user22057: On a couple of occasions I or others have voted to close a question off-topic and the poster has responded by saying that the tag he has used exists and therefore he assumed the topic of the question was valid. The most recent example was in relation to the tag ‘animal husbandry’. 
Now I am aware that a question can be off-topic even if the subject of the tag is valid, but in this case there was a statement that animal husbandry was off topic. Perhaps that is wrong, or perhaps the problem is that people with a relatively low reputation (300) create new tags to fit a question and that those that are inappropriate escape the tag review process for some reason (lack of personel, low priority?. I am quite unfamiliar with the procedure. Is the system working properly or is there a need for change.

user27148: I think that a reasonable first pass to deciding whether a tag should possibly be removed is to ask:
What do you think of the existing questions with that tag (both in quality of question and applicability of the tag)?
I don't know what guidelines the moderators actually follow with respect to tag removal, but I'm guessing it's something similar to what I just suggested.
As far as the particular post you mention, I think @anongoodnurse really meant to say not that animal husbandry is off-topic, but rather that simply being about animal husbandry does not make a question on-topic - it needs to be something about biology.
"Food" is another, more-popular example. There are lots of on-topic questions about food, but not all questions about food are on-topic. Posting a question that applies to an existing tag does not make it on topic.
I know you have run into a similar issue with the "terminology" tag when you vote to close a question that is mostly about etymology. If there isn't biological basis for the question, it's off-topic, but terminology questions can be on-topic, as well, so the tag should stay.
Overall, I think we could do a better job explaining in our comments why a particular post is not on-topic, especially for new users. Where appropriate, this could include a brief explanation of the (lack of a) role for tags in determining on-topicness.

22057: <p>On a couple of occasions I or others have voted to close a question off-topic and the poster has responded by saying that the tag he has used exists and therefore he assumed the topic of the question was valid. The most <a href="https://biology.stackexchange.com/questions/70180/how-many-calories-does-an-adult-male-goat-need-per-day">recent example</a> was in relation to the tag ‘animal husbandry’. </p>

<p>Now I am aware that a question can be off-topic even if the subject of the tag is valid, but in this case there was a statement that animal husbandry was off topic. Perhaps that is wrong, or perhaps the problem is that people with a relatively low reputation (300) create new tags to fit a question and that those that are inappropriate escape the tag review process for some reason (lack of personel, low priority?. I am quite unfamiliar with the procedure. Is the system working properly or is there a need for change.</p>
 27148: <p>I think that a reasonable first pass to deciding whether a tag should possibly be removed is to ask:</p>

<p><em>What do you think of the existing questions with that tag (both in quality of question and applicability of the tag)?</em></p>

<p>I don't know what guidelines the moderators actually follow with respect to tag removal, but I'm guessing it's something similar to what I just suggested.</p>

<p>As far as the particular post you mention, I think @anongoodnurse really meant to say not that animal husbandry is off-topic, but rather that <em>simply being about animal husbandry</em> does not make a question on-topic - it needs to be something about biology.</p>

<p>"Food" is another, more-popular example. There are lots of on-topic questions about food, but not all questions about food are on-topic. Posting a question that applies to an existing tag does not make it on topic.</p>

<p>I know you have run into a similar issue with the "terminology" tag when you vote to close a question that is mostly about etymology. If there isn't biological basis for the question, it's off-topic, but terminology questions can be on-topic, as well, so the tag should stay.</p>

<p>Overall, <strong>I think we could do a better job explaining in our comments why a particular post is not on-topic</strong>, especially for new users. Where appropriate, this could include a brief explanation of the (lack of a) role for tags in determining on-topicness.</p>
