When a horse or pony has multiple issues then we have to establish which is the greatest or most imminent threat to their health and welfare. Historically, the advice for horses with liver disease has been to avoid oil as an energy source and keep protein levels low. As your horse has had laminitis in the past, oil would be a safer energy source to use in preference to cereals which contain lots of starch. More recent advice such as that by Andy Durham Bsc BVSc CertEP DEIM DipECEIM MRCCS writing in Equine Applied and Clinical Nutrition suggests that inclusion of oil at 0.1ml/kg bodyweight is perfectly acceptable for horses with liver disease and that levels up to 1ml/kg bodyweight might be required to safely maintain or promote weight gain.
With regard to protein intake, it’s most definitely a case of low protein but not no protein as protein is needed as part of the immune system, hormones and building tissues such as muscle. Although the level of protein in pure alfalfa horse feeds often looks high and deters people from using it, it is important to consider that a large Stubbs scoop only holds 400grams of Alfa-A Oil so the actual amount of protein supplied is not excessive by any means. Given that alfalfa is so low in sugar and starch naturally, it is a really useful way to help horses maintain their weight, particularly those with a history of laminitis. Therefore, feeds such as Alfa-A Oil are suitable when used in moderation for your horse.