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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Food Animal Metabolism Research » Research » Publications at this Location » Publication #384478

Research Project: Detection and Fate of Environmental Chemical and Biological Residues and their Impact on the Food Supply

Location: Food Animal Metabolism Research

Title: Plasma cannabinoid concentrations determined from heifers fed hempseed cake in finishing diets by rapid screening with mass spectrometry

item Serum, Eric
item CHAKRABARTY, SHUBHAHIS - North Dakota State University
item WINDERS, THOMAS - North Dakota State University
item Neville, Bryan
item SWANSON, KENDALL - North Dakota State University
item Smith, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/20/2021
Publication Date: 8/4/2021
Citation: Serum, E.M., Chakrabarty, S., Winders, T.M., Neville, B.W., Swanson, K.C., Smith, D.J. 2021. Plasma cannabinoid concentrations determined from heifers fed hempseed cake in finishing diets by rapid screening with mass spectrometry. Meeting Abstract.

Interpretive Summary:

Technical Abstract: Hempseed cake, a byproduct of hempseed oil production, could contribute protein and fiber to the dietary requirements of ruminants. However, there are no data documenting the appearance or clearance of phytocannabinoids in animals fed hemp processing products. To investigate the impact of feeding hempseed cake on production endpoints and cannabinoid residues in cattle, 32 cross-bred heifers were fed rations containing either hemp-seed cake or distiller’s grains (control) for approximately 112 days. Plasma and urine were collected throughout the feeding period and tissues were collected after withdrawal periods of 0, 1, 4, and 8 days. Plasma samples (d 2, 7, 14, 42 and 98) from a cohort of six control and six treated animals were evaluated for phytocannabinoid content by rapid screen electrospray ionization mass spectrometry. Cannabinoids measured included: tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) cannabichromenic acid (CBCA), cannabigerolic acid (CBGA), cannabidivarinic acid (CBDVA), cannabinolic acid (CBNA), tetrahydrocannabinol (THC), cannabidiol (CBD), cannabidivarin (CBDV) and cannabinol (CBN). CBD and THC as well as CBDA and THCA were quantified together due to their identical molecular ion peaks and fragmentation patterns. Following facile workup, extracts (5 µL) were injected onto a Sciex 5600+ time-of-flight mass spectrometer for rapid analysis. The methodology was extended to analysis of the hempseed cake fed during the cattle study to estimate dietary exposures. Concentrations of phytocannabinoids in the hempseed cake ranged from 0.01–9.15 mg/kg in ascending order: CBN, CBNA, CBDV, CBGA, CBDVA, CBCA, CBD/THC, and CBDA/THCA. Plasma concentrations ranged from 0.1–10 ng/mL listed in no particular order: CBNA, CBDA/THCA, CBGA, CBCA, CBDVA. CBD/THC, CBN, and CBV were not detected (LODs 0.4–2.9 ng/mL for CBN, CBDV, CBD/THC). The character and relative distribution of phytocannabinoids in plasma were consistent with the cannabinoids measured in hempseed cake and with a study in which industrial hemp flower was fed to young steers. The rapid screening approach was able to completely delineate which cattle had been exposed to the hempseed cake diet without false positives. Cattle fed hempseed cake met comparable production endpoints as controls but did contain carboxylic acid type phytocannabinoids in plasma without apparent bioaccumulation.