Necesidades de treonina en pollos sometidos a dos calendarios de vacunación

Abstract

A STUDY WAS CONDUCTED WITH THE GOAL OF SEARCHING IF THREONINE REQUIREMENT IS NOT INCREASED WHEN BROILERS ARE SUBJECTED TO A CLOSED VACCINATION PROGRAM WHICH REPRESENTS STRESSFUL HANDLING. NINE HUNDRED AND NINETY MALE AND FEMALE 1 DAY AGE ARBOR ACRES BROILERS WERE DIVIDED INTO 6 TREATMENTS, WITH 6 REPETITIONS OF 30 CHICKENS EACH. A COMPLETELY RANDOMIZED DESIGN WITH A FACTORIAL ARRANGEMENT 3 €” 2 WAS EMPLOYED INCLUDING 3 THREONINE LEVELS ACCORDING TO NRC (1994) REQUIREMENTS (95%, 100% AND 105%), AND TWO VACCINATION PROGRAMS: OPEN (TWO NEWCASTLE DISEASE VACCINES) AND CLOSED [TWO NEWCASTLE DISEASE VACCINES, INFECTIOUS BURSAL DISEASE (IBD) VACCINE AND E. COLI BACTERIN]. DIETS BASED ON SORGHUM SOYBEAN MEAL WERE USED WITH SYNTHETIC L-THREONINE TO ACHIEVE THE REQUIRED LEVELS. RESULTS AT 42 DAYS FOR BODY WEIGHT GAIN, FEED CONVERSION, GROSS MORTALITY AND ANTIBODY TITERS IN SERUM BY THE HEMOAGGLUTINATION INHIBITION TEST FOR NEWCASTLE DISEASE SHOWED NO STATISTICAL DIFFERENCES (P > 0.05) FOR VACCINATION CALENDARS NOR FOR THREONINE LEVELS. RESULTS OF THIS STUDY SUGGEST THAT THREONINE REQUIREMENTS AT 95% OF THOSE RECOMMENDED BY THE NRC (1994) ARE THE ADEQUATE ONES ON BROILER PERFORMANCE AND IMMUNITY.