Effect of multi-phase feeding on growth, main carcass parts, and nitrogen content in faeces of broiler chickens.

The objective of this paper is to investigate the effect of multiphase feeding, i.e. the effect of different mash feeds with multi-phase protein reduction, on growth, main carcass parts and nitrogen content in faeces of broiler chickens. The experiment was conducted on 1216 chickens of Ross 308 provenience, separated by sex. The experiment lasted for 42 days and the standard technology was used. The groups differed in a type of a mash (treatment) given in the starter period, as follows: T1 (control group) was given a mash with 23% crude proteins from day 1 to day 21; T2 - a mash with 23% proteins from day 1 to day 7, followed by a mash with 21.5% proteins given from day 7 to day 21; T3 - a mash with 23% proteins from day 1 to day 14, followed by a mash with 21.5% proteins given from day 14 to day 21; T4 - mashes changed every three days, having 23%, 22.55%, 22.10%, 21.65% , 21.20%, 20.75% and 20.30% of crude proteins, respectively. Slaughtering performance was investigated on a total of 64 broiler chickens, with eight male and eight female chickens used separately for each of the treatments. Nitrogen content in faeces was determined using the pooled sample of faeces. The obtained results showed some differences in the average daily growth of the male and female chickens when comparing the control (T1) and the experimental groups. Those differences were not statistically significant. However, when comparing the male-only groups, it was determined that the experimental group T4 had statistically significantly higher growth than T2 and T3 group. The effect of the multi-phase feeding programme on the breast, thigh and drumstick share of both male and female broilers was not significant. The applied multi-phase feeding programmes resulted in a reduction in the nitrogen content in the faeces. Considering the obtained results, it can be concluded that the multi-phase feeding programmes had no negative effect on the growth and slaughtering performances of broilers. This goes in favour of these programmes, since they can result in some positive economic and environmental effects of production.