Once Upon a time, Great and Powerful Indra decided to do Yajña, there were large scale preparations, Rishis were chanting mantras, then Indra decided to SIay animals there

Rishis stopped him, Rishis clearly told him that There is NO mention of K!lling animals in Yajñas in shastras, K!lling animals in Yajñas is against Dharma, hence please allow Brahmins to perform it according to shastras

Rishis said, Yajña must be done with seeds, this is what Dharma says. But Imdra had a Big ego, he refused to follow Dharma

So they went to King Vasu and asked him, who is correct, King lied that you can do yajña with anything, because if this he was punished. (Mahabharata AshwamedhikaParva adhyay 91)

Same even is mentioned in Shanti parva 337. Devtas wanted to k!ll Goat in Yajña, Rishis told them that Aja means seed, K!lling animals in Yajña is not allowed

King Vasu came and he said animal sacrifice is allowed, Rishis got angry and they said "If Shastras allow animal sacrifice then we will fall down, But if shastras prohibit animal sacrifice then you will fall down" Because 9f this King Vasu fell down proving Rishis were right.

In Anushasana Parva Bheeshma says Animal sacrifice is not allowed in Yajñas, this was started by some Dhoorta people. Hence according to him too, It is not allowed

Also Nirukta clearly says Yajña is without Himsa. I will make separate threads explaining about Pashu Yajñas, Pashubandh Yajñas and how animals were not harmed there and what was role of animals in Rituals. नमो नारायणाय

Same thing in Matsya Purana chapter 143 Rishis clearly declared K!lling animals in Yajña is Adharma amd must not be done, They Said it is GREAT ADHARMA to harm any animals in Yajñas and not in accordance with Vedas

Exactly same thing in Vaayu Purana Chapter 57 Rishis clearly said Vedas do not allow K!lling of animals in Yajñas, and also that this is Great Adharma, One must follow Vedas for Yajña hence do it with seeds

Also Muni Nārada criticizes animal sacrifice in Bhagwatam 4.25.7-8.

From all these Evidences it is very clear that Vedas do not allow K!lling of animals in Yajña.

Adding One more, Brahmanda Purana 1.2.30 Exactly same

Scriptural Reference used- 1. Mahabharata Ashwamedhika Parva Chapter 91 2. Mahabharata Shanti Parva chapter 337 3. Mahabharata Anushasana Parva chapter 115 4. Matsya Purana chapter 143 5. Vaayu Purana Chapter 57 6. Bhagwatam 4.25.7-8 7. Brahmanda Purana 1.2.30

Also see 8. Nirukta 1.8 ( अध्वरिति यज्ञ नाम ।। ध्वरिति हिंसाकर्माः, तत्प्रतिषेधः) 9. Rigveda (1.1.4), (1.19.1), (1.14.11) 10. Atharva Veda (1.4.1)

Its a Typo, Ignore

Please refer to Geeta press translation

A lot of people are saying that

Yes, but these verses are in all editions. The chapter and verse number might differ