The objective of this experiment was to explore the nutritional components of industrial hemp byproducts (industrial hemp ethanol extraction byproduct, IHEEB; industrial hemp stalk, IHS; industrial hemp seed meal, IHSM; industrial hemp oil filter residue, IHOFR) and provide theoretical support for the application of industrial hemp byproducts in dairy cattle production. This experiment used a combination of a wet chemical method with Cornell Net Carbohydrate and Protein System, in situ nylon bag technique, and three-step in vitro method to compare the chemical composition, carbohydrate and protein composition, in situ ruminal degradability and intestinal digestibility of industrial hemp byproducts and conventional feeds (alfalfa hay, AH; soybean meal, SBM). Available energy values were estimated based on the National Academies of Sciences, Engineering, and Medicine. The results showed that the nutritional composition of different feeds varied greatly. The two types of IHEEB were enriched with ash, crude protein (CP), neutral detergent fiber (NDF), and calcium, while the contents of neutral detergent insoluble crude protein, acid detergent insoluble crude protein, and acid detergent lignin were higher. As a result, the non-degradable carbohydrate and protein components were higher, and the effective degradation rate of rumen dry matter and protein was lower. IHS contains higher non-protein nitrogen and NDF, which enables it to provide more CP rumen effective degradation rate and carbohydrates, but the high acid detergent fiber also limits its application. IHSM possesses 296 g/kg CP and high rumen undegradable protein and intestinal digested protein, which can provide rumen bypass protein in dairy cows, making it a potentially good protein source. IHOFR had higher ether extract, rumen available protein degradation rate, and total tract digested protein, which can provide more energy and easily degradable protein for lactating cows. The available energy value of IHEEB and IHS was lower than AH, while SBM is between IHFOR and IHSM. In addition, the tetrahydrocannabinol of three industrial hemp byproducts that have not been assessed by the European Food Safety Authority (EFSA) was tested to evaluate their safety, and all of them were less than the limit set by ESFA. In conclusion, industrial hemp byproducts can be considered for inclusion in dietary formulations as unconventional feed sources for dairy cattle, but the purpose of use needs to be properly considered.

Background/Objectives: Branched-chain fatty acids (BCFAs) exhibit a range of biological activities; however, their limited natural abundance and high cost have constrained in vivo research. Lanolin represents a promising source for enriching BCFAs. Nevertheless, the in vivo application, safety, and dose-effect relationship of BCFAs derived from lanolin (BCFAs-DFL) remain unassessed. Methods: In this study, the acute toxicity in C57BL/6J mice was first evaluated for 7 days by a single oral administration of 5000 mg/kg BW of BCFAs-DFL. Subsequently, 40 mice were divided into four groups (control group, low dose of 100 mg/kg BW, medium dose of 300 mg/kg BW, and high dose of 600 mg/kg BW) and were continuously administered by gavage for 28 days to study the effects of BCFAs-DFL on the growth, blood biochemistry, intestinal morphology, and intestinal flora of the mice. Results: In the acute toxicity test, BCFAs-DFL exhibited no lethality or abnormalities in mice, indicating its non-toxic nature. Throughout the 28-day trial, mice in the medium- and high-dose groups experienced a notable decrease in average daily feed intake (p < 0.05), yet their weight gain remained unaffected (p > 0.05). Hemoglobin and hematocrit levels declined in the high-dose group (p < 0.05). Conversely, serum aspartate aminotransferase and total bilirubin levels escalated in the medium- and high-dose groups, while triglycerides and urea nitrogen levels decreased (p < 0.05). The serum’s total antioxidant capacity and immunoglobulin levels (IgA, IgG) rose in proportion to the dosage (p < 0.05). BCFAs-DFL notably enhanced the villus height of the jejunum and ileum in mice (p < 0.05). Gut microbiota analysis indicated no significant impact on overall α and β diversity. Conclusions: The 28-day intervention revealed that BCFAs-DFL can modulate feeding behavior, TG, T-AOC, and immunoglobulin levels in mice. Additionally, it promotes the development of intestinal villi. Based on various indicators, a dosage of 100 mg/kg BW effectively induces beneficial metabolic regulation, such as the reduction of triglycerides, without causing a burden on liver metabolism. This dosage may represent a more suitable application for potential use.