The present study aimed at evaluating the effect of vitamin K (VK) supplementation on bone health of laying hens challenged by Salmonella Enteritidis. A total of 80 32-week-old double negative salmonella-free brown-egg laying hens were randomly assigned to 4 treatments with 20 replicates each (1 bird per replicate) according to a 2 × 2 factorial design with 2 dietary VK supplementation levels [0 mg/kg (VK0) vs 2 mg/kg VK (VK2) and 2 challenge treatments [Salmonella Enteritidis (SE) vs physiological saline solution (PS)]. During the last 3 days of week 43 of age, birds of both VK treatments were either orally challenged with 1.0 mL suspension of 109 cfu/mL S. Enteritidis daily or received the same volume of PS. The laying rate, daily egg mass, tibia strength, CT, cOC and cOC/(cOC + ucOC) of VK2 treatment increased (P < 0.05) in contrast to VK0, however, the medullary area and ucOC of VK2 treatment decreased (P < 0.05) in contrast to VK0. Mortality, medullary area, serum Ca content of SE treatments increased (P < 0.05) in contrast to PS treatments. In both SE treatments, the decrease (P < 0.05) in birds’ tibia strength was associated with higher (P < 0.05) Ca levels in serum. There is an interaction (P < 0.05) between SE challenge and VK levels with regard to tibia strength and serum Ca levels. At week 42, serum CT was positively correlated with cOC (R = 0.99, P = 0.009); at week 44, tibia strength was positively correlated with BMD (R = 0.95, P = 0.045), but negatively correlated with medullary area (R = − 0.98, P = 0.018). VK (2 mg/kg) supplementation to diets of laying hens can enhance bone strength under challenge situations with Salmonella Enteritidis. Medullary area has proven to be a sensitive biomarker for bone calcium loss caused by SE infection.

中文翻译：

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维生素K的缓解骨钙质流失引起的沙门氏菌通过骨钙素的羧化肠炎

本研究旨在评估补充维生素 K (VK) 对感染肠炎沙门氏菌的蛋鸡骨骼健康的影响。根据 2 × 2 因子设计和 2 种日粮 VK 补充水平，将 80 只 32 周龄双阴性无沙门氏菌褐蛋蛋鸡随机分配到 4 个处理，每个处理 20 个重复（每个重复 1 只鸡）。 0 mg/kg (VK0) 与 2 mg/kg VK (VK2) 和 2 种攻击处理 [肠炎沙门氏菌 (SE) 与生理盐水溶液 (PS)]。在 43 周龄的最后 3 天，两种 VK 处理的家禽要么每天口服 1.0 mL 109 cfu/mL 肠炎沙门氏菌悬浮液，要么接受相同体积的 PS。与 VK0 相比，VK2 处理的产蛋率、日产蛋量、胫骨强度、CT、cOC 和 cOC/(cOC + ucOC) 增加（P < 0.05），然而，与 VK0 相比，VK2 处理的髓质面积和 ucOC 减少（P < 0.05）。与 PS 处理相比，SE 处理的死亡率、髓质面积、血清 Ca 含量增加（P < 0.05）。在两种 SE 处理中，鸟类胫骨强度的降低 (P < 0.05) 与血清中较高 (P < 0.05) 的 Ca 水平相关。在胫骨强度和血清 Ca 水平方面，SE 挑战和 VK 水平之间存在相互作用（P < 0.05）。42周时，血清CT与cOC呈正相关（R=0.99，P=0.009）；在第 44 周，胫骨强度与 BMD 呈正相关（R = 0.95，P = 0.045），但与延髓面积呈负相关（R = - 0.98，P = 0.018）。蛋鸡日粮中添加 VK (2 mg/kg) 可以增强肠炎沙门氏菌攻击情况下的骨骼强度。