Digestibility, ruminal characteristics, and meat quality of fattening lambs fed different levels of fennel (Foeniculum vulgare) seed powder

The objective of this experiment was to evaluate of effect of fennel seed powder (FSP) on digestibility, ruminal characteristics, and meat quality. In a completely randomized design, three diets containing zero (without FSP), 0.75% and 1.5% FSP were fed to 30 Kermani fattening male lambs (eight months old), with an average initial body weight of 27.5 ± 0.450 kg for 80 days. There was no effect of diets on apparent nutrient digestibility, but dry matter intake (DMI) was higher (P<0.05) for the diets containing FSP. The lambs fed the FSP diets had more final body weight (BW), weight of warm carcass and lean meat than lambs fed control diet (P<0.05). Ruminal pH, and NH3-N and acetic acid concentrations were higher in lambs on FSP diets than in control group (P<0.05). Ruminal protozoal population and propionic acid concentration were lower (P<0.05) in lambs fed FSP than the control diets. The meat fat content decreased but protein content increased in lambs fed on FSP diets. The malondialdehyde concentration in Longissimus dorsi of lambs fed FSP diets was lower compared with the control lambs. The results suggested that fennel seed feeding to fattening lambs, by improving the ruminal fermentation and meat quality, might be a suitable natural antioxidant for the meat production industry.