Coefficients of apparent absorption of the dietary nutrients from broiler feeds that include oil industry by-products (rapeseeds, grapes, buckthorn, flax and pumpkin meals)

A 42-day feeding trial was conducted on 120, day-old ROSS 308 chicks assigned to 4 (C; E1; E2; E3) groups. The broilers were housed in three-tier digestibility cages (5 broilers/cage) which allowed the daily recording of the feed intake and excreta located in an experimental hall with controlled environmental conditions (27.07±2.750 C; humidity 64,80±9,57%; light regimen 23h). During the starter stage (1-10 days) all chicks received a conventional compound feed (C). During the grower and finisher stages, compared to C formulation, the experimental diets different proportions, varying with the stage of development, of rapeseeds and grape meals (E1), buckthorn and flax meals (E2), pumpkin meal (lot E3). The balance study was conducted for 5 days, during weeks 4 and 6. During this period, average weights from each two cages (6 samples/group) of feed consumed and excreta voided (dry matter basis) were recorded and sampled for: dry matter, nitrogen, fat, fibre, ash and gross energy analysis. The chicks from E1 group had a lower (P≤0.05) coefficient of dietary nitrogen absorption than E2 chicks. The coefficients of apparent absorption of the dietary fat varied with the period of development. During the finishing stage, E3 chicks had a higher (P≤0.05) coefficient of fibre absorption than groups C, E1 and E2.