Ciona (Ciona intestinalis) as a source of fibre for chickens : Effects on productive performance, organs weights and caecal microbiota

Abstract: In this experimental study broiler birds were fed in a randomized block design for 32 days on a control diet (C) based on wheat and soy bean meal and two experimental diets containing 2% (C2) and 4% ciona meal (C4) to examine the suitability of Ciona intestinalis in poultry feed as a source of fibre and its effects on growth performance, microbial composition and digestive traits. Luminal content was taken from caeca at day 12 and 32 and analysed for microbiota profile and short chain fatty acids (SCFA). Diversity and abundance of microbial population was determined by sequencing of amplicons generated from 16S rRNA (bacteria) genes. Effect of inclusion of ciona meal on growth performance and digestive traits were analysed by weighing the birds and visceral organs at different ages and comparing it with control diet. In addition, the analysis of different feeds and sticky dropping tests were also performed. The results indicate that there was no significant effect (P ≥ 0.05) of any dietary treatments on individual weight gain and feed intake while feed conversion ratio was higher for C4 diet than C2 diet. No difference in occurrence of sticky droppings were observed and all modules had good condition during assessment of litter scoring. Birds fed with C4 showed lower dry matter of excreta. No effect of any treatment on relative weight of different organs were observed except for liver and spleen, where an interaction between treatment and day was observed. There was no significant effect of treatments on lactic acid and SCFA concentrations. The effect of diet on similarities and dissimilarities of microbial profile was tested with principal coordinate analysis (PCoA) and showed no clear pattern for any treatment. There was effect of age but no effect (P ≥ 0.05) of any dietary treatment on caecal microbial composition except Lachnoclostridium, where effect of treatment was observed and an interaction between age and treatment for unclassified Lachnospiraceae1. Generally, all birds stayed healthy but a decreased dry matter (DM) of excreta in C4 diets were observed. In conclusion, inclusion of C. intestinalis in poultry diets showed no clear effects as a source of fibre.