| Popis: |
SUMMARY Two experiments were conducted to evaluate the effect of titrated levels of spray-dried plasma (SDP) in broilers diets submitted to various types of health challenge. In experiment 1, dietary plasma levels (%) during the periods of 1 to 7, 8 to 21, and 22 to 42 d were T1 (0/0/0), T2 (1.5/0/0), T3 (1.5/0.5/0), T4 (3.0/0/0), and T5 (3.0/0.5/0), respectively. In experiment 2, dietary plasma levels were T1 (0/0/0), T2 (1.5/0/0), T3 (1.5/0.5/0), and T4 (1.5/0.5/0.25) fed during the periods of 1 to 8, 9 to 21, and 22 to 42 d, respectively. In both experiments, flock uniformity and livability were not affected by SDP. In experiment 1, SDP addition resulted in lower feed intake (FI) and improved FCR from d 1 to 21. Lower FI was also observed during wk 2 for broilers fed SDP from d 1 to 7, even if SDP was or was not provided during this time period. Performance variables were not different by treatments from d 22 to 42, neither was carcass yield at 42 d. In experiment 2, there was higher weight gain from d 8 to 21 and 1 to 42 in birds fed SDP relative to those not fed plasma. Broilers submitted to T2 had higher FI during the total experimental period as compared with T1. Dietary inclusion of SDP may change the performance of broilers reared under challenge conditions, with a positive effect particularly in the first stages of life. |
