Empa, Laboratory for Advanced Analytical Technologies, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland; Ruminant Research Group, Agroscope, CH-1725, Posieux, Switzerland.
Empa, Laboratory for Advanced Analytical Technologies, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland.
Chemosphere. 2022 Nov;307(Pt 2):135745. doi: 10.1016/j.chemosphere.2022.135745. Epub 2022 Jul 18.
Grass-based suckling beef-derived foods occasionally exceed regulatory levels for polychlorinated biphenyls (PCBs) and dibenzo-p-dioxins/dibenzofurans (PCDD/Fs). Ensuring chemical safety requires understanding the cow-calf transgenerational PCB and PCDD/F fate. The current focus was on dairy cows, omitting transgenerational fate and suckling beef-related physiological effects. This study aimed to investigate PCB and PCDD/F absorption, distribution, metabolism, and excretion within 12 Simmental cows (six primiparous/six multiparous) and 12 calves fed with the milk of their respective mothers for 109 days prepartum until 288 days in milk (DIM), i.e., slaughter time. Eight cows were exposed to a grass silage-soil mixture. Four were decontaminated after DIM164 by receiving uncontaminated grass silage, which four control cows received. An input-output balance during gestation and lactation was computed from PCB, PCDD/F, and lipid inputs (solid feed/milk intakes), outputs (fecal/milk excretions), and body storage (initial/final burdens). At slaughter, PCB and PCDD/F tissue distribution, and lipid allometry were linked. Apparent PCB and PCDD/F absorption rates and metabolized fractions decreased with increasing chlorination. In calves, PCB absorption showed no effect due to chlorination (steady range: 71-87%). High-chlorinated PCB and PCDD/F absorption rates decreased when provided through soil. Cows excreted PCBs and PCDD/Fs via feces (50% relative to input) and milk (9%) and accumulated only 5% in their body, whereas calves accumulated the largest fraction of the total input in their bodies (44%). Cow physiology affected accumulation and excretion, as in primiparous cows, net body burden and milk assimilation efficiencies were higher and lower, respectively, than in multiparous. Liver-specific enrichment was observed in cows and calves (7.0- and 3.2-fold iPCB and dlPCB + PCDD/F TEQ, compared to empty body-based lipid concentrations), whereas iPCBs were also enriched in kidneys (3.1-fold) and muscles (1.5-fold). Consequently, adipose concentrations did not perfectly represent most edible beef tissues. This highlights the essence of integrating the interplay between physicochemical pollutant properties and animal physiology in transgenerational transfer assessments of PCBs and PCDD/Fs.
以草为基础的哺乳期牛肉衍生食品偶尔会超过多氯联苯 (PCBs) 和二恶英/呋喃 (PCDD/Fs) 的监管水平。确保化学安全性需要了解牛-小牛跨代 PCB 和 PCDD/F 的命运。目前的重点是奶牛，忽略了跨代命运和哺乳期牛肉相关的生理效应。本研究旨在调查产前 109 天至哺乳期 288 天（即屠宰时间）期间，12 头西门塔尔奶牛（6 头初产/6 头经产）及其 12 头小牛对 PCB 和 PCDD/F 的吸收、分布、代谢和排泄，12 头小牛均食用其各自母亲的牛奶。8 头奶牛暴露于草青贮-土壤混合物中。其中 4 头在 DIM164 后通过接受未受污染的草青贮进行脱污染，而 4 头对照奶牛接受了未受污染的草青贮。从 PCB、PCDD/F 和脂质投入（固体饲料/牛奶摄入量）、产出（粪便/牛奶排泄量）和体储（初始/最终负担）计算了妊娠期和哺乳期的输入-输出平衡。在屠宰时，将 PCB 和 PCDD/F 组织分布与脂质体进行了关联。随着氯化程度的增加，PCB 和 PCDD/F 的表观吸收速率和代谢分数降低。在小牛中，由于氯化作用，PCB 吸收没有影响（稳定范围：71-87%）。当通过土壤提供高氯化 PCB 和 PCDD/F 时，吸收速率降低。奶牛通过粪便（相对于输入的 50%）和牛奶（9%）排泄 PCBs 和 PCDD/F，并仅在体内积累 5%，而小牛则在体内积累了总输入的最大部分（44%）。牛的生理学影响了积累和排泄，因为在初产奶牛中，净体负荷和牛奶同化效率分别高于经产奶牛。在奶牛和小牛中观察到肝脏特异性富集（与空白体脂浓度相比，iPCB 和 dlPCB+PCDD/F TEQ 分别为 7.0 倍和 3.2 倍），而 iPCBs 也在肾脏（3.1 倍）和肌肉（1.5 倍）中富集。因此，脂肪浓度并不能完全代表大多数可食用的牛肉组织。这凸显了在 PCB 和 PCDD/F 的跨代转移评估中整合物理化学污染物特性和动物生理学相互作用的重要性。
