Animal milk sustains micronutrient nutrition and child anthropometry among pastoralists in Samburu, Kenya

Milk has been integral to pastoralist nutrition for thousands of years, but as communities move toward settled livelihoods, milk consumption is dropping with only minimal evidence for the health and nutrition implications. This longitudinal study aimed to first test whether increased dependency on agriculture reduced household milk production and consumption, and ultimately, nutrient adequacy among the Samburu pastoralists. Second, we investigated whether household milk availability affected child milk intakes and anthropometry. Socioeconomic and dietary intake data were collected from households (n = 200) in 2000, 2005, and 2010, and anthropometric measures and individual child milk intakes in 2012. Nutrient intakes were assessed by the probability of nutrient adequacy method, and generalized least-squared regression modeling with mixed effects was applied to identify predictors of milk consumption. Milk contributed 10% of energy intakes, below maize (52%) and sugar (11%), but over one-half of critical micronutrients, vitamins A, B ₁₂, and C. Livestock holdings and income increased the likelihood of higher milk intakes (overall adj R² = 0.88, P < 0.001). Undernutrition was widely prevalent among young children: stunting (30.6%); underweight (23.9%); and wasting (8.6%). There was evidence for a previously described Nilotic body type in the youth, who were taller and thinner than the international reference. Milk consumption at the household level was positively associated with higher body mass index z scores among youth (P < 0.001). Programming for livestock development may better ensure micronutrient nutrition in Samburu, while deeper investigation into the diet and growth patterns of pastoralists could provide insight into leaner and taller anthropometrics for other populations globally.