Associations between livestock keeping, morbidity and nutritional status of children and women in low- and middle-income countries: a systematic review

Abstract

Livestock keeping can positively influence nutritional status of populations and households through increased consumption of animal-source foods (ASF) and other indirect pathways, but can also adversely affect health by increasing the risk of diseases. We conducted a systematic review synthesizing the current state of knowledge on the associations between livestock keeping and infectious disease and nutritional status of under-five children and women of reproductive age in low- and lower middle-income countries (LMICs). A comprehensive search of 12 electronic databases and grey literature sources published from 1991 to the end of December 2020 was conducted. Investigations exploring relationships between livestock keeping and risk of infectious disease transmission and nutritional status were selected using pre-defined inclusion criteria. After screening and filtering of 34,402 unique references, 176 references were included in the final synthesis. Most (160/176, 90.1%) of the references included in the final synthesis were from sub-Saharan Africa (SSA) and Asia. About two out of every five (42%) studies reviewed showed that livestock production is associated with improved height-for-age Z scores (HAZ) and weight-for-length/height Z scores (WHZ), while close to a third (30.7%) with improved weight-for-age Z scores (WAZ). Similarly, livestock production showed a positive or neutral relationship with women’s nutritional status in almost all the references that reported on the topic. Conversely, four-fifths (66/81, 79.5%) of the references reporting on infection and morbidity outcomes indicated that livestock keeping is linked to a wide range of infectious disease outcomes, which are spread primarily through water, food, and insects. In conclusion, in many LMIC settings, livestock production is associated with better nutritional outcomes but also a higher risk of disease transmission or morbidity among women and children.

The impact of livestock interventions on nutritional outcomes of children younger than 5 years old and women in Africa: a systematic review and meta-analysis

“…Furthermore, studies on fecal pathogen pathways should be studied when assessing nutrition-based interventions. In addition, there is increasing evidence of the negative impacts of livestock on child gut health and child nutrition (25). Exposure to enteric pathogens leads to chronic infection of the intestines and inflammation of the gut leading to dietary deficits.…”

“…Exposure to enteric pathogens leads to chronic infection of the intestines and inflammation of the gut leading to dietary deficits. To ensure a comprehensive assessment of the effects of livestock on nutrition and health outcomes, there is an urgent need to include poor gut health as an immediate determinant of child undernutrition, hence effectively expanding the UNICEF framework to include inadequate dietary intake, disease, and poor gut health as immediate causes of malnutrition (25).…”

“…Future studies need to incorporate an economic evaluation component to determine the cost-effectiveness of nutrition-sensitive livestock interventions in improving nutritional outcomes in women and children. Although livestock interventions have shown the potential to improve children's diets through the consumption of nutrientdense ASFs and improving dietary diversity, more research is required to understand the risks posed by animal rearing on child nutrition, particularly on morbidity, disease, and gut health in the African setting (25,74).…”

“…However, the nexus between the malnutrition-environment-infection axis is complex, and evidence, particularly on the effect of infectious zoonotic diseases on child nutritional status, is limited (37). Furthermore, livestock interventions may also lead to nutritional risks (25,38). For example, increased household income through the sale of milk, meat, or eggs may not translate into improved nutrition as a result 10.3389/fnut.2023.1166495 of household social dynamics (39-41).…”

Perspective: Connecting the dots between domestic livestock ownership and child linear growth in low‐ and middle‐income countries

“…As a result, the relationship between DLO and child stunting and growth as a whole is unclear. A recent systematic review by Zerfu et al ( 2023 ) identified a significant volume of research identifying a positive association between livestock keeping and children's HAZ, but also many, albeit significantly fewer, papers finding neutral and inverse associations (Zerfu et al, 2023 ). Such ambiguous findings on the effect of exposure to animals/animal faeces were also briefly described in the review by Penakalapati et al ( 2017 ).…”