I have an old bag at the yard somewhere, good stuff- can try and dig it out and list the ingredients- if I remember!! - have you tried phoning spillers in the meantime they may be able to tell you, although I don't think they make their ingredients "public" on their website for some reason I don't know!, its very similar consistency to Happy Hoof but the fattening version!!
I have fed this stuff, it is basically chaff with oil but as K27 said more fattening than say Happy Hoof.
Did wonders for my old Warmblood when I first bought her she was lacking condition. I no longer feed as my Warmblood has been sold and my Sports Horse gets fizzy so very very easily, he just gets HI Fi Lite, H&P cubes and Cool Mix.
Digestible Energy (MJ/kg) 11.0
Oil 10%
Protein 12%
Fibre 21%
Starch 7%
Vitamin A (iu/kg) 10,000
Vitamin D (iu/kg) 1,000
Vitamin E (iu/kg) 400
Selenium (mg/kg) 0.2
Copper (mg/kg) 25
Zinc (mg/kg) 110
Formulated to help build condition without excitability. Good quality protein to support muscle tone and topline. Soya oil for non heating calories and coat condition. Enriched with a broad spectrum of vitamins and minerals, to provide your horse or pony with more nutrition than any other chopped fibre blend. Can be combined with a mix or cube or fed as a replacement for compound feed. Contains a palatable blend of dried alfafa and straw carefully chosen for consistent nutritional quality.