The Influence of Wavelength on Production, Behaviour, Health, and Welfare of Broiler Chickens
Two experiments (one which included two separate trials) were conducted to examine the effect of wavelength treatments (blue (BL), green (GL), or white (WL)), sex and genotype (YPMx708 and EPMx708) on broiler production, behaviour, vision, and health. Broilers were raised from 0-35d in 9 rooms, with sexes and genotypes housed in 12 separate pens per room. In experiment 1, data collected included production, health, ocular characteristics, and behavioural expression. Experiment 2 focused on spatial vision. Data were analyzed using Proc Mixed (SAS 9.4) or Proc Par1way (non-normally distributed data), with Tukey’s range test to separate means. Differences were considered significant when P≤0.05. Broilers raised under WL were heavier than those under BL or GL at d7, and GL at d14. WL broilers had higher mortality than under BL in week 5, as were males raised under WL compared to WL or BL females. Broilers raised under BL preened for a higher percentage of time than those raised under GL. At 33-34d, broilers raised under WL were more active; those under BL spent more time resting. EPMx708 females raised under GL spent a higher percentage of time at the feeder; EPMx708 females raised under WL at the drinker. EMPx708 males raised under WL and EPMx708 females raised under GL exhibited running behaviour the most. YPMx708 raised under BL, YPMx708 females and EPMx708 males raised under WL spent a higher percentage of time dustbathing. Broilers raised under BL were less fearful and less stressed. Visually, birds raised under BL were more hyperopic than those raised under GL and WL had improved spatial vision than those raised under WL. Broilers raised under BL had lower serum melatonin levels during one scotoperiod time-point only. A higher percentage of pens housing YPM-708 broilers under GL had drier litter compared to others. Males raised under WL had a higher incidence of skeletal mortality. In conclusion, when using various wavelength treatments (BL, GL, or WL), small impacts were perceived on production and health. Significant effects were perceived on behaviour of broilers raised under BL, which can partially be explained by the impacts on ocular health and spatial vision.
Doctor of Philosophy (Ph.D.)
Animal and Poultry Science