Effect of dietary supplementation of licorice extract and a prebiotic on performance and blood metabolites of broilers

Abstract

Six hundred Ross 308 male broiler chickens were used to study the effect of licorice extract and the prebiotic, fermacto, on performance, blood metabolites and gastro-intestinal transit time (GTT) of feed in the birds. The birds were fed according to a three phase feeding programme on a starter, grower and finisher diet during the ages of 1 -14 day, 15 -35 days and 35 -49 days of age, respectively. The basic diets during each phase contained either 100 or 95% of recommended digestible amino acid (RDAA) concentrations. The two basic starter diets were divided into five treatment diets: No supplement (control); and supplemented with 2.0 g fermacto/kg; and 2.0 (high); 1.0 (medium) and 0.5 (low) g licorice extract/kg diet. In the grower diets half the levels of these supplements were included, while the two finisher diets were fed without containing any of the experimental supplements. There was not a significant difference in body weight, feed intake and feed conversion ratio between the birds fed the control and the diets supplemented with the prebiotic or the different levels of licorice. However, birds receiving diets containing licorice extract had lighter abdominal fat pads compared to those fed the prebiotic or control diets. Blood cholesterol concentrations decreased significantly in birds receiving the high level of licorice in their starter and grower diets as compared to the control. The GTT of feed in the birds fed diets containing the prebiotic or licorice extract did not differ from that of the birds in the control. A 5% reduction in dietary RDAA concentration caused an increase in feed conversion ratio of chickens on the starter and grower diets and for the total duration of the experiment. ________________________________________________________________________________

Response of broiler chickens reared at high density to dietary supplementation with licorice extract and probiotic

“…These results are in agreement with those of Pooryousef and Hosseini (2012), who indicated that carcass percentage and carcass component ratios were not affected by addition of licorice root extract and probiotic in Japanese quail diets. Sedghi et al (2010) added LE to broiler diets and did not find any effect on relative weight of carcass and body parts such as breast, femur, liver, heart, spleen and bursa, in line with the present results.…”

“…Although a limited number of reports on use of licorice extract in broiler nutrition have been published, the results have been inconsistent. Neither Sedghi, Golian, Kermanshahi, and Ahmadi () nor Salary, Kalantar, Sahebi, Ranjbar, and Hematimatin () found significant improvement of BWG of broilers when supplementing their diet (0.05%, 0.1% and 0.2%) or water (0.2% and 0.4%) respectively with licorice extract. Al‐Daraji () showed that licorice extract, especially at the level of 450 ppm, effectively diminished the detrimental effects of aflatoxicosis on the general physiological status of broiler chickens.…”

Prebiotics, probiotics and thyme (Thymus vulgaris) for broilers: performance, carcass traits and blood variables

“…Lee et al (2004) discussed that essential oils could inhibit hepatic 3-hydroxy-3-methylglutaryl coenzyme A -which is involved in cholesterol synthesis-while Rahimi and Khaksefidi (2006) reported that probiotics are able to reduce cholesterol absorption and synthesis in the gastrointestinal tract of broilers. However, these hypotheses do not seem to be confirmed in our study, which is in agreement with results by Sedghi et al (2010), who supplemented broiler diet with 2 g/Kg Fermacto. Our results differ with those by Bölükbaşi et al (2006), who showed an increase of serum triglyceride and HDL in broilers fed 1 g/Kg thyme oil, and with those by Ebrahimi et al (2012), who showed that probiotics reduce serum cholesterol in broilers.…”

Scientific Opinion on the safety and efficacy of glycyrrhizic acid ammoniated (chemical group 30, miscellaneous substances) when used as a flavouring for all animal species

“…Blood cholesterol concentrations decreased significantly in birds receiving the highest liquorice dose. A reduced abdominal fat content was found at all doses (Sedghi et al, 2010); because of this a NOAEL could not be derived. Kobuke et al (1985) found no effect on the incidence of any tumour when disodium glycyrrhizinate was administered to B6C3F 1 mice at concentrations of up to 0.15 % (males) or 0.3 % (females) in drinking water for 96 weeks in a carcinogenicity study.…”