Two pregnant barn cats are eating very little

I have two cats that  are pregnant and  recently have not been eating any of the soft can food i have been feeding them and they are eating very little dry food. Please can someone reccomend something I can try ? Im really starting to worry about them. I tried feeding them Mackeral but they only like the juice and dont eat all the mackeral

Thanks for your help

PS  they will be spayed once they ween the kittens

 Hmmm..   some people say that cats are often tempted by Fancy Feast .   I would try the paté style ones.   

 or Royal Canin Babycat seems to often be tempting.    both the cans and the dry. 

Another idea is get some Fortiflora probiotic powder.    It can't hurt to give a probiotic but the reason I'm mentioning it here is that the flavor is often very helpful at getting cats to eat.   You can buy it from a vet,  or maybe a Feed Store.  ,  or  I have bought it online from Petfooddirect.com  you just sprinkle it on their food. 

Are they hunting?    could there be more prey around lately for some reason?  

If theyre starting to look thin except for being pregnant ,   I would get them to a vet  to check if they might be sick.   and maybe get an appetite stimulant medicine.     

Thank you very much. I will try all that you mentioned.   Yes I did see one of them a mole or gopher the other day . They are allways at my back door begging for something else other than what I have been giving them

Also you could try feeding them smelly food, such as fish, to 'wet' their appetite.

And hopefully, they are hunting and eating their catch.

Yes, buy some of the stinkiest decent wet food you can find. I think the Friskies salmon pate and the poultry platter pate are the funkiest ones.