for people who love the littlest dairy goats
Hi Kim- yes, high calcium diets can certainly contribute to stone formation for the boys. They are called calcium carbonate stones, where those formed from high grain consumption are typically struvite or apatite stones. The good news is that management techniques for avoiding them are basically all the same =)
If that is the only hay you can find, I do understand your concern, especially since you have dealt with stones in the past. They do still need that long stem roughage in their diet, so increasing the pellets to offset the amount of hay they are consuming is a great idea. The other upside is that you were able to find a blend, instead of just straight alfalfa, so I honestly think that is very helpful.
Keep in mind that stone formation has other contributing factors than diet. Urine pH and total water balance within the animal have great impacts. Ammonium chloride is a great tool to acidify the urine and help keep stones at bay. It is effective for all 3 of the stone types mentioned above because they tend to form in alkaline urine. You may want to add some over their pellets.
The other thing that stones like to form in is very concentrated urine. Water consumption tends to go down in winter, so I would consider warming their buckets a couple times a day to encourage plenty of water intake.
I hope this info is helpful =)