In various ancient Hindu texts, much has been described the holiness and sacredness of cows and bulls.
According to Rig Veda 4.1.6
अस्य शरेष्ठा सुभगस्य संद्र्ग देवस्य चित्रतमा मर्त्येषु |
शुचि घर्तं न तप्तम अघ्न्याया सपार्हा देवस्य मंहनेव धेनोः ||
asya śreṣṭhā subhaghasya saṃdṛgh devasya citratamā martyeṣu |
śuci ghṛtaṃ na taptam aghnyāyā spārhā devasya maṃhaneva dhenoḥ ||
The brightest splendor is in the glance, which the auspicious God bestows on mortals. The God’s glance, longed-for even as the butter, pure, heated, of the cow, the milk cow’s bounty.
Other Vedic injunctions are:
Rig Veda 6.28.5
गावो भगो गाव इन्द्रो मे अछान गावः सोमस्य परथमस्य भक्षः |
इमा या गावः स जनास इन्द्र इछामीद धर्दामनसा चिदिन्द्रम ||
ghāvo bhagho ghāva indro me achān ghāvaḥ somasya prathamasya bhakṣaḥ |
imā yā ghāvaḥ sa janāsa indra ichāmīd dhṛdāmanasā cidindram ||
To me the Cows seem Bhaga, they seem Indra, they seem a portion of the first-poured Soma. These present Cows, they, O ye Indra. I long for Indra with my heart and spirit.
Rig Veda 7.69.9
एष सय कारुर्जरते सूक्तैरग्रे बुधान उषसां सुमन्मा |
इषा तं वर्धदघ्न्या पयोभिर्यूयं पात … ||
eṣa sya kārurjarate sūktairaghre budhāna uṣasāṃ sumanmā |
iṣā taṃ vardhadaghnyā payobhiryūyaṃ pāta … ||
With his fair hymns this singer, too, extols you, waking with glad thoughts at the break of morning. May the cow nourish him with milk to feed him. Preserve us evermore, ye Gods, with blessings.
The cow is also defined as the mother of Adityas, daughter of Vasus, and the very soul of people, according to the ArthavaVeda (Arthava Veda 1.22.1). Even the panchgavya, which is produced by the cow, is a remedy for heart and liver diseases.
Arthava Veda Veda 9.10.5
hiṅkr̥ṇvatī́ vasupátnī vásūnāṃ vatsám ichántī mánasābhyā́gāt |
duhā́m aśvíbhyāṃ páyo aghnyéyáṃ sā́ vardhatāṃ mahaté sáubhagāya ||5||
She, Lady of all treasures, hath come hither, yearning in spirit for her calf, and lowing. May this Cow yield her milk for both the Asvins, and may she prosper to our high advantage.
The cow can have great, incomparable value, according to Yajurveda, that she has unlimited qualities and virtues. In the Vedas, there is no such concept of eating the meat of cows. Even the Holy Koran says that eating the meat of cow can invite various diseases. Muni Vashitha is believed to have said King Soudasa, in the Mahabharat, that the cow is and should be sacred everywhere in the world, and Lakshmi stays in where cows stay. The dung produced by the cow is also sacred, and as such, people are advised to clean how with the cow dung. Even scientifically, it has anti-microbial and mosquito repellent property.
The Brihadaranyaka Upanishad says:
vācaṃ dhenum upāsīta
tasyāś catvāraḥ stanāḥ
svāhākāro vaṣaṭkāro hantakāraḥ svadhākāraḥ
tasyai dvau stanau devā upajīvanti
svāhākāraṃ ca vaṣaṭkāraṃ ca
tasyāḥ prāṇa ṛṣabho mano vatsaḥ
As it were, the cow should be meditated upon the Vedas. There are four sounds of her: “Svaha”, “Vasat’, “Hanta” and “Svadha”. Among them, the gods live on two – “Svaha” and “Vasat”; men live on “Hanta” and manes live on “Svandha”. The vital force lies in the bull, and the mind lies in the calf.
It is said that Lord Krishna, Lord Shiva, and goddesses are associated with cows and bulls, especially Krishna who is the protector of cow and Lord Shiva who carries the bull Nandi.