Feeding of poultry for liver production Flashcards
Intro into liver production
- France (mostly ducks) and Hungary (mostly geese)
- forced feeding is required (animal protection)
Physiological background of force feeding, fastened liver
- ducks and geese are migrating birds —> in autumn they prepare for long flight —> higher appetite, making fat reserves in the body. Not an obesity, it’s normal physiological process
- overfeeding of CHs, especially starch —> production of triglycerides in the liver —> normally leave liver in the form of VLDL and go to storage places (SC)
- but to make big fatty liver we want to avoid transport of fats from the liver —> transport capacity will be overload because fat production is higher than transport capacity —> less fats will leave liver —> fat in the liver
- we want to have low transport capacity !!
Fattened liver production. Prerequisites
- only special genotypes can be used for fattened liver production
- sex: ducks: only males (drakes), in geese: both sexes
- feeds rich in CHs (corn)
- low level of lipotropes (then transport capacity will be lower)
- lipotropes: Methionine, choline (in this case corn is also good because is poor in methionine and poor in choline)
- flexible membranes in the liver needed to keep fat inside of liver cels
- liver size before forced feeding is also important (larger -> more liver cells, can keep more fat)
- age of animals (younger the better)
Qualification of liver
- foa gra: fattened liver - very different from normal liver
- producers: muscovy, mulard ducks; geese of special genotypes
- duck liver: minimum 300g (weight of normal liver: 150g)
- goose liver: minimum 400 g
Fattened liver production. Ducks vs Geese
Ducks advantages
- geese have extremely poor reproduction performance (in 1 laying period goose: 30-50 eggs, ducks: ~250 eggs) —>
- ducklings are cheaper; can be obtained continuously during the year
- ducks are in the same age at he onset of force feeding
- ducks tolerate force feeding better
Geese advantages:
- higher quality of fattened liver
- both sexes are used to
Genotypes used for duck liver production
- Muscovy: duck-like birds
- Moulard duck: hybrid, better than Muscovy
Moulard - intervening hybrid = Pekin female x Muscovy drake
- ONLY MALES
- in Muscovy females liver is too small
- in Moulard females: disgusting (veins) —> females will be used as roasting ducks
Preparation of ducks for force feeding
- 0-7 weeks: keeping them like roasting ducks (by the end ~ 3kg)
- preparation phase: increase CP: Muscovy 8th-11th weeks, Mulard: 8th week
- aim of preparation phase: enlarging the oesophagus
- how: reduction of meals per day —> they will overeat —> enlargement of oesophagus
Forced feeding in ducks
Muscovy ducks
- once of FF depends on genotype (worse in Muscovy ducks)
- BW in the beginning of FF: 4,5 kg
- length of FF: 2 weeks (in Muscovy): twice a day, altogether ~500g/duck/day (normal feed intake is 2x less)
- liver weight ~ 450g
- lipid loss when roasting ~ 30%
Moulard ducks;
- younger in the beginning of FF (9 weeks vs 12 in Muscovy)
- BW in the beginning of FF: 4 kg (it’s good because our goal id not fatty bird but fatty liver)
- length of FF: 10 days
- fed 2x/day - 800g/duck/day
- liver weight in the end: 600g
- lipid loss during roasting ~ 15 %
Forced feeding in ducks
Muscovy ducks
- once of FF depends on genotype (worse in Muscovy ducks)
- BW in the beginning of FF: 4,5 kg
- length of FF: 2 weeks (in Muscovy): twice a day, altogether ~500g/duck/day (normal feed intake is 2x less)
- liver weight ~ 450g
- lipid loss when roasting ~ 30%
Moulard ducks;
- younger in the beginning of FF (9 weeks vs 12 in Muscovy)
- BW in the beginning of FF: 4 kg (it’s good because our goal id not fatty bird but fatty liver)
- length of FF: 10 days
- fed 2x/day - 800g/duck/day
- liver weight in the end: 600g
- lipid loss during roasting ~ 15 %
Genotypes of geese used for fattened liver production
- grey landaise goose (earlier)
- now hybrids from this grew landasie goose
Preparation of geese for FF
- starter period: first 6 weeks are kept as roasting geese, consumption of green forages helps to enlarge the oesophagus
- grower period: slight restriction of feeding
- preparation period: back to ab libitum feed —> overeating
Fattened liver production in geese
- onset of FF: 12-14 weeks old
- length of FF: 2 - max 3 weeks
- after 2 weeks of FF less fat will be built in the liver and more water (limitation of possible length of FF)
- 14 days FF period -> 600 g liver (<-> 14-150 g of normal liver). DMI = 13 kg/bird/14 days ~1 kg/goose/day
- 21 days FF period -> 700-750 g liver; DMI = 22kg/bird/21days = >1kg/goose/day
What is frequency of feeding during FF of geese for fattened liver production?
- 1st day: twice a day
- 2nd day: 3x/day
- from 3d day: 4x/day (up to 5-6x/day)
Feed used in FF of geese (check the practical slides)
