THE FEASIBILITY OF REPLACEMENT OF GRAIN BY TAPIOCA IN DIETS FOR GROWING-FATTENING CATTLE

Tapioca is produced by the tubers of Manihot esculenta Crantz which gr ow in tropical areas. It is high in starch and very low in protein con tent, and cheaper than grains. The replacement of grain by tapioca in diets for cattle was studied in an in vivo digestibility trial and two feeding trials. The source of supplemental protein was soya bean meal (SBM) in the first feeding trial and ensiled poultry litter (PL) in t he second. Two diets were fed in the digestibility trial: (i) 100% vet ch hay and (ii) 50% vetch hay -50% tapioca. The values for tapioca wer e calculated by difference. The digestibility coefficients of dry (DM) and organic matter (OM), crude protein (CP) and neutral detergent fib er (NDF) of tapioca were 78.8, 83.5, -32.8 and -8.1%, respectively, in dicating erosion of endogenic protein by the tapioca. The calculated m etabolizable energy value of tapioca was 12.80 MJ/kg DM. There were no significant differences in the performance of the animals in the feed ing trials when up to 40% of the grain was replaced by tapioca, except for a small increase in DM intake. When SBM was the sole source of su pplemental protein, the replacement of 20 and 40% of the grains by tap ioca led to a reduced efficiency, of energy conversion into live weigh t, by 13 and 10%, respectively. Whereas when PL was used for the same purpose the efficiency of energy conversion was about 2% lower but the cost of feed per kg live weight was reduced by 14%. It was concluded that the combination of tapioca and PL in growing-fattening diets is f easible and has no ill effects.