Abstract:
Understanding the impact of climate variability (CV) on milk yield and composition is essential to
appreciate the need for adoption climate smart dairy adaptation practices. A study was conducted
in Mbarara district, Uganda to generate information about climate variability and livestock
management adaptation options employed by smallholder dairy farmers using a survey, monitoring
and laboratory analysis. Monitoring was used to quantify effects of wet and dry season on cow milk
yield while laboratory analysis was employed to determine the chemical composition of raw cow
milk produced during wet and dry seasons for local and crossbred cattle through composite milk
sampling of parity one to four cattle. The survey was done on 200 households, milk yield records
taken from 20 Ankole long horned for 70 days (35 dry, 35 wet) and F2 Friesian crossbred cattle for
84 days (42 dry, 42 wet), respectively of both early and mid-lactation within parity one to four from
18 households while milk composition analysis was done on eight cattle of either breed and season
from eight households. Fat, solids not-fat (SNF), Lactose, Proteins, Total solids (TS) and Total salts
composition were analysed. Phosphorous (P) concentration was analysed using molybdovanadate
colorimetry method while Calcium (Ca) and Magnesium (Mg) concentrations were determined.
Results indicated a low level of below 40% Climate smart dairy adaptation options except dry
season destocking, increased water access to livestock, planting shade trees, climate resilient
napier grass, supplementing cattle on banana peelings and disease prevention. The leading barriers
to adaptation were lack of adequate capital, land and labor constraint. Climate variability, breed,
parity, lactation stage as well as CV and breed, and CV and parity interactions had significant
effects on cattle milk yield at P<0.05. Ankole cattle had a mean milk yield of 2.6L with 2.342L in
dry season and 2.86L in wet season while crossbred cattle mean was 4.95L with 4.43L in dry season
and 5.47L in wet season. Milk yield increased with increasing parity but decreased in dry season.
Ankole cattle milk had a higher Fat, SNF, Protein, Lactose, TS, Total salts, Mg and P content except
Ca that was higher in crossbred milk. All milk composition parameters were affected by season and
breed except Fat, Ca and P. Fat, SNF, Lactose, Protein, TS, Total salts, Mg and P composition
increased in wet season in both breeds compared to the dry season. Ankole cattle lost 18.1% of milk
yield in dry season while Friesian crossbred cattle lost 19.1% of milk yield. In conclusion, climate
variability affects cattle milk yield and most constituents except P, Ca, and Proteins though milk
composition was more affected than milk yield with crossbred cattle being affected more than
Ankole cattle. It is recommended that there is need for an increase in adoption of climate smart
practices to alleviate the negative effects of climate variability on cattle milk yield and composition.