Kabunga Nassul S, Ghosh Shibani, Webb Patrick
International Food Policy Research Institute (IFPRI), Kampala, Uganda.
Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, United States of America.
PLoS One. 2017 Nov 10;12(11):e0187816. doi: 10.1371/journal.pone.0187816. eCollection 2017.
The promotion of livestock production is widely believed to support enhanced diet quality and child nutrition, but the empirical evidence for this causal linkage remains narrow and ambiguous. This study examines whether adoption of improved dairy cow breeds is linked to farm-level outcomes that translate into household-level benefits including improved child nutrition outcomes in Uganda. Using nationwide data from Uganda's National Panel Survey, propensity score matching is used to create an unbiased counterfactual, based on observed characteristics, to assess the net impacts of improved dairy cow adoption. All estimates were tested for robustness and sensitivity to variations in observable and unobservable confounders. Results based on the matched samples showed that households adopting improved dairy cows significantly increased milk yield-by over 200% on average. This resulted in higher milk sales and milk intakes, demonstrating the potential of this agricultural technology to both integrate households into modern value chains and increase households' access to animal source foods. Use of improved dairy cows increased household food expenditures by about 16%. Although undernutrition was widely prevalent in the study sample and in matched households, the adoption of improved dairy cows was associated with lower child stunting in adopter household. In scale terms, results also showed that holding larger farms tends to support adoption, but that this also stimulates the household's ability to achieve gains from adoption, which can translate into enhanced nutrition.
人们普遍认为，促进畜牧业生产有助于提高饮食质量和儿童营养水平，但这种因果联系的实证证据仍然有限且不明确。本研究考察了采用改良奶牛品种是否与农场层面的成果相关联，而这些成果又能转化为家庭层面的益处，包括改善乌干达儿童的营养状况。利用乌干达全国面板调查的全国性数据，倾向得分匹配法基于观察到的特征创建了一个无偏反事实，以评估采用改良奶牛的净影响。所有估计值都针对可观察和不可观察混杂因素的变化进行了稳健性和敏感性测试。基于匹配样本的结果显示，采用改良奶牛的家庭牛奶产量显著增加，平均增幅超过200%。这导致了更高的牛奶销售量和牛奶摄入量，证明了这种农业技术在使家庭融入现代价值链以及增加家庭获取动物源食品机会方面的潜力。采用改良奶牛使家庭食品支出增加了约16%。尽管在研究样本和匹配家庭中营养不良现象普遍存在，但采用改良奶牛与采用家庭中儿童发育迟缓率较低有关。从规模角度来看，结果还表明，经营较大的农场往往有助于采用改良奶牛，但这也会增强家庭从采用中获得收益的能力，进而转化为营养状况的改善。
