APPARENT ILEAL DIGESTIBILITY OF AMINO ACIDS IN GROUNDNUT CAKE-BASED DIETS FOR BROILERS

Abstract

The apparent ileal amino acid digestibility of groundnut cake (GNC) at varying inclusion (0, 10, 20 and 30%) was determined for broiler chicks in a 7-day experiment. The feed ingredient used served as the sole source of amino acids, as other feed ingredients were fixed. The birds received a commercial broiler starter diets during the first 14 day post hatch. On day 14, birds were sorted by body weight and randomly distributed into 4 dietary treatments in a completely randomized design. Each diet comprised 4 replicates of 5 birds per replicate from day 14 to 21 post hatch. On day 21, all birds were asphyxiated with CO, and digesta samples from the terminal ileum were collected. Titanium dioxide was included as the indigestible dietary marker at a level of 5g/kg. In overall, the concentration of essential amino acids (AAs) analyzed in groundnut cake-based diets was highest in diet 4 with 30% GNC level as compared to other lower levels of GNC inclusion, least values for all the essential AAs were recorded in the control diet. The digestibility of all the essential AAs in birds on GNC diets increases as the level of GNC increased in the diets except for tryptophan which was significantly (P<0.05) lowered in diet 4 containing 30% GNC. In addition, digestibility of threonine was lowered compared to other essential AAs. Similar trend was observed in the digestibility ofnon-essential AAs in birds on the experimental diets. Digestibility ofnon-essential AAs increased as GNC level increases across the diets except for glycine, hydroxyproline and serine. The data from the present study showed that there were considerable differences in CP and AA digestibility of varied levels of groundnut cake in broiler starter diets.