ChileanJAR

Two hundred day old broiler chicks, White Cornish X White Rack were ramdomly distributed into .five treatments whith four replications of 10 chicks each. The chicks were kept in hrooderbatteries (0-4 weeks) and floor pens (4-12 weeks) .
Five proteins sequences were tested mantaining the metabolizable energy/protein ratio constant for each of the three periods as follows: 128 (0-4 weeks); 151 (4-8) and -173 (8-12).
Similar rbody weight gains .were obtained at four weeks of age when 24% or 22% protein were included within diets but feed eHiciency favored the higher level used. At 10 and 12 weeks of age, body weight gain andfeed efficiency favored treatments with higher protein levels from 4 to 10 or 12 weeks. It isconcluded that the longer the fattening period, higher levels of protein (16-20%) are required for higher weight and more efficient chicks.
The protein sequence 22-20-16 was economically better whatever the extension of the computed period. was.