Search Results (120)

Clays are increasingly incorporated as feed additives for ruminants, partly inspired by animals’ natural geophagic behaviour. However, their effects on rumen function and productivity remain inconsistent in the literature. This meta-analysis synthesised 39 controlled studies (73 treatment means) to quantitatively evaluate the effects of clay supplementation on fermentation, digestibility, metabolic health, and productivity. Clay supplementation improved rumen fermentation efficiency, as indicated by reductions in methane emissions (−20.45%; p < 0.001) and ammonia-N (−11.51%; p = 0.033), along with an increase in propionate production (+4.35%; p = 0.046). These findings are consistent with proposed mechanisms not directly evaluated in this meta-analysis. Total volatile fatty acid concentration (+3.25%; p = 0.20) and rumen pH (+0.25%; p = 0.75) were not significantly altered by clay supplementation. Digestibility responses were moderately improved, particularly for neutral detergent fibre (+7.32%; p = 0.011) and organic matter (+3.06%; p < 0.001). These improvements may reflect enhanced microbial colonisation and substrate utilisation. Blood urea nitrogen decreased (−5.64%; p = 0.002) with minimal systemic effects, consistent with a primarily rumen-localised mode of action. These responses were associated with increases in weight gain (+7.96%; p = 0.002) and milk fat yield (+9.19%; p = 0.030). Meta-regression identified inclusion level and clay type as significant sources of variability (p < 0.05 for multiple outcomes). The findings indicate that clay supplementation supports methane abatement while improving rumen fermentation, digestibility, health, and productivity in ruminants. Full article

This study evaluated the effects of precision dietary crude protein (CP) reduction through corn dust substitution for soybean meal on lactational performance, milk fatty acid composition, and antioxidant status in mid-lactation dairy cows. Six Holstein Friesian cows were assigned to a replicated 3 × 3 Latin square design with three 28-day periods and fed total mixed rations containing 17.40% (TMR17), 16.29% (TMR16), or 15.18% CP (TMR15). Forage was maintained at 40% of dietary dry matter. Dry matter intake and plasma metabolites were unaffected by dietary treatment (p > 0.05). However, apparent digestibility of dry matter, organic matter, and crude protein declined significantly (p < 0.05), while acid detergent fiber digestibility showed a linear downward tendency (p = 0.06). Actual milk yield, lactose yield, and solids-not-fat (SNF) yield were unaffected by treatments (p > 0.05), but milk protein percentage decreased linearly (p = 0.01) as dietary CP declined. Body weight change also tended to decline (p = 0.09), suggestive of possible increased body reserve mobilization, although this was not confirmed with body condition score or direct metabolic indicators. Milk urea nitrogen decreased linearly (p = 0.05), which suggested improved nitrogen utilization. Plasma superoxide dismutase (SOD) activity, GSH-Px activity, and total antioxidant capacity were not significantly modified (p > 0.05); however, plasma DPPH radical scavenging capacity increased linearly with higher protein levels (p = 0.01; Trt: p = 0.02). Conversely, TMR15 improved milk lipid quality by significantly increasing monounsaturated fatty acids (p = 0.03; Trt: p = 0.05), particularly oleic acid (p = 0.05), whereas total saturated fatty acids remained unchanged (p = 0.55). Overall, reducing dietary CP improved MUFA proportions and nitrogen efficiency but decreased milk protein percentage and plasma DPPH antioxidant protection, highlighting a trade-off between production performance, animal health, and milk quality. Full article

Background/Objectives: This study aimed to compare the effects of two distinct dietary protein sources, soybean meal (SBM, 454 g CP/kg dry matter [DM]) and fermented protein source (FPS, 635 g CP/kg DM), on milk yield (MY), milk quality traits, and serum biochemistry in crossbred dairy cows. Methods: This study employed a randomized complete block design with four groups (n = 6 per group): Control (120 g/kg SBM), FPS30 (30 g/kg FPS and 75 g/kg SBM), FPS40 (40 g/kg FPS and 60 g/kg SBM), and FPS50 (50 g/kg FPS and 45 g/kg SBM). Results: After 66 days (21-day adaptation period and 45-day feeding trial), DM intake, milk protein content, and milk density did not differ significantly across groups. However, MYs were significantly higher in the FPS50 group (p = 0.043). Additionally, milk fat (p = 0.021), DM (p = 0.013), solids-non-fat (SNF, p = 0.047), and lactose content (p = 0.007) were significantly higher in the FPS groups. Although serum biochemistry did not differ across groups on day 0, blood urea nitrogen (BUN, p = 0.044) and serum Ca (p = 0.041), P (p = 0.039), and Mg (p = 0.041) concentrations were significantly lower in the FPS groups on day 66. Moreover, FPS intake correlated positively with MY (R = 0.680), milk DM (R = 0.706), fat (R = 0.665), SNF (R = 0.566), lactose content (R = 0.653), and fat-to-protein ratio (R = 0.507) and negatively with milk density (R = −0.429) and mineral content (R = −0.271). Conclusions: These findings indicate that FPS is effective in increasing productivity and improving/maintaining milk quality traits in cows fed diets substituting specific amounts of SBM with FPS. The induced reduction in BUN can be interpreted as increased protein utilization. Full article

This study evaluated the effects of replacing alfalfa hay with sulla [Sulla coronaria (L.) B.H. Choi & H. Ohashi] hay or sulla haylage in pasture-based diets for lactating Sarda ewes on milk production, milk composition, and nutrient utilization efficiency. Seventy-two mid-lactation ewes were assigned to three dietary treatments for 56 days—alfalfa hay (AH), sulla hay (SH), or sulla haylage (SHL)—all combined with 3 h/day grazing and a fixed amount of supplemental concentrate. The diets were formulated to be theoretically isoenergetic and isoproteic. Pasture nutritive value was generally comparable among the groups throughout the experimental period. Milk yield did not differ among treatments; however, fat- and protein-corrected milk (FPCM) and milk fat and protein concentrations were higher in AH compared with the sulla-based diets. Actual nutrient intake differed among treatments, with nitrogen intake (NI) being greatest in AH, consistent with the higher milk urea concentration observed in this group. Estimated apparent energy utilization efficiency (FPCM/UFL intake) showed treatment-associated differences in exploratory analyses, with lower values observed in SH compared with AH and SHL. Similarly, exploratory estimates of apparent nitrogen utilization efficiency (Milk N/NI) were highest in SHL, intermediate in SH, and lowest in AH (p < 0.001). Condensed tannins were not detected in the conserved sulla forages under the analytical conditions adopted in this study. Therefore, the observed responses were unlikely to be directly associated with detectable condensed tannin activity. Overall, the results suggest that forage conservation method may influence milk composition and estimated apparent nutrient utilization indices, with sulla haylage showing higher exploratory estimates of apparent nitrogen utilization efficiency without negative effects on milk yield under the conditions of the present study. Full article

The use of natural nutritional supplements has become increasingly common in livestock nutrition; nevertheless, because of its additional costs, a careful cost/benefit evaluation is essential to justify their practical application. The present study aimed to evaluate the effects of a blend of essential oils (EOs) included in the diet of dairy buffaloes on milk yield, chemical composition, milk urea nitrogen (MUN), and fatty acid profile. In addition, a detailed economic analysis was conducted to assess the overall profitability of this dietary strategy. A total of 98 buffaloes were enrolled in the trial and divided into two groups: a control group (C) and a treated group (T). The treated animals received 45 g/head/day of an essential oil blend in addition to a total mixed ration. An increase in milk yield was observed in the treated group at two sampling points, whereas no significant differences emerged in milk chemical composition. In contrast, MUN levels were consistently lower in the treated group throughout the trial. The fatty acid profile remained largely unchanged, except for higher levels of trans vaccenic acid (TVA) and eicosapentaenoic acid (EPA) in the treated animals. The economic analysis indicated that EO supplementation was financially advantageous for the farm. Overall, these findings suggest that essential oil blends may represent a promising nutritional strategy to improve production efficiency and milk quality in dairy buffalo. Future studies should investigate long-term effects, optimal dosages, and the mechanisms underlying the observed metabolic responses to support wider practical adoption. Full article

Ketosis is a prevalent metabolic disorder in early-lactation dairy cows, significantly affecting animal health, milk production, and farm profitability. Developing accurate and non-invasive methods for early risk detection is therefore of critical importance. In this study, a hybrid optimization framework integrating an Improved Whale Migration Algorithm (IWMA) with a Light Gradient Boosting Machine (LightGBM) is proposed to predict ketosis risk based on the milk fat-to-protein ratio (F/P) using Dairy Herd Improvement (DHI) records. The proposed IWMA enhances optimization performance through cubic chaotic initialization, elite opposition-based learning, and a Cauchy–Gaussian hybrid mutation strategy, enabling improved global exploration and convergence stability. A dataset comprising 25,155 DHI records collected from multiple commercial dairy farms over seven months was used for model development and evaluation. Experimental results demonstrate that the IWMA–LightGBM model achieves a classification accuracy of 0.8997 and a mean squared error of 0.289, consistently outperforming six benchmark optimization methods. Feature analysis identifies Herd Within Index (WHI), Energy Corrected Milk (ECM), Days in Milk (DIM), Milk Urea Nitrogen, and Foremilk as key predictors associated with metabolic risk. Overall, the proposed approach provides a robust and effective non-invasive solution for early-stage metabolic risk screening at the herd level, offering practical value for precision dairy management. It should be noted that the model is intended for risk assessment rather than clinical diagnosis of ketosis. Full article

This study evaluated the effects of replacing soybean meal with cashew nut roasting residue (CNRR) on feed intake, nutrient digestibility, rumen fermentation, blood metabolites, and economic efficiency in lactating crossbred Saanen goats. Fifteen does were assigned to a completely randomized design with three treatments: 0% CNRR (T1), 10% replacement of soybean meal protein (T2), and 20% replacement (T3). Goats were fed pangola hay ad libitum and concentrate according to milk yield (1:2). Total dry matter, organic matter, crude protein, and fiber intake were not affected by dietary treatments (p > 0.05). However, crude protein digestibility decreased from 68.83% in the control group to 52.72% and 51.21% in the CNRR treatments (p < 0.05). Rumen pH and total volatile fatty acids remained within normal physiological ranges, suggesting stable rumen fermentation. Blood parameters, including packed cell volume, glucose, and blood urea nitrogen, were not influenced by CNRR supplementation (p > 0.05). Economic analysis showed reduced feed cost with increasing CNRR inclusion. In conclusion, CNRR can replace soybean meal protein at rates of up to 20% without affecting feed intake, ruminal pH, or measured blood metabolites; however, crude protein digestibility was reduced, indicating that dietary formulation may require adjustment. Full article

The present study evaluated the effects of sugarcane-derived polyphenol nutritional supplement on milk production, milk composition, and somatic cell count (SCC) in lactating Holstein cows. A second objective was to evaluate the quality and stability of yogurt produced with milk from supplemented cows. Sixteen cows (20 ± 2 L/d milk, 120 ± 21 days in milk, 550 ± 82 kg body weight) were assigned to either a control group or a polyphenol-supplemented group in a randomized block design for a six-week evaluation period. Milk yield and individual milk samples for composition analysis (fat, protein, lactose, non-fat solids, casein, free fatty acids, and milk urea nitrogen) were recorded weekly, and only SCC was monitored three times per week. Yogurt was produced from pooled milk of each treatment and evaluated for fermentation parameters (pH, titratable acidity), shelf life, and sensory attributes were evaluated using a triangle test (discriminative sensory analysis). Polyphenol supplementation did not significantly affect milk yield or composition (p > 0.05), but reduced SCC considerably (238 × 10³ vs. 593 × 10³ cells/mL; p < 0.01). Yogurt fermentation and storage parameters were not significantly affected by supplementation, although pH and titratable acidity changed considerably over time (p < 0.01). Sensory analysis indicated that only 37.3% of panelists correctly identified differences between yogurts, which did not differ from chance expectation in the triangle test. These results demonstrate that polyphenol supplementation can improve udder health, evidenced by reduced SCC, without compromising milk yield, composition, or yogurt quality. Polyphenols thus represent a promising nutritional supplement for enhancing dairy cow health and maintaining product quality. Full article

Pasture-based ruminant systems link nitrogen (N) nutrition with ecosystem N cycling. Grazing ruminants convert fibrous forages into milk and meat but excrete 65 to 80% of ingested N, creating excreta hotspots that drive ammonia volatilization, nitrate leaching, and nitrous oxide (N₂O) emissions. This review synthesizes ecological and ruminant nutrition evidence on N flows, emphasizing microbial processes, biological N₂ fixation, plant diversity, and urine patch biogeochemistry, and evaluates strategies to improve N use efficiency (NUE). We examine rumen N metabolism in relation to microbial protein synthesis, urea recycling, and dietary factors including crude protein concentration, energy supply, forage composition, and plant secondary compounds that modulate protein degradability and microbial N capture, thereby influencing N partitioning among animal products, urine, and feces, as reflected in milk and blood urea N. We also examine how grazing patterns and excreta distribution, assessed with sensor technologies, modify N flows. Evidence indicates that integrated management combining dietary manipulation, forage diversity, targeted grazing, and decision tools can increase farm-gate NUE from 20–25% to over 30% while sustaining performance. Framing these processes within the global N cycle positions pasture-based ruminant systems as critical leverage points for aligning ruminant production with environmental and climate sustainability goals. Full article

Grape pomace (GP), a by-product of winemaking, is rich in polyphenols and fiber, making it a promising and sustainable feed supplement for ruminants. This study evaluated the safety and productive impact of a 5% GP-supplemented diet (GP5) including non-lactating end-cycle (EC) ewes regularly destined for slaughter and human consumption, and lactating (LAC) ewes, over a 30-day period. Control (CTRL) animals received a standard pellet diet with no GP inclusion. Sampling was performed at four time points (T0, T10, T20, and T30), corresponding to days 0, 10, 20, and 30 of the experimental period. The study assessed clinical status, hematology/biochemistry (T0 and T30), milk composition (T0, T10, T20, and T30), meat quality traits and oxidative stability in EC ewes (T30). Since no significant differences were observed in the CTRL animals, the effects were evaluated within the GP5 group by comparing T0 vs. T30. Meat quality was assessed by comparing EC-GP5 to CTRL at T30. The GP extract showed a high total phenolic content (254.02 ± 20.39 mg GAE/g DW). No clinical or hematological alterations were observed, and most values remained within physiological ranges. Biochemical analysis revealed significant increases in albumin, bilirubin, creatinine, and triglycerides (p < 0.05), with significant decreases in plasma urea and glucose (p < 0.05). In LAC-GP5 ewes, milk urea and lactose concentrations decreased (p < 0.05), while pH increased (p < 0.05), with no significant changes in fat or casein content. These findings are consistent with reduced ruminal propionate availability, leading to decreased hepatic gluconeogenesis and lactose synthesis, with secondary effects on nitrogen metabolism and the acid–base profile of milk. In EC-GP5 ewes, meat quality traits were unaffected, and DPPH scavenging activity did not differ from CTRL (p > 0.05). GP5 was metabolically safe, induced adaptive changes in milk composition, and had no negative effects on meat quality, supporting the valorization of grape pomace as a sustainable feed resource. This trial was designed as a metabolic safety assessment, representing a preliminary step toward future mechanistic and molecular investigations. Full article

Enhancing productivity while reducing environmental impact presents a major engineering challenge in sustainable dairy farming. This study proposes an engineering-oriented explainable machine learning and digital twin framework for multi-objective optimisation of milk yield and nitrogen-related emissions. Using the CowNflow dataset, which integrates individual-level nitrogen balance, feeding, and production data collected under controlled experimental conditions, the framework combines data analytics, feature selection, predictive modelling, and SHAP-based explainability to support decision-making in dairy production. The stacking ensemble model achieved the best predictive performance ($R^2$ = 0.85 for milk yield and $R^2$ = 0.794 for milk urea), providing reliable surrogates for downstream optimisation. Predicted milk urea values were further transformed using empirical equations to estimate urinary urea nitrogen (UUN) and ammonia (NH₃) emissions, offering an indirect yet practical approach to assess environmental sustainability. Furthermore, the predictive models are integrated into a digital twin platform that provides a dynamic, real-time simulation environment for scenario testing, continuous optimisation, and data-driven decision support, effectively bridging data analytics with sustainable dairy system management. This research demonstrates how explainable AI, machine learning, and digital twin engineering can jointly drive sustainable dairy production, offering actionable insights for improving productivity while minimising environmental impact. Full article

The incorporation of Camelina sativa and its by-products (oil, meal, seeds, and expellers) into ruminant diets improves feed efficiency and reduces environmental impacts. This systematic review and meta-analysis, conducted in line with PRISMA guidelines, identified 79 studies, of which 8 met strict inclusion criteria, yielding 23 comparisons. Data were analyzed using random-effects models in R with additional meta-regression and sensitivity analyses. Camelina supplementation significantly reduced dry matter intake (DMI; MD = −0.63 kg/day, p = 0.0188) with high heterogeneity (I² = 98.6%), largely attributable to product type and dosage. Although the pooled effect on daily milk yield was non-significant (MD = −1.11 kg/day, p = 0.1922), meta-regression revealed a significant positive dose–response relationship (β = 0.3981, p < 0.0001), indicating higher milk yield at greater Camelina inclusion levels. Camelina oil and its mixtures reduced rumen pH and methane emissions, consistent with polyunsaturated fatty acid (PUFA)-mediated suppression of methanogenesis. Impacts on milk fat and protein are inconsistent, but improvements in unsaturated fatty acid profiles, including omega-3 and conjugated linoleic acid (CLA), have been reported. Camelina also lowered milk urea (MD = −1.71 mmol/L), suggesting improved nitrogen utilization. Despite promising outcomes, substantial variability and limited sample sizes restrict generalizability, underscoring the need for standardized, long-term trials. Full article

Background: The hemoglobin-to-red-cell distribution width ratio has emerged as a novel prognostic marker in various clinical settings. However, its association with total bone mineral density in adolescents remains inadequately explored. Methods: This cross-sectional study was based on data from the 2011–2018 National Health and Nutrition Examination Survey, including adolescents aged 12–19 years with complete data on hemoglobin, red cell distribution width, and total bone mineral density. Weighted multivariable linear regression models and generalized additive models were used to evaluate the association between hemoglobin-to-red-cell distribution width and total bone mineral density. A two-piecewise linear regression model was applied to assess potential threshold effects, with log-likelihood ratio tests used to determine the significance of inflection points. Subgroup and interaction analyses were further conducted to examine whether age, sex, race, and milk product consumption modified this association. Results: A total of 3789 adolescents were included. Participants in the highest hemoglobin-to-red-blood-cell distribution width ratio quartile had significantly higher hemoglobin levels, lower red blood cell distribution width, greater total bone mineral density, higher total calcium and blood urea nitrogen levels, and lower body mass index, high-density lipoprotein cholesterol, and serum 25OHD levels compared to lower quartiles. The hemoglobin-to-red-blood-cell distribution width ratio was positively associated with total bone mineral density (fully adjusted β = 0.078, 95% CI: 0.053, 0.104, p < 0.0001). A two-piecewise linear regression model identified an inflection point at the hemoglobin-to-red-cell distribution width ratio = 1.055; the positive association became stronger above this threshold (β = 0.143 vs. β = 0.039 below the threshold, p = 0.003 for nonlinearity). Subgroup analysis revealed significant gender interactions (p < 0.0001). A higher HRR was significantly associated with greater total BMD in males (β = 0.130, 95% CI: 0.089–0.171, p < 0.0001), whereas no significant association was observed in females (β = −0.009, 95% CI: −0.043–0.025, p = 0.604). Positive associations were also observed among participants aged 12–15 years, non-Hispanic Whites, non-Hispanic Blacks, other Hispanics, Mexican Americans, and frequent milk consumers. Conclusions: Our results indicate that the hemoglobin-to-red-cell distribution width ratio shows a potential association with bone mineral density in male adolescents, which may offer supportive value for bone health assessment but requires further validation. Full article

This study examined the effects of alfalfa silage versus alfalfa hay in a total mixed ration (TMR) on milk yield, rumen fermentation, and nutrient digestibility in dairy cows. Hydrolyzed tannins (HT) were supplemented individually to assess changes. Thirty-two multiparous Holstein cows (DIM: 94 ± 8 d; milk yield: 41 ± 2 kg) were assigned to four treatments in a 2 × 2 factorial design: basal diet (alfalfa hay, H, or alfalfa silage, S) and additive (control, C, or 100 g/d HT, T). Production performance, rumen fermentation, nutrient digestibility, and blood metabolites were evaluated. Compared with group H, group S had a 0.16% higher milk protein percentage and significantly higher fat-corrected milk yield, milk fat percentage, fat-to-protein ratio, total solids, and milk urea nitrogen. After feeding, the ST group had increased ruminal pH. HT supplementation significantly decreased ruminal NH₃-N levels (p < 0.05) and increased microbial crude protein (MCP) content (p < 0.05). Group H showed no significant changes, and the effects of HT were less evident in hay-fed cows than in silage-fed cows. In summary, alfalfa silage feeding increased ruminal microbial populations, while HT supplementation mitigated the post-feeding decline in ruminal pH. Considering the relatively small sample size (n = 32), the results should be viewed as indicative rather than conclusive, and future studies with larger cohorts will be valuable to confirm and extend these findings. Full article

Chinese milk vetch (CMV; Astragalus sinicus L.), serving as winter green manure in rice cropping systems, is widely adopted in the southern China. Field experiments including different incorporation regimes (CMV incorporation, urea substitution incorporation and fertilizer-free incorporation), times (45 days, 30 days and 15 days before rice transplanting) and methods (no flooding, intermittent flooding and continuous flooding) were conducted from 2022 to 2024 to determine the optimal time and method for CMV incorporation that could improve soil nutrients, reduce rice-associated weed infestation, and increase rice yield. Delaying CMV incorporation was beneficial to the accumulation of dry matter and organic matter content in CMV shoots and the increase in the total nitrogen content of the soil before rice transplanting. Broadleaf weed infestation was significantly influenced by flooding method, CMV incorporation and incorporation time. Delaying CMV incorporation combined with flooding significantly reduced the density of broadleaf weeds. Grassy weed infestation was only significantly affected by the flooding method, with significantly lower density under flooding conditions compared to non-flooding conditions when other treatments were consistent. Sedge weed infestation was not affected by any of the experimental treatments. Compared with conventional CMV incorporation (incorporated 30 days before rice transplanting without flooding), incorporating CMV 15 days before rice transplanting with flooding (continuous or intermittent flooding) resulted in a 59.20–66.86% reduction in rice-associated weed infestation. Rice yield was also increased with a delay in CMV incorporation, which mainly manifested in increases in panicle number and seed setting rate. Incorporating CMV 15 days before rice transplanting increased rice yield by 5.34–13.24% compared to conventional CMV incorporation. Therefore, considering the comprehensive effects on soil nutrients, weed infestation and rice yield, incorporating CMV 15 days before rice transplanting combined with intermittent flooding is a recommended green manure management practice in green manure–rice rotation systems. Full article