Prevention of the dry season peak in child wasting in Chad: Evidence from a cluster randomised controlled trial of integrated livestock interventions

A cluster-randomised controlled trial in Chad demonstrates that an integrated livestock intervention combining feed supplementation, zoonotic risk mitigation, and nutrition counselling effectively prevents the dry-season peak of child acute malnutrition by sustaining milk production and reducing disease, while delivering a high return on investment.

The Gist

Imagine a village in Chad as a small, tight-knit family living in a house with a very special, fragile roof: their livestock. In this region, the year has two distinct seasons. The rainy season is like a feast where the grass is green, the animals are healthy, and the family has plenty of milk to drink. But then comes the dry season, a harsh, scorching time when the grass turns to dust, the animals get thin, and the milk supply dries up.

For years, this dry season has been a "perfect storm" for children. When the milk stops flowing, children stop growing strong, and many fall sick from hunger or diseases carried by the thirsty animals. Usually, aid groups wait until the children are already starving before rushing in with medicine and food. It's like waiting for a house to catch fire before calling the fire department.

The Experiment: A New Kind of Fireproofing

This paper describes a bold experiment where researchers tried a different approach: prevention. They asked, "What if we help the family fix their roof before the storm hits?"

They picked 76 villages and split them into two groups, like two teams in a game:

• The Control Team: They got the usual help (waiting until things got bad).
• The Intervention Team: They got a special "Dry Season Survival Kit" starting in December.

What was in the Survival Kit?
Instead of just giving food to the children, the researchers helped the source of the food: the animals.

1. Animal Food: They gave the livestock extra feed so the animals stayed fat and healthy even when the grass was gone. This meant the mothers could keep producing milk.
2. Health Shield: They taught families how to stop germs from jumping from animals to humans (zoonotic diseases), acting like a protective shield against sickness.
3. Nutrition Coaching: They gave advice on how to feed the children the best way possible.

The Results: A Miracle in the Dust

When the dry season hit its worst point in May, the difference between the two teams was shocking.

• The Hunger Gap: In the villages that didn't get the kit, nearly half the children (47%) were severely malnourished. It was a crisis. But in the villages with the kit, only about 1 in 5 children (22%) were malnourished.
• The Milk Flow: Because the animals were fed, the intervention families had 588 extra milliliters of milk every single day. That's like giving every child in the house an extra large glass of milk every day.
• The Health Boost: Because the animals were healthier and the families knew how to stay safe, the children got sick much less often. Colds and stomach bugs dropped by about 80%.

The "Bang for the Buck"

The researchers also looked at the money. They found that for every dollar spent on this prevention plan, the community got back $5.40 in just six months. If they looked at the long-term benefits (like healthier kids growing up to be productive workers and less money spent on emergency food later), that return jumped to $16.40 for every dollar spent.

The Big Picture

Think of this study as proving that fixing the engine is better than towing the car.

By helping the livestock (the engine) survive the dry season, the whole family (the car) keeps moving forward. This approach doesn't just stop hunger; it keeps the family dignified, saves them from selling their animals in panic, and stops diseases before they start. It's a smart, high-return way to protect children in some of the world's toughest places, turning a predictable disaster into a manageable season.

Technical Summary

1. Problem Statement

In the Sahelian drylands of Chad, child acute malnutrition consistently exceeds emergency thresholds. A critical, predictable, yet often overlooked driver of this crisis is the dry season peak (typically May), which correlates with:

• Declining pasture and livestock productivity.
• Reduced availability of milk, a critical nutrient source for children.
• Heightened exposure to zoonotic infections due to close human-animal contact in lean conditions.

Current humanitarian responses in the region are predominantly reactive and treatment-focused (e.g., treating severe acute malnutrition after it occurs). There is a significant evidence gap regarding preventive strategies that address the root causes embedded in local livelihood systems, specifically the intersection of livestock management, nutrition, and disease control.

2. Methodology

The study employed a cluster-randomised controlled trial (cRCT) design to evaluate an integrated intervention.

• Setting: Kanem and Barh-El-Gazel provinces in Chad (pastoral and agro-pastoral communities).
• Sample: 76 villages (clusters) were randomised 1:1 to intervention or control arms.
• Eligibility: Households with at least one child aged 6–59 months and access to milking livestock during the dry season.
• Intervention Period: December 2024 to June 2025.
• Intervention Components: A multi-sectoral package designed to sustain livelihoods and health:
  1. Livestock Feed Supplementation: To maintain milk production near households during the dry season.
  2. Zoonotic Risk Mitigation: Household-level measures to reduce disease transmission from animals.
  3. Nutrition Counselling: Education on optimal child feeding practices.
• Data Collection & Analysis:
  • Primary Assessment: A prespecified random subsample of 52 clusters assessed at the dry-season peak (May 2025).
  • Secondary Assessment: All 76 clusters assessed post-peak (July 2025).
  • Statistical Approach: Intention-to-treat (ITT) analysis using mixed-effects models.
  • Economic Evaluation: A societal Return on Investment (ROI) analysis conducted over 6 months with projections to 24 months.

3. Key Results

The intervention demonstrated statistically significant improvements across nutritional, health, and economic indicators.

Nutritional Outcomes (at Dry Season Peak):

• Global Acute Malnutrition (GAM): Reduced from 47.4% in control villages to 22.2% in intervention villages (Adjusted OR 0.29; 95% CI 0.18–0.49; p<0.001).
• Severe Acute Malnutrition (SAM): Reduced from 19.4% in controls to 4.4% in intervention villages (Adjusted OR 0.17; 95% CI 0.08–0.37; p<0.001).

Mechanisms of Action:

• Milk Availability: Intervention households had 588 mL more daily milk availability per household (p<0.001).
• Child Consumption: Children in intervention villages consumed 102 mL more milk per day (p=0.008).
• Disease Burden: Significant reductions in self-reported diarrhoeal disease (aOR 0.21) and acute respiratory infections (aOR 0.22).

Post-Peak and Socio-Economic Outcomes:

• Women's Health: Dietary diversity scores increased significantly (aOR 3.68).
• Livelihood Resilience: Reduced workload for women, lower household food insecurity, and a decrease in distress livestock sales.
• Livestock Condition: Improved health and condition of the animals.
• Economic ROI:
  • Benefit-Cost Ratio (BCR) at 6 months: 5.40.
  • Projected BCR at 24 months: 16.40.

4. Key Contributions

• Evidence for Preventive Action: This study provides robust empirical evidence that anticipatory action (acting before the crisis peaks) is more effective than reactive treatment for seasonal wasting.
• One Health Approach: It validates a "One Health" livelihood model, demonstrating that integrating animal health (feed), human health (zoonosis control), and nutrition (counselling) creates a synergistic effect greater than the sum of its parts.
• Economic Viability: The high ROI (rising to 16.40 over two years) challenges the notion that preventive livelihood interventions are too costly, proving they are highly cost-effective compared to emergency treatment.
• Scalability: The intervention targets the specific drivers of the Sahelian lean season, offering a scalable model for similar pastoral and agro-pastoral settings globally.

5. Significance and Interpretation

The findings suggest that protecting livestock productivity and ensuring sustained access to milk during the pastoral lean season is a critical, yet underutilized, strategy for preventing child acute malnutrition.

By shifting the paradigm from reactive treatment to integrated prevention, humanitarian actors can:

1. Save Lives: Drastically reduce the incidence of severe wasting and associated mortality.
2. Preserve Dignity: Support local livelihoods rather than creating dependency on food aid.
3. Optimize Resources: Achieve a high return on investment, freeing up resources for other critical needs.

The study concludes that this integrated, livelihood-based approach offers a dignifying, high-return, and lifesaving model for humanitarian settings facing seasonal food and nutrition insecurity.