Analysis of joint and endogenous technology choice for protein supplementation by smallholder dairy farmers in Zimbabwe

Survey data on observed choices of protein feed supplements by smallholder dairy farmers in Chikwaka communal area of Zimbabwe were analyzed for factors affecting use of a specific agroforesty practice. The observed protein supplementation choices included multipurpose tree [MPT] fodder and purchased concentrates. These supplements were used mostly in combination and were thus considered jointly by multivariate probit analysis. The results indicated significant positive correlation suggesting joint use of the two protein supplements by these smallholder dairy farmers. Significant correlations also indicated that relative specialization in the dairy enterprise, where milk revenue is cited as the primary income source, is an endogenous factor in the choice of both protein supplements by farmers. Multinomial logit analysis was also applied to determine significant explanatory factors in supplement choice. It was found that dependence on off-farm wages, cropping season labor constraints and receipt of crop revenue as the primary income source each significantly reduced the probability of using both purchased concentrates and multipurpose tree fodder. The probability of using multipurpose tree fodder alone was reduced by relatively fewer years of experience in the dairy industry and in growing MPT fodder trees, but increased by having greater areas planted. Overall, continued use of MPT fodder and the potential of this technology to substitute for purchased concentrates appeared to be dependent on the ability to generate income from milk production and fodder yields from the technology in the short-term, and the learning curve with fodder tree growing in the long-term.