Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 5 · Omens
शकुनानि
अभक्ष्यं भक्षयन्त्यश्च गावो दत्तास्तथा स्वकाः ।त्यक्तस्नेहाः स्ववत्सेषु गर्भक्षयकरा मताः ॥ २३ ॥
In the full Agni Purana this is chapter 232, verse 23.
Cows that eat what should not be eaten are said to cause loss of the unborn. So are cows that stop loving their calves, whether given away or one's own.
Simple meaning: Cows that eat wrong things or drop love for their calves are said to bring a loss of the unborn.
भूमिं पादैर्विनिघ्नन्त्यो दीना भीता भयावहाः ।
Cows pawing the ground and frightened bring fear. Wet cows with soil on their horns are good.
महिष्यादिषु चाप्येतत्सर्वं वाच्यं विजानता ।
All this holds for buffaloes too. Someone else riding one's saddled horse is not good.
जलोपवेशनं नेष्टं भूमौ च परिवर्तनम् ।
A horse sitting in water, rolling on the ground or sleeping for no reason brings trouble.