In their cultural notes in Sing Chinese, Cindy Mao and Ma Baolin explain that "Little Cowherd" is a title shared by several folks songs from Herbei Province and that this is the most famous one. Like the other songs with the same name, it is sung by young cowherds and adopts the question-and-answer form.
In this version the questions are: Who built the Zhaozhou Bridge, who built its marble rail, who rode it on a donkey and who left a cart trail on the bridge? The answers being: Lu Ban (a master carpenter some 2000 years ago), a holy man, Zhang Guo Lao ( one of the eight Taoist immortals know to ride backwards on a whit donkey) and a kitchen god respectively.
Fascinating stuff, dear surfer, what! For me this also another good tune for the concertina/recorder combination.

Verse 1.
Which man built the Zhou Zhou Bridge?	Zhào zhōu qiáo lái shén me rén xiū?
Which man built the marble rail?	yù shí lán gān shén me rén liú?
Which man rode on it with a donkey	shén me rén qí lǘ qiáo shàng zǒu?
Which man left a cart trail on the bridge me yi yo hay?	shén me rén tuī chē yà le yí tàng gōu me yí yo hai?
Verse 2.
Lu Ban built the Zhou Zhou Bridge	zhào zhōu qiáo lái lǔe bān xiū
The Holy Man built its marble rail	yù shí lán gān shèng rén liú
Zhang Guo Lao rode on it with a donkey.	zhāng guǒ lǎo qí lū qiáo shàng zoǔ
Kitchen God left a cart trail on the bridge me yi yo hay?	chái wáng yé tuī chē yà le yí tàng gōu me yí yo hai