That human beings have the ability to exploit non-human animals does not in the least imply that the world’s non-human animals exist for the purpose of being exploited.

The anthropocentric claim that non-human animals were put on Earth for the benefit of H. sapiens constitutes an empirical claim about the world that contradicts an enormous number of respected and well-supported theories within the realm of science. All of the available data support the universal scientific consensus that all forms of life on this planet owe their existence to the slow, gradual process of evolution by natural selection and random mutation. That human beings have the ability to exploit non-human animals does not in the least imply that the world's non-human animals exist for the purpose of being exploited. Pigs and chickens do not exist for the benefit of human beings anymore than human beings exist for the benefit of the Yersinia pestis, the bacteria responsible for the bubonic plague.

There is nothing in the fossil record or in the modern scientific canon to suggest that either human or non-human animals were placed on this planet by anyone or anything. All of the available data and the prevailing scientific theories based upon them indicate very clearly that, just like us, everyone and everything else in the plant and animal kingdoms have evolved over the course of vast stretches of time. This inarguable fact reveals the assertion that animals were “put here” as a patent and absurd falsehood. And if animals were not put here, then it is impossible to adduce that they were put here for a specific purpose: least of all to be bred, enslaved, slaughtered, and eaten by human beings, whose anatomies are simply not suited to digest them.

The fossil record also leaves no question that in almost* all cases, the animals were here well before us. As a species, H. sapiens has been around for only about 300,000 years, whereas fossil evidence clearly suggests that all manner of birds, hooved mammals, and other vertebrate and invertebrate species on whom humans routinely raise and slaughter for food have been around for much, much longer. So, anyone who claims that humans somehow have seniority on planet Earth simply doesn't know his science. And in any case, arriving someplace earlier than others doesn't give one carte blanche to do as one pleases with those who arrive later. 

Your argument is invalid.

  This rare and fascinating photograph of a pig being put on Earth to satisfy the caprices of human beings shows with extraordinary clarity precisely what did not happen to the world's billions of non-human animals. 

This rare and fascinating photograph of a pig being put on Earth to satisfy the caprices of human beings shows with extraordinary clarity precisely what did not happen to the world's billions of non-human animals. 

*We qualify this statement with the word "almost" because some species of animals, such as the modern cow,  Bos taurus, are the result of thousands of years of selective breeding on the part of human beings. The modern cow is, in a manner of speaking, a human invention, although the evolutionary precursor to the cow, the aurochs, was around long before the first Homo sapiens arrived on the evolutionary scene. So, your argument is still invalid.

See also But They're Just Dumb Animals! and The Bible Says We Should Eat Meat!