Impact of Mootral Ruminant© on methane emissions and performance on Dairy Cows in real farm conditions

The reduction of enteric methane in ruminants is a key objective to mitigate greenhouse gas emission in agriculture. Under research conditions, the impact of different feed additives on enteric methane emissions have been already tested in-vitro or in-vivo but there is a lack on studies that directly measure the effect on methane emissions in real farm conditions. Therefore, the objective of this study was to evaluate the effects of the natural feed supplement, containing organosulphur compounds from Garlic (Allium sativum) and flavonoids, on methane emissions and performance in Dairy Cows under real farm conditions. In total, 275 Holstein Friesian (HF) and 121 Jersey (average days in milk: 150) were housed in a sand-bedded free stall barn. Cows were milked twice a day. The basal diet (control) was a total mixed ration (TMR) with grass silage as primary forage source. The treatment diet (treatment) had the feed supplement in form of a pellet (500g/head/day (3% garlic-citrus powder)) mixed in the TMR. The trial was conducted using the complete herd in a 23 weeks feeding trial, where the first 7 weeks and the last 4 weeks served as control (no garlic-citrus powder supplementation) (control). Milk yield, milk composition and dry matter intake (DMI) was monitored weekly. Estimations of methane production were obtained on 15 HF and 15 Jerseys from approximately 6:15 am after milking during 3 consecutive days in week 12 of treatment and 4 days in week 4 post treatment (control) using the hand-held laser methane detector. The milk yield increased by 7.8 % (P < 0.05) in the HF herd and by 5 % in the Jersey herd (P < 0.05) comparing the pre-treatment period with the treatment period. In the post-treatment period, the milk yield remained consistent. No significant differences were detected in milk composition except for a decrease in somatic cell count during the treatment period. The DMI decreased slightly during the treatment period in Jersey herd and increased in HF. A significant methane reduction of 20.7 % and 38.3 % respectively in HF and Jersey was detected in the treatment period (P < 0.05). Overall, these results demonstrate efficacy of the garlic-citrus powder in reducing enteric methane emissions and increasing performance in Dairy Cows in real farm conditions.