DISCUSSION
SEPARATION
This study examined the effectiveness of a 3 year information only, nutrition‐ and gender‐sensitive poultry value chain intervention, with and without additional livestock WASH behaviour change, to reduce child morbidity symptoms and improve anthropometric indicators in children of 2−4 years of age at baseline in rural Burkina Faso. In addition, through a trial substudy, we also examined whether the treatment effects of the intervention varied by season. At endline, after 3 years of programme implementation, there was evidence that the SELEVER intervention had increased caregiver knowledge of WASH‐related livestock risks for young children. This resulted in some improvements in WASH‐related livestock practices, particularly those involving the separation of small livestock and children in the household compound. Improvements in practices were particularly apparent in the WASH substudy population during the lean season, with larger effects in the SELEVER + WASH compared to the SELEVER study arm. In the main trial, there was no evidence of positive effects of the SELEVER intervention on index children's prevalence of caregiver‐reported morbidity symptoms or of measured child anthropometric outcomes. Results from the WASH‐substudy suggest a negative, albeit very small, effect on index children's height (−0.5 cm; 95% CI (−1.09 to 0.01), marginal statistical significance There are several potential explanations for the overall modest positive to null impacts of the studies on child morbidity and anthropometry and for the suggestive negative effects of the programme on index children's height and on younger siblings' anthropometry. For interpretation, we draw on the results from the intermediary outcomes reported in this analysis and those of the analyses on the primary outcomes of the SELEVER trial reported elsewhere. First, the lack of impacts on child outcomes may be due to low programme participation. Overall programme exposure was low, peaking at 3 extra training sessions attended over the prior 12 months compared to the control group, equivalent to 1 extra training session every 3 months, which is well below the expectations of monthly training sessions. Second, our results show that although the SELEVER intervention had some positive impacts on livestock‐hygiene‐related knowledge and some livestock‐hygiene‐related practices, these gains were not sufficient to improve the overall WASH environment and reduce child morbidity. This may, in part, be due to the low participation of households in SELEVER and WASH interventions. In addition, we documented previously that the SELEVER intervention had small effects on household poultry production and no effects on household profits due to an increase in the costs of production. Thus, households had no economic returns from poultry production that they could use to invest in improving the nutrition and health of their children (Leight, Awonon, Pedehombga, Ganaba, Gelli, Another aspect that could explain the reduced differences in WASH environment between control and intervention groups at endline compared to baseline is the fact that WASH levels improved over time in both SELEVER and control groups and that increases were slightly greater in the control group compared to the to SELEVER group (Annex Table With regard to the differential effects of the SELEVER and SELEVER + WASH intervention, the descriptive analysis of baseline levels of the WASH indicators suggests that the overall WASH environment, as well as conditions in each of the WASH sub‐domains, were considerably lower in the SELEVER + WASH group compared to both SELEVER and control groups. As such, our findings may reflect the fact that improving WASH‐related behaviours and practices from a very low base may require a much larger step‐wise investment, as highlighted by the recent literature on WASH and child nutrition outcomes (Cumming et al., There are some clear programming implications of these findings. First, the study population includes households living in deep poverty and food insecurity and with very low baseline WASH conditions. In these contexts, the objectives of a nutrition‐sensitive livestock and nutrition behaviour change intervention should primarily focus on improving knowledge and practices and secondarily on child nutrition, with particular caution on avoiding unintended effects. From an implementer's perspective, a particular emphasis on increasing coverage and implementation intensity is important. However, achieving improvements in practices is also not a given without additional support, particularly in a context where financial constraints are binding and improving practices requires financial investment. To some degree, this was the case with corralling poultry in Burkina Faso, where poultry corralling was associated with increased costs of production related to the coop itself but also with regard to feed necessary to compensate for lack of scavenging opportunities for free‐roaming poultry (Leight, Awonon, Pedehombga, Ganaba, Gelli, 