Effects of rearing cage type and dietary limestone particle size (LPS) on growth, apparent retention (AR) of nutrients, and bone quality were investigated. The treatments were arranged in a 2 × 3 factorial with cage (conventional, CON and furnished, FUR) and LPS (fine, < 0.595 mm, F; medium, 0.595 to < 1.68 mm, M; and 1:1 mixture of F and M wt/wt; FM). A total of 900-day-old Lohmann LSL-Lite chicks were placed in CON (20 chicks/cage) and FUR (30 chicks/cage) based on BW. The diets were formulated according to breeder's nutrient specifications for starter, grower, and developer phases. At the end of 4, 12, and 16 wk of age (woa), 2 pullets/cage were euthanized for samples. At 12 and 16 woa, 1 pullet/cage was transferred to metabolism cages for AR measurements. There was no interaction (P > 0.05) between cage type and LPS on response variables. At 4 woa, body (P = 0.002) and bone (P < 0.05) weight was higher for CON than FUR pullets, but this was reversed (P < 0.01) at 16 woa. Pullets fed M LPS had higher (P < 0.05) AR of Ca, whole body mineral density (BoMD), and whole body mineral content (BoMC) than pullets fed F LPS. However, pullets fed F LPS had higher (P < 0.05) femur bone mineral density (BMD) and tended (P = 0.059) to have higher tibia bone breaking strength (BBS) than pullets fed M LPS at 16 woa. Pullets reared in CON cages had higher (P < 0.05) AR of Ca than FUR pullets. At 4 woa, CON pullets had lower (P < 0.05) femur and tibia BMD but higher tibia (93 vs. 83 N P = 0.012) BBS than FUR pullets. However, at 16 woa, FUR pullets had higher (P < 0.05) BoMD, BoMC, and tibia BBS than CON pullets. In conclusions, cage type and dietary LPS had independent effects on Ca utilization and skeletal development. Despite poor Ca retention, FUR caged pullets showed improved bone quality at 16 woa. Finer LPS improved femur mineral density suggesting coarser LPS had limited effects on pullet bone quality.

中文翻译：

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饲养笼的类型和饮食中石灰石的粒度：I，对Lohmann精选的Leghorn-Lite母鸡的生长，钙的表观截留率和长骨属性的影响。

研究了饲养笼的类型和饮食中石灰石颗粒大小（LPS）对生长，营养物表观保留率（AR）和骨骼质量的影响。处理安排在2×3阶乘中，笼子（常规，CON和配备，FUR）和LPS（精细，<0.595 mm，F；中等，0.595至<1.68 mm，M；以及F和1：1的混合物） M wt / wt； FM）。根据体重，将总共900天的Lohmann LSL-Lite小鸡置于CON（20只小鸡/笼）和FUR（30只小鸡/笼）中。日粮是根据育种者在开始阶段，生长阶段和发育阶段的营养指标制定的。在4、12和16周龄（周岁）结束时，对2个小母鸡/笼子实施安乐死作为样本。在12和16 woa时，将1个小母鸡/笼子转移到代谢笼中进行AR测量。没有相互作用（P> 0。05）保持架类型和响应变量上的LPS之间。在4 woa时，CON的体重（P = 0.002）和骨骼重量（P <0.05）比FUR母鸡高，但在16 woa时体重（P <0.01）则相反。饲喂M LPS的小鸡比饲喂F LPS的小鸡具有更高的Ca（P <0.05）AR，全身矿物质密度（BoMD）和全身矿物质含量（BoMC）。然而，饲喂F LPS的母鸡比饲喂M LPS的母鸡在16 woa时具有更高的（P <0.05）股骨矿物质密度（BMD），并且倾向于（P = 0.059）具有更高的胫骨骨折强度（BBS）。在CON笼中饲养的小鸡的钙的AR比FUR小（P <0.05）。在4 woa时，CON母猪的股骨和胫骨BMD较低（P <0.05），但胫骨（FBS）的胫骨较高（93 vs. 83 NP = 0.012）。然而，在16 woa时，FUR母鸡的BoMD，BoMC和胫骨BBS高于CON母鸡（P <0.05）。总之，笼型和饮食脂多糖对钙利用和骨骼发育具有独立的影响。尽管Ca保留能力差，但FUR笼养的小母鸡在16 woa时仍显示出改善的骨质。LPS越细，股骨矿物质密度越高，表明LPS越粗对母鸡骨质量的影响就越有限。