Growth performance, carcass characteristics, and meat quality in broilers supplemented with fever tea (Lippia Javanica) leaf powder
The present study was conducted to determine the effect of supplementing Lippia javanica (fever tea) leaf powder in broiler diets on growth performance, carcass characteristics and meat quality. One hundred and eighty Cobb 500 broiler chickens were allocated to four diets with three replicates of 15 chicks per pen. Fresh leaves of L. javanica were collected, dried and ground before addition to broiler diets. Two levels L. javanica were tested: 5 g/kg and 12 g/kg of L. javanica leaf powder. The other treatments were negative control group (without supplementation) and positive control group (with antibiotics). The experimental study lasted for 42 days. Body weight (BWT), feed intake (FI) were recorded weekly and used to calculate feed conversion ratio (FCR) at 42 days. At the end of the trial (42 days) three chickens (one chicken per replicate) were randomly selected for sampling blood before being slaughtered for assessment of internal organs, fatty acids profiles and sensory evaluation of meat. The results indicated that supplementing broiler diets with 5 g/kg of L. javanica leaf powder significantly increase body weight (P < 0.05) among the treated groups. With regards to survival rates, only one bird in the 12 g/kg of L. javanica treatment group died. Broilers fed were supplemented with 12 grams of L. javanica meal in their diet had the highest (P < 0.05) weights for the proventriculus, gizzard and small intestines and also had the longest small intestines. On the other hand, broilers were supplemented with 12 grams of L. javanica meal in their diet also had the lowest weights for liver and pancreas had the highest weight in positive control treatment group. There was no difference (P >0.05) observed across the treatments in terms of heart and spleen sizes. The inclusion of L. javanica in broilers diet had no effect on the breast and thigh weights (P>0.05). Differences were observed on the weight of abdominal fat pad, carcass weight and dressing percentages. Broilers that were receiving L. javanica in their dietary treatment had significantly higher abdominal fat weight compared with the other two groups (P<0.05). High haematological values were also obtained in broilers fed L .javanica. The fatty acids (FA) composition of the subcutaneous adipose was also determined. Dietary treatments significantly (P < 0.05) affected subcutaneous fat (SCF %). The broilers that were supplemented with 12 grams L. javanica meal in diet had the lowest proportion of SCF while positive control had the highest proportion of subcutaneous fat (SCF). Diet, however, had no effect on fat free dry matter (FFDM) and moisture. Sensory evaluation was done on boiled and fried meat using 30 panellists. Aroma intensity and atypical flavour intensity were not significantly affected by diet (P>0.05). However, diet had an effect on other sensory attributes with the meat from broilers fed L. javanica being rated more superior than from the control groups. The results from this experiment indicated that L. javanica can be used as a growth promotant in broiler diets.