Fu Yu, Zhou Jianmin, Schroyen Martine, Lin Jing, Zhang Haijun, Wu Shugeng, Qi Guanghai, Wang Jing
Key Laboratory of Feed Biotechnology, Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing), Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Precision Livestock and Nutrition Laboratory, TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liège, B-5030 Gembloux, Belgium.
Anim Nutr. 2024 Apr 20;18:340-355. doi: 10.1016/j.aninu.2024.04.007. eCollection 2024 Sep.
This study was aimed to investigate the effects of dietary calcitriol or quercetin supplementation on eggshell and bone quality of laying hens. In trial 1, 72 Hy-Line Brown layers (80-week-old) with weak-shelled strength (25 to 30 N) were assigned into 4 dietary treatments with 6 replicates of 3 birds and fed a basal diet (4% calcium level) or basal diets supplemented with 0.5% calcium, 5 μg/kg calcitriol or 500 mg/kg quercetin for 4 weeks. In trial 2, 360 Hy-Line Brown layers (60-week-old) were divided into 3 groups with 8 replicates of 15 birds: control group (basal diet), calcitriol group (basal diet + 5 μg/kg calcitriol), and quercetin group (basal diet + 500 mg/kg quercetin). This trial lasted for 12 weeks. The results showed that dietary calcitriol or quercetin improved eggshell quality in both trials ( < 0.05). In trial 2, compared with the control group, both calcitriol and quercetin supplementations improved femoral bone quality, calcium retention of hens and calcium content in uterine fluid at 18.5 h post-oviposition (PO) ( < 0.05), along with enhancing uterine morphology. Compared to the control group, supplemental calcitriol or quercetin up-regulated the relative mRNA expression levels of uterine transient receptor potential cation channel, subfamily V, member 6 () at 8.5 h PO and plasma membrane calcium-ATPase (), vitamin D receptor (), estrogen receptor alpha () at 18.5 h PO ( < 0.05), but down-regulated the uterine caspase 3 () relative mRNA expression level at 8.5 h PO ( < 0.05). Meanwhile, the femoral relative mRNA expression levels of tartrate-resistant acid phosphatase () (up-regulated at 8.5 and 18.5 h PO) and alkaline phosphatase () (up-regulated at 8.5 h PO but down-regulated at 18.5 h PO) were also affected by calcitriol or quercetin supplementation ( < 0.05). Compared to the calcitriol, quercetin increased hen-day egg production and femoral medullary bone volume/bone tissue volume but reduced femoral stiffness ( < 0.05), which were accompanied by increased relative mRNA expression levels of uterine , estrogen receptor beta () at 18.5 h PO ( < 0.05). Overall, both dietary calcitriol and quercetin could improve eggshell and bone quality by modulating calcium metabolism of aged layers. Compared to calcitriol, dietary quercetin up-regulated the expression of uterine calcium transporters, without affecting eggshell quality.
本研究旨在探讨日粮添加骨化三醇或槲皮素对蛋鸡蛋壳及骨骼质量的影响。在试验1中，将72只（80周龄）蛋壳强度较弱（25至30 N）的海兰褐蛋鸡分为4种日粮处理组，每组6个重复，每个重复3只鸡，分别饲喂基础日粮（钙含量4%）或添加0.5%钙、5 μg/kg骨化三醇或500 mg/kg槲皮素的基础日粮，持续4周。在试验2中，将360只（60周龄）海兰褐蛋鸡分为3组，每组8个重复，每个重复15只鸡：对照组（基础日粮）、骨化三醇组（基础日粮 + 5 μg/kg骨化三醇）和槲皮素组（基础日粮 + 500 mg/kg槲皮素）。本试验持续12周。结果表明，在两个试验中，日粮添加骨化三醇或槲皮素均改善了蛋壳质量（P < 0.05）。在试验2中，与对照组相比，添加骨化三醇和槲皮素均改善了股骨骨骼质量、母鸡的钙保留率以及排卵后（PO）18.5小时子宫液中的钙含量（P < 0.05），同时增强了子宫形态。与对照组相比，添加骨化三醇或槲皮素上调了排卵后8.5小时子宫瞬时受体电位阳离子通道亚家族V成员6（TRPV6）的相对mRNA表达水平，以及排卵后18.5小时质膜钙ATP酶（PMCA）、维生素D受体（VDR）、雌激素受体α（ERα）的相对mRNA表达水平（P < 0.05），但下调了排卵后8.5小时子宫半胱天冬酶3（Caspase 3）的相对mRNA表达水平（P < 0.05）。同时，日粮添加骨化三醇或槲皮素也影响了股骨抗酒石酸酸性磷酸酶（TRAP）（在排卵后8.5和18.5小时上调）和碱性磷酸酶（ALP）（在排卵后8.5小时上调但在18.5小时下调）的相对mRNA表达水平（P < 0.05）。与骨化三醇相比，槲皮素提高了日产蛋量和股骨骨髓骨体积/骨组织体积，但降低了股骨硬度（P < 0.05），同时伴随着排卵后18.5小时子宫TRPV6、雌激素受体β（ERβ）相对mRNA表达水平的升高（P < 0.05）。总体而言，日粮添加骨化三醇和槲皮素均可通过调节老龄蛋鸡的钙代谢来改善蛋壳和骨骼质量。与骨化三醇相比，日粮添加槲皮素上调了子宫钙转运蛋白的表达，且不影响蛋壳质量。
