Performance and selected blood parameters of broiler chickens fed diets with skullcap { Scutellaria baicalensis Georgi ) root

One hundred and twenty one-day-old małe broiler chickens were allocated into four groups, 5 replicates of 6 birds in each. Chickens were fed either a control diet or the same diet with the addition of 5, 10 or 15 g per kg of dried skullcap (Scutellaria baicalensis Georgi SCR) root. The addition of 5 and 10 g SCR per kg diet had little effect on performance and blood parameters. In the group fed the diet with 15 g SCR, body weight gain, red blood celi count and haemoglobin level was higher (PO.05), while the HDL, LDL, and total cholesterol levels in blood serum (PO.05) were lower than in the control group. The glucose level in blood serum was variable, aspartate aminotransferase and alkaline phosphatase activities were similar, while alaninę aminotransferase activity, higher (PO.05) in all groups fed diets with SCR than in the control group. KRY WORDS: skullcap root, blood, performance, broiler chickens


INTRODUCTION
In recent years, new additives of plant origin, considered to be natural products that consumers would accept, have been offered to livestock producers as an alternative for antibiotic growth promoters.For some of them, beneficial effects on health and productivity, including feed conversion ratio, have been reported (Hernandez et al., 2004).Skullcap (Scutellaria baicalensis Georgi) root (SCR) is well known and widely applied in China and Japan.It has a particularly high content of flavonoids, which are modifiers of inflammatory processes, prevent bacterial infections and have antiviral, antitumor and antioxidative properties as well as hepatoprotecive effects (Gao et al., 1999;Chan et. al., 2000;Bochorakova et al., 2003).The objective of this study was to evaluate the effect of SCR on the performance of broiler chickens and selected blood parameters.

MATERIAŁ AND METHODS
One hundred and twenty one-day-old małe Hubbard-ISA broiler chickens were randomly allocated into four groups, each group comprised 5 cages (replicates) with 6 birds.The birds were fed either a control basal diet (Table 1) or the basal diet with the addition of 5, 10 or 15 g of ground dried SCR per kg diet.Starter diets were fed from day 1 to 14 of life, grower diets from day 15 to 42 of life.Body weight and feed intake were measured at weekly intervals and body weight gain (BWG) and feed conversion ratio (FCR) were calculated.At the end of the experiment, blood samples were collected from the v. jugularis from 10 birds in each group.Glucose, total protein, triglycerides, HDL, LDL and total cholesterol contents were measured in serum using BioSystems kits.The activity of alaninę aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AP) were determined with the use of Aqua Medica kits and a Pharmacia Biotech Ultrospec 2000 spectrophotometer.The effects of dietary treatments were compared by one-way ANOYA (Statistica, 1997).

RESULTS
In the groups fed diets with 5 and 10 g of added SCR, feed intake was significantly lower, but BWG was similar as in the control group, while in the group fed the diet with 15 g of SCR, feed intake was similar and BWG was significantly higher (P<0.05) in comparison with the control group (Table 2).The addition of 5 and 10 g SCR per kg diet had little effect on the measured blood parameters, whereas in the group fed the diet with 15 g SCR, the red blood celi count and haemoglobin level were higher (P<0.05),HDL, LDL and total cholesterol levels in serum were lower (P<0.05)than in the control group.The glucose level was variable, ALT and AP activities were similar, while AST activity, higher than in the control group in all of the groups fed SCR diets.

DISCUSSION
The decrease in the blood cholesterol level is in agreement with the results of Hamada et al. (1993), who reported that flavonoids lowered the ąuantity of cholesterol in blood and of Harborne et al. (1986), who reported that flavonoids lowered the LDL level in blood.Also, according to Tang and Eisenbrandt (1992) flavonoids from skullcap root can lower the total blood cholesterol content.A high serum LDL level is associated with an increased risk of cardiovascular diseases, so lowering this fraction may lower broiler mortality.It seems that the amount of flavonoids in diets with 5 or 10 g SCR was too Iow to affect performance, but chickens fed the diet with highest amounts of SCR had a higher finał body weight in comparison with the control group.There was no information in the available literaturę about the influence of S. baicalensis Georgi on the performance of chickens, but Hernandez et al. (2004) reported that the addition of vegetable extracts from the Labiatae family to broiler diets positively affected the growth rate.
The results of the study indicated that addition of 15 g of scullcap root to the diet may positively affect the growth rate and blood parameters of broiler chickens.