In order to keep their protein level adequate, you should raise that too at the same time you are adding more fats and carbs to their winter diet. So if you have access to a high protein Game Bird feed, a 20% protein layer feed or even something like Flock Raiser, then you can add some cracked corn or scratch for the fat and carbs... (or in my case my birds love sweet feed/wet cob) that will help. Try not to go below a combined protein level of 16% tho (Guinea's minimum requirement). The scratch and corn will bring the protein level down, so that's why I suggested bumping up the protein also, to even it out. Fine stem leafy alfalfa gives them extra nutrients, something green and something to do/pick at while they are confined because of the snow/bad weather. You may have to feed the corn/scratch as treats only because just like little kids they will pick out all the "candy" and leave the rest, lol.
