The meaning of "became smaller at the shoulders"

[optimistic pessimist]

Hi, everyone.

I'm reading a passage of a book titled "The Long Summer".

"...cattle throughout the world became smaller at the shoulders, perhaps because Roman cross-breeding practices were abandoned."

I don't understand the meaning of "became smaller at the shoulders".

Does that mean "the cattle's height up to the shoulders became shorter"?

Or "their shoulder parts became smaller"?

Thank you!

optimistic pessimist

[fromatto]

Hi, everyone.

I'm reading a passage of a book titled "The Long Summer".

"...cattle throughout the world became smaller at the shoulders, perhaps because Roman cross-breeding practices were abandoned."

I don't understand the meaning of "became smaller at the shoulders".

Does that mean "the cattle's height up to the shoulders became shorter"?

Or "their shoulder parts became smaller"?

Thank you!

optimistic pessimist

It PROBABLY means that they became smaller across the width of their shoulders. I'm sure it has nothing to do with their height.