Nutritive value of leaf protein concentrates for young chicks.

Abstract

Eight-day old chicks were fed the diets containing leaf protein concentrates (LPCs) with or without supplementation of deficient amino acids as a sole protein source to supply 19-20% crude protein in the diet. The performance of the chicks fed the LPC diets was compared with that fed the methionine supplemented soybean protein control diet. The LPCs used here were obtained from the mixture of alfalfa+barnyard grass (LPC A), from the mixture of oat+annual meadow grass (LPC B) and from ladino clover (LPC C). Chemical analysis showed that the LPC A diet was deficient in arginine and methionine and the LPC C diet in arginine, when compared to the NRC requirements for chicks. Feed intake of the birds fed the LPC A or LPC A+Arg+Met were not significantly different from that of the control diet, while the birds received the LPC B consumed significantly more diet than the control. Feed intake of the birds fed the LPC C or LPC C+Arg were significantly lower than that of the control. Body weight gain and feed efficiency were significantly lower in the LPCs than in the control. Even when the deficient amino acids were supplemented to the LPC diets no significant improvement of both body weight gain and feed efficiency was observed. Nitrogen retention rate was significantly lower in the LPC diets than in the soybean protein control diet even when the LPCs were supplemented with deficient amino acids. Energy metabolizability was extremely low in the LPC diets compared to that of the soybean protein diet. Among the LPCs including those supplemented with deficient amino acids, LPC B (oat+annual meadow grass) showed the highest protein utilization and energy metabolizability. The inferiority of LPCs in protein and energy utilization might lead the low nutritive value of LPCs for poultry.