Effects of dietary crude protein and tannic acid on nitrogen excretion, urinary nitrogenous composition and urine nitrous oxide emissions in beef cattle
Effects of dietary crude protein and tannic acid on nitrogen excretion, urinary nitrogenous composition and urine nitrous oxide emissions in beef cattle
复制标题
日粮粗蛋白和单宁酸对肉牛氮排泄、尿含氮成分和尿一氧化二氮排放的影响
DOI：
10.1111/jpn.13186
复制
发表时间：
2019
影响因子：
2.7
通讯作者：
Guangyong Zhao
中科院分区：
文献类型：
--
作者：
Ke Zhou;Yu Bao;Guangyong Zhao
Two consecutive trials were carried out to study the effects of dietary crude protein (CP) and tannic acid (TA) on nitrogen (N) metabolism of beef cattle and consequently, the N2O emissions from the urine of cattle. In Trial I, eight growing castrated cattle were used as the experimental animals. Two levels of dietary CP (110.6 and 135.7 g/kg dry matter [DM]) and two levels of TA (0 and 16.9 g/kg DM) were allocated in a replicated 2 × 2 crossover design. In Trial II, the N2O emissions from the urine of cattle collected from Trial I were determined using the static incubation technique. An interaction between dietary CP and TA on the urinary N excretion (p< .05) was found but not on the N2O‐N emission of cattle urine. Increasing dietary CP level from 110.6 g/kg DM to 135.7 g/kg DM increased the total N excretion (p< .001), the N retention (p< .05) and the ratio of urinary urea‐N/urinary N (p< .01), did not affect the N use efficiency (NUE;p> .05) and shifted the N excretion from faeces to urine. Increasing the dietary CP level increased the N2O‐N emission of cattle urine. Dietary addition of TA decreased the urinary excretions of urea (p< .001) and shifted the N excretion from urine to faeces, did not affect the NUE of beef cattle (p> .10), and decreased the N2O‐N emission of cattle urine. Pyrogallol and resorcinol of the TA metabolites were detected in urine with dietary addition of TA. Feeding beef cattle with relatively low CP level and adding TA in rations are effective approaches to mitigate the N2O‐N emissions from cattle urine.
