Seasonal rainfall variability across Nigeria’s climatic zones and its relationship with national livestock production

Livestock production in Nigeria is threatened by climate change, as seasonal rainfall that sustains agricultural water supply varies substantially across space and time. This study evaluates seasonal rainfall variability and trends across Nigeria's Sahel, Savanna, and Rainforest climate zones, and separately examines the national-level relationship between seasonal rainfall and national livestock production. Observational rainfall data from the Climatic Research Unit (CRU) and national livestock production output from the Food and Agriculture Organization (FAO) were analyzed over 44 years (1979-2022). Raw cattle milk recorded the highest mean national production, 416,380.26 T, while sheep recorded the lowest, 98,598.79 T. Raw cattle milk, sheep, pig, goat, and chicken showed statistically significant positive trends from the modified Mann-Kendall (MMK) Z-test, which accounts for serial autocorrelation, while cattle did not. Seasonal rainfall variability was greatest in the Sahel, while increasing trends were observed at selected Sahel locations and declining trends across parts of the Savanna and Rainforest. Kendall's tau analysis showed a positive association between national seasonal rainfall and goat production (τ = 0.301, p = 0.004), but the raw-series association is interpreted as descriptive because both rainfall and livestock series contain secular temporal structure. After detrending, the positive goat association was weaker (τ = 0.222, p = 0.034) and did not meet the Bonferroni-adjusted significance threshold. These findings provide a national-scale description of rainfall-livestock association while distinguishing it from evidence of interannual or causal rainfall effects.