Material and Methods
Ethics statement
This study was carried out in strict accordance with the recommendations of the National Ethic Commission (Warsaw, Poland). All procedures and experiments complied with the guidelines and were approved by the Local Ethic Commission of the Poznań University of Life Sciences (Poznań, Poland) with respect to animal experimentation and care of animals under study, and all efforts were made to minimize suffering.
Birds and Housing
In total, 720 one-day-old male Ross 308 chicks were randomly distributed to 6 experimental groups using 12 replicate pens per treatment and 10 birds per pen. The broiler chickens were kept in floor pens (1.2 × 0.8 m) over a production period of 35 d. The birds were given 23 h of light and 1 h of dark during the first week and then 19 h of light and 5 h of dark from d 7 to 21. From 22 to 42 d of age, there was 23 h of light and 1 h of dark.
Diets and Feeding Program
The composition of the experimental diet is shown in Table 1. The nisin activity was expressed in international activity unit (IU). The diet was formulated to stimulate the proliferation of C. perfringens by use of viscous cereals (barley/wheat), animal fats (beef tallow/pig lard), and fishmeal [11-13]. The diets were prepared in mash form; all raw materials were ground by disc mill (Skiold A/S, Denmark) at 2.5 mm disc distance, mixed without any heat treatment, and fed ad libitum to the birds.
Material and MethodsEthics statementThis study was carried out in strict accordance with the recommendations of the National Ethic Commission (Warsaw, Poland). All procedures and experiments complied with the guidelines and were approved by the Local Ethic Commission of the Poznań University of Life Sciences (Poznań, Poland) with respect to animal experimentation and care of animals under study, and all efforts were made to minimize suffering.Birds and HousingIn total, 720 one-day-old male Ross 308 chicks were randomly distributed to 6 experimental groups using 12 replicate pens per treatment and 10 birds per pen. The broiler chickens were kept in floor pens (1.2 × 0.8 m) over a production period of 35 d. The birds were given 23 h of light and 1 h of dark during the first week and then 19 h of light and 5 h of dark from d 7 to 21. From 22 to 42 d of age, there was 23 h of light and 1 h of dark.Diets and Feeding ProgramThe composition of the experimental diet is shown in Table 1. The nisin activity was expressed in international activity unit (IU). The diet was formulated to stimulate the proliferation of C. perfringens by use of viscous cereals (barley/wheat), animal fats (beef tallow/pig lard), and fishmeal [11-13]. The diets were prepared in mash form; all raw materials were ground by disc mill (Skiold A/S, Denmark) at 2.5 mm disc distance, mixed without any heat treatment, and fed ad libitum to the birds.
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