Does this kibble have low phosphorus to protect the kidneys of older cats?

I contacted Blue Buffalo regarding their phosphorus levels in their Healthy Aging Chicken & Brown Rice. They admitted The Healthy Aging Mature Chicken & Brown Rice dry cat formula contains 0.97% phosphorus, as-fed basis. For animals with specific medical conditions that can be managed through nutritional therapy, Blue Buffalo does offer Natural Veterinary Diet formulas. These formulas are available with a prescription from your veterinarian. They recommend speaking with your veterinarian, as he or she should be able to direct you to a product that is best suited for your pet should they have specific medical conditions that may benefit from nutritional therapy.

What is the min./max. phosphorus content of this food? It's unfortunate Blue doesn't mention phosphorus in the guaranteed analysis of their products.

I always find that with very specific questions, it is best to contact the company directly - especially when it comes to my critters' health . Amazon can not possibly have the very specific info on the products of ALL the companies with which it does business, particularly for me to ask questions. The contact page for Blue Buffalo is here: https://bluebuffalo.com/about/contact/. The telephone number is: By Telephone, please call us at (800) 919-2833 between Monday - Friday, 8:00 am - 4:00 pm MST. Also, there is an email fom on the "CONTACT" page, but it sounds like you may need to ask questions. Hope is helps!!

Is the kibble for the senior blend any softer than the blue buffalo wilderness brand?

I'm not sure as they've been on the senior brand for a while now. Even our oldest kitty likes it. I have softened it, from time to time, with a few spoons of hot water over it to soften it up. We always leave The Blue Buffalo Senior food out & supplement that with canned food (with gravy so there are no revolts! lol). I hope this helps. ( :