because xylasine provide sedation and analgesia and ketamine itself not- it just make immobilistion of the muscles. You may use just xelasine by ruminants, if you will perforem short and simple procedure (like decornuation for example) but not ketamine alone

To get to the chirurgic tolerance stadium III for anesthesia only one of those will not fulfill the criteria  - you need to combine sedation with analgesia, like Małgorzata states before.

thank you Malgorzata madam

that means cocktail of these two provides such anesthetic  effect that i can use in less invasive procedure, 

the cocktail of both of them LETS you make an invasive procedure - one alone is simply not sufficient and  the animal will still feel pain.

I agree the explanations given by f the above observers viz. Małgorzata Raś-Noryńska and Dirk Kamin. Hopefully this will minimize your problem.

thank you Dirk sir, thank you jana sir 

Hello Alok, In addition to all this information, the recovery of an animal with this combination is very smooth as compared to other anaesthetics and/or their per se use.

i ll look forward...thank you Ignacio alvarez Gomez sir

I anaesthetize human patients. This can be accomplished with ketamine as a sole agent. It is a potent analgesic, also in subhypnotic doses. But I agree with Dr. Segura that an alpha-2 agonist like Xylazine may help preventing rigidity.

I would like to add up the information...Ketamine is known as dissociative anaesthesia so better to give with sedative..

because xylazine works as anaestesia and anaelgesia and ketamine itself have poor anaelgetic  properties and can cause convulsions when given alone