The Influence of Nutritive Characteristics and of the Period of Administration of Concentrated Mixture on the Productive Performances of Broilers Raised in Organic System

The objective of this experiment was to assess the nutritional characteristics (metabolisable energy (ME) with values between 2850-3000 kcal, crude protein (CP) from 21 to 17%) and mixture concentrated (MC) administration period (biphasically or triphasically) on the productive performance of broilers raised in organic system. The experiment was conducted on a total of 108 ROSS 308 commercial hybrids for 84 days under specific feeding ecological system. The experimental design consisted of 3 treatments with three replicate cages per treatment. It was found that the higher energy MC1 caused a lower average daily consumption in offspring of V1 (43.00 g) compared to broilers of the other two versions, a trend that is maintained in the following phases. Experimental variants V2 and V3 which have consumed in the first phase MC2 with 10% egg in structure obtained a higher average daily gain (23.90 and 23.23 g) in the first phase as well as in the growth and finishing phases. At the age of slaughter (84 days) V2 stands with 3867.33 g body weight which consumed MC2 in phase I (with 10% egg in structure), triphasically fed variant, followed by V3 (3710.96 g) (p> 0.05) biphasically fed. Also the introduction in MC2 of a protein source of high biological value generated in the first phase an feed conversion ratio (FCR) of 1.75, respectively 1.80, higher than recorded in V1 2.08. European production index (EPI) shows a high value (161.06) in the version triphasically fed with MC2, MC4, MC6, with values close to the version MC2 and MC6 biphasically fed (152.80). The costs of feeding are for V3 version biphasically fed even if the first phase feeding costs are higher due to the introduction in the MC2 structure of 10% egg. Given the productive performance and expenses incurred in feeding it should be used in organic farming and growing household a biphasically feeding containing the nutritional requests set.