No light, no problem: provision of light during simulated transport does not alter broiler chick performance or...

Commercial transport of newly hatched poultry species typically occurs under darkness. The impact of providing light during chick transportation has not been investigated and previous research suggests blue light may have a calming effect on broilers. This study investigated how chicks responded to simulated transportation under dark compared to white or blue light at two durations (4 or 7 h). Commercial chick transport baskets containing Ross 308 broiler chicks (n = 11,340) were placed onto separate vibration platforms located in 9 rooms (3 per light treatment), each with two vertical stacks of baskets (1 per duration treatment). Immediately after simulated transport, 5 chicks from each room were euthanized to assess blood parameters, gastrointestinal tract length and weights, and residual yolk sac weight. Remaining chicks were housed in floor pens under white light until 35 d. Performance data collected included body weight, feed intake, feed efficiency, and mortality. Welfare data included heterophil/lymphocyte (H/L) ratio, novel object test, and tonic immobility. The experimental design was a 3 × 2 factorial arrangement in a completely randomized block design consisting of 2 trials, with trial as block. Data were analyzed using Proc Mixed (SAS 9.4) and Tukey's range test, with differences declared significant when P ≤ 0.05. Light treatment did not affect any performance or welfare parameters. Immediately post transport, chicks in the 7-h treatment had higher partial pressure of carbon dioxide (P = 0.03), sodium (P = 0.01), reduced plasma glucose (P = 0.01), shorter ileum (P = 0.05), and heavier cecum (P = 0.01). Throughout rearing, birds that underwent simulated transport for 7 h had reduced growth from 0 to 14 d (P < 0.01) and consumed less feed from 0 to 35 d (P = 0.01). At 32 d, birds exposed to simulated transport for 7 h had lower H/L ratios (P = 0.04). Mortality was unaffected by light and duration. The results suggest that changing the current industry practice of transporting chicks in darkness, compared to white or blue light, does not improve broiler performance or welfare. Duration of simulated transport influenced early life performance and physiology.