I've quickly hunted around and found a few meshes which may be of use to ye. I'm not sure if they're exactly what you're looking for, but within the time I had these are the ones I found. Hope they're alright and will do ye, if not I'll hunt around a little more later and see if I can hunt down ones more fitted for ye.
http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=18553.0 (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=18553.0)
Tetsu has a trough mesh, and a few others which may come in handy.
http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=8896.0 (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=8896.0)
Babylon has a cow mesh.
http://www.deviantart.com/art/Animal-Pack-508185599 (http://www.deviantart.com/art/Animal-Pack-508185599)
Bloopaloozer has an animal pack with a saddled and unsaddled horse.
http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=10365.0 (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=10365.0)
Wombat meshes may be more useful for yer horses/cattle, I think.
Great, glad they were what you needed! :)