本试验通过在基础饲粮中添加不同水平的锌，研究其对京红1号蛋鸡产蛋高峰期组织器官锌沉积和胫骨指标的影响。选择20周龄540只健康产蛋高峰期京红1号蛋鸡，随机分为6组，每组6个重复，每个重复15只鸡。对照组饲喂基础饲粮（含锌25 mg/kg），试验组饲喂在基础饲粮中分别添加25、50、75、100和125 mg/kg锌（以一水硫酸锌为锌源）的试验饲粮，预试期2周，正试期24周。结果显示：1）饲粮中添加不同水平的锌显著或极显著提高了京红1号蛋鸡33周龄末血清锌含量（P<0.05或P<0.01），但对46周龄末血清锌含量无显著影响（P>0.05）。2）饲粮添加不同水平的锌极显著影响了京红1号蛋鸡46周龄末肝脏锌含量（P<0.01），且肝脏锌含量随锌添加水平的升高而增加，但对骨骼肌和胰腺锌含量无显著影响（P>0.05）。3）饲粮添加不同水平的锌对京红1号蛋鸡46周龄末胫骨指标（胫骨重、无脂胫骨重、胫骨灰分重及胫骨锌和胫骨灰锌含量）未产生显著影响（P>0.05）。4）饲粮添加不同水平的锌极显著影响了京红1号蛋鸡46周龄末粪便锌含量和锌表观利用率（P<0.01），粪便锌含量随着锌添加水平的升高而增加，而锌表观利用率则随着锌添加水平的升高而降低。综合考虑各因素，以一水硫酸锌为锌源，产蛋高峰期京红1号蛋鸡基础饲粮（含锌25 mg/kg）中锌适宜添加水平为75 mg/kg。

The present study evaluated the effects of zinc supplemental level on tissue and organ zinc deposition and tibia indexes by adding different levels of zinc into the basal diet of Jinghong No.1 layer hens during laying peak period. Five hundred and forty 20-week-old healthy Jinghong No.1 layer hens were randomly allotted to 6 groups with 6 replicates per group and 15 layer hens per replicate. Birds in control group was fed a basal diet (contained 25 mg/kg zinc), and birds in trial groups were fed experimental diets which added 25, 50, 75, 100 and 125 mg/kg zinc (using sulfate zinc monohydrate as zinc source) on the basis of the basal diet. The pre-feeding period was 2 weeks and the experimental period was 24 weeks. The results showed as follows:1) adding different levels zinc into diets significantly or extremely significantly enhanced the serum zinc content of Jinghong No.1 layer hens at the end of 33 weeks of age (P<0.05 or P<0.01), but it did not significantly affect the serum zinc content at the end of 46 weeks of age (P>0.05). 2) Adding different levels zinc into diets extremely significantly affected the liver zinc content of Jinghong No.1 layer hens at the end of 46 weeks of age (P<0.01), and the liver zinc content was enhanced as the zinc supplemental level increasing, but did not significantly affect the muscle and pancreas zinc content (P>0.05). 3) Adding different levels zinc into diets did not significantly affect the tibia indxes including tibia weight, fat free weight, tibia ash weight, tibia zinc content and tibia ash zinc content of Jinghong No.1 layer hens at the end of 46 weeks of age (P>0.05). 4) Adding different levels zinc into diets extremely significantly affected the feces zinc content and zinc apparent availability of Jinghong No.1 layer hens at the end of 46 weeks of age (P<0.01), the feces zinc content was enhanced and the zinc apparent availability was reduced as the zinc supplemental level increasing. Comprehensive consideration, the optimal supplemental level of zinc is 75 mg/kg using sulfate zinc monohydrate as a zinc source in the basal diet containing 25 mg zinc of Jinghong No.1 layer hens during laying peak period.