Highly digestible forages are associated with anin vitrolow-methane (CH₄) rumen fermentation profile and thus the possibility of reducing CH₄emissions from forage-based systems. We aimed to assess thein vitroruminal fermentation profile, including CH₄production, of the top stratum of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov) harvested at different sward heights (10, 15, 20, 25, and 30 cm). Herbage samples (incubating substrate) were analyzed for their chemical composition,in vitroorganic matter digestibility (IVOMD), and morphological components.In vitroincubations were performed under a randomized complete block design with four independent runs of each treatment. Gas production (GP),in vitrodry matter digestibility (IVDMD), CH₄production, total volatile fatty acid (VFA) concentration, and their acetate, propionate, and butyrate proportions were measured following 24 and 48 h of incubation. Herbage samples had similar contents of organic matter, neutral detergent fiber, and crude protein for all treatments. However, a higher acid detergent fiber (ADF) content in taller sward heights than in smaller sward heights and a tendency for metabolizable energy (ME) and IVOMD to decrease as sward height increased were found. Similarly, the stem + sheath mass tended to increase with increasing sward height. Amongst the nutrients, ME (r= −0.65) and IVDMD (r= −0.64) were negatively correlated with sward height (p< 0.001) and ADF was positively correlated with sward height (r= 0.73,p< 0.001). Both the GP and IVDMD were negatively related to the sward height at both incubation times. Sward heights of Kikuyu grass below 30 cm display anin vitroprofile of VFAs high in propionate and low in acetate, with a trend toward lower methane production of CH₄per unit of IVDMD. These findings are important to aid decision-making on the optimal sward height of Kikuyu grass and manage animal grazing with the opportunity to reduce CH₄production.

Understanding the grazing process and animal response to sward structures (e.g., sward height) is key to setting targets for efficient grazing management. We hypothesized that the short-term intake rate (STIR) of dry matter (DM) and digestible organic matter (OM) by dairy heifers is maximized with Kikuyu grass (Cenchrus clandestinus—Hochst. ex Chiov.) of intermediate sward heights. The treatments consisted of five pre-grazing sward heights (10, 15, 20, 25, and 30 cm) randomly assigned to two of ten paddocks. The experimental design included two measurements of each paddock at different periods and times of day. Three Holstein heifers (440 ± 42 kg body weight) were used to determine the STIR, which was estimated using the double-weighing technique with correction for insensible weight losses. The bite mass (BM), bite rate (BR), sward structural characteristics, and nutritional value of herbage samples were assessed. The data were analyzed using mixed models with a factorial arrangement of five sward heights, two times of day, and two evaluation periods. The sward height of Kikuyu grass that maximized both STIRs was approximately 20 cm. The STIR of the DM was 30% and 15% lower than the maximum in the shortest and tallest swards tested, respectively. In swards shorter than 20 cm, the STIR was lower because the BM decreased with sward height, whereas in those greater than 20 cm, the lower BM and STIR of DM was explained by a decrease in bulk density and bite volume. The top stratum was composed mainly of highly digestible leaf blades with similar nutrient content across sward heights; therefore the STIR of digestible OM was also maximized at 20 cm. Hence, the optimal pre-grazing sward height of Kikuyu grass should be managed at 20 cm under rotational stocking systems to maximize nutrient intake rate of dairy heifers.

Latin America and the Caribbean (LAC) is the world’s largest net exporter of agricultural products and a region marked by persistent rural poverty, inequality, and climate vulnerability, making its agrifood systems central to global food security. Sustainability functions as a structural, cross-cutting determinant of food security, shaping availability, access, utilization, and stability through the environmental, economic, and social conditions under which agrifood systems operate. Drawing on three coordinated scoping reviews covering 226 peer-reviewed and grey literature studies across 15 countries, Avanzar2030 examines how public policy, livestock technology, and climate-related institutional mechanisms interact to shape outcomes for productivity, equity, and sustainability — the mechanisms through which food security is determined in the region. The evidence identifies three recurring constraints on transformation: fragmented governance and policy coherence, weak delivery and implementation capacity, and structural inequalities in producers’ access to resources, services, and markets. Interventions that address these constraints together —bundling economic, environmental, and social objectives, embedding programs in coherent institutional arrangements, and centering inclusion— consistently outperform siloed efforts. As a global testing ground for agrifood innovation, LAC's experience offers lessons for advancing food security in other regions confronting similar structural trade-offs between short-term economic gains and long-term resilience. For policymakers and donors, durable food security outcomes depend on treating sustainability as integral to, rather than in tension with, agrifood transformation, and on building the governance, delivery, and equity foundations needed to sustain it at scale in the region.