Three broiler trials were conducted to age of 7-days, 21-days and 42-days, for trials 2, 3, respectively and I. In trial 1, two treatments were used: 1) the control (c) in which chicks received no preventive medication in the form of chlortetracycline (tetracycline HCL); 2) preventive medication (m-7) in which one day old chicks were given a preventive course (for seven days) of chlortetracycline at 0.5 g/L drinking water. In trial 2, three treatments were used: treatments 1 (c) and 2 (m-7) where similar to those in trial 1; however, chicks in treatment 3 (m-10) were given the preventive course for 10 days. In the third trial, four treatments were used, 1) common broiler house clean-out and chicks were given no medication (c-nm); 2) common broiler house clean-out and one day-old chicks were given a preventive.
This experiment was conducted to investigate the effect of microbial phytase supplementation on broilers performance, nutrient digestibility, carcass cuts and body status of Ca and P. A total of 200 day-old Cobb-500 chicks were used in the experiment. Birds were partitioned into five experimental groups of 40 birds each treatment was composed of 4 replicates with 10 birds in each. The control group was fed a commercial starter and finisher diet. The second treatment group was fed a phosphorus deficient diet, while the third, fourth and fifth treatments groups were fed a phosphorus deficient diets plus the microbial phytase. Phytase enzyme was incorporated at levels 1000, 2000 and 3000 PU/kg feed for the last three treatments, respectively. In the last week of experimment, four birds from each replicate were used in metabolic trial. However, at time of termination of the experiment, the same birds were killed for carcass cuts and tibia ash content investigations. Results of the experiment showed that the addition of phytase enzyme to P- deficient diets significantly improved (P<0.5) broilers performance. Howeever, feed intake, feed conversion ratio and tibia minerals were significantly increased (P0.05) in birds fed P- deficient diets supplemented with phytase. Phytase supplemmentation had no significant effect on carcass cuts and dressing percent compared to birds fed the low P diets. Also, results of this investigation showed that phytase enzyme increased (P0.05) the digestibility of dry matter, crude protein and ash.
The current investigation was conducted to study the effects of olive pulp on the carcass composition, gastrointestinal tract, and visceral organ mass of broiler chicks. A total of 250 one-day-old chicks were used in this research and were divided into five experimental groups with five replicates in each. Olive pulp was incorporated in four of the experimental groups at rates of 25, 50, 75 and 100 g/kg in both starter and finisher feeds to replace similar amounts of maize. Diets were fed for 35 days. At the end of the experiment, four birds of each group were slaughtered in similar routine followed in regular slaughterhouses. Regression analysis (linear and quadratic) showed that level of olive pulp had no significant effects on visceral organ mass, gastrointestinal tract weight, carcass cuts, carcass composition, and dressing percent. However, chicks consuming 100 g olive pulp/kg had heaviest (P<0.05) average live weights.