Duarte F, Sandoval-Castro C

Language: Spanish
References: 16
Page: 116-119
PDF size: 22.35 Kb.

ABSTRACT

Introduction. The detoxification of the cyanogenic glucosides (HCN) contained in cassava (Manihot esculenta) involves metabolic pathways which require sulphur. Cassava is deficient in sulphur and sulphur-amino acids and hence they maybe limiting its metabolism in sheep.
Objective. To evaluate the use of supplementary methionine as a mechanism to facilitate HCN detoxification in sheep fed whole cassava silage.
Materials and methods. Three sheep (40.7 kg average live weight) were employed in a changeover design in 2 periods of 20 d (10 d adaptation, 5 d control diet, 5 d experimental diet). Diets were a) whole cassava silage only, b) whole cassava silage + 20 g methionine/d. Animals were kept in metabolic crates and fed whole cassava silage ad libitum. Voluntary intake and urinary excretion of thiocyanate were measured daily. Data was analysed with the general lineal model (GLM) taking into account animal and period for model error partition.
Results. Both diets had similar voluntary intakes (p›0.05) of cassava silage (c. 930gMS/d). Methionine caused an increase (p=0.067) in the urinary excretion of thiocyanate (11.6 vs 28.8 ± 5.42 mg/d, with and without methionine respectively).
Discussion. Methionine is probably playing the role of sulphur donor in HCN detoxification process. Methionine supplements in whole cassava silage diets might help to improve its utilization by helping sheep detoxify HCN. Additional studies are needed to confirm these findings.

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