The effect of the inclusion of recycled poultry bedding and the physical form of diet on the performance, ruminal fermentation, and plasma metabolites of fattening lambs1

During a 125-d experimental period, 24 Afshari × Kurdish male lambs initially weighing 25.2 ± 1.2 kg were grouped by BW and randomly assigned to treatments under a completely randomized design with a 2 × 2 factorial arrangement of treatments to evaluate the effects of feeding recycled poultry bedding (RPB; 0 and 200 g/kg DM) and the physical form of the diet (mash and block) on nutrient intake and digestibility, ruminal and plasma parameters, microbial N supply, N balance, feeding behavior, and growth performance of the lambs. Two diets with and without RPB in both mash and block form were prepared. Neither the inclusion of RPB nor the physical form of the diet affected the concentration of VFA or the total tract apparent digestibility of nutrients. Dietary RPB inclusion increased DMI (P < 0.01), tended (P = 0.10) to reduce ADG, and decreased G:F (P = 0.05). The physical form of the diet had no effect on DMI but decreased ADG (P = 0.01) and G:F (P = 0.02) in lambs fed on the block diet compared with those fed on the mash diet. Neither the inclusion of RPB nor the physical form of the diets had any effect on microbial N supply (g/d) and N retention. Rate of eating (P = 0.07), time spent eating (P = 0.87) and ruminating (P = 0.28), and total chewing activity (P = 0.65) were not affected by dietary RPB inclusion. Rate of eating decreased (P < 0.01) and time spent eating and total chewing activity increased (P = 0.01 and P = 0.02, respectively) in lambs fed on the block diet compared with those fed on the mash diet. Results of the current study showed that inclusion of RPB up to 200 g/ kg DM in diets for fattening was possible without any effect on performance and animal health. Processing of feed into the mash form gave higher livestock productivity in comparison to the block form.