Keep it simple, keep it healthy and keep it cost effective
As elite athletes, expected to perform to their optimum, throughout their lives greyhounds have been reared on the very best quality foods.
In their retirement the same philosophy should apply but with one proviso. A retired dog still needs quality food, but the physical requirements of retired life means that there are differences in the feeding of a racing to a retired dog.
The key is high quality human grade, beef or chicken, good quality kibble (not the most expensive), rice, pasta, vegetables, fish with oils, natural yoghurt and beef brisket bones for dental health.
In the warm weather, the occasional "kibble pops" or chicken floating in diluted milk will encourage them to drink and eat.
The key is quality and variety, without creating fussy eaters and minimising treats and snacks.
Keep to the 10 minute rule. if it is not eaten in ten minutes it is taken away, so no grazing.
Of course a supply of fresh water is essential.