Intake, nutrient digestibility, rumen parameters, growth rate, carcase characteristics and cannabinoid residues of sheep fed pelleted rations containing hemp (Cannabis sativa L.) stubble

Cannabinoid residuals in tissues of lambs fed spent hemp biomass and consumer's exposure assessment

Spent hemp biomass (SHB) contains trace amounts of cannabinoids, including Δ9-tetrahydrocannabinol (Δ9-THC), that may accumulate in the tissues of animals consuming SHB. We measured cannabinoid residues in the liver, adipose tissue, and muscle of finishing lambs fed either 10% or 20% SHB for 8 weeks, or 4 weeks followed by 4 weeks SHB withdrawal. We detected multiple cannabinoids in the liver at a similar proportion to the SHB. However, CBD and Δ9-THC were enriched >20-fold in the adipose and muscle, compared to their proportion in SHB. The highest concentration of Δ9-THC was detected in adipose tissue and was 7.4-times higher than in muscle. Most cannabinoids were undetectable in tissues after 4 weeks of clearance. The consumers' exposure assessment on Δ9-THC revealed tissue levels of total THC (THCA+Δ9-THC) that exceed the acute reference dose of 1 μg/kg BW across population groups. When consuming meat from the lambs fed 10% and 20% SHB, the maximum total THC exposure was 2.03 and 7.32 μg/kg BW, respectively, equal to or below the Lowest Observed Adverse Effect Level of 36 μg/kg BW, the No Observed Adverse Effect Level of 12 μg/kg BW or a tolerable dose intake of 7 μg/kg BW.

Partially substituting alfalfa hay with hemp forage in the diet of goats improved feed efficiency, ruminal fermentation pattern and microbial profiles

The use of hemp as a forage source in livestock diets has been less studied because bioactive residues in animal tissues may pose a risk to consumers. This study investigated the effects of partial substitution of alfalfa hay (AH) with hemp forage (HF) in growing goat diets on growth performance, carcass traits, ruminal fermentation characteristics, rumen microbial communities, blood biochemistry, and antioxidant indices. Forty Xiangdong black goats with body weight (BW) 7.82 ± 0.57 kg (mean ± SD) were grouped by BW and randomly assigned into one of the four treatment diets (n = 10/treatment) in a completely randomized design. The goats were fed ad libitum total mixed rations containing 60% forage and 40% concentrate (DM basis). The diets included control (CON; 60% AH and 40% concentrate), 55% AH and 5% HF (HF5), 50% AH and 10% HF (HF10), and 40% AH and 20% HF (HF20). Increasing the substitution of HF for AH linearly decreased (P < 0.01) DM intake and improved feed conversion efficiency. However, final BW, average daily gain, carcass traits, meat quality, and most blood biochemistry indices did not differ among treatments. The ruminal NH3-N concentration and blood urine nitrogen linearly increased (P < 0.01) with increasing substitution rate of HF, whereas the total volatile fatty acids concentration quadratically changed (P < 0.01). Substitution of AH with HF had no effect on the diversity and richness of ruminal microbes, though it linearly decreased (P = 0.040) Prevotella_1 and linearly increased (P = 0.017) Rikenellaceae_RC9_gut_group. The cannabinoids and/or their metabolites were detected in both ruminal filtrates (8) and plasma (4), however, no detectable cannabinoid-related residues were observed in meat. These results indicate that the HF could be used to partially substitute AH in goat diets, whereas the effects vary between substitution rates of HF for AH. Although no cannabinoid-related residues were detected in meat, the presence of cannabinoids residues in blood warrants further study of HF feeding to confirm the cannabinoids residues are not present in the animal products.

Comparative Study of Gas and Liquid Chromatography Methods for the Determination of Underivatised Neutral and Acidic Cannabinoids and Cholesterol

The aim of our study was to develop a gas chromatographic method coupled with mass spectrometry (GC-MS) for the determination of underivatised neutral (CBDs-N) and acidic (CBDs-A) cannabinoids (CBDs) and cholesterol (Chol). Emphasis was also placed on comparing our original GC-MS method with the currently developed C18-high-performance liquid chromatography with photodiode detection (C18-HPLC-DAD). A combination of a long GC column, shallow temperature column programme, and mass-spectrometry was employed to avoid issues arising from the overlap between CBDs and Chol and background fluctuations. The pre-column procedure for CBDs and Chol in egg yolks consisted of hexane extractions, whereas the pre-column procedure for CBDs in non-animal samples involved methanol and hexane extractions. CBDs-A underwent decarboxylation to CBDs during GC-MS analyses, and pre-column extraction of the processed sample with NaOH solution allowed for CBD-A removal. No losses of CBDs-N were observed in the samples extracted with NaOH solution. GC-MS analyses of the samples before and after extraction with NaOH solution enabled the quantification of CBDs-A and CBDs-N. CBDs-A did not undergo decarboxylation to CBDs-N during C18-HPLC-DAD runs. The use of the C18-HPLC-DAD method allowed simultaneous determination of CBDs-N and CBDs-A. In comparison to the C18-HPLC-DAD method, our GC-MS technique offered improved sensitivity, precision, specificity, and satisfactory separation of underivatised CBDs and Chol from biological materials of endogenous species, especially in hemp and hen egg yolk. The scientific novelty of the present study is the application of the GC-MS method for quantifying underivatised CBDs-A, CBDs-N, and Chol in the samples of interest.

Fast and sensitive LC-MS/MS method for quantification of cannabinoids and their metabolites in plasma of cattle fed hemp

Hemp-based materials have gained interest as alternative feed ingredients for livestock. However, safety concerns arise regarding the transfer of cannabinoids from the plant to the animals. Addressing these concerns requires the use of methods capable of detecting and quantifying cannabinoids in livestock. In this study, a fast and sensitive method was developed for quantification of cannabinoids and cannabinoid metabolites in cattle plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The extraction of cannabinoids from the plasma matrix was achieved by combining the Captiva Enhanced Matrix Removal-Lipid clean-up and salting-out assisted liquid-liquid extraction procedure. The developed method underwent validation using various analytical parameters, and the results demonstrated good accuracy, precision, specificity, and high sensitivity. The method was applied to real plasma samples obtained from cattle fed hemp for 2 weeks, and successfully detected various cannabinoids, including delta-9-tetrahydrocannabinol. Furthermore, the study revealed that 7-carboxy cannabidiol, a metabolite of cannabidiol, was the predominant cannabinoid present in the cattle plasma throughout the feeding period, which could remain detectable for weeks after the hemp feeding had ended.

Quality and safety of hemp meal as a protein supplement for nonlactating dairy cows

Hemp seed meal may be a suitable protein supplement for dairy cows, but its quality and safety as a dairy cow feed has not yet been fully investigated. As a result, dry matter intake (DMI), rumen fermentation, blood metabolites, total-tract digestibility, and concentrations of cannabinoids in blood plasma, urine, muscle, and adipose tissues were compared among nonlactating Holstein dairy cows receiving a basal partial mixed ration that was supplemented with either 10.2% dry matter (DM) hemp meal (HM treatment), 13.5% DM canola meal (CM treatment), or 6.25% DM hemp meal and 6.16% DM canola meal (HC treatment). Diets were formulated to be isoenergetic and isonitrogenous. Six nonlactating, nonpregnant Holstein cows were used in a repeated 3 × 3 Latin square design trial with three 3-wk experimental periods. The first 2 weeks of each served as adaptation. Sample and data collection occurred during the third week of each period. Neither the partial mixed ration nor canola meal contain cannabidiol (CBD), cannabidiolic acid (CBDA), d9-tetrahydrocannabinol (THC), or tetrahydrocannabinolic acid A (THCA). However, the hemp meal contained 3.0, 4.4, 0, and 0.1 μg/g DM of CBD, CBDA, THC, and THCA, respectively. Treatment did not affect DMI, pH, concentrations of volatile fatty acids or ammonia in the rumen, total-tract digestibilities of DM and crude protein, or blood plasma concentrations of glucose, urea, β-hydroxybutyrate, and nonesterified fatty acids. Hence, based on these metabolites, treatment did not affect the nutritional status of the cows. However, the total-tract neutral detergent fiber digestibility of the CM treatment (43%) was higher than that of the HM treatment (38%). No cannabinoids were detected in blood plasma, rumen fluid, and urine. Cannabinoids were also not detected in kidney, liver, urine, muscle, or adipose tissues at the end of the experiment when cows had undergone all treatments. Feces from all treatments did not contain detectable concentrations of THC or THCA, but feces of cows on the HC treatment contained 0.42 and 0.40 μg/g DM of CBD and CBDA, respectively. Feces of cows on the HM treatment contained 0.68 and 0.67 μg/g DM of CBD and CBDA, respectively. This indicated that most ingested CBD and CBDA were not absorbed but instead were excreted in the feces. Our data show dietary inclusion rates of up to 10.2% of DM. We find that hemp meal is a high-quality and safe protein supplement for nonlactating dairy cows.

Bioavailability of bioactive phytochemicals in selected tissues and excreta from goats fed hempseed cake (Cannabis sativa L.) finisher diets

Hempseeds are rich in bioactive phytochemicals, yet little is known about their bioavailability in tissues and excreta of animals fed hemp seed cake. The study evaluated the bioactive phytochemicals and their antioxidant activity in the blood, liver, meat, feces, and urine from goats fed finishing diets containing graded inclusions of hempseed cake (HSC). Twenty-five wether goats (26.8 ± 2.9 kg) of 4-5 months were randomly allocated to five experimental diets containing increasing levels of HSC (0, 25, 50, 75, 100 g/kg DM) substituted for soybean meal (SBM) as the main protein source. Goats were allowed for period of 21 days for adaptation, and blood, fecal, and urine samples were collected on the 28th day of the experiment. The liver and right longissimus thoracis et lumborum were respectively collected at 60 min and 24 h after slaughter. Linear increases (P ≤ 0.05) in blood, liver, and urine magnesium; fecal manganese; and fecal copper were observed with increasing HSC inclusion in the diet. Liver and fecal selenium exhibited a decreasing linear trend (P ≤ 0.05) with HSC increment in diets. Diet did not affect (P > 0.05) meat and urine mineral contents, except urine magnesium. The 2,2-diphenyl-1-picrylhydrazyl, and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) of the blood, liver, and meat linearly increased (P ≤ 0.05) with dietary inclusion of HSC. Blood and liver ferric reducing antioxidant power quadratically increased (P ≤ 0.05) with HSC inclusion reaching a maximum at 50 g/kg dry matter. Current results suggest that inclusion of HSC up to 100 g/kg substituting SBM in goat diets can improve bioavailability of bioactive phytochemicals in the blood, liver, and meat.

UHPLC-ESI-QqTOF Analysis and In Vitro Rumen Fermentation for Exploiting Fagus sylvatica Leaf in Ruminant Diet

In recent years, animal husbandry has aimed at improving the conditions of livestock animals useful for humans to solve environmental and health problems. The formulation of animal feeds or supplements based on antioxidant plant compounds is considered a valuable approach and an alternative for livestock productivity. Forest biomass materials are an underestimated source of polyphenolic compounds whose sustainable recovery could provide direct benefits to animals and, indirectly, human nutrition. In this context, an alcohol extract from leaves of Fagus sylvatica L. was first investigated through an untargeted ultra-high-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) approach. Then, it was fractionated into a fatty acid-rich and a polyphenolic fraction, as evidenced by total lipid, phenol, and flavonoid content assays, with antiradical and reducing activity positively correlated to the latter. When tested in vitro with rumen liquor to evaluate changes in the fermentative parameters, a significant detrimental effect was exerted by the lipid-rich fraction, whereas the flavonoid-rich one positively modulated the production of volatile fatty acids (i.e., acetate, butyrate, propionate, etc.).