ABSTRACT
1. The aim of this study was to assess the feasibility of 100% organic feed for organic broilers by comparing it with 80% organic feed (situation at the time of the experiment; 2004) and 95% organic feed (alternative). 2. Diets were optimised for nutritional value, allowing a maximum 10% increase in feed price when using 100% organic feedstuffs. This could only be achieved at the expense of the methionine content. 3. The birds were reared from 0 to 3 weeks of age in a broiler house in three groups of 500 broilers each on either an 80, a 95 or a 100% organic starter diet. At 3 weeks of age, they were transferred to 15 pens with an outdoor run. Each treatment group of 500 birds was divided into 5 groups of 95 and given an 80, a 95 or a 100% organic finisher diet. 4. Broilers receiving 100% organic feed reached a lower body weight and grew more slowly than those receiving 95% organic feed, mainly because of a lower feed intake. 5. Broilers on 95 or 100% organic feed had a higher incidence of breast blisters than broilers receiving 80% organic feed. 6. The cost price for meat from broilers that received 80% organic feed was euro1.83 per kg live weight. The cost prices for broilers that received 95 and 100% organic feed were euro1.84 (+0.8%) and euro1.93 (+5.4%) per kg live weight, respectively. 7. In conclusion, 95% organic feed led to a better performance than 100% organic feed in this study. Probably, the lower methionine content in the 100% organic feed negatively affected performance. The results for 95% organic feed were similar to 80% organic feed, except for a higher incidence of breast blisters.
