Effect of herb mixture on productivity, mortality, carcass quality and blood parameters of broiler chickens.

a total of 608 ross 308 chickens were studied for the effect of diets with added 1% herb mixture in the presence of mannan oligosaccharide and fumaric acid (WhE), compared to the group receiving no herbs (nhE), the control group (con) and the group receiving antibiotic (ant). in the antibiotic group (ant) and in the group receiving no herb mixture (nhE), the final body weight of the broilers increased significantly compared to the control group (con; p<0.01). mannan oligosaccharide and fumaric acid with herbs (WhE) did not increase broilers’ body weight either, compared to the control group (con) and reduced it significantly compared to the group given no herbs (nhE; p<0.01). mannan oligosaccharide and fumaric acid with (WhE) and without (nhE) herb mixture reduced chicken mortality compared to the control group (con). it did not differ from that in the antibiotic group (ant). compared to no herb supplementation (nhE), herb mixture (WhE) had no significant effect on chicken mortality. there were no significant differences in feed intake and conversion between the groups. mannan oligosaccharide and fumaric acid with (WhE) and without (nhE) herb mixture significantly increased the weight of carcasses compared to the control group (con; p<0.01). the treatment factors had no effect on dressing percentage. the herb mixture (WhE) significantly increased gizzard weight compared to the other groups (p<0.01). it is concluded that the experimental herb mixture given to broiler chickens in the presence of mannan oligosaccharide and fumaric acid did not have a beneficial effect on production and carcass quality parameters and failed to reduce chicken mortality. key words: broilers, herb mixtures, body weight, feed conversion, mortality, meat composition, blood serum The lack of antibiotics in feed mixtures increases inflammation of the intestinal mucosa and the incidence of diarrhoea, reduces the rate of growth, and increases broiler mortality and production costs (Davidson, 2003). It increases the use of infeed antibiotics in the form of medicated feeds. Although there are no official data available in Poland, this view is held by most veterinarians who work in practice (personal communication). F. Brzoska et al. 158 Researchers are still looking for a bactericidal substance to replace feed antibiotics in livestock feeding. The search is on for dietary supplements that have a negative effect on gastrointestinal pathogens such as Clostridium, Escherichia coli, Campylobacter and Salmonella Spp. Earlier findings show a positive effect on chicken performance of probiotic bacteria, mannan oligosaccharide and feed acidifier in the form of fumaric acid (Patterson and Burkholder, 2003; Chung and Day, 2004; Brzoska et al., 2005, 2007). Certain types of herbs which are considered an antibacterial factor, are made into mixtures or extracts for piglets, fattening pigs, laying hens or broiler chickens. Herb mixtures contain biologically active substances that are formed during plant photosynthesis and are classified as alkaloids, saponins, tannins, flavonoids, aromatic substances, volatile oils, terpens or mucilages (Grela and Klebaniuk, 2001). Increasing immunobiological resistance in addition to antibacterial action is an important role of herbs in diets for living organisms (Łuczkowska et al., 2005). Research to date concerning the use of herb mixtures in broiler diets has produced inconsistent results (Fritz et al., 1990; Fritz et al., 1992; Fritz et al., 1993). Fritz et al. (1992) showed no significant effect of herb mixture on chickens’ body weight, with an increase in mortality in relation to the control group receiving the antibiotic Avotan. Earlier studies published by Fritz et al. (1990, 1992) reach different conclusions, namely that herbs can replace antibiotics in broiler feeds and have a positive effect on body weight and feed conversion. It was hypothesized that combined use of mannan oligosaccharide and fumaric acid with herb mixture in broiler diets may increase the power of herbs to influence the digestive system of chickens, and thus to reduce mortality and improve productivity. The objective of the study was to determine the effect of giving chickens dietary herbs with and without prebiotic and acidifier on body weight, mortality, dressing percentage, weight of carcass and carcass cuts, and basic parameters of blood plasma. material and methods A total of 608 day-old Ross 308 broiler chickens were randomly assigned to 4 groups and placed in 16 pens. Each group had 4 replications with 38 birds per replication. Chickens were kept in wire-mesh pens on wood-shavings litter with free access to feed and water. Stocking density was 16 chicks/m2 at the beginning of rearing and 34 kg of body weight/m2 at the end of rearing. Chickens were maintained in a centrally heated facility. Until 21 days of age, they were heated with panel heaters. The treatment factor was commercial herb mixture for growing poultry, used in starter and grower diets (Table 1). The herb mixture contained the following herbal plants (% by weight): chamomile inflorescence (Metricaria chamomilla), peppermint (Mentha piperita), marigold flower (Calendula officinalis), St. John’s wort (Hypericum perforatum), marshmallow root (Althaea officinalis), yarrow (Achillea millefolium) and stinging nettle (Urtica dioica). Effect of herb mixture in broiler chickens 159 Table 1. Feed ingredients and additives and nutritive value of starter and grower diets (g/kg)