I´ve been offering only the new grass hay for three weeks now, and they haven´t eaten more than a few mouthfuls between them. Of course I give them pellets and vegs, same as before, but now they´re cleaning out every last crumb of their Cavy Cuisine pellets and wheeking for more.
I´ve never been one to give in to picky animals. With my other pets I just hold out until they´re hungry enough to eat whatever they´re given. However, I´m concerned that the pigs aren´t getting enough fiber to keep their digestion running properly and also that their teeth aren´t getting worn down sufficiently.
It seems different hays appeal differently -- even at diferent growth times. If you have determined they like orchard grass, for example, or timothy -- maybe you need to ensure that is what you get by the bale. It is always possible they are eating more than you think but hard to tell.
I get orchard grass by the bale and put fresh hay on the top of their litter trays over the shavings. Nina just hangs around waiting for me to put the clean tray down and always jumps in, joyfully chomping away. I think there are some other varieties of grass that appeal to cavies. I don´t remember what Kleenmama uses, but it is very green and soft.
So find out what grass hays you have in the area and get feedback on how popular they are with gps. For what it´s worth, there is a page on selecting and storing hay here:
Usually the Oxbow Timothy has been great - green, soft and the pigs loved it. But I´m not going to pay a premium price for stalky brown hay!
I´ve identified the new grass hay as primarily Bermuda. The House Rabbit Society have some useful pictures and descriptions of nutritional value at their web site. It´s supposed to be good for bunnies and looks nice and green with a very soft fine texture. I tried Oxbow´s Orchard Hay and the finicky little devils wouldn´t touch that either!