Livestock manure management plays a critical role in sustaining agricultural productivity, in the absence of no or a limited supply of inorganic fertilizers, while also enhancing soil organic carbon (SOC) storage. Yet, its effects on greenhouse gas (GHG) emissions remain uncertain. Using the Denitrification-Decomposition (DNDC) model, this study assessed the long-term impacts of pig and cattle manure applications on grass silage yield, SOC, and nitrous oxide (N₂O) emissions at a grassland site in Northern Ireland. The model was calibrated using SOC observations from 2012 to 2013 and grass yield observations from 2010 to 2013, and validated against 2016 measurements; N₂O performance was evaluated using annual cumulative emissions measured in 2016. It was then applied under future climate scenarios (SSP1–2.6, SSP3–7.0, SSP5–8.5) projected by the IPSL-CM6A-LR model. The DNDC model reproduced observed SOC, grass silage yield and annual N₂O emissions with acceptable performance, although N₂O emissions from the high cattle slurry treatment were underestimated. Across future SSP scenarios, high manure inputs increased silage yield and SOC storage, but also strongly enhanced N₂O-derived GWP estimates. The N₂O-derived GWP exceeded the SOC sequestration benefit by 2.0–5.7 times in several manure treatments. High pig manure produced the greatest yield and GHGI, whereas high cattle manure resulted in the largest SOC accumulation and N₂O emissions. Increasing manure loading enhanced SOC storage but also disproportionately increased N₂O-derived GWP and GHGI, particularly in the high-input treatments. These results indicate that manure-derived climate benefits are conditional rather than universal and depend strongly on manure type, application rate and future climate forcing.
Foodborne parasites cause significant morbidity and mortality worldwide, with developing countries disproportionately affected due to inadequate sanitation and health infrastructure. In Low- and Middle-Income Countries (LMICs), where human and financial resources are limited, risk ranking of parasitic food safety hazards is essential to guide national authorities in prioritising those posing the greatest public health burden. This study ranked One Health-relevant parasites by public health importance and mapped their prevalence nationally and across provinces in Zimbabwe. Twenty-three experts from veterinary medicine, livestock production, and meat hygiene were recruited through professional networks to participate in a structured, three-round Delphi process. Prevalence data were obtained from the National Veterinary Authority database. A Multi-Criteria Decision Analysis (MCDA) framework was applied. Four parasites were ranked in descending order of national public health priority: Taenia saginata (rank 1), Taenia solium (rank 2), Echinococcus granulosus (rank 3), and Fasciola spp. (rank 4), with corresponding prevalences of 1.10%, 0.08%, 0.53%, and 0.64%, respectively. National rankings were largely consistent across provinces, though disparities in a few regions reflected divergent local epidemiological conditions. Risk ranking exercises of this nature serve a foundational role in food safety governance. By systematically prioritising hazards according to their public health significance, they enable regulatory authorities to establish evidence-based meat inspection priorities, allocate resources efficiently, and assess whether existing policy frameworks are proportionate to the burden posed by individual hazards.
The potassium (K) balance is a key indicator of the suitability and sustainability of grassland nutrient management practices. K inputs can impact soil fertility, biomass yield and herbage quality. This study evaluated data from a long-term grassland experiment established in 1970 in Northern Ireland with eight treatments: control, mineral fertilizer (NPK), cow and pig slurry at three application rates (50, 100 and 200 m3/ha). The objectives were to investigate the nutrient treatment effects on: (i) soil extractable K (SEK) (using a ammonium acetate solution), (ii) herbage K concentration and K offtake and (iii) the long-term K balance. Cow slurry provided significantly greater K inputs than pig slurry. Thus, the concentrations of SEK increased for the cow slurry treatments, but decreased significantly for the pig slurry, NPK and control treatments. The decrease in SEK was greater with soil depth. Increasing slurry rate had a positive effect on the concentrations of SEK and herbage K. The low rate of pig slurry had a herbage K concentration less than the required critical level. High rates of cow slurry led to luxury consumption of K which increases the risk of herbage cationic imbalance that could trigger tetany for livestock. Assessment of the long-term partial K balance revealed a K deficit for the NPK and pig slurry treatments, however high rate of cow slurry had a large K surplus. Refinement of nutrient management should carefully balance K inputs and losses to avoid K deficiency and excessive K inputs to grasslands.
