Effect of Origanum vulgare L. leaves on rumen fermentation, production, and milk fatty acid composition in lactating dairy cows

Abstract

This experiment investigated the effects of dietary supplementation of Origanum vulgare L. leaf material (OR) on rumen fermentation, production, and milk fatty acid composition in dairy cows. The experimental design was a replicated 4 × 4 Latin square with 8 rumen-cannulated Holstein cows and 20-d experimental periods. Treatments were control (no OR supplementation), 250 g/cow per day OR (LOR), 500 g/d OR (MOR), and 750 g/d OR (HOR). Oregano supplementation had no effect on rumen pH, volatile fatty acid concentrations, and estimated microbial protein synthesis, but decreased ammonia concentration and linearly decreased methane production per unit of dry matter intake (DMI) compared with the unsupplemented control: 18.2, 16.5, 11.7, and 13.6g of methane/kg of DMI, respectively. Proportions of rumen bacterial, methanogen, and fungal populations were not affected by treatment. Treatment had no effect on total-tract apparent digestibility of dietary nutrients, except neutral detergent fiber digestibility was slightly decreased by all OR treatments compared with the control. Urinary N losses and manure odor were not affected by OR, except the proportion of urinary urea N in the total excreted urine N tended to be decreased compared with the control. Oregano linearly decreased DMI (28.3, 28.3, 27.5, and 26.7 kg/d for control, LOR, MOR, and HOR, respectively). Milk yield was not affected by treatment: 43.4, 45.2, 44.1, and 43.4 kg/d, respectively. Feed efficiency was linearly increased with OR supplementation and was greater than the control (1.46, 1.59, 1.60, and 1.63 kg/kg, respectively). Milk composition was unaffected by OR, except milk urea-N concentration was decreased. Milk fatty acid composition was not affected by treatment. In this short-term study, OR fed at 250 to 750 g/d decreased rumen methane production in dairy cows within 8h after feeding, but the effect over a 24-h feeding cycle has not been determined. Supplementation of the diet with OR linearly decreased DMI and increased feed efficiency. Oregano had no effects on milk fatty acid composition.

Evaluation of the Effects of Mitigation on Methane and Ammonia Production by Using Origanum vulgare L. and Rosmarinus officinalis L. Essential Oils on in Vitro Rumen Fermentation Systems

“…Lin et al [36] observed a NH3 inhibition with a mixture of EOs composed of clove, oregano, cinnamon and lemon in sheep (1 g/day). Contrasting results on in vivo NH3 production were found by Hristov et al [31] and Tekippe et al [32] by feeding dairy cows with a supplementation of oregano leaves. However, as confirmed by the present study, the positive effects of EOs on CH4 and NH3 production are frequently associated to negative effects on feed digestibility, especially at the highest doses [28,37,38].…”

“…Some in vivo tests confirmed the potential of these plants and their extracts in CH4 mitigation. Hristov et al [31] demonstrated a CH4 production reduction (−16.5, −11.7 and −13.6 g of methane per kg of DM intake) by three different doses of dietary oregano leaves (respectively 250, 500 and 750 g/animal per day) in dairy cows. Tekippe et al [32] found similar results in dairy cows fed by oregano leaves at a 500 g/d rate (40% reduction in methane production).…”

OreganoExtract Added into the Diet of Dairy Heifers Changes Feeding Behavior and Concentrate Intake

“…The inclusion of spices, especially those containing essential oils, into the diet of ruminants is increasing due to their effects on ruminal fermentation [5, 6] and animal health [10, 24, 25], although there are reduced evidences of spices' effects improving animal performance [26]. In nonruminants, essential oils have been used in a wide scale due to their potential as replacement of antibiotics [27, 28].…”

Feeding strategies to design the fatty acid profile of sheep milk and cheese

“…Indeed, Benchaar et al (2007) found on dairy cattle that the profile of milk fatty acids of cows was not influenced by the supplementation with 750 mg per day of a mixture of EO compounds. Similarly, Hristov et al (2013) did not observe variations in milk fatty acids when supplementing the diet of lactating cows with three dosages of Origanum vulgare leaves.…”