Gastrointestinal modification based on probiotic feed additive enviro-alleviators to reduce enteric methane production in ruminant and non-ruminant livestock

In West Africa, trees and shrubs are important for feeding ruminant livestock during the dry season. This study aimed to determine the in vitro digestibility of organic matter from eight woody species using a gas test with and without the addition of polyethylene glycol (PEG), and evaluate their preference by sheep using a cafeteria test. Plants cited by farmers as being palatable to sheep were Lannea microcarpa (La), Ficus sycomorus (Fi), Pterocarpus erinaceus (Pt), Khaya senegalensis (Kh), Azadirachta indica (Az), Bombax costatum (Bo), Guiera senegalensis (Gu) and Ziziphus mauritiana (Zi). For the preference test, two groups of fresh and dried leaves from each time four species were offered in a 4 × 4 Latin square to four 18-24-month-old rams for 8 days each. The in vitro organic matter digestibility (IVOMD) was determined using the modified Hohenheim gas test. The quantity of dry matter ingested within 30 min, along with consumption time, ingestion rate, and the preference coefficient, served as indicators of leaf preference. Bo, Kh, and Zi leaves had the highest preference coefficients both in the dried (0.7, 0.3 and 0.2) and fresh (0.7, 0.5 and 0.3) state. Fresh Fi leaves had a higher preference coefficient (0.4) than dried ones (0.1), while the reverse was observed for Pt leaves (fresh: 0.1, dried: 0.6). PEG addition increased IVODM and in vitro methane production of ligneous forage plants by 1.2% (Kh) to 44.7% (La) compared to the incubation without PEG. In conclusion, fresh and dried leaves of B. costatum, K. senegalensis, and Z. mauritiana are highly palatable to sheep, making them good candidates for inclusion in dry season rations, despite their moderate IVOMD. In contrast, L. microcarpa and G. senegalensis exhibit both low preference and poor IVOMD, rendering them less recommendable as forage resources.

The issue of ruminant livestock feed shortages can be addressed by utilizing innovative feed that is both nutritionally rich and available year-round. The study aimed to examine how silage influences the growth performance of thin-tailed sheep. The study was conducted in Sleman, Yogyakarta. The study involved thirty thin-tailed ewes, aged 10 to 12 months and weighing 15.03±1.09 kg. A completely randomized design (CRD) with a unidirectional arrangement was applied, involving three diet treatments and ten replications. In this study, the silage consisted of Pennisetum purpureum cv. Gama Umami and Calliandra calothyrsus in a 70:30 ratio, respectively. The diets were as follows: T0 = 60% concentrate and 40% water spinach straw, T1 = 40% concentrate and 60% silage, and T2 = 60% concentrate and 40% silage. The study focused on variables such as growth performance, apparent nutrient digestibility, and nitrogen (N) utilization. The data were examined through analysis of variance (ANOVA), followed by Duncan’s new multiple range test (DMRT) for comparisons of significant differences. The performance indicators for treatments T0, T1, and T2 were as follows: dry matter intake (DMI) of 57.99, 60.12, and 65.57 g/kg LW0.75/day, respectively; crude protein intake (CPI) of 5.98, 8.36, and 6.78 g/kg LW0.75/day; average daily gain (ADG) of 38.96, 43.94, and 49.10 g/sheep/day; N intake of 0.90, 1.34, and 1.09 g/kg LW0.75/day; N digestible of 0.70, 0.95, and 0.80 g/kg LW0.75/day; and N retention of 0.56, 0.85, and 0.70 g/kg LW0.75/day. Therefore, no single dietary treatment was universally superior, but each offered unique advantages.

Mammal diversity around the world has been increasingly threatened by a myriad of anthropogenic drivers, but particularly overhunting and natural habitat loss. These threats alter the structure of local mammal assemblages and, consequently, their associated ecological interactions. Here, we assess the degree to which the mammal fauna has been defaunated across the 862,818-km2 Caatinga tropical dry forest region of northeastern Brazil. Specifically, we examine potential changes in the structure of medium- to large-bodied mammal assemblages, large-scale spatial patterns of local extinctions, the loss of ecosystem functionality, and the role of human disturbance and protected areas in mammal defaunation. We compiled empirical data for 51 species representing a total of 73 local mammal assemblages that could be defined as exhaustively sampled throughout the region and compared species distribution estimates between contemporary and historical times. Our results show that 90% of the Caatinga lost between 20% and 80% of its mammal species, and the structure of coexisting local assemblages was further downsized by ~77%. Among all 51 species, 37 lost over 50% of their geographic range across the region. Caatinga defaunation is currently associated with a severe loss of ecosystem functionality. Overhunting, agropastoral habitat conversion and ruminant livestock were the main drivers of the extent and severity of local defaunation rates, which were conversely buffered by protected areas. This study informs conservation efforts in arid tropical forest regions dominated by the rural poor, including protection of remnant dry forests and restoration of mammal- and habitat- mediated ecosystem services.

Abstract This article explores the representation of silvopastoral systems in European art from the 16th to the nineteenth century, with a specific focus on ruminant livestock grazing in wooded environments. Drawing from a wide interdisciplinary body of literature in agroforestry, environmental history and art history, this study adopts a scoping review approach combined with visual analysis of selected artworks. While not a systematic review, it synthesizes existing scientific knowledge on silvopastoralism (defined as the integration of trees, forage, and livestock) and applies this lens to historical paintings. By analyzing key botanical, forestry, zootechnical and land use elements in selected works, the research highlights the relationship between humans, animals, and natural ecosystems as captured through visual art. Particular attention is given to silvopastoral elements such as grazing patterns, tree cover, and animal breeds. Methodologically, the paper integrates knowledge from plant and animal sciences, ecology, and livestock management to assess how these elements are portrayed. The study indicates how artistic depictions provide valuable insights into historical land-use practices, animal husbandry, tree species, and rural socio-ecological dynamics that shape the European agroforestry heritage.

Livestock production is a significant contributor to global greenhouse gas (GHG) emissions, particularly methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O), which are primarily generated through enteric fermentation and manure management. Methane alone is over 23 times more potent than carbon dioxide (CO<sub>2</sub>) in terms of global warming potential, making its reduction a critical target for climate change mitigation. This review explores the role of improved forage management as a sustainable strategy to reduce GHG emissions from ruminant livestock. Enhanced forage quality through the use of high-protein species, digestible silage, and legumes rich in plant secondary compounds such as tannins, saponins, essential oils, and flavonoids has demonstrated potential in mitigating CH<sub>4</sub> production by altering rumen fermentation and reducing methanogenic activity. Additionally, incorporating alternative forage crops like Medicago sativa (lucerne), Plantago lanceolata (plantain), and Brachiaria spp. can improve nitrogen use efficiency and reduce N<sub>2</sub>O emissions from excreta. Improved forage systems also contribute significantly to soil carbon sequestration, enhancing soil fertility and water retention while offsetting atmospheric CO<sub>2</sub>. By integrating these climate-smart forage practices, livestock systems can increase productivity and resilience while lowering their environmental footprint. The findings of this review highlight the critical importance of forage-based strategies in supporting global efforts to achieve methane reduction targets and promote sustainable livestock development.

South Africa has a long history of studying specific dietary deficiencies in livestock grazing natural pastures (veld), with these pastures generally regarded as deficient in protein and phosphorus. The pioneering work by Sir Arnold Theiler and co-workers focused on addressing the cause of bovine botulism, but a direct link to an underlying phosphorus deficiency was later established. Other minerals have also received attention in South Africa, but since the early 1900s, the focus has mainly been on the phosphorus nutrition of grazing ruminant livestock. The initial focus on a primary phosphorus deficiency evolved and became the catalyst for renewed and comprehensive studies at Armoedsvlakte and elsewhere in southern Africa. The information obtained from these studies improved the understanding of the important roles and interactions between the selective grazing behaviour of ruminants and the composition of the veld, which serves as their primary source of daily nutrient intake. Supplementing grazing ruminants with various minerals and rumen-stimulating licks became routine practice, but results have varied and expected animal performance has not always been attained. This review provides a perspective of the nutrition of ruminant livestock grazing veld, with reference to the role of supplementary feeding, especially of phosphorus and the ever-present sodium chloride. Reference is also made to arthrosis or osteochondrosis, a phenomenon observed in grazing cattle since 1982. (Submitted 09 July 2025; Accepted 16 September 2025; Published 04 November 2025)

Bovine Viral Diarrhoea Virus (BVDV), Border Disease Virus (BDV), and Bovine Herpesvirus-1 (BoHV-1, the cause of Infectious Bovine Rhinotracheitis, IBR), are economically important endemic viruses in ruminant livestock in the United Kingdom and Ireland. Deer could undermine control efforts in livestock by contributing to virus transmission and maintenance, but information on the presence of these viruses in the wild deer population is lacking. Blood samples from wild fallow and sika deer culled in Northern Ireland were collected opportunistically in the 2022–23 hunting season and tested using enzyme-linked immunosorbent assay (ELISA) for the presence of antibodies to these viruses (n = 116). No antibodies against BoHV-1 were detected. Antibodies against pestivirus were detected in three samples (2.6%), all from sika deer, and constitute the first report in this species in Europe. Virus strain differentiation by virus neutralization test (VNT) was inconclusive. Results therefore indicate no evidence of exposure to BoHV-1 and very low levels of pestivirus exposure in these deer populations. Based on these results there are currently no grounds to implicate deer as significant wildlife reservoirs of these viruses.

Graduate Student Literature Review: Limitations in feeding red seaweed Asparagopsis species for enteric methane mitigation in ruminants.

IntroductionEnteric methane (CH4) emissions from ruminant livestock production systems pose a significant challenge to efforts to mitigate global climate change. The novel feed additive 3-nitrooxypropanol (3-NOP) has the capacity to inhibit rumen methanogenesis and significantly reduce the volume of enteric CH4 emissions produced by livestock systems. However, heterogeneity in CH4 mitigation from 3-NOP supplementation prevents livestock producers from determining the actual impact of supplementation on CH4 emissions. This meta-analysis aimed to understand the variables responsible for the heterogeneity in CH4 mitigation from 3-NOP supplementation in confinement-fed beef and dairy cattle.MethodsUsing 30 in vivo studies (83 treatments) that continuously supplemented 3-NOP at a range of doses from 40mg to 338mg dose (mg 3-NOP/kg dry matter intake; DMI), a mixed-effects multistep regression examined the impact of 3-NOP supplementation on CH4 yield.ResultsOn average, 3-NOP supplementation reduced CH4 yield by 25.9% in beef cattle and 26.4% in dairy cattle, at the recommended dose of 60mg 3-NOP/kg DMI. Results showed that the anti-methanogenic potential of 3-NOP was influenced by 3-NOP dose (mg 3-NOP/kg DMI) and DMI kg/head-1/day-1.DiscussionAlthough studies showed a strong positive relationship between 3-NOP dose and CH4 emissions (P <0.0001), DMI was observed to have a greater influence of CH4 abatement than 3-NOP dose. This suggests that the volume and timing of CH4 production influences the availability of 3-NOP in the rumen during methanogenesis more than 3-NOP dose itself. This paper uses this understanding to develop equations that can estimate future CH4 abatement in real farm systems, allowing producers the capacity to quantify the impact of 3-NOP on their greenhouse gas emissions and receive recognition for avoided CH4 emissions. However, these equations are highly influenced by DMI and are only suitable for confinement-fed systems that consume an equal or greater volume of ration and are not a substitute for measuring CH4 emissions, which would provide producers with the actual volume of CH4 emissions avoided.

Abstract Abstracts: The drive to increase product output per animal in some sectors of ruminant livestock production and the expansion of monogastric livestock production has led to greater use of feeds such as cereal grains and soyabean meal that are potentially human edible. This trend has caused concern with livestock competing directly with the human population for a limited global area of cultivatable land on which to produce grain and legume crops. Monogastric livestock require similar nutrient provision as humans with high digestibility and quality, especially in relation to bioavailable protein and essential nutrients (fats, minerals and vitamins). Reasons for using potentially human-edible feeds in ruminant diets, as there are not the same direct nutrient requirements as with monogastrics, include increased total daily energy intake, greater supply of essential amino acids and improved ruminal balance between fermentable energy and degradable protein in high producing systems (e.g. intensive dairy and beef finishing). Soyabean meal, produced on land that has been in arable cultivation for many years can fulfill a useful role as a supplier of undegraded dietary protein in diets for high-yielding dairy cows and is the major protein source for pigs and poultry. However, in the context of sustaining the production of high-quality foods from livestock to meet the demands of a growing human population, the use of potentially human-edible feed resources should be reduced and restricted to scenarios where the crop has no discernable use as human food and then it should be used to strategically support livestock with the highest daily nutrient requirements (i.e. meeting requirements for energy and protein and rectifying imbalances in nutrient supply from human inedible basal feeds). There is therefore a need to optimize human inedible feeds for both monogastric, to supply the required level of high-quality digestible nutrients, and ruminant livestock, as currently forage-only systems can be associated with relatively low output per head and low nitrogen use efficiency compared to systems with greater reliance on human-edible feeds. Profitability on farm is driven by control of input costs as well as product value and examples are given of low-cost bovine milk and meat production with little or no reliance on potentially human-edible feeds. The potential of all-forage diets should be demonstrated for a wide range of ruminant milk and meat production systems. The development of human in-edible plant by-products, food waste, insect meal and processed animal protein for different livestock species is critically needed. The challenge for the future development of sustainable circular livestock systems will rely on the reduction of environmental pollutants and the optimization of human-inedible by-products to form the basal diet of monogastric livestock and are used to complement pastures and forage crops strategically rather than replace them in ruminant livestock.

Abstract Alterations in tryptophan metabolism and serotonergic processes have recently been implicated in the onset of tall fescue toxicosis in cattle, with ergot alkaloid ingestion resulting in decreased serum serotonin concentration. Biochanin A (BCA), an isoflavone produced in legumes, has been documented to influence ruminal fermentation by inhibiting hyper-ammonia producing bacteria. Therefore, the hypothesis of this experiment was that biochanin A would inhibit ruminal tryptophan-utilizing bacteria in vitro. The objectives of this study were to evaluate the effects of increasing BCA levels on digestibility, ruminal fermentation, and microbial populations associated with N digestion in fescue-based diets using an in vitro fermentation model. Ruminal contents were obtained from Angus × Holstein steers (body weight = 390 ± 4.49 kg; n=2) fed a diet of 90% tall fescue hay and 10% cracked corn. Treatments included: basal substrate (negative control; 0 mg/g DM BCA), basal substrate + monensin (positive control; 1.5 or 15 mg/g DM), and basal substrate + BCA (2.5, 5.0, 10, 20 mg/g DM). The basal substrate was a mixture of 80% tall fescue hay and 20% ground corn and the fermentation vessels were incubated for 48 h. Data were analyzed using the GLM procedure of SAS and contrasts were used to assess treatment effects. The apparent dry matter (DM) digestibility, true DM digestibility, and neutral detergent fiber digestibility were lesser (P< 0.03) for monensin-containing diets compared with negative control or BCA-containing diets. Biochanin A inclusion decreased (P< 0.04) the rate of gas production and linearly decreased cumulative gas production. Total volatile fatty acid concentration decreased linearly (P=0.02) with increasing BCA inclusion. Monensin increased (P< 0.002) the molar propionate proportion compared with negative control and BCA treatments. Increasing BCA inclusion linearly increased (P< 0.02) molar branched-chain fatty acid proportions (valerate, isovalerate, isobutyrate) in the fermentation media. Monensin inclusion decreased (P< 0.001) cellulolytic, peptide- and amino acid-utilizing, hyper-ammonia producing, and tryptophan-utilizing bacterial concentration in the fermentation media compared with negative control. Cellulolytic bacterial and peptide and amino acid-utilizing bacterial concentrations responded quadratically (P< 0.001) to increasing BCA inclusion, with nadirs observed at 10 mg BCA/g DM. Hyper-ammonia producing bacteria and tryptophan-utilizing bacteria responded quadratically (P< 0.001) to increasing BCA inclusion, decreasing up to 2.5 mg BCA/g DM and plateauing thereafter. This experiment demonstrated that dietary BCA inclusion altered microbial populations associated with ruminal fiber and protein fermentation similarly to monensin. Decreased viable tryptophan-utilizing bacterial concentration with monensin or BCA inclusion might suggest that these antimicrobial compounds could potentially increase ruminal tryptophan availability in cattle consuming tall fescue-based diets. More research is needed to investigate the effects of BCA inclusion on ruminal tryptophan utilization in vivo to better understand potential implications for reducing the negative effects of fescue toxicosis on ruminant livestock production.

Abstract The Global Farm Platform initiative (www.globalfarmplatform.org), established in 2014, is a network of research farms and institute members working collaboratively to enhance the sustainability of ruminant livestock systems through the development of transformational regional solutions to global challenges and promote their adoption. This multidisciplinary international network provides a unique combination of research and practice for diverse ruminant production systems in various cultural, socioeconomic, and climatic zones. Our steps for sustainable livestock include: 1) Feeding animals less human food, focusing on forage-based systems and reducing reliance on supplementary feeds; several research farms (RFs) are exploring sustainable practices, such as the Kenian “Tumbukiza” method and increased plant diversity in grazing systems, to enhance resilience and productivity. 2) Raising regionally appropriate animals adapted to local conditions; RFs are engaged in crossbreeding and selecting animals for resilience to climate change challenges, ensuring they can thrive in specific environments. 3) Keeping animals healthy; RFs employ various approaches, including technology like sensors and video cameras for monitoring animal health, as well as vaccine development to combat specific diseases. 4) Smart supplements; RFs explore options like spontaneous vegetation and innovative legumes to enrich soil quality and provide nutrition. 5) Focusing on quality over quantity in food production; RFs are implementing measures such as CT scanning for carcass confirmation and assessing the nutritional value and carbon footprint of forage-based beef systems. 6) Tailoring practices to local culture; promoting the transfer of research outcomes to stakeholders and farming communities. This includes initiatives to transform agriculture for environmental and economic benefits. 7) Tracking costs and benefits; involves assessing the environmental and economic impacts of sustainable grazing systems, utilising Life Cycle Assessment approaches, and collating databases for comprehensive analysis. 8) Studying best practices; involves the Global Farm Platform initiative’s network of research farms globally. The initiative aims to optimise livestock use in various regions, considering local resources, breeds, and feedstuffs.

Abstract Sustainable food systems can be defined as those that deliver nutritional security to all in a way that economic, social, and environmental bases used to generate food for current and future generations are not compromised. Such systems need to succeed across various climates, soil types, topographies, cultures, and states of economic development. As with ecosystems that depend upon multiple trophic levels of biotic factors (e.g., microorganisms, plants, animals, fungi), agroecosystems that provide food depend upon different trophic levels to enhance provisioning, regulating, cultural, and supporting ecosystem services. Livestock specifically can contribute to ecosystem services and disservices depending upon management decisions, location, and concentration relative to resource (e.g., forage) availability. From a macro perspective, livestock are essential to food systems. Livestock upgrade plant protein quality for human consumption via upcycling plant sourced feedstuffs, and can enhance the availability of essential micronutrients in the food supply via meat, milk, egg, and fish products. Additionally, ruminant livestock production can take place on landscapes unsuitable for cultivated crop systems, providing food production while supporting wildlife habitat, recreational value, soil carbon storage, and water filtration among other goods and services. Livestock production is beneficial in enhancing nutrient cycling through agricultural systems and offsetting the requirement for synthetic fertilizers via connecting manure nutrients to cultivated and other food cropping systems. Economically, livestock production supports the livelihoods of over 1 billion people across the world. Livestock production also contribute to ecosystem disservices, such as greenhouse gas emissions and through water use that exceeds recharge rates in water scarce regions. Ultimately, when assessing the ecosystem services and disservices of livestock systems, globally, livestock are a clear net benefit to humanity. However, further improvements in production systems via management, genetics, herd/flock health, and nutrition can be made to minimize negative impacts and enhance positive contributions of livestock.

Abstract The ruminant livestock sector contributes to global greenhouse gas emissions. Thus, there is a need to develop novel mitigation strategies, especially for pasture-based systems as less than half of the identified strategies are applicable to grazing systems. This study aimed to examine the use of pelleted bromoform-containing seaweed (Asparagopsis taxiformis) marketed as Brominata, as an enteric methane (CH4) inhibitor in grazing beef cattle under real-world farm conditions. The study was conducted at the Selkirk division of Matador Ranch and Cattle in Dillon, Montana, USA, situated in a semi-arid climate with cold, dry winters and hot, wet summers. Twenty-four crossbred Wagyu-Angus beef steers, with an average liveweight of 399 ± 21.7 kg, were allocated to two treatment groups: Control and Brominata. Measurements of CH4, carbon dioxide (CO2), and hydrogen (H2) emissions were conducted using the GreenFeed system which also was used to administer the pelleted supplements. The control group received a pellet composed of 65% wheat mids, 15% molasses, and 20% bentonite (CHS Nutrition, Great Falls, Montana, USA). The Brominata group received a pellet containing Brominata (20%, Blue Ocean Barns, Kailua Kona, HI, USA), distillery solubles (15%), wheat mids (65%), a palatability enhancer (Inhace, 0.25%, Qualitech, Chaska, Minnesota, USA), molasses coating, and wheat mids dusting. The bromoform concentration in the pellets was 1.4 mg g/dry matter. The study was conducted in an intensive irrigated pasture, where the steers remained together throughout the experiment. Central pivot irrigation and rotational grazing management were used with a fixed stocking rate. Statistical analysis was conducted using SAS 9.4, with a model incorporating fixed effects for treatment, time, their interaction, and a covariate, while accounting for animal variations as a random effect within each phase. Three phases of bromoform intake were identified: a 3-week ramp-up phase, a 3-week optimal phase, and a 2-week decreasing phase. No differences were observed between the groups in terms of weekly initial and final liveweight, average daily gain, or predicted dry matter intake. However, during the optimal and decreasing phases, average enteric CH4 emissions were significantly (P < 0.05) reduced in steers that received Brominata supplementation compared to the Control (115 vs. 185 g/d, respectively). CO2 emissions were similar between the two groups (6.8 vs. 7.2 kg/d), while H2 emissions were lower (P < 0.05) in the control group (3.4 vs. 1.8 g/d). The findings suggest that pelleted bromoform-containing feed additive has the potential to reduce enteric CH4 emissions from grazing beef cattle. The observed 37.7% average reduction in CH₄ production, achieved without compromising animal performance, suggests a promising approach for mitigating the environmental impact of livestock farming.

The considerable contribution of ruminant livestock to methane emissions has become a major global concern in recent years. Although dietary approaches for reducing ruminant methane emissions have been explored, the sustainable potential of probiotics to influence rumen function and lower methane production has increasingly attracted research attention. While previous studies have focused on single or dual-strain probiotics, this study is among the first to evaluate the synergistic effects of quadric-strain formulations. Hence, this study aimed to evaluate the impact of multi-strain probiotic blends, each at two distinct concentrations on rumen fermentation, nutrient degradability, and methane emission in sheep using an in vitro gas production technique following a completely randomized design. The basal diet with no probiotic supplements served as a control, while the supplemented bacterial combinations were Bacillus licheniformis, Lactobacillus acidophilus, L. bulgaricus, and Bifidobacterium bifidum (ABLB; at a ratio of 1:1:1:1) at levels of 2 × 109 (ABLB2) and 4 × 109 (ABLB4) CFU/g of feed, and Lactobacillus casei, Lactobacillus plantarum, Bacillus subtilis plus Bifidobacterium bifidum (CPSB; at a ratio of 1:1:1:1) at levels of 2 × 109 (CPSB2) and 4 × 109 (CPSB4) CFU/g of feed. Probiotic supplementation significantly improved in vitro dry matter and fiber degradability (IVDMD and IVCFD), with the most effective results observed in ABLB treatments. These blends also reduced methane production and ammonia-N concentrations, while increasing total volatile fatty acids (TVFA), indicating more efficient fermentation. Protozoa counts were notably lower in treated groups, supporting the role of probiotics in mitigating methane via microbial modulation (P < 0.01). Probiotic supplementation did not affect the values of pH (P > 0.05). Predictive values for metabolizable energy (ME), net energy for lactation (NEL), and organic matter digestibility (OMD) were improved across treatments. These findings highlight the potential of targeted probiotic formulations to enhance rumen efficiency and reduce environmental emissions in ruminant systems.

Genome-based analysis for the identification of candidate genes associated with skin-photosensitization tolerance in sheep.

Rapid visual detection of Moniezia spp. in sheep feces via Recombinase Polymerase Amplification-Lateral Flow Dipstick (RPA-LFD) assay.

Dairy cow- and avian-origin clade 2.3.4.4b H5N1 induce severe mastitis in lactating goats and transmission to suckling goats.

Background: With diminishing communal grazing lands, cost-effective protein supplementation for ruminant livestock is crucial. Utilizing nano-formed urea and a novel nano-formed nitrogen source, in conjunction with balanced energy sources, is anticipated to decrease the feeding costs for ruminant livestock. Nano-urea alone or with neem-coated urea supplementation may be used as good economic source of nitrogen, if found suitable. Methods: Two doses of Nano-urea (160 µL Nu) and combined with neem-coated urea (160 µL Nu+1% Ncu) were selected for lactation trial based upon in vitro rumen fermentation system. Result: Addition of Nano-urea and combination of Nano-urea and neem-coated urea enhanced voluntary intake of different nutrients and increased DCP value in crossbred dairy cows. TDN intake pattern was similar among all treatment groups. However, DCP intake was greater (p less than 0.001) and increased blood urea nitrogen in T1 and T2 compared to T0 groups. However, Feeding nano-urea and combination of nano-urea + neem-coated urea marginally benefitted in terms of feeding economics for milk production.