Effect Of Oregano Oil On Rumen Fermentation, Methane Production, Nutrients Degradability And Performance Of Sheep

The objective of this study was to investigate the effects of different dose of oregano oil on sheep rumen fermentation,methane production,ruminal nutrients degradability and production performance by gas production technique in vitro,nylon bag experiment and feeding experiment,respectively.Experiment one: In this study,a single-factor experimental design was used to explore the effect of oregano oil on sheep rumen fermentation using gas production technique in vitro.The oregano oil was added at levels 0,100,200,300 and 400 mg /L.Concentrations of total volatile fatty acids,total nitrogen,ammonia nitrogen,urea nitrogen,protein nitrogen of cultivated fluid,the pH of cultivated fulid,and ratio of acetate/propionate,acetate,propionate,butyrate and other acids of cultivated fulid,and methane production and gas production were measured.Compared to the control,the results showed that 1)The pH of cultivated fulid significantly increased with the increase of oregano oil adding levels(P < 0.05).The higher dose oregano oil(300,400 mg / L)decreased the concentrations of total volatile fatty acids and the proportion of propionate(P < 0.05),and significantly increased the proportion of acetic and ratio of acetate/propionate(P < 0.05).2)The concentration of ammonia nitrogen was significantly decreased except for adding 100 mg / L oregano oil(P <0.05).3)The higher dose oregano oil significantly decreased methane production and total gas production(P < 0.05).In conclusion,the oregano oil can regulate rumen fermentation and reduce methane production,and the optimum adding level is 200 mg/ L in vitro.Experiment two: This experiment was conducted to study the effects of oregano oil on ruminal fermentation and ruminal nutrients degradatibility of sheep.Four healthy sheep with eternal rumen fistulas(Northeast fineaool sheep × Dorper,average weight was 40.83± 4.11 kg)were used in a 4 × 4 Latin square design.Sheep in different groups were fed basal diets supplemented with 0(control group),0.015 %(test group ?),0.030 %(test group ?)and 0.045 %(test group ?)oregano oil,respectively.The experiment consisted of 4 stages with 12 days per stage,and each stage including10 days acclimation and 2 days experimentation.Ruminal fluid wascollected after 0,2,4,6 and10 h of feeding in the morning to measured concentraton of volatile fatty acid,total nitrogen,ammonia nitrogen,urea nitrogen,protein nitrogen and pH.Rumninal nutrients degradatibiligy was determined by nylon bag technique.The results showed as follows:1)compared with control group,adding oregano oil had no significant influence on ruminal dry matter,neutral detergent fiber and acid detergent fiber degradatibility(P > 0.05).2)compared with control group,there were no significant influence on pH,concentraton of total nitrogen,ammonia nitrogen,urea nitrogen,protein nitrogen of ruminal fluid(P > 0.05),and there was no significant difference between groups at different period(P > 0.05).In conclusion,adding oregano oil had no significant influence on ruminal nutrinent degradatibility and ruminal fermentation of sheep.Experiment three: The aim of this study was to study the effects of oregano oil on performance and methane production of sheep.Twenty healthy sheep(Northeast fineaool sheep × Merino,average weight was 32.16±4.02 kg)were randomly divided into 4 groups.Sheep in different groups were fed basal diets supplemented with 0,0.015 %,0.030 % and 0.045 % oregano oil,respectively.The experiment lasted for 70 days,including 10 days acclimation and 60 days experimentation.The growth performance,blood biochemical indicators and methane production of the sheep were measured.The results showed that: 1)compared with control group,adding 0.015%oregano oil significantly increased dry matter intake,average daily gain and feed conversion efficiency(P < 0.05).2)there were no significant differences on blood biochemical indicators and methane production(P > 0.05).In conclusion,methane production of sheep was not affected by oregano oil,however,adding 0.015 %oregano oil could boost the growth.The results of the three experiments showed that higher dose oregano oil restrain the ruminal fermentation.In reality,0.015 % dose should be used in sheep feeding.