In the dairy farms of Uganda’s South-Western Cattle Corridor, the grass that cows eat is often not good enough to make high-quality milk. A new randomised feeding trial now reports that a modest, locally mixed supplement can shift the composition of that milk in measurable ways. Over 30 days, cows given a locally formulated dairy meal showed significant increases in solids-not-fat and protein content compared with animals grazing natural pasture alone, according to a study published in the journal Dairy Science and Management on 13 November 2025. The changes were modest in absolute terms but statistically clear, and they arrived in a region where milk quality has long lagged behind the volumes the corridor produces.
The South-Western Cattle Corridor is Uganda’s leading milk-producing region, accounting for nearly a quarter of national production. Despite that output, the study’s authors note that milk quality in the region remains below acceptable standards, undermining both local consumption and export potential. The primary cause, they argue, is reliance on natural pastures that are nutritionally poor and highly seasonal; recent assessments cited in the paper indicate these pastures are insufficient to meet dairy cows’ dietary needs, resulting in poor milk composition. Feed supplementation is recognised as a key strategy for improving productivity and quality, but adoption rates in Uganda remain low. The paper reports that fewer than 71 percent of farmers in the corridor use supplementary feeds, and those who do often rely on unformulated inputs such as maize bran or brewer’s mash, which vary in nutritional quality and lack standardised administration protocols.
The supplement at the centre of the trial, known as locally formulated Dairy Meal or LFDM, is a concentrate mixed from readily available ingredients. Each 100-kilogram batch combines 5 kilograms of a macro mineral mix, 20 kilograms of broken maize, 58 kilograms of maize bran and 17 kilograms of soya oilcake. Preliminary analysis of the final mix showed a crude protein content of approximately 16.1 percent, crude fibre of about 8.3 percent, ether extract or crude fat of roughly 4.5 percent and ash of around 4.7 percent. The soya oilcake, with a crude protein content of 44 percent, supplies most of the protein, while the maize and maize bran contribute fermentable energy and the macro mix contributes a mineral fraction with an ash content of about 30.4 percent.
To test the supplement’s effects, the researchers enrolled 60 dairy cows across ten farms in four districts of the corridor: Ntungamo, Mbarara, Kiruhura and Isingiro, chosen for their high milk production and prior involvement in dairy development projects. The farms were selected from a pool of 203 previously characterised farms, with criteria including a minimum of ten lactating cows, at least six cows having calved within the previous two months, cows of similar breed and comparable productivity levels. Cows with a parity of three or less were preferred, since parity is associated with changes in milk physicochemical composition. The animals were randomly assigned to three groups in a randomised complete block design, with blocks based on parity, breed and lactation stage to account for herd heterogeneity.
The three groups received different feeding regimes. A control group continued on natural pasture alone with no supplementation, a first treatment group received 2 kilograms of LFDM per day, and a second treatment group received 4 kilograms per day. The feeding trial lasted 30 days, preceded by a monitoring period of 7 to 14 days to establish baseline milk quality. Milk samples were collected under sterile conditions at baseline and at the end of the trial, and analysed for fat, protein, solids-not-fat, density and other physicochemical properties using standard dairy analytical procedures. Before any comparison of outcomes, the researchers used one-way analysis of variance to confirm that baseline milk parameters did not differ significantly among the three groups, a precondition for attributing later changes to the intervention rather than to pre-existing differences.
The results focused on changes from baseline to endline, calculated for each parameter and compared across groups. Solids-not-fat, the portion of milk that remains after water and fat are removed, rose by 1.37 percent in the 2 kilogram group and by 1.66 percent in the 4 kilogram group, while the control group’s solids-not-fat declined by 0.50 percent over the same period, a difference the authors report at p = 0.005. Protein content followed a similar pattern, increasing by 0.37 percent in the 2 kilogram group and 0.67 percent in the 4 kilogram group, against an increase of 0.11 percent in the control group, at p = 0.022. Tukey’s honestly significant difference post hoc tests, applied to parameters showing p values below 0.2 in the initial analysis, confirmed these differences: solids-not-fat rose by 1.37 percent in the 2 kilogram group with a 95 percent confidence interval of 0.65 to 2.09 and p = 0.003, and by 1.66 percent in the 4 kilogram group with a 95 percent confidence interval of 0.99 to 2.54 and p = 0.001. For protein, the post hoc comparisons showed increases of 0.26 percent in the 2 kilogram group with a 95 percent confidence interval of 0.05 to 0.47 and p = 0.018, and 0.56 percent in the 4 kilogram group with a 95 percent confidence interval of 0.31 to 0.81 and p = 0.002, relative to the control.
Other milk parameters told a quieter story. The authors report that no other measured parameters showed significant differences between groups, and that lactose, salts and pH remained stable over the trial period. In their discussion, they interpret this stability as evidence that some milk constituents are inherently less responsive to short-term nutritional interventions than fat and protein fractions. The pattern also carries a dose signal: the greater improvements observed in the 4 kilogram group suggest a dose-dependent response, particularly for solids-not-fat and protein enrichment, although the authors caution that variation across cows, likely influenced by breed, parity and lactation stage, shaped how individual animals responded to the dietary intervention.
The mechanism the authors propose runs through the rumen. The supplement’s moderate fibre level of 8.3 percent and ether extract level of 4.5 percent are described as enhancing acetate production in the rumen, a key precursor for de novo fatty acid synthesis in the mammary gland, while the 16 percent crude protein concentration supports rumen microbial protein synthesis, increasing amino acid flow to the small intestine and mammary tissue and thereby promoting casein and whey protein synthesis. Balanced energy and protein, the paper notes, ensure efficient microbial nitrogen utilisation, minimising ammonia losses and maintaining milk urea nitrogen within an optimal range of 10 to 16 milligrams per decilitre, an indicator of good energy-protein synchrony. The mineral fraction supplies essential ions including calcium, magnesium, sodium and phosphorus that help sustain milk pH in the range of roughly 6.6 to 6.8 and support casein micelle stability, while fermentable energy from maize starch and bran drives propionate formation that supports hepatic gluconeogenesis and lactose synthesis.
The economic context gives these laboratory-scale shifts practical weight. Uganda is preparing to introduce a quality-based milk pricing system in which higher payments are tied to improved fat and protein content, and the authors argue that improvements in protein and solids-not-fat, which raise milk density and processing value for cheese and yoghurt, are precisely the attributes most valued by processors under such frameworks. Comparable findings from East Africa, cited in the paper, indicate that supplementation with balanced concentrates has enhanced milk yield, protein and fat quality in smallholder dairy systems in Tanzania and Kenya, though effects there varied across production systems and cow categories. The authors also stress that supplementation should be integrated with herd management strategies, including targeted breeding and health programmes, rather than adopted as an isolated intervention, and that farmer uptake will depend on effective implementation of quality-based pricing that rewards higher protein and fat content.
The study’s limitations are set out plainly by its authors. The trial was restricted to a 30-day intervention and a single geographic region, which may restrict generalisability, and cow-level factors such as genetics, lactation stage and management practices can influence outcomes. The authors call for future research to evaluate longer-term supplementation across diverse breeds and production systems, to involve larger sample sizes across multiple regions, and to investigate the links between feed supplementation, milk quality and farmer adoption, including advanced microbial profiling methods to capture nutritional and safety impacts. Within those boundaries, the trial offers a concrete data point for a region where such data have been scarce: a locally mixed, ingredient-transparent concentrate, fed at 2 to 4 kilograms per day for one month, measurably raised the protein and solids-not-fat content of milk from cows grazing nutritionally poor pastures, while leaving lactose, salts and pH essentially unchanged.
Subject of Research: The effect of a locally formulated dairy meal supplement on the physicochemical composition of milk from cows grazing poor natural pastures in South-Western Uganda
Article Title: Effects of a nutrient-balanced supplement on milk physicochemical composition in low-input dairy systems in South-Western Uganda
Article References: Atusasiibwe, J. M., Olet, E. A., Wangalwa, R., Twongyirwe, R., & Bithell, M. (2025). Effects of a nutrient-balanced supplement on milk physicochemical composition in low-input dairy systems in South-Western Uganda. Dairy Science and Management, 2(1), Article 18. https://doi.org/10.1186/s44363-025-00020-y
Image Credits: AI Generated
DOI: 10.1186/s44363-025-00020-y
Keywords: dairy science, milk quality, feed supplementation, Uganda, smallholder farming, solids-not-fat, milk protein, randomised controlled trial, livestock nutrition, South-Western Cattle Corridor, dairy meal, milk composition
News Source: William Thompson. (October 28, 2026). Local Feed Supplement Boosts Milk Protein and Solids in Ugandan Dairy Cows. Scienmag.
