At the end of the joke she gave a horse laugh that could be heard a street away.

笑话讲完后，她发出一阵狂笑，隔着一条街都能听到。

He came out with a horse laugh that caused some eyebrows to raise.

他出来讥讽了一番，使得好些人直皱眉头。

You put a twenty in the jar, then if you can make my horse laugh, You win all the money!

现在你可以往瓶子里放进一张20元的钞票，如果你能让我这匹马笑出声来，你就可以把这一大瓶票子拿走。