Nutrition of egg producing poultries Flashcards
Chicken hybrids kept for market egg production
LW = light weight
What are 2 phases of life of laying hens?
- Pullet period = from hatching till start of egg production
- Laying period
Length of rearing in case of pullers
-
pullets should start egg production on 18th week
1. Starter diet (0-8th week )
2. Grower diet (9th week - 17th week)
Aim of the feeding:
- to set up the onset of egg production
- we should regulate the development of pullets so they start laying eggs on 18th week
Why is bad if chicken start egg production earlier than 18th week?
When they start earlier, they will produce smaller eggs
Pullet eggs
Isometric growth of sexual organs, what does it mean?
Development of sexual organs correlates with body development (in broilers we dont care about development of the body, we just want faster BWG)
Nutrient content and the physical form of diets in pullets
- protein: S:17% (comparing to 23% in broilers), G: 15% —> they don’t grow as fast as broilers
- energy: 11,7 MJ/kg (comparing to 12,6 in broilers)
- Ca and P: quite same as in broilers (at this stage)
Physical form of feeds: mash
Because we want to decrease voluntary feed intake
Practical feeding of pullets
- 0-3 weeks: ad libitum feed (mash)
- from week 4: controlled feeding (control of BW)
- if BW is low: pellets or increased nutrient density
- if BW is too high: slight limiting of feed intake (e.g. we dont give more food for older age)
- week 9: change to grower diet (according to BW, if BW is lower - keep them longer on starter diet (more CP) and vice versa)
- week 17: housing: moving to layer house
Light program in pullet rearing
- reproduction in birds is strongly regulated by the amount of lighting hours an intensity of the light
- first: 24 h of lighting
- then amount of light hours is decreasing and stays low (~autumn, winter —> physiological time of not laying eggs)
- if we increase amount or intensity of light =spring, we’ll start process of laying eggs! WE DON’T WANT IT
Egg production data
- aim: production of commercial eggs (hybrids!)
- length of laying period: 1 year —> hens become 76 weeks old
- 320-350 eggs per year
- making 1 egg takes ~26 h
- hens don’t lay eggs after noon
- egg weight ~60g (~3% of BW)
Colour of egg shell
- white: Leghorn-type hybrids: very thin. Adult BW: ~1,7 kg
- brown: Rhode type hybrids (white leghorn x Rhode Island) : adult BW: ~2 kg
Levels of egg production
- 18th week: 5% (from 100 chicken we have 5 eggs per day)
-20th week: 10% - 21-23d week: 50-60%
- 24-26th week: 95% - peak production
Nutrient requirements of commercial hens
- prelayer: 18-20th w: transition between grower and layer diet
- layer 1: egg production = 50-95%
- layer 2: egg production = ~75%
- protein: CP: 17-18%
- energy: ~12%
- Calcium: that’s main difference!!! during laying periods ~ 35 g/kg
- P: quite same
Why is calcium in layer 2 diet the highest if egg production drops?
- although the number of eggs will be lower, size of eggs will be bigger > 60 g —> Calcium requirement does not decrease proportionally with number of eggs
- these birds have very intensive calcium turnover (bones!) —> calcium reserves of bones decrease —> supplementation needed
Practical feeding of commercial hens
- ad libitum feeding (mash - to avoid overeating)
- grits - small limestones (Calcium)
- feed efficiency: 2 kg / 1 kg eggs (efficient!!)
- end of laying period: slaughter (pet food) or induced moult followed with 2nd laying period (2 periods are max)
2nd laying period
- after induced moulting
- can be beneficial if pullets are expensive
- less eggs will be layed
- higher mortality rate of layers
- eggs will be larger
- egg shell will be firmer
