The effect of adding fennel (Foeniculum vulgare) seed powder to the diet of fattening lambs on performance, carcass characteristics and liver enzymes

Abstract

The objective of this research was to investigate the effects of adding fennel (Foeniculum vulgare) seed powder (FSP) to the diet on dry matter intake (DMI), live weight gain and carcass characteristics in fattening male lambs. Thirty lambs (27.5 ± 0.45 kg body weight (BW) at eight months of age) were allotted to three experimental diets in a completely randomized design. Experimental diets were 1) control diet (no FSP); 2) diet containing 0.75% FSP and 3) diet containing 1.5% FSP. The ratio of forage to concentrate in diets was 40:60 (dry matter basis). The lambs were allocated to three groups with equal animals and fed the diets for 80-days. At the end of the experiment, all animals were slaughtered on the same day. The day before slaughter blood samples were taken 3 h after morning feeding. Lambs fed the 1.5% FSP diet had greater (P < 0.05) DMI, final BW, live daily gain, the weights of warm and cold carcass, lean meat, loin, leg, gallbladder, testis and eye muscle area than those fed control diet. The best feed conversion (FC) was achieved in lambs fed 1.5% FSP diet (P < 0.05). Adding FSP to the diet of lambs decreased (P < 0.05) the liver and cooled shrink weights. The back fat depth and weight of empty rumen in lambs fed 0.75% FSP were lower in comparison to other diets (P < 0.05). Adding FSP increased the concentration of blood testosterone (P < 0.05). The lower concentrations of liver SGPT and SGOT in lambs fed 0.75% FSP compared with other diets were observed. Results of this research showed that adding 1.5% FSP to the diet of fattening lambs increased their finishing performance and muscle tissue yield, and improved FC.