Vājasaneyi Saṃhitā describes the title Pashunapati as the “Lord of Sacrifice of Pashu”; here Sacrifice of Cattle means to donate cattle as Dakshina during Yajñás like Rājasuya. The sacrifice of Cattle doesn’t always denote killing them, during the Vedic times human consciousness evolved towards sacrifices that do not require killing, but we will come to that, first, let’s go over what these Pashus and how the Vedas describe them.

So, what are these Paśūs? Taittirīya Saṃhitā 3.1.4 says “पशुपतिः पशू॒नां चतुष्पदामुत च द्विपदाम्” meaning “He is Paśūspati to Paśūs that is two-footed and four-footed”. Vājasaneyi Saṃhitā 8.2.1.6 Brahmāṇa 1.2 describes 5 types of Paśūs sought by Prajāpati – man, horse, bull, ram, and goat, similarly Atharva Veda 11.2.9 defines Paśūs as cows, horses, man, goats, and sheep. But if we take the dictionary definition then Paśū means cattle or animals that are tamed, or a group of creatures, or creatures used as sacrificial gifts given to rishis, scholars, and Devas. But Paśu has a broader meaning, it includes all beings who are tied to the material world in the loop called Samsara. So Paśūs are those who are in bondage or tied/fetter, hence the term Pãsha. We can notice that they both have the same root (Paśū and Pãsha). Many western scholars limit Paśu to just farmed cattle, but that would make Mahadeva’s Paśupatiastra, the most powerful weapon given to Arjuna and Sri Krishna in Mahābhārata Itihāsa, was meant to kill cattle in the war.

How did the concept of Rudra diversify into Paśūspati? Across Vedas, there are numerous instances wherein Rudra emerged and took ownership of all Bhutas (beings) and Paśūs. Two events take high precedence, one is from Kausitaki Shankhyayana Brāhmaṇa Kanda 6.1-9 and Śatapatha Brāhmaṇa Kanda 6 Brahmāṇa 3 wherein Rudra expands into Paśūspati title by encompassing all flora/fauna. Second is the famous event of Tripurasuras from Taittirīya Saṃhitā 6.2.3 wherein Rudra claims the title Tripuravijaya. Other Brahmāṇa sections like the story of Bhutavān AB3.3.33 do talk about many exploits wherein Rudra emerges and claims this title. Since Rudra expanded as Paśūspati and claims ownership of their sacrifice, one has to take Rudra’s permission before such an act.
भव राजन् यजमानाय मृड पशूनां हि पशुपतिर् बभूथ । यः श्रद्दधाति सन्ति देवा इति चतुष्पदे द्विपदे ऽस्य मृड ॥11.2.28
Atharva Veda 11.2.28
Oh Bhava (भव ) you are the ruler/king (राजन् ) be gracious/favorable, pardon/spare (मृड ) towards the one hosting the Yagna (यजमानाय ) especially which donating cattle as sacrifice (पशूनां ) especially you are the one to reach (बभूथ ) being the lord of cattle (पशुपतिर् )| those who (यः ) have faith in the divine (श्रद्दधा श्रद्-दधान देवा ) view graciously (सन्ति) thus on (इति ) our four legged (चतुष्पदे ) and two legged (द्विपदे )
Please note: Yajamāna = the host of the ceremony, Adhvaryu = the one making oblations
Do Vedas use the term Pãsha as the bonds that tie us to material worlds? Does Rudra free the Paśūs from these Pãsha? Of course, let’s examine the Upaniṣhads and link them back to Vedic Saṃhitās.
देवं ज्ञात्वा सर्व-पाशापहानिः भवति । क्षीणैः क्लेशैः जन्ममृत्युप्रहाणिः। तस्य अभिध्यानात् देहभेदे तृतीयं विश्वैश्वर्यं च सः केवलः आप्तकामः च भवति ॥ 1.11
With the knowledge (ज्ञात्व) of the divine (देवं) all (सर्व) bondages/fetters (पाशा) looses (हानि) its existiance (भवति) | With the depletion (क्षीणै) of disturbances in mind (क्लेशैः) and knowledge all the cycle of birth (जन्म) and death (मृत्यु) ceases ((हानि)) | Therefore (तस्य) through meditative (ध्याना) states overcome bodily desires and changes (देह-भेदे) and enter into the Turiya (तृतीयं) state (third state) and (च) in turn realizes that/His (सः) Sovereign Authority of entirety (विश्वैश्वर्यं). In this state one alone (केवलः) exists without a second, and all notion of self and its desires reach completion (आप्तकामः).घृतात् परं मण्डम् इव अतिसूक्ष्मं शिवं सर्वभूतेषु गूढं ज्ञात्वा विश्वस्य एकं परिवेष्टितारं देवं ज्ञात्वा सर्वपाशैः मुच्यते॥4.16
like the cream (मण्डम् ) above (परं) the clarified butter (घृतात्) the hidden within (गूढम् ) in all beings/existences (सर्व+भूतेषु ), Knowing (ज्ञात्वा ) him who is exceedingly (अति) subtle (सूक्ष्मं ) who is Sivam/the auspecious one (शिवं ) in all, knowing (ज्ञात्वा ) that divine (देवं ) who along (एकं ) encompasses all (विश्वस्य परिवेष्टितारं ), one is released (मुच्यते) from every bondage (सर्व+पाशैः ).
Svetasvatara Upaniṣhad 1.11/ 4.16
This is not the only statement, Svetasvatara Upaniṣhad 1.8, 4.15-16, 6.13 and Taittirīya Āraṇyaka 10.47.74 talk about releasing oneself from Pãsha in clear detail.
Dose sacrifice mean killing?
The sacrifice of Cattle doesn’t always denote killing them, during the Vedic times human consciousness evolved towards sacrifices that do not require killing. The Vedas are a massive body of literature that documented various aspects of life, both social and personal, physical and metaphysical, ritual and spiritual, and many more. Animal Sacrifices were also documented but at the same time, they documented how the civilization evolved towards a much more pure and compassionate sacrifice. Following is the literary evidence from Vedas to Itihasa and Yoga that shows us why and how the evolution of spiritual practice took its course.
न ता अर्वा रेणुककाटो अश्नुते न संस्कृतत्रमुप यन्ति ता अभि । उरुगायमभयं तस्य ता अनु गावो मर्तस्य वि चरन्ति यज्वनः ॥ ४
“The war-horse never catches them, they never go to the place of slaughter or sacrifice. The Cows always roam without fear on the wide-spreading land of the mortal worshiper.”Please note: Rig Veda 6.28 is an entire hymn dedicated to cow.
Rig Veda 6.28.4
“He replies, ‘The mother of the Rudras, the daughter of the Vasus, the sister of the Âdityas, the navel of immortality. To the people who understand me, I say, “Do not kill the guiltless cow, which is Aditi.” I kill my sin,’—thus, if he chooses to have it killed. But if he chooses to let it loose, he should say, ‘My sin has been killed. Om! Let it loose! Let it eat grass!‘”
Grihya-sutra of Paraskara Sukla Yajur Veda 1.3
The above perfectly landed in Mahabharata Itihasa Anugita Parva of Ashvamedhika Parva 91 wherein Janamejaya explains the 3 types of sacrifices and how the rituals moved from Vedic to Agamas (belonging to Tantra):
“O puissant Rishi, Kings are attached to sacrifices. The great Rishis are attached to penances. Learned Brahmanas are observant of tranquillity of mind, peacefulness of behavior, and self restraint…..
Mahabharata Itihasa Anugita Parva of Ashvamedhika Parva 91, Mohan Ganguli 1842
When the animal is selected for sacrifice were seized, the great Rishis, O king, felt compassion for them. Beholding that the animals had all become cheerless, those Rishis, endued with wealth of penance, approached Cakra and said unto him, This method of sacrifice is not auspicious. Desirous of acquiring great merit as thou art, this is verily an indication of thy acquaintance with sacrifice. O Purandara, animals have not been ordained to be slaughtered in Sacrifice. This sacrifice is not consistent with righteousness. If thou wishest it, let thy priests perform thy sacrifice according to the Agamas. By performing a sacrifice according to the (true import of the) scriptural ordinance, great will be the merit achieved by thee.
In that great sacrifice, O King, all the required atricles were collected. No animals were slain in it. The king had ordained it so. He was full of compassion. Of pure and libral mind, he has cast off all desires, and was well conversant with all rites. The requistes of the sacrifie all consisted of the products of the wilderness. The ancient God of Gods became highly gratified with the king on the account of this sacrifice.
Mahabharata Itihasa Shanti Parva 337, Mohan Ganguli 1842
So the rituals moved from Vedic Sacrifice to Agamic rituals that originate from Tantras. Even Buddhism integrated a vast among of Tantric methodology into them. Today most of the temples and their working practice rely on the Agamic methodology. All major sects have their own version of Agamas. It was Adi Shankara who consolidated the Tantric wisdom into his famous literature called Prapancha-Sara-Tantra. Almost all temples operate on the set-up established by Adi Shankaracharya. Yoga also evolved mainly from the methods postulated in the Tantra schools and took the highest prominence by the time of Itihasa of Mahabharatam which is highly influenced by Sankhya and Yoga Darshanas/Philosophies. So, how does one equate the Vedic Animal Sacrifice with that of Yoga? The following answers this question:
Bhisma says: The merit that attaches to a thousand ashva-medha (ashva-horse) or a hundred Vajapeyas cannot come close up to even a sixteenth portion of the merit that arises from Yoga.
Mahabharata Itihasa Shanti Parva 324, Mohan Ganguli 1842