416 www.roavs.com EISSN: 2223-0343 RESEARCH OPINIONS IN ANIMAL & VETERINARY SCIENCES Effect of methanolic extract of nettle (Urtica dioica) on in vitro fermentation and gas production of canola meal Pashachalandari H, Palizdar * MH, Mohammadian-Tabrizi HR, Niasati M. Department of Animal Science, Islamic Azad University, Chalous Branch, Mazandaran, Iran Abstract A study was conducted to evaluate the effect of methanolic extract of nettle on fermentation pattern of canola meal. The experiment was conducted in a completely randomized design using four levels of nettle extract (zero, 0.2, 0.4 and 0.6 ml). The amount of gas produced during different hours (2 to 96 h) of incubation was measured. The chemical composition of canola meal regarding crude protein, crude fat and ash was 36.05, 0.84 and 7.35% respectively. The results showed that in all hours of incubation effect of treatment on gas production was significant (P<0.05). After 2, 4, 6, 8 and 12 h of incubation, in vitro gas production of canola meal significantly decreased compared to control treatment in addition to increased gas production in the other hours of incubation. Rate of gas production for canola meal significantly declined relative to the control. Potential of gas production and gas production from the insoluble fraction increased with increasing doses of nettle extract (P<0.05). The amount of organic matter digestibility, metabolizable energy and net energy for lactation increased with addition of increasing doses of nettle extract (P<0.05). In conclusion, the nettle extract in 0.2 ml level could successfully reduce gas production and degradability of canola meal in vitro. Keywords: Nettle extract; canola meal; in vitro gas production To cite this article: Chalandari PH, MH Palizdar, HR Mohammadian-Tabrizi, M Niasati, 2014. Effect of methanolic extract of nettle on in vitro fermentation and gas production of canola meal. Res. Opin. Anim. Vet. Sci., 4(7): 416-419. Introduction Structural carbohydrates are essential for proper rumen microbial activity and synthesis of microbial protein in ruminants. However, microbial fermentation may result in considerable energy and protein losses in the form of methane and ammonia (Cardozo et al., 2012). About 8 to 12 percent of the digestible energy may be lost in the rumen as methane (Salamatazar et al., 2011a). Currently, to meet protein requirements of lactating dairy cows and finishing steer, animal nutritionists are focussing on rumen un-degradable protein in the diet which could be digested in the small intestine efficiently (Van Soest, 1994). Additives such as antibiotics and growth promoters have been used to reduce methane and ammonia emission from ruminants. Because of the risk of the presence of antibiotic residues in milk and meat and its effects on human health, the use of these additives was prohibited by the European Union in 2006 (Sallam et al., 2009). Since natural plant extracts have antimicrobial properties (Kamel, 2001) and according to the relative safety of these extracts, nowadays, most researchers focused on plant extracts to alter protein fermentation in the rumen (Salamatazar et al., 2011b). Many plants produce secondary metabolites such as phenolic compounds, essential oils, and sarsaponins that affect microbial activity (Kamel, 2001). It has been shown that methanolic extract of thyme (0.15 ml) decreased gas production of soybean meal in vitro up to 8 h of incubation (Salamatazar et al., 2012). It was also reported that adding 0.5 ml of thyme extract to soybean meal reduced gas production at all incubation times in comparison to the control (Rezaei, 2011). Many studies also showed that nettle extract has antibacterial effects (Obertreis et al., 1996). Nettle leaves contain chlorophyll, carotene, xanthophylls, and flavonoid compounds (Iranian Herbal Pharmacopoea Committee, *Corresponding author: Palizdar MH, Department of Animal Science, Islamic Azad University, Chalous Branch, Mazandaran, Iran; E-mail: mh_paliz@yahoo.com