基于定位栏试验的奶牛粪便中雌激素含量特征

为探究奶牛粪便中雌激素含量特征,采用定位栏试验收集奶牛粪便样,采用超高效液相色谱串联(UPLC-MS/MS)法对粪便中4种天然雌激素(雌酮;17α-雌二醇,17β-雌二醇,雌三醇)和2种人工合成雌激素(17a-炔雌醇,己烯雌酚)的含量进行测定,结果表明:6种雌激素的检出率居于8.33％～98.89％之间,4种天然雌激素...

Characterizing the estrogen content in cow feces based on gestation crate experiment

To explore characteristics of estrogen content in cow feces, fecal samples were collected from the gestation crates to quantify the contents of 4 natural estrogens (including estrone, 17α-estradiol, 17β-estradiol, estriol) and 2 synthetic estrogens (17α-ethinylestradiol, diethylstilbestrol) with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the detection frequency (DF) of 6 estrogens ranged from 8.33% to 98.89%. The DF of detected natural estrogens was higher than 90%, except for estriol (8.33%); while the DF of synthetic estrogens were 52.22% and 64.44% for 17α-estradiol and diethylstilbestrol, respectively. The total content of 6 estrogens was in the range of 1.15~658.91μg/kg (dry weight, dw). The total estrogenic activity was equivalent to the content of 3.76~478.50μg/kg (dw). A significant difference in the total content (median) of 6 estrogens among different growth stages was observed in the order of: lactating cows (79.21μg/kg)>calves (47.20μg/kg)>heifers (25.72μg/kg). The content of estrogens in fecal samples demonstrate large seasonal variations: relatively higher in winter and spring than in summer and autumn andthe lowest concentration of 6 estrogens was observed in autumn. The total concentration of 6 estrogens in the feces collected from fecal stock dump ranged from 7.63 to 3921.92μg/kg which were significantly higher than that in fresh feces from gestation crate. Clearly, cow growth stage, sampling time (season) and sampling sites influenced the content of estrogens in cow feces, which should be fully considered in the investigation and risk assessment of estrogen emissions for cow breeding.