孵化率和雏鸡质量。为了解其潜在机制，我们研究了胚内补充益生菌对肉鸡糖原储备和胚胎发育的影响。总共900枚种蛋（罗斯308）在孵化期间要么喷洒磷酸盐缓冲盐水（PBS；对照组），要么喷洒益生菌[约9 log CFU/枚蛋的鼠李糖乳杆菌NRRL B - 442（LR）或副干酪乳杆菌DUP 13076（LP）]。在第18天，将种蛋转移至孵化机并准备孵化。在孵化的第10、12、14、16、18、19、20和21天，处死胚胎进行形态测量。此外，收集卵黄囊膜（YSM）、卵黄囊内容物（YSC）、胸肌和肝脏样本用于糖原分析和基因表达测定。总体而言，胚内喷洒益生菌显著增加了胚胎相对重量、相对胸肌和孵化肌重量（P < 0.05）。此外，在整个孵化期及雏鸡中，YSM、YS、肝脏和胸肌中的糖原含量均显著升高（P < 0.05）。此外，我们观察到在第21天，YSM、肝脏和胸肌中与糖异生途径相关的基因包括PYGL、FBP1、PEPCK - C、PEPCK - M和GK显著下调（P < 0.05），从而无需分解肌肉蛋白。这进而表明围产期胚胎中有足够的糖原储备来为孵化过程提供能量。总之，胚内喷洒益生菌可改善胚胎中的糖原储备，从而支持胚胎的最佳发育并提高孵化率和雏鸡质量。
