The objective of this study was to investigate the effects of feeding a high-concentrate corn straw diet on the release of endotoxin in the rumen and the changes of pro-inflammatory cytokines in the mammary gland of dairy cows in comparison with a low-concentrate corn straw diet and a low-concentrate mixed forage diet. Thirty second-parity Chinese Holstein cows in mid-lactation with a body condition score of 2.86 ± 0.29, weighing 543 ± 57 kg and producing 24.32 ± 3.86 kg milk per day were randomly assigned to 1 of the 3 diets (n = 10 per treatment): 1) low-concentrate mixed forage diet (LCF) with a concentrate to roughage ratio of 46 : 54; 2) high-concentrate corn straw diet (HCS) with a concentrate to roughage ratio of 65 : 35; 3) low-concentrate corn straw diet (LCS) with the same concentrate to roughage ratio (46 : 54) as LCF. The experiment lasted 6 weeks, and samples were collected in the last week. Milk samples were analyzed for conventional components, rumen fluid samples were analyzed for pH and endotoxin, and mammary arterial and venous plasma samples were analyzed for concentrations of interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). Concentrations of endotoxin in rumen fluid and feces of cows fed HCS were significantly higher than those of cows fed LCS and LCF. Feeding HCS increased the release of IL-1β, IL-6 and IL-8 in the mammary gland compared with feeding LCS. Concentrations of cytokines (IL-1β and IL-8) in mammary venous plasma had a negative correlation with milk production efficiencies. Results indicated that the high-concentrate corn straw diet increased the concentrations of endotoxin in rumen fluid and feces. Furthermore, feeding the high-concentrate corn straw diet stimulated the mammary gland to release more pro-inflammatory cytokines. The results suggest that feeding a high-concentrate corn straw diet induce a higher pro-inflammatory response in the mammary gland and thus may partly decrease the milk production efficiencies in dairy cows.

The aim of this study was to evaluate the effects of Allium mongolicum Regel ethanol extract (AME) on the serum index and meat quality of lambs. A total of 30 male Small-tailed Han sheep (3 months old) with an average weight of 33.60 ± 1.23 kg were divided randomly into one of two groups: the control group (CON) was offered a basal diet, and the AME group was offered a basal diet with supplementation 2.8 g·lamb⁻¹·day⁻¹ AME. The trial lasted for 75 days. AME supplementation significantly decreased the concentration of triglyceride and total cholesterol (p < 0.05), and tended to lower the concentration of non-esterified fatty acids (0.05 < p < 0.1), but significantly increased the concentration of high-density lipoprotein, leptin, and insulin (p < 0.05) in the serum of lambs. AME also decreased cooking losses and shear force and increased the content of intramuscular fat in the longissimus dorsi (LD) muscle of lambs (p < 0.05). In addition, there was no difference in the composition of hydrolyzed protein amino acids in the LD muscle among treatments (p > 0.05). However, AME changed the composition of free amino acids and promoted MUFA and PUFA deposition in the LD muscle of the lambs. These findings indicate that a diet supplemented with AME may improve the lipid metabolic capacity and meat quality of lambs.

The objective of this study was to investigate the effects of Allium mongolicum Regel (AM) and AM extracts on the growth performance, carcass parameters and meat quality of sheep. Forty sheep were randomly divided into four groups. The groups consisted of CON (basal diet), AM water extract (AWE; basal diet + 3.4 g/sheep/day AWE), AM ethanol extract (AEE; basal diet + 2.8 g/sheep/day AEE) and AM (basal diet + 10 g/sheep/day AM). The average daily gain (ADG) was improved (p < .05) and feed conversion ratio (FCR) was decreased (p < .05) in AWE, AEE and AM compared to CON. The loin eye area (LEA) and intramuscular fat (IMF) percentage were improved (p < .05) and cooking loss (CL) was decreased (p < .05) in AM, AWE and AEE compared to CON. The water holding capacity (WHC) was improved (p < .05) in AM and AWE compared to CON. The Warner–Bratzler shear force (WBSF) was decreased (p < .05) in AWE and AEE compared to CON. The levels of Σ polyunsaturated fatty acid (ΣPUFA) was increased (p < .05) and Σ saturated fatty acids (ΣSFA) was decreased (p < .05) in AM, AWE and AEE compared to CON. The levels of C18:1t-9, C18:1t-10 and C18:1t-11 were increased (p < .05) in AM and AEE compared to CON. The levels of C16:0 and n6/n3 ratio were decreased (p < .05) and levels of Δ⁹-desaturase C16 and elongase enzymatic activity were improved (p < .05) in AWE and AEE compared to CON. In conclusion, supplementation with AM and AM extracts could increase the growth performance, carcass quality traits and some healthier fatty acids.

Feeding Allium mongolicum Regel (AMR) could improve lamb growth, immunity, and antioxidant capacity. These effects were supposed to be mediated by the rumen microbiota, as reported in our previous studies, but further verification is required. The purpose of this study was to verify whether changes in serum immunity, antioxidant, and biochemical indicators of meat sheep mediated by AMR are achieved via rumen microbiota regulation. The experiment included two phases. In phase I, twelve 90-day-old male lambs (25 ± 1 kg) were used as rumen fluid donors and consumed a basal diet with 15 g/day AMR for 135 days to induce changes in their rumen microbiota. In phase II, thirty 90-day-old male lambs (23 ± 2 kg) were split into three groups (n = 10 each): the control group (CON) fed the basal diet; the AMR-supplemented group (AMG) fed the basal diet supplemented with 15 g/day of AMR; and the rumen fluid recipient group (RTG) fed the basal diet and received rumen fluid transplantation. The CON and AMG groups received four oral infusions of 250 mL saline, while the RTG group received four oral infusions of 250 mL donor rumen fluid. Phase II lasted for 75 days, and the blood samples were collected on the last day. Rumen fluid transplantation was performed every 15 days, with a total of four infusions of 250 mL each. The results showed that the final body weight and average daily gain (ADG) of the AMG and RTG groups were higher than those of the CON group (p < 0.05), while there were no significant differences between the AMG and RTG groups (p > 0.05). On day 30, the levels of interleukin-10 (IL-10), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) in the AMG and RTG groups were increased (p < 0.05), and malondialdehyde (MDA) was significantly decreased (p < 0.05), with no significant differences between the AMG and RTG groups. On day 60, total antioxidant capacity (T-AOC), IgM, IgG, and catalase (CAT) were increased in the AMG and RTG groups, while tumor necrosis factor alpha (TNF-α), low-density lipoprotein cholesterol (LDL-C), and blood urea nitrogen (BUN) were decreased (p < 0.05), and there were no significant differences between the AMG and RTG groups (p > 0.05). High-density lipoprotein cholesterol (HDL-C) in the RTG group was significantly lower than in the CON and AMG groups, while the AMG group had significantly higher HDL-C than the CON group (p < 0.05). Microbial analysis indicated that Mitsuokella, VUNI01, and Caecibacter were positively correlated with IgM; Mitsuokella, CAG 791, Desulfovibrio R, Porcincola, VUNI01, and UBA 7741 were negatively correlated with TNF-α; CAG 791 was positively correlated with T-AOC; VUNI01 was positively correlated with CAT; MDA was negatively correlated with Mitsuokella; Allisonella and UBA 7741 were negatively correlated with HDL-C; and Porcincola, VUNI01, Allisonella, and UBA 7741 were negatively correlated with LDL-C. Therefore, the study indicates that both supplementation with AMR and transplantation of rumen fluid from sheep fed with AMR can enhance the immunity and antioxidant capacity of lambs by increasing the abundance of the aforementioned bacteria. It also verified that the improvement in immunity and antioxidant capacity mediated by Allium mongolicum Regel is driven by the rumen microbiota.

The extent of consumer approval for lamb is intimately connected to meat quality standards. Within this context, the distinctive ‘mutton taint’ serves as a critical benchmark for assessment, a characteristic that is largely governed by the concentrations of three fundamental branched-chain fatty acids (KBCFA), specifically 4-methyloctanoic acid (MOA), 4-ethyloctanoic acid (EOA), and 4-methylnonanoic acid (MNA). While Allium mongolicum Regel (AMR)—an Allium species prevalent in arid Asian regions known for its abundant bioactive constituents—is known to improve meat quality and mitigate these off-flavors, the potential mediating role of the rumen fluid in this process remains unclear. This study investigated whether rumen fluid transplantation (RFT) from AMR-fed donors could mimic the impacts of directly adding AMR to the diet on KBCFA accumulation and meat attributes. Thirty male lambs (23 ± 2 kg BW) were allocated at random into three distinct treatments (n = 10): a control set (CON), a dietary supplementation group administered 15 g/d of AMR (AMG), along with a rumen fluid transplantation treatment (RTG) inoculated with rumen fluid from AMR-fed donors. The carcass traits, physicochemical properties, and makeup of amino acids, as well as the fatty acid constitution of the longissimus thoracis muscle, were subjected to analysis. Data revealed that the levels of KBCFAs associated with off-flavors were markedly lowered in both the AMG and RTG. Specifically, decreases ranging from 49% to 64% were observed in MOA, EOA, and MNA concentrations (p < 0.05). Relative to the control group, drip loss and cooking loss were reduced in the treatment groups (p < 0.05), whereas ash (p = 0.047) and crude protein (p = 0.001) were increased. Moreover, the interventions improved the composition of essential amino acids (EAA), flavor-enhancing amino acids, and polyunsaturated fatty acids (PUFAs). In conclusion, rumen fluid transplantation effectively replicates the beneficial effects of dietary AMR on meat quality, particularly in reducing taint-related KBCFA. Such outcomes imply that rumen microbial communities likely act as a crucial mediator in controlling meat flavor.

Deposition of three key 4-alkyl branched-chain fatty acids (KBCFA), including 4-methyloctanoic acid (MOA), 4-ethyloctanoic acid (EOA), and 4-methylnonanoic acid (MNA), causes the gamey flavor in sheep meat. This study integrated metagenomics and metabolomics to evaluate how Allium mongolicum Regel (AMR) supplementation (15 g/d) and rumen fluid transplantation (RFT) modulate rumen microbiota and hepatic metabolism to reduce KBCFA in lamb longissimus thoracis muscle. The experiment consisted of two phases. In Phase I, twelve 3-month-old male Dorper × Small Tailed Han sheep (25 ± 1 kg) were selected as the rumen donor group. These sheep were supplemented with 15 g/d/head of AMR powder in their basal diet until the end of the experiment. In Phase II, thirty 3-month-old male Dorper × Small Tailed Han sheep (23 ± 2 kg) were randomly assigned to one of three groups (n = 10 per group): the control group (STG), which was fed the basal diet and received a physiological saline transplant; the AMR group, which was fed the basal diet supplemented with 15 g/d/head of AMR powder and received a physiological saline transplant; and the rumen fluid transplant group (RTG), which was fed the basal diet and received a rumen fluid transplant from the donor group. Compared to the STG, results showed that the MOA, EOA, and MNA in the AMG decreased by 64.51%, 54.72%, and 49.34%, respectively. Similarly, the MOA, EOA, and MNA in the RTG were reduced by 63.13%, 56.17%, and 49.60%, respectively (p < 0.001). For the rumen metagenome, AMR enriched the genus Prevotella, while RFT increased Butyrivibrio. Hepatic metabolomics revealed a distinct shift where AMR elevated amino acid derivatives and RFT enhanced carnitine-related metabolites. These alterations indicate a potential metabolic shift associated with amino acid metabolism and mitochondrial β-oxidation, rather than lipid elongation. We postulate that this coordinated regulation across the rumen–liver–muscle axis may alter the availability of lipogenic precursors for KBCFA synthesis, ultimately contributing to improved meat flavor.