饲粮不同磷水平和钙磷比对冬毛期水貂生长性能、营养物质消化率及氮、钙、磷代谢的影响

摘要

本试验旨在研究饲粮不同磷水平和钙磷比对冬毛期水貂生长性能、营养物质消化率及氮、钙、磷代谢的影响。选取（130±10）日龄体重相近的健康雌性水貂90只，随机分为9组，每组10个重复，每个重复1只。采用3×3双因子试验设计，设3个磷水平分别为1．0％、1．4％、1．8％，3个钙磷比分别为1．0、1．5、2．0，配制9种试验饲粮，9种试验饲粮的钙、磷水平实测值如下：1．03％钙、0．97％磷（Ⅰ组），1．47％钙、0．98％磷（Ⅱ组），1．98％钙、0．99％磷（Ⅲ组），1．45％钙、1．37％磷（Ⅳ组），2．08％钙、1．38％磷（Ⅴ组），2．79％钙、1．38％磷（Ⅵ组），1．81％钙、1．75％磷（Ⅶ组），2．70％钙、1．79％磷（Ⅷ组），3．59％钙、1．80％磷（Ⅸ组）。预试期10 d，正试期67 d。结果表明：1）饲粮磷水平和钙磷比以及二者的交互作用极显著影响冬毛期水貂的末重、平均日增重（P＜0．01）。Ⅴ组的末重、平均日增重极显著高于其他组（P＜0．01）。2）干物质、蛋白质、脂肪消化率有随着饲粮钙磷比和磷水平的升高先增加后降低的趋势，且均在Ⅲ组达到最大值。3）饲粮磷水平和钙磷比以及二者的交互作用对冬毛期水貂食入氮、尿氮、粪氮、氮沉积、净蛋白质利用率、蛋白质生物学价值的影响不显著（P＞0．05）。4）随着饲粮磷水平的升高，粪钙含量随之增加，组间差异极显著（P＜0．01）；Ⅷ、Ⅸ组粪钙含量显著或极显著高于除Ⅶ组外的其他各组（P＜0．05或P＜0．01）。随着饲粮磷水平的升高，粪磷含量随之增加，组间差异显著或极显著（ P＜0．05或P＜0．01）；饲粮钙磷比为2．0时粪磷含量最低，极显著低于饲粮钙磷比为1．0和1．5时（ P＜0．01）；Ⅷ、Ⅸ组粪磷含量显著或极显著高于除Ⅶ组外的其他各组（ P＜0．05或P＜0．01）。饲粮磷水平和钙磷比极显著影响钙消化率（ P＜0．01）。随着饲粮钙磷比的升高，钙消化率极显著升高（P＜0．01）。Ⅲ组钙消化率最高，极显著高于除Ⅵ和Ⅸ组外的其他各组（P＜0．01）。饲粮磷水平和钙磷比对磷消化率的影响不显著（P＞0．05），但二者的交互作用对磷消化率有显著影响（P＜0．05）。磷消化率以Ⅰ组最低，Ⅲ组最高。综合各项指标，从降低饲粮成本、保护环境和维持冬毛期水貂生长性能的角度出发，饲粮磷水平在1．4％、钙磷比在1．5～2．0时较为适宜。%This study was conducted to study the effects of different dietary phosphorus levels and calcium/phosphorus ratios on growth performance, nutrient digestibility, and nitrogen, calcium and phosphorus metabo⁃lism of minks during winter fur⁃growing period. Ninety healthy female minks at the age of ( 130 ± 10 ) days with the similar body weight were randomly divided into 9 groups with 10 replicates each and 1 mink per repli⁃cate. Nine experimental diets were formulated by using 3×3 double factorial experiment design, firstly, setting 3 phosphorus levels:1. 0%, 1. 4% and 1. 8%; secondly, setting 3 calcium/phosphorus ratios: 1. 0, 1. 5 and 2.0. The minks in 9 groups were fed experimental diets with 1. 03% calcium and 0. 97% phosphorus ( groupⅠ) , 1.47% calcium and 0.98% phosphorus ( groupⅡ) , 1.98% calcium and 0.99% phosphorus ( groupⅢ) , 1.45% calcium and 1. 37% phosphorus ( group Ⅳ) , 2. 08% calcium and 1. 38% phosphorus ( group Ⅴ) , 2.79% calcium and 1. 38% phosphorus ( group Ⅵ) , 1. 81% calcium and 1. 75% phosphorus ( group Ⅶ) , 2.70% calcium and 1.79% phosphorus (group Ⅷ), 3.59% calcium and 1.80% phosphorus (group Ⅸ),re⁃spectively. The adaptation period lasted for 10 days and the formal period lasted for 67 days. The results showed as follows:1) dietary phosphorus level and calcium/phosphorus ratio had significant effects on the fi⁃nal weight, average daily gain ( P<0.01) , and the interaction of them was also significant ( P<0.01) . The fi⁃nal weight and average daily gain in group Ⅴ was significantly higher than those in other groups (P<0.01). 2) The dry matter digestibility, fat digestibility and protein digestibility had the same trend of firstly increase and then decrease, and the highest values of them all appeared at the group Ⅲ. 3) Dietary phosphorus level, calcium/phosphorus ratio and the interaction of them had no significant effects on nitrogen intake, urine nitro⁃gen, fecal nitrogen, nitrogen retention, biological value of protein and net protein utilization (P>0.05). 4) The content of fecal calcium was increased with the dietary phosphorus level increasing, and the difference was significant among all groups (P<0.01). The content of fecal calcium in groups Ⅷ and Ⅸ was significantly higher than that in other groups ( P<0.05 or P<0.01) . The content of fecal phosphorus was increased with the dietary phosphorus level increasing, and the difference was significant among all groups ( P<0.05 or P<0.01) . When the calcium/phosphorus ratio was 2.0, the content of fecal phosphorus was the lowest, and the differ⁃ence was significant compared with when the calcium/phosphorus ratio were 1.0 and 1.5 ( P<0.01) . The con⁃tent of fecal phosphorus in groupsⅧ and Ⅸ was significantly higher than that in other groups except group Ⅶ( P<0.05 or P<0.01) . Dietary phosphorus level and calcium/phosphorus ratio had a significant effect on calci⁃um digestibility ( P<0.01) , and the calcium digestibility was significantly increased with dietary calcium/phos⁃phorus ratio increasing ( P<0.01 ) . The calcium digestibility in group Ⅲ was the highest, and significantly higher than that in other groups except groups Ⅵ and Ⅸ (P<0.01). Dietary phosphorus level and calcium/phosphorus ratio had no significant effect on phosphorus digestibility (P>0.05), but the interaction of them had a significant effect on phosphorus digestibility ( P<0.05) . The lowest phosphorus digestibility was found in group Ⅰ, and the highest phosphorus digestibility was found in groupⅢ. Comparing all measured indices, di⁃etary 1.4% phosphorus level and 1.5 to 2.0 calcium/phosphorus ratio are considered to be optimal supplemental levels for minks during winter fur⁃growing period in terms of reducing feed expenses, protecting the environ⁃ment and maintaining growth performance.