Davalac krvi je ispunio uslove i dao krv.

Literally, davalac krvi means giver/donor of blood.

• davalac = donor, giver
• krvi = of blood

Yes, this is a normal and natural Serbian expression for blood donor. In this sentence, it refers to the person who donates blood.

Because krvi is the genitive singular form of krv.

• krv = blood
• krvi = of blood

After a noun like davalac (donor), Serbian often uses the genitive to show what someone is a donor/giver of. So:

• davalac krvi = donor of blood / blood donor

This is a very common structure in Serbian.

This is the perfect tense, which is the normal past tense in Serbian for completed actions.

It is formed with:

• the auxiliary je (is/has)
• the past participle: ispunio, dao

So:

• je ispunio = has fulfilled / fulfilled
• je dao (understood in the sentence) = has given / gave

In natural English, you would usually translate the whole sentence with a simple past:

• The blood donor met the requirements and gave blood.

Because in Serbian, when two past-tense verbs share the same subject, the auxiliary is often used only once.

So this is completely normal:

• Davalac krvi je ispunio uslove i dao krv.

The second je is understood from the first one. This is similar to English omitting repeated elements in coordinated structures.

You can sometimes repeat the auxiliary for emphasis or style, but normally Serbian prefers not to repeat it here.

Because je is a clitic, and Serbian clitics usually go in the second position of the clause.

Here, the first unit is:

• Davalac krvi

So the clitic je comes right after that:

• Davalac krvi je ispunio uslove i dao krv.

This may feel unusual to an English speaker, but it is a very important Serbian word-order rule.

Uslove is the accusative plural of uslovi (conditions, requirements).

The verb ispuniti (to fulfill, satisfy, meet) takes a direct object, so the noun goes into the accusative:

• uslovi = requirements/conditions (nominative plural)
• uslove = requirements/conditions (accusative plural)

The phrase ispuniti uslove is a very common Serbian expression meaning:

• to meet the requirements
• to satisfy the conditions

They agree with the subject, davalac, which is a masculine noun.

In Serbian past participles, gender and number matter:

• ispunio / dao = masculine singular
• ispunila / dala = feminine singular
• ispunilo / dalo = neuter singular
• ispunili / dali = masculine plural or mixed group
• ispunile / dale = feminine plural

Since davalac is masculine singular, the sentence uses:

• ispunio
• dao

Yes. In this context, dao krv literally means gave blood, but idiomatically it means donated blood.

This is a very natural Serbian way to say it. Serbian often uses dati krv where English would say donate blood.

So:

• dao krv = gave blood / donated blood

Both meanings point to the same real-world action here.

Both are perfective here:

• ispuniti = perfective, to fulfill / to meet completely
• dati = perfective, to give

That matters because the sentence describes completed actions:

1. the donor met the requirements
2. the donor gave blood

Perfective verbs are very common when you are talking about a finished result.

Compare the imperfective partners:

• ispunjavati = to be fulfilling / to fulfill repeatedly
• davati = to be giving / to give repeatedly

Those would not fit as well here, because this sentence is about a completed event.

Yes, Serbian word order is more flexible than English, but the original order is the most neutral.

Neutral version:

• Davalac krvi je ispunio uslove i dao krv.

You could change the order for emphasis, for example:

• Krv je dao davalac koji je ispunio uslove.
• Uslove je ispunio i dao krv davalac krvi.

But these sound more marked or stylistically special. For a learner, the original sentence is the best default pattern to remember.