N-Acetyl-DL-Methionine: Effects on Environmental Parameters in Rumen and Apparent Disappearance Rate in Forestomach of Sheep

This study was conducted to study the effects of N-acetyl-DL-methionine( NAM) on environmental parameters in rumen and the apparent disappearance rate in forestomach of sheep. Four 35 kg Boer goat w ethers fitted w ith ruminal and duodenal cannulas w ere used in a 4×4 Latin square design,and w ere ruminally administered w ith graded levels of NAM( 0,4,6 and 8 g /d,respectively); the experiment consisted of 4 periods w ith 16 days per period( 10-day pre-experiment and 6-day experiment). The samples of rumen fluid and duodenal chymus w ere collected in the first 3 days and the last 3 days of experimental period,respectively,to determine evacuation rate,pH and osmotic pressure of rumen fluid,and the apparent disappearance rate of NAM.The results show ed as follow s: 1) the evacuation rate and pH of rumen fluid of sheep administered w ith 6 and8 g /d NAM w ere significantly decreased( P0.05),how ever,the osmotic pressure of rumen fluid w as significantly increased( P0.05). 2) The mean of apparent disappearance rate of NAM in forestomach after administered for 1.5 to 12.0 hours w as 68.0% to 74.9%,and the disappearance rate of NAM in rumen after administered for 12.0 hours w as 79.8% to 86.9%. In conclusion,NAM is not beneficial for ruminal digestion environment,it can decrease evacuation rate and pH,but increase osmotic pressure of rumen fluid,meanw hile,it has high apparent disappearance rate in forestomach( about 80% after 12 hours). Under condition in the present study,the ruminal administration of 6 and 8 g /d NAM has greater adverse impacts on sheep.