VIABILIDADE ECONÔMICA DA UTILIZAÇÃO DA SILAGEM DA RAIZ DE MANDIOCA NO SUPLEMENTO DE VACAS LEITEIRAS

Abstract

The objective was to determine if there is economic viability in including cassava root silage (SRM) in the food supplement of dairy cows. Ten primiparous Girolando F1 cows (Holstein + Gyr) distributed in two simultaneous 5 × 5 Latin squares were used. Five treatments were evaluated: I – grazing cows without concentrate supplementation (SSC); II - grazing cows receiving 5 kg of concentrated supplement with 0% SRM; III - grazing cows receiving 5 kg of concentrated supplement with 26% SRM; IV - grazing cows receiving 5 kg of concentrated supplement with 52% SRM and V - grazing cows receiving 5 kg of concentrated supplement with 78% SRM. There were analyzes about the cost of the ingredients in the supplement, the cost per ingredient consumed per cow per day, the cost of milk production generated only by the concentrated supplementation, the profit of the milk production generated by the supplementation and the costs, margins, rates and profits of the supplement milk production. The supplementation cost increased linearly as the SRM supplement inclusion. The highest level of SRM inclusion increased the cost of the supplement by 30.69%. The cost of the extra kg of milk produced by concentrated supplementation (Marginal Production) increased linearly with the inclusion of SRM in the supplement (P<0.05). Profitability of supplementation decreased linearly with increasing SRM inclusion (P<0.05). The profitability index of supplementation was reduced by 61% as more SRM was included in the supplement. Increasing the inclusion of SRM in the supplement, until the total replacement of corn, did not increase milk production. The inclusion of SRM in the supplement does not affect milk production and its qualitative aspects, but it increases the cost per kg of the supplement, reducing its viability.