The significance of Old Major's message to the animals exists on two levels. The first is to raise awareness to the unfairness and exploitation that exists when humans control "the means of production" on the farm. Old Major wants the animals to comprehend how the humans abuse the animals and how they benefit from the animals' labor. He does this through discussing how the hens do not get to keep their eggs, how the pigs will be carved up by the humans for profit, and how Boxer will be sent off to the Knacker's when he is deemed without value. For Old Major, it becomes vitally important for him to be able to convince the animals of how human rule and control is synonymous with cruelty and unfairness.
The second part of Old Major's message is to inform the animals of his philosophy of Animalism. This becomes the theoretical antidote to the abuse of the humans. If animals can control "the means of production" and assert power over their own world, Old Major convinces them that they will possess more autonomy and will treat one another better than if humans are in control. Animalism is bound by specific commandments that are also a part of Old Major's message. In this, Old Major has been able to show the animals how their life can be better if the farm is under animal rule and apart from human control. Both of these messages are essential to Old Major's addressing of the animals in the opening chapter of Orwell's work.