Beak trimming is commonly used to reduce the incidence of feather pecking but this practice is more and more under discussion and banned in several EU countries. The side effects of non-trimmed beaks is an increased feed intake, as the birds have less plumage to keep them warm. Probiotics can be part of the solution.
Laying hens provided with Bacillus subtilis showed better performance (egg weight, egg mass & FCR) in the early stages of production, and persistent larger eggs over the whole period, without negative impact on feed conversion, hen weight and egg shell quality.
See full article by Pauline Rovers-Paap, Orffa Additives in Poultry World, Feb 20 here.