Comparison of Different Levels of Vitamin Premix on Meat Lipid Oxidation in Floor and Battery Cage Broiler Raising Systems

A total of 1260 male broiler chicks (Ross 308) were allocated to 7 treatment groups (different levels and access time to vitamin premix (VP)) at 29 to 42 days of age, in floor system (Experiment 1) and battery cage system (Experiment 2). The oxidative stability was evaluated by thiobarbituric acid reactive substances (TBARS) on the thigh yield that were storage for 180 days in -20˚C. Results of experiment 1 showed that VP reduction and withdrawal from 29 d of age did not impair body weight, feed intake and feed conversion ratio during the final period of treatments (29-42d).Results of experiment 2 showed that there were no significant differences in the birds’ performance with reduction or withdrawal of VP from diets in 29-35 days among the experimental groups, but in 36-42 days of age, the performance of the group of birds fed with diet without VP (T1) was significantly lower than other groups. The results of experiment 2 showed that the performance of birds fed with diet without VP was significantly lower than other treatments in 36-42 days of age. The results of TBARS values in experiment 1 for thigh meat samples of birds slaughtered at 42 days of age showed that TBARS values of treatments without VP were significantly higher than other treatments. However in experiment 2, TBARS values of treatments without VP and with 33% VP were significantly higher than other treatments for birds slaughtered at 42 days of age. Finally, the results of this study demonstrate firstly that it is not possible to withdraw but it can be possible to reduce VP in finisher broiler's diets without negative effects on performance and meat quality during the time of freezing in both methods of rearing. Secondly, it is possible to reduce the VP levels in diet of broilers reared in floor system more than battery cage system

Effects of different levels of vitamin premix in finisher diets on performance, immuno - competence and meat lipid oxidation of chickens fed on corn - soybean meal

The present study was carried out to examine the effects of a vitamin premix (VP)reduction or withdrawal from finisher diet (29-43 days) on performance,immuno-competence,and characteristicsof leg bones and meat lipid oxidation of chickens fed oncorn-soybeanmeal based diet. A total of 900 male broiler chickens (Ross 308) were allocatedtofivetreatment groups(0, 33%, 66%, 100% and 133% VP), withninereplicates per treatmentgroup. At 29 and 36 days of ages, four birds from each replicate were injected with sheepredblood cells (SRBC). The cell-mediated immunity was determined via phytohemagglutinin(PHA) and 1-chloro 2-4-dinitrobenzen (DNCB)at 34 and 42 days of ages.At 33, 38 and 43days of age, 42 days of ages, and two birds of each replicate were slaughteredand boneparameters measured. The oxidative stability was evaluated by thiobarbituric acid reactivesubstances (TBARS) on the thigh samples that were stored for 90 day at-80 ̊C. The resultsshowed that reduction or withdrawal of VP from diets at different time points of the finisherperiod did not affect performance, immunocompetence and characteristics of leg bones.Results of TBARS showed thatlipid peroxidation of the treatment without VP wassignificantly higher than of the other treatments when slaughtered at 43 days of age. Finally,the results of this study demonstrated that it is not possible to reduce the VP in finisherbroilers’ diets without negative effects on meat quality during the time of freezing

Decreasing vitamin premix on chicken carcass composition and blood chemistry in floor and battery cage systems

Two experiments were conducted the to compare the effect of a decreasing amount of vitamin premix in diets inbroilers from 29 to 42 days of age on carcass composition and blood chemistry in floor (Experiment 1) and battery cage (Experiment 2) systems. At 35 and 42 days of ages, one bird of each replicate was slaughtered and carcass composition was measured. Blood concentrations of alkaline phosphatase (ALP) and Ca were used to diagnose vitamin D3 deficiency and enzymes aspartate amino transferase (AST) to identify vitamin E deficiency. Floor raised birds showed that vitamin premix reduction/withdrawal at 29 days of age did not impair body weight (BW), carcass composition, ALP and Ca during the final rearing period. However, diet without vitamin premix (T1) had a higher AST at 42 days of age than the other diets. Birds reared in cages were slightly more sensitive to vitamin premix reduction/withdrawal, probably due to the impracticality of performing coprophagy. Diet without vitamin premix (T1) had a lower BW, carcass breast and thigh yield at 42 days of age; also serum ALP, AST and Ca were impaired. In conclusion, the withdrawal of vitamins is not a reasonable option but it is possible to reduce vitamin premix in finisher broilers’ diets without negative effects on performance and on some metabolic traits during the finisher period with both methods of rearing