Carcass Characteristic, Caecal Metabolites and Dropping Quality in Broiler Chickens Fed Diets Containing a Humic Substances

The objective of the study was to determine the effect of humic substances added to diets on carcass characteristics, weight of visceral organs, fermentation process in the caecum and excretion of dry matter and crude protein in broiler chicks. One hundred one day old broiler chicks were assigned in two equal groups. Birds of the experimental group were fed with diets supplemented with humic substances (in amount: 5 g.kg-1 during the first two weeks and 7 g.kg-1 from the 3rd to the 6th week). No significant effect of humic substances supplementation was observed on carcass characteristics (carcass weight, carcass yield, abdominal fat pad) as well as the relative weight of the liver, the heart, the spleen and the bursa of Fabricius. On the other hand, in the experimental group was found significantly higher relative weight of the pancreas (P < 0.05). Also, the concentration of short-chain fatty acids in the caecum content was not significantly affected, but tested substance lowered the pH value in caecum (P < 0.05). Significantly lover content of crude protein (P < 0.05) and also significantly higher concentration of dry matter (P < 0.01) in the droppings of chicks was found in experimental group than in the control group. It was concluded that the addition of humic substances to the diets can contribute to reducing the burden on the environment from poultry farms.