Gooch, C.A.Ludington, D.C.2014-07-162014-07-162002-08-02https://hdl.handle.net/1813/36950Reports from photoperiod manipulation studies mainly focus on cow related variables and provide little information relative to the lighting system designs employed. Light levels are generally reported but lack lighting uniformity information. Consequently, little dairy-specific background information is available for lighting designers to use when designing lighting systems for photoperiod manipulation. The objective of this paper is to provide information for designing lighting systems for photoperiod manipulation based on experience obtained from designing systems for six production dairy farms (three tie stall barns and three freestall barns) that are participating in a field trial in New York State.en-USdairyphotoperiodlightingreport