The Effect of pH and Fennel, Pine and Eucalyptus Essential Oils on Rumen Fermentation Properties (in vitro)

In the ruminant animal, rumen fermentation provides nutrients, energy and protein needed for livestock, but this process is accompanied by the loss of energy in the form of methane and protein as ammonia nitrogen. Methane released from ruminants as an environmental pollutant with 38% greenhouse gases is one of the most important reasons for global warming. On the other hand, it reduces 2 to 15 percent of the energy consumed by the livestock. Ammonia nitrogen and nitric oxide are excreted through urine and fertilizers and pollute the environment. Therefore, researchers have tried to eliminate these problems from the past to add some supplements to animal feed to improve fermentation performance. Over the past few decades, ionophors and probiotics have been marketed as methane reducers. However, the antibiotic concerns and the level of these compounds in animal products have limited their use. To solve this problem, the use of herbs, essential oils and their extracts in the replacement of antibiotics and improvement of rumen function has been suggested. Essential oils are aromatic, volatile and oily compounds extracted from plants. They have antimicrobial properties against many bacteria, yeasts, and fungi. Due to the fact that herbal essential oils have strong antimicrobial properties, they are used as additives in livestock feeding. The purpose of this study was to evaluate the effect of some essential oils and pH on rumen fermentation parameters in different diets in in vitro. In this study, the essential oils of Fennel (Foeniculu vulgare), Eucalyptus (Eucalyptus camaldulensis) and Pinus pumilio (Pinus pumilio) were used. For the extraction of pine and fennel seeds and Eucalyptus leaves were used. Water extraction was used to extract essential oils from Clevenger apparatus. For this purpose, 1Lit glass balloons (pine and fennel seeds were cut and Eucalyptus leaf grinding), 70 grams were used and 750 ml of distilled water was added to each balloon. Samples and distilled water were warmed up at 100°C. Heating was performed for 4 hours to evaporate the contents of the balloons. The essential oils of each sample were extracted on the cooled water from the evaporation procedure. Finally, each of the essential oils was stored in dark glass containers until refrigerated at 4 ° C. The first phase consisted of incubation 4 basal diet: 100% alfalfa hay, 100% concentrate (barley), mixed concentrate with alfalfa with levels of 80 to 20 and 60 to 40% of concentrates to alfalfa hay with zeros, 3 and 30 mg/l of essentiol oils pine, eucalyptus and fennel mixed with 30 ml of rumen fluid for 72 hours at pH different (5 = pH, 6 = pH and 7 = pH). The pH were set at desired levels using NaOH and HCl at the beginning of incubation to investigate the effect of essential oils and different pH on different parts fermentation, the result of test gas production (a and b) .The second experiment tested the same conditions but in the first 24 hours for examining their effects on pH medium, the concentration of ammonia nitrogen and dry matter disappearance. The highest average gas production from fermentable partion in treatment of hay with eucalyptus oil and the lowest at 7 = pH in the treatment of 60 to 40 percent with pine essential oil was observed at 6 = pH. At the end of incubation the treatment of 60% concentrate with essential oils of fennel, pine and eucalyptus in 6 = pH and highest for alfalfa with pine oil was at 7 = pH. The lowest concentration of ammonia nitrogen in the treated hay with pine essential oils 7 = pH and the highest 80 percent concentrate treatment with essential oils in fennel was 7 = pH. The disappearance of dry matter in the hay treated with essential oils of pine was 7 = pH. These results suggest that high levels of essential oils effect on rumen microbial fermentation, which confirmed the antimicrobial activity. The results of this study show that of the added essential oils in tested pH, pine essential oil in 3 μl and less in the amount of 30 μl of eucalyptus essential oil, resulted in further reduction of ammonia nitrogen production, increased pH of the culture medium and decreased disappearance dry matter was found in all foods. Therefore, it can be concluded that the essential oils of pine and eucalyptus can control the degradation of the microbial protein in the rumen by reducing the ammonia nitrogen content and improve the nitrogen yield in ruminants. Since the amount of gas produced from an indigenous feed is due to the fermentation of that feed, and hence its energy value, it can be concluded that the use of pine essential oils, because it reduces gas production and consequently reduces feed fermentation, The fermentation process is not suitable.