Climate change is a global challenge that impacts rangeland and pastureland landscapes by inducing shifts in temperature variability, precipitation patterns, and extreme weather events. These changes alter soil and plant conditions, reducing forage availability and chemical composition and leading to nutritional stress in cattle. This stress occurs when animals lack adequate water and feed sources or when these resources are insufficient in quantity, composition, or nutrient balance. Several strategies are essential to address these impacts. Genetic selection, epigenetic biomarkers, and exploration of epigenetic memories present promising avenues for enhancing the resilience of cattle populations and improving adaptation to environmental stresses. Remote sensing and GIS technologies assist in locating wet spots to establish islands of plant diversity and high forage quality for grazing amid ongoing climate change challenges. Establishing islands of functional plant diversity improves forage quality, reduces carbon and nitrogen footprints, and provides essential nutrients and bioactives, thus enhancing cattle health, welfare, and productivity. Real-time GPS collars coupled with accelerometers provide detailed data on cattle movement and activity, aiding livestock nutrition management while mitigating heat stress. Integrating these strategies may offer significant advantages to animals facing a changing world while securing the future of livestock production and the global food system.

Tannins are naturally occurring polyphenolic compounds increasingly recognized for their potential benefits to ruminants. Tannins can be extracted from plants' roots, bark, leaves, and seed husks. Management of plant communities to produce a diverse array of secondary compounds, particularly tannins, is a promising strategy for holistically enhancing agroecosystems on rangelands and benefiting free grazing ruminant animals. Deterioration of rangelands constrains plant diversity, reducing tanniferous forage plants and limiting tannin availability to free-grazing ruminants. Ruminants supplemented with tannin extracts in confined feeding operations have gained several reported benefits. Commercial industries are also expanding to extract and process tannin extracts. The beneficial effects of tannins depend on many factors, including plant species, plant part, tannin type (condensed tannins (CTs) or hydrolyzable tannins (HTs), and dose. Tannin binds with proteins, enhances the diversity and abundance of amino acids in the small intestine, and improves overall protein absorption and utilization. Compiled with other mechanisms, tannins can improve the quality, quantity, shelf life, and consumer preference of meat and milk products. Tannins also possess antimicrobial, anti-parasitic, antioxidant, immunomodulatory, and anti-inflammatory properties. CTs also impact rumen microbial populations, decreasing methane production, improving ruminal microbiota diversity, and lowering ammonia nitrogen production. Therefore, the use of tannin from tannin extracts and tanniferous forage plants presents a promising avenue for enhancing confined and free-grazing ruminant animals' health, productivity, and environmental sustainability.

This study classified cows’ foraging behaviors using machine learning (ML) models evaluated through random test split (RTS) and cross-validation (CV) data partition methods. Models included Perceptron, Logistic Regression, Support Vector Machine, K-Nearest Neighbors, Random Forest (RF), and XGBoost (XGB). These models classified activity states (active vs. static), foraging behaviors (grazing (GR), resting (RE), walking (W), ruminating (RU)), posture states (standing up (SU) vs. lying down (LD)), and posture combinations with rumination and resting behaviors (RU_SU, RU_LD, RE_SU, and RE_LD). XGB achieved the highest accuracy for state classification (74.5% RTS, 74.2% CV) and foraging behavior (69.4% CV). RF outperformed XGB in other classifications, including GR, RE, and RU (62.9% CV vs. 56.4% RTS), posture (83.9% CV vs. 79.4% RTS), and behaviors-by-posture (58.8% CV vs. 56.4% RTS). Key predictors varied: speed and Actindex were crucial for GR and W when increasing and for RE and RU when decreasing. X low values were linked to RE_SU and RU_SU, while X and Z influenced RE_LD more. RTS showed higher accuracy in activity states classification while CV in foraging behaviors and by posture classification. These results emphasize CV in RF’s reliability in managing complex behavioral patterns and the importance of continuous recording devices and movement data to monitor cattle behavior accurately.

Muzzo BI, Maleko DD, Thacker E, Provenza FD. 2023. Review: Rangeland management in Tanzania: Opportunities, challenges, and prospects for sustainability. Intl J Trop Drylands 7: 83-102. Rangelands in Tanzania play a crucial role in supporting local livelihoods and the country's economic development. However, their long-term sustainability is threatened. This review paper identifies challenges and explores opportunities to ensure their continued sustainability. Opportunities include implementing dedicated policies and regulations, using expertise in range science, leveraging technological advancements, investment land for opening private ranches, ample bushes and shrub resources for small ruminants, and high market demand for milk and meat from ruminants. Major challenges include insufficient technology and limited technical know-how, low and erratic rains leading to dry season pasture scarcity, infectious diseases, and the spread of invasive species. Other challenges include conflicting interests from other land users that have led to the massive conversion of communal rangelands to croplands, areas to protect wildlife, and human settlements. These challenges can be addressed by policy enforcement, strengthening pastoral organizations, fostering the growth of experts in climate-adapted forage breeding, and embracing advanced technology. Active involvement of local communities in decision-making processes and facilitating rangeland restoration can ensure the sustainable management of rangelands in Tanzania. Another promising avenue is the strategic use of locally adapted livestock species to control invasive plants, complemented by governmental enforcement of a grading system for meat and establishing a price-based quality meat market. Incorporating these prospects into rangeland management strategies can enhance the ecological sustainability and resilience of rangelands while supporting local livelihoods. Future research should focus on evaluating and implementing these strategies to promote sustainable rangeland management practices in Tanzania and elsewhere with similar environment.

The nutritional value of grasslands declines as the season progresses, negatively impacting cattle nutrition. Protein supplementation may reverse this trend, although high rates of ruminal proteolysis reduce the efficiency of N utilization. Tannins decrease protein degradability in the rumen, although they are also plant defenses with potential to influence animal behavior. The objective of this study was to determine in protein-supplemented cows grazing meadow bromegrass (MB) the influence of tannins on blood urea nitrogen (BUN), and on behavioral levels of activity. Twenty-four Black Angus cow [body weight (BW) = 614 ± 20 kg]-calf (BW = 244 ± 4 Kg) pairs were allotted to six 9-acre paddocks (4 pairs/paddock); animals in the Control (Ctrl; n = 3) and Tannin treatments (TT; n = 3) grazed meadow bromegrass (MB) and had a supplement of dried distillers grains with solubles (DDGS; (1 kgּ cow^-1ּ d^-1), with the addition of a mix of condensed (2/3): hydrolizable tannins(1/3; SilvaTeam) at 0.4% of the diet for TT. Grazing occurred from July to September 2023 with four experimental periods of 15 d each, the first being the adaptation period (no tannins; Baseline). Data were analyzed as a mixed-effects model with repeated measures and paddock as the experimental unit. Cows were fitted with accelerometers on their left back leg to determine activity, and blood samples were collected from all animals at the end of each period to estimate BUN. Representative samples of grass and supplement were collected from each period and paddock and analyzed for CP and fiber content. Herbage availability (DM basis) in each paddock was assessed before and post-grazing during each period using a rising plate meter and calibration curves. neutral detergent fiber (NDF) (62.9 to 65.1 ± 0.5%) and and acid detergent fiber (ADF) (38.7 to 43.9 ± 0.3%) increased, whereas CP (6.8 to 3.9 ± 0.1%) declined from Period 1 to 4 (P < 0.05). Initial biomass was 5,272 ± 211 Kg/ha and it declined after grazing (Period 4) to 2,319 ± 94 Kg/ha (P < 0.05) with no differences between treatments (P > 0.05). No differences between treatments were observed on motion index, number of steps taken per day, and the proportional percentage of time cows spent standing (9,379 ± 740, 2,611 ± 300, and 54.9 ± 0.02%, respectively; P > 0.05), suggesting that cows in TT did not invest extra time in searching activities or resting relative to Ctrl. It was only detected a greater percentage of transitions from lying to standing in TT than in Ctrl (7 to 3.4 ± 0.003%; P < 0.001). Values for BUN did not differ between treatments (P > 0.05), although they declined from Baseline to Period 4 by 28 % (8.2 to 5.9 ± 0.2mg/dL) in TT and by 2.6 % (5.75 to 5.6 ± 0.01 mg/dL) in Ctrl (P < 0.05). These results suggest that the addition of low levels of tannins to a protein supplement in cows grazing a low-quality grass diet reduces ruminal proteolysis without adversely influencing biomass removal or animals’ levels of activity.

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.