No it is not mandatory to eat cows and beef in Islam, they are mentioned 12-20 times in different synonyms, it's a word used on the subject of false idols and rural scenes mostly:
The greatest significance of oxen in the Quran is in chapter 2, 285 verses, the longest chapter, titled "The Cow", the re-telling of the warning of Moses to the ancient peoples when they worshipped a bull...
The word calf and cow in 2nd and longest chapter of the Quran, is used in god's epic warning to describle those who do not believe in the Quran, in chapter 2, and to forment against the Quran's detractors that they are the same as cow worshippers of Moses.
Oxen and Calf and Cow are mentioned both by the Quran and Bible a dozen times, both in terms of gifts and religious scenes, and because of the worship of Taurus. Cows were a major image of worship for Persians, Babylonians and Egyptians, basically the entire planet worshipped cows, Ibis, monkeys and animals prior to the books on monotheism.
The bull, previously to moses, was worshipped as a god, as the rising constellation of a most holy day of ancient peoples like egyptians and celts, the rising constellation on the shortest day of sun in the sky, and a precise marker in syncrony with the seasons of the Nile... in the sequence of constellations ram-taurus-fish-aquarius...