Effect of powder or extracted oil of Foeniculum vulgare root on the performance of fattening Mehraban lambs

Fennel (Foeniculum vulgare) is one of the herbal additives which is considered as an alternative for gowth promoter instead of antibiotics in farm animals. This plant has some oestrogenic characcyeristics, enhancing the appetite and feed intake which may result in a increased growth rate in farm animals, however, there is very limited information on this context. Therefore this research was conducted to study the effect of using powder and ectract of fenenl on the fattening performance of Mehraban lambs.

Twoenty five Mehraban male lambs with an initial bodey wieght of 27.87±4.53kg were used in a completely randomized desing feeding experiment, with 5 treatments and 5 replications. The Foeniculum vulgare plant was harvested from research farm of Hamedan and the rootes were cut down, cleaned and washed with tap water then allowed to dry under the sun. The dried rootes were ground into a fine powder using a 1mm sived ball mill and used as powder form or proceesed to ectarcted form for using in the experiment. The treatments were: T1) Basal diet (C), T2) C+5g Foeniculum vulgare root powder (FVP), T3) C+10g FVP, T4) C+7.5ml alchoholic extracted Foeniculum vulgare root (AEFV), T5) C+15ml AEFV per animal per day. The animals were fed a total mixed ration ad-libitum three times daily and had free access to drinking water, during 103 days experiment (14 days for adaptability and 89 days for dta coleection). Body weight gain and feed intake were recorde and feed conversion ratio was calculatd. At the end of the experiment, all animals were slaughtered and then the cacass dressing was determined and internal organs were visually considered.

Results showed that the body weight gain were 215.10, 274.40, 262.90, 275.30 and 217.70 g/d respectively for the animals allocated to treatments 1 to 5 that were significantly different between the treatments (P<0.05). The maximum (275.30) and minimum (217.70) daily gain were obtained in T4 and T5 respectively (P<0.05). These results are in agreement with the finding of other researchers where they reported 178 to 259 g/d for Mehraban male lambs (3. 14, 20). The average daily dry matter intake were different between the treatments throughout the experiment period where the highest intake (1893g) was found in T3 but the lowest intake (1345g) in T1 (P<0.05). Average feed conversion ratio was also different between the treatments with the highest amount (7.75) for T5 and the lowest amount (5.87) for T2 (P<0.05) during the whole experiment period. Results of slaughtering sowed that the warm and cold carcass weights were significantly (P<0.05) different between the treatments but carcass dressing percentages were not statistically affected by the treatments. Visual assessment of post slaughtering shwoed that the carcass characteristics and internal organs including heart, liver, kidneys, spleen, lungs, kidney and digestive tract were normal and no statistical differences were obsereved for the wieght of internal organs between the lambs in different treatments.

It was concluded that utilization of fenel (Foeniculum vulgare) powder in amounts of 5 and 10 g as well as 7.5 ml fenel extracted per animal per day, positively affected growth rate and resulted in a higher live weight and carcass weight of lambs. However, othe carcass traits and internal organs were not affected by the treatments. Key words: Fattening performance; Foeniculum vulgare plant; essential oil, Mehraban lambs