动物营养学报2017，Vol.29Issue(11)：3932-3941,10.DOI:10.3969/j.issn.1006-267x.2017.11.013
饲粮氮水平对牦牛尿嘌呤衍生物排出量与瘤胃微生物氮产量的影响
Effects of Dietary Nitrogen Level on Urine Purine Derivatives Excretion and Microbial Nitrogen Production in Yaks
摘要
Abstract
This experiment was conducted to explore the regularity of urine purine derivatives ( PD) excretion respond to dietary nitrogen level, and based on this, ruminal microbial nitrogen ( MN) production was esti-mated, thus provided references for appropriate feeding of yaks in cold farming area. Four 3-year-old castrated male yaks [body weight was (192±12) kg] were divided into 4 groups with 1 yak per group in a 4×4 Latin square design. Dietary nitrogen levels of different groups were 1. 03%, 1. 95%, 2. 85% and 3. 76%, respectively. The experiment consisted of 4 periods, each lasted for 21 d, allowing a 15-d pre-test period and a 6-d test period. The results showed that urine PD were mainly consist of allantoin and uric acid, allantoin/PD and uric acid/PD were 0.69 to 0.76 and 0.23 to 0.30, respectively, and negligible contents of xanthine and hy-poxanthine were found. As dietary nitrogen level increasing, urine PD, allantoin, uric acid and hippuric acid extractions were increased linearly ( P<0.05) , however, uric acid/PD and purine nitrogen index ( PNI) were linearly decreased ( P<0.05) . With the increase of dietary nitrogen level, ruminal bacterial purine bases ( RNA equivalent) content, bacterial nitrogen ( BN) content and MN production were linearly increased ( P<0.05) , and efficiency of dietary nitrogen converted into MN [ ruminal MN/nitrogen intake ( NI ) ] was linearly de-creased ( P<0. 05 ) . There were a strong relationship between urine PD extraction ( mmol/d ) , ruminal MN ( g/d) and NI ( g/d) , the following mathematical equations were established as follows: PD=0. 58NI+18.28, MN=0.18NI+22.18. In summary, ruminal MN production is the highest (42.60 g/d) when dietary nitrogen level is 2.85%, whereas PNI and efficiency of NI converted into MN are the highest under the condi-tion of low dietary nitrogen level (1.03%). The results indicate the great efficiency of nitrogen utilization when low nitrogen provision in yaks, and their adaptation nutrition mechanism to the deficiencies in intake of nutrient of yaks in Tibetan plateau.关键词
牦牛/饲粮氮水平/尿中嘌呤衍生物/瘤胃微生物氮产量Key words
yak/dietary nitrogen levels/urine purine derivatives/ruminal microbial nitrogen production分类
农业科技引用本文复制引用
王惟惟,王传洋,郝力壮,刘浩,仲崇亮,周建伟,龙瑞军..饲粮氮水平对牦牛尿嘌呤衍生物排出量与瘤胃微生物氮产量的影响[J].动物营养学报,2017,29(11):3932-3941,10.基金项目
国家自然科学基金(31672453) （31672453）
中国博士后科学基金(2016M600825) （2016M600825）
兰州大学"中央高校基本科研业务专项资金"(lzujbky-2015-bt08) （lzujbky-2015-bt08）
