Abstract:

The study was conducted to determine trends of variability and extremes of rainfall and temperature;
pastoralists’ perceptions to the changes in rainfall and temperature extremes and predict future
livestock productivity in the pastoral rangelands under changing climatic conditions. Data on daily
linfall, maximum and minimum temperatures from 1960 - 2013 were obtained from the National
Meteorological Authority (NMA). Daily rainfall and temperature data were subjected to trend
nalysis using non-parametric Mann-Kendall tests. Rainfall and temperature extremes were
nalysed using RClimdex. Data to establish fanner’s perceptions to trends in climate extremes
questionnaire. Data was analysed by descriptive statistics and multinomial logistic regression
nodels using SPSS software. To predict future livestock productivity heat stress was determined
ind used to derive its implication on future milk production. Temperature -relative humidity index
THI) was used as an indicator of heat stress. ARIMA models in SPSS Expert modeller were used
b predict futuristic trends of heat stress. Annual rainfall received showed non-significant
ncreasing trends. Annual total wet days were increasing but not significant (p > 0.05). Consecutive
vet days (CWD) were increasing while consecutive dry days, CDDs revealed increasing trends (p
: 0.05). Trends in annual temperature indices revealed significant increases in hot days (TX90p)
nd warm nights, TN90p (p < 0.05). The number of warmest nights (TNx) and hottest days (TXx)
vas significantly increasing (p < 0.05). Mean diurnal temperature range, DTR showed significant
lecreasing trends (p 0.05). Severe droughts and floods, changes in day hot temperatures and
varm nights, shift in start and cessation of rains, were the most perceived climate extremes. Key
adaptation strategies pastoralists used included; fencing off grazing land, integration of crop into
ivestock production systems, diversification of livestock species kept, control of stocking rates
nd changing grazing time. Age of the household head, marital status of household head,
household size, cattle herd
household size, cattle herd
und the best fit model as it could perfectly produce an excellent match with THI values. Predicted
'edicted THI will be 80 far higher than 72 maximum threshold beyond which Friesian lactating
,kely to negatively impact on milk production since the current livestock production system is
predominantly grassland based with open grazing as the major feed source. Therefore the current
rive of pastoralists improving to high grade animals (pure Friesian) is likely not to be sustainable
unless appropriate interventions are adopted. Therefore, it’s recommended that pastoralists in the
rangelands of Uganda should keep livestock genotypes that will tolerate the increasing heat stress
specifically, indigenous genotypes
strategies that minimize heat stress like planting of trees (Silvo-pastoralism) to provide shade in
pen grazing lands and construction of shades.