Influence of oregano added to diets on performance, selected organs as well as morphometric traits and pH of digestive tract of broiler chickens

Abstract

The aim of the study was to evaluate the effect of the addition of dried oregano from different regions of the world to diets on the production results, selected organs, as well as the morphometric characteristics and pH of the gastrointestinal tract of broiler chickens. The research feedstuff was dried oregano from Poland, Turkey and Egypt and diets containing these herbs. The oregano from Poland, Turkey and Egypt was added to a wheat-corn-soybean diet in an amount of 2%. The experiment was carried out on 168 broilers Ross 308, 84 males and 84 females, randomly divided into 4 groups of 42 birds each. In this experiment, four diets for the starter period (from 1 to 21 days of age) and four for the grower period (from 22 to 42 days of age) were prepared. The control group (K) were fed a wheat-corn-soybean diet without oregano, whereas chickens from the experimental groups were fed diets with oregano from Poland (OP group), Turkey (OT group) or Egypt (OE group). During the experiment, the body weight at 1, 2, and 42 days of age, feed consumption and mortality were recorded. At 42 days of age, after 14 hours of fasting, the birds were killed and from the body of 32 chickens (8 chickens from each group) the digestive tract, heart, liver, pancreas and spleen were prepared and weighed. The gastrointestinal tract was divided into sections, and their weight and length were measured. Then, in particular segments of the gastrointestinal tract, pH values were determined. The body weight of chickens determined at 21 and 42 days of age were not significantly different between the groups. Significant differences between the groups were noted in feed efficiency during the grower period. The diet containing oregano from Turkey was utilized significantly better than the control diet. Significant differences in the pH of the glandular stomach and caecum were found. Compared with pH in the control group, pH in the glandular stomachs of chickens fed diets containing dried oregano from Egypt was significantly decreased, whereas pH in the caecum of chickens from the OT group was increased. In comparison with the control group, chickens from the groups fed diets containing oregano (except the OP group) had a significantly shorter ileum and larger intestines, and chickens fed a diet with oregano from Turkey had a smaller spleen and gizzard. The results obtained show that the chemical composition of dried oregano from different regions was differential. The addition of 2% of dried oregano to the wheat-corn-soybean diet had no significant influence on the body weight of chickens, but decreased their mortality. Oregano from Turkey added to the wheat-corn-soybean diet improved the feed efficiency in the second period of rearing. These results show that oregano may be a potentially effective supplement for broiler chickens, and the most effective was the oregano from Turkey....