A study was conducted to find out the effect of different colours of light during incubation on hatchability performance of commercial layers, at a Commercial Hatchery, Tamil Nadu and India. For that a total of 270-layer (Hy-Line) hatching eggs from Layer parent stock were used. The 270 eggs were grouped into three treatments of 90 eggs per treatment namely, T1 (incubated under dark), T2 (incubated under green light), T3 (incubated under blue light). The 90 eggs per treatment were further grouped into 30 eggs per replicate as three replicates per treatment in total. The light sources used were Light Emitting Diode (LED). Light intensity at the egg surface was adjusted to 300-400 lux. The T1, T2 and T3 eggs were incubated in setters. The LED lights of different colours were fixed above the treatment eggs, except T1 as those eggs were incubated under dark. The different colour of lights were provided for the first 18.5 days (444 hours) of incubation for 12 hours a day. At 18.5th (444 hour) day of incubation all the eggs were candled and clear eggs or the eggs which obstruct lesser light with respect to the age of embryo were separated and subjected to break open analysis. The hatching eggs were transferred to the hatcher on the 18th day of incubation. In hatcher, all the eggs were incubated under dark for the last 3 days (60 hours) of incubation. The eggs were incubated under standard temperature of 99.5 to 100oF and relative humidity of 58 to 60% for the first 18 days and 99oF temperature and 72% RH for the last three days of incubation. On the 21st day, the good quality chicks were separated. Chicks were weighed, sex separated. During incubation, the data on hatchability of total egg set, hatchability of fertile egg set, moisture loss, chick yield, chick weight at hatch, embryonic mortality (early; mid; late embryonic mortality), number of chicks with unhealed navel were recorded.
The hatchability performance had a significant effect, with T3 (Blue) showing the highest hatchability on fertile eggs (91.87%±1.12), followed by T1 (Dark), while T2 (Green) had the lowest. No significant differences were noted in early, mid and total embryonic mortality, but T2 (Green) had significantly lower late embryonic mortality (1.10%). Chick yield showed no significant variations. No significant differences were noted in moisture loss. In terms of chick quality, T2 (Green) had the highest percentage of good navel chicks (13.67%±0.44%) and active chicks (35.96%±2.00%), while T3 (Blue) had the lowest percentage of active chicks (10.67%±0.44%). Overall, blue light incubation improved hatchability and reduced embryonic mortality but resulted in lighter and less active chicks, while green light increased embryonic mortality but yielded more active chicks and good quality chicks and fetched higher return.
International Journal of Veterinary Sciences and Animal Husbandry
