UTILIZATION OF LUPIN (Lupinus angustifolius) SEEDS SUPPLEMENTED WITH AMINO ACIDS BY CHICKS

The utilization of feeding white sweet lupin (Lupinus angustifolius cv. Uniwhite) seeds supplemented with the limiting amino acids were investigated in day-old single comb White Leghorn male chicks. These were fed a commercial chick mash for the first 10 days and on a semi-synthetic protein-free diet for the next 6 days. For the subsequent 6 days of experimental feeding period, the birds were fed on the protein-free diet, basal diet containing 9.31% of lupin seed meal (LSM) protein, diets supplemented with methionine, methionine + tryptophan or methionine + tryptophan + lysine in the basal diet, and diet containing 9.84% of soybean meal (SBM) protein. When the LSM protein was supplemented with methionine, protein intake, body weight gain, protein efficiency ratio (PER) and net protein ratio (NPR) were increased (p<0.05). The birds excreted lower urinary nitrogen and fecal nitrogen per protein comsumption, had improved apparent (AD) and true (TD) digestibility but did not alter biological value (BV) of the protein. Metabolizability (MEn/GE) and heat production (HP) per MEn intake (HP/MEn) was lowered while energy retention (ER) was highered (p<0.05) compared with those of the basal diet. Also the body weight gain, PER, NPR and ER was increased but the BV and HP/MEn was lowered compared with those of the SBM protein. The results indicated that lupin seed supplemented with methionine increase body weight gain and energy rentention but did not alter biological value compared with those of lupin seed and soybean meal.