4 – Table Egg Production Flashcards
Components of light to consider
- Light wavelength
- Light intensity
- *photoperiod length and distribution
Photoperiodism
- Long vs. short day breeders
- Reason for photoperiodism=neonatal survive in the wild
- Synchronize and improve and maintain reproduction
o *change light from a short day to a long day! - Control of sexual mature
What age is desired for sexual maturity?
- Intermediate age
What happens if too early age at sexual maturity?
- Small eggs
- Lower rate of lay
- Increased prolapse
What happens if too late age at sexual maturity?
- Fewer days to collect eggs
What is the result with gradual changes to photoperiod?
- Gradual increase in maturity
What is the result of abrupt changes to photoperiod?
- Faster change in maturity level!
What are the 3 rules of thumb with lighting for laying hens?
- Never increase photoperiod length during brooding and rearing
a. Increase photoperiod beyond CRITICAL PHOTOPERIOD
b. Increase at 17-18 weeks - Minimum of 12hrs of light required for maximum stimulation
a. Maybe increase to 14hr day light at 22-24 weeks - Never decrease photoperiod length during egg production
Brown hen egg production curve
- Peak production at 25 weeks of age and then stable decline
o Till 68% when at 100 weeks of age (usually raise them till 75 weeks of age: 80% egg production)
White hen egg production curve
- *slightly better than browns=common strain to use in NA for egg production
- At 100 weeks of age=70%
- At 75 weeks=well over 80%
How does egg weight relate to the age of birds?
- Slowly increases as they reach the peak age
o Levels off, but slight increase
o NO decline
What happens with egg shell quality with the age of the flock?
- more cracked eggs with age of flock
- 0.5% increase in % cracks per month of production
- *due to calcium deposits depleting as they age
o Maybe supplement diet
Storage of eggs on farm
- Storage time: 4-7 days (usually picked up within 1 day in SK)
- Temperature: 5-10 degree C
- Relative humidity: 70-80%
- *clean conditions
What are the 5/6 egg processing ‘steps’?
- washing
- egg candling
- ultrasound
- sizing
- cartooning
- *grading
Washing eggs
- High pH solution to eliminate bacteria
- All eggs washed=why we need to refrigerate our eggs in NA
Egg candling
- Eliminate blood spots, meat spots, double yoked eggs, abnormal shapes
- Blood spot=from where the egg ‘pinched’ off during ovulation
- *go to ‘breaker’ plant=grade B or C eggs
o Need to pasteurize grade C eggs (bacterial contamination from cracks)
Ultrasound
- Detect cracked eggs
Sizing
- Each egg weighed and sorted
Grading involves looking at
- Shell quality
- Interior quality (yolk and albumen)
- *egg candled
What are the 3 characteristics looked at with shell quality?
- Cleanliness
- Soundness
- Shape
What are the changes that happen with interior quality due to storage?
- Albumen thins (mucin degradation)
- Moisture loss
- Loss of CO
- Yolk enlargement
What happens with moisture loss during storage?
- Decreased egg weight and increased size of air cell
What happens with loss of CO during storage?
- Change in egg pH (7.6-9.5)
- Loss in flavour
What happen with yolk enlargement during storage?
- Larger and more fragile yolk
- *larger=usually more fragile
