Artificially extending photoperiod improves milk yield in dairy goats and is most effective in late lactation

Abstract

Short day length (i.e. winter) is associated with reduced milk yield from dairy animals. Dairy cows and sheep have been successfully housed under lights throughout winter to extend the day length and increase milk yield, very little data exists on the effect of extended day length on the milk yield of dairy goats. The current study was conducted over an eight week period from June to August, 2009. A total of 542 Saanan and Saanan British Alpine cross goats were used, all producing ≥1.5. L of milk per day, 253 in early lactation (5-20 days in milk) and 289 in late lactation (190-210 days in milk). Does were randomly allocated to either the control or the long day photoperiod (LDPP) groups, bo..