A garlic and citrus extract: Impacts on behavior, feed intake, rumen fermentation, and digestibility in sheep

There is global interest in decreasing methane (CH 4 ) emissions from ruminants due to their negative impacts on the efficiency of the livestock industry and the environment. The present study was conducted to evaluate the effects of a natural combination of garlic and citrus, Mootral, as a novel feed supplement on behavior, feed intake (FI), rumen fermentation, digestibility, growth performance, and CH 4 reduction in sheep. Four Corriedale wether sheep, kept in individual metabolic cages and used in a 4 × 4 Latin square design, were fed a 50 : 50 grass hay : concentrate ratio diet at 55 g dry matter/kg BW 0.75 /day. Mootral was supplemented at four concentrations: 0 (control), 1, 5, and 10 g/kg on a dry matter (DM) basis. The experiment was performed over four 21-day periods, each consisting of 14 days for the adaptation period and 7 days for sample collection. Health status was checked daily, while body weight was recorded weekly. Refusal feed, fecal, and urine samples were collected for 5 days. Behavioral observations were performed for 2 continuous days. CH 4 and carbon dioxide (CO 2 ) emissions were quantified by an open-circuit respiratory system on days 19 and 20, while rumen fluid was collected three times, both before (0 h) and after (3 and 6 h) morning feeding on day 21. The results of the current study showed that animals supplemented with Mootral dedicated more time to eating ( P < 0.05) and had a higher frequency of lying around feeding time ( P < 0.001) than non-supplemented animals. Continuous observation revealed that Mootral supplementation decreased the incidence of oral non-nutritive behaviors ( P < 0.001) and abnormal behavior ( P = 0.016) of the sheep around feeding times compared with the control group. Moreover, rumination activity was observed to be higher for supplemented animals through instantaneous scan sampling data ( P < 0.001). Mootral supplementation did not affect total FI or any rumen fermentation parameters, digestibility, or growth performance. Compared with the control group, 5 and 10 g Mootral/kg DM decreased the CH 4 emission yield per digestible DM intake up to 7 % ( P < 0.05) and 12.8 % ( P < 0.01), respectively, while no effect on CO 2 emissions was observed. In conclusion, Mootral, a combination of garlic and citrus, is a promising natural feed supplement that can be used to reduce CH 4 emissions from ruminants without causing any negative impact on FI, rumen fermentation, or digestibility, thereby leading to improved animal welfare.