Wilbur was what farmers call a spring pig, which simply means that he was born in springtime. (2.9)
The early summer days on a farm are the happiest and fairest days of the year. Lilacs bloom and make the air sweet, and then fade. Apple blossoms come with the lilacs, and the bees visit around among the apple trees. (6.1)
"Well, I don't like to spread bad news," said the sheep, "but they're fattening you up because they're going to kill you, that's why."
"They're going to what?" screamed Wilbur. Fern grew rigid on her stool.
"Kill you. Turn you into smoked bacon and ham," continued the old sheep. "Almost all the young pigs get murdered by the farmer as soon as the real cold weather sets in. There's a regular conspiracy around here to kill you at Christmastime." (7.10-12)