Hi Zakir and welcome back.
Your essay is 232 words long which would lead to a penalty in IELTS. Just adding one more sentence would avoid this problem!
Make intros specific!
In your intro, try to make the thesis sentence specific. It should rephrase some of the words in the question.
In this essay I will highlight its positive and negative aspects.
This might be better as:
In this essay I will look at the positive and negative aspects of animal testing in the development of new drugs.
Organization: make your arguments symmetrical (equal weighting)
You have two advantages or uses of animal testing (space exploration, cloning and hybrids - although I think you have some other ideas in this section also. Remember: one sentence, one idea!)
However, you have only one argument against animal testing – you didn't develop the ethical issues, but focused in on a detail about animals dying outside testing centers, which seems a little obscure or relatively minor.
In your last paragraph, I'm not really sure what you mean in the last part of the sentence
… animals should be used for medicinal practices , and the government should check that they are not only made for death but for death to life.
There's no need to be too dramatic or flowery in IELTS – just be as plain and direct as you can. In the speaking exam you will have an opportunity to use rhetoric, but simpler is generally better in the writing test.