Kine from the highest food. They are the best Havi for the celestials. The Mantras called Svaha and Vashat are forever established in kine.
अन्नं हि परमं गावो देवानां परमं हविः। स्वाहाकारवषट्कारौ गोषु नित्यं प्रतिष्ठितौ॥