Metabolic Disorders of poultriews

Question 1

Most important metabolism,sleep troubles in poultries

Answer 1

1. Early mortality of day-old chicks
2. Acute death syndrome: M
3. Malabsorption syndrome: M
4. Ascites syndrome: M
5. skeletal disorders: M
   - Rickets (juvenile osteomalatia)
   - perosis (chondrodystrophy)
   - torsion of the tibia
   - dyschondroplasia
   - cage layer fatigue L
6. Fatty liver haemorrhagic syndrome

Meat birds are at greater risk of developing metabolic diseases because of their rapid growth rate and allometric growth of some organs

Question 2

Early mortality of day-old chicks

Answer 2

• nutritional cause: due to inadequate micro element and vitamin supply of the parents’ generation -0> yolk low in this elements
• management causes (tº, humidity, stock density, etc)
• infections diseases (E.coli, Salmonella)

Question 3

Acute death syndrome (=flip-over disease; dead in good condition)

Answer 3

• birds show no signs
• usually 3-4 weeks old birds flip over and die on their back
• short convulsions (wing-beating) can be seen before death
• broiler chicken, turkey hybrids
• 60-80% are males - higher BW
• cause of death: breakdown of heat function —> collapse of the blood circulation
• usually stress triggers this condition —> cardiac arrhythmias —> predisposition to death from ventricular fibrillation
• predisposition: genetics (hybrids) + intensive feeding
• BW develops much faster than heart
• prevalence: 0,5-4%
• prevention: feed restriction around day 20, diet texture (mash) (there wont be effect on final BW because of compensatory growth)

Question 4

Malabsorption syndrome (=stunting syndrome = helicopter disease = “pale bird syndrome”

Answer 4

• symptoms (day 4-7): not specific: growth depression, uneven growth; lack of pigmentation in skin, leg weakness, higher early mortality, diarrhea, undigested feed in feces
• symptoms (week 3-4): incomplete feathers (helicopter appearance)
• broiler chicken, turkey hybrids
• possible causes: nutrition: anti nutritive factors, mycotoxins; heat stress; viral infections (?)
• consequences: enteritis, insufficient enzyme activity —> malabsorption, slow development of an active immunity
• treatments: check quality of diet, extra vitamin supply in water

Question 5

Ascites syndrome (=pulmonary hypertension syndrome, waterbelly)

Answer 5

• symptoms: serum-containing liquid; loose abdominal wall; cyanosis; frequently die on their backs
• broiler chicken (mainly males on 3-4 week of life) with genetic predisposition to pulmonary hypertension
• cause: increased vascular pressure in the venous system which is most commonly caused by right ventricular failure
• allometric growth of the lungs —> tissues are poorly oxygenated —> heart pumps more blood to meet the demand —> pulmonary hypertension —> congestive heart failure —> ascites
• predisposition factors: high growth rate —> higher oxygen demand comparing to small lung capacity; intensive feeding; poor air quality
• treatment: if symptoms developed, no way to treat
• prevention: less intensive feeding (mash), better ventilation

Question 6

Skeletal disorders in birds

Answer 6

• rickets (juvenile osteomalatia)
• perosis (chondrodystrophy)
• torsion of the tibia
• dyschondroplasia
• cage layer fatigue

Question 7

Predisposing factors to skeletal diseases in poultries

Answer 7

• genotype (hybrids for intensive production)
• intensive feeding
• deficiency of minerals and vitamins!
• anti nutritive factors, mycotoxins

Question 8

DD of non-infectious skeletal disorders

Answer 8

Infectious skeletal disorders:
- Mycoplasma synovial
- E.coli
- Staphylococci

Question 9

Rickets (juvenile osteomalatia)

Answer 9

• chicks develop rubbery bones that can’t support their BW
• deficiency of Ca and vit D, vit K def
• inadequate Ca : P ratio
• inadequate nutrition or intestinal disease with malabsorption
• abnormal ossification with a failure of mineralization

Question 10

Perosis (chondrodystrophy)

Answer 10

• deficiency of other deficiencies (choline, biotin, folic acid, etc …)
• retarded growth of long bones, widening of the tibia metatarsal joint, slipping of the gastrocnemius muscle tendon from its condyles (usually 1 leg is affected)

Question 11

Torsion of the tibia

Answer 11

• turkeys!
• I balance newer BW increase and bone maturation
• most of the in both legs

Question 12

Tibial dyschondroplasia

Answer 12

• abnormal cartilage development, mainly in the proximal end of the tibia
• failure of chondrocyte differentiation
• various degrees of severity
• dyschondroplastic lesions are masses of avasculat cartilage extending from the growth plate into the metaphysis
• focal thickening of the growth plate and is most commonly seen in the proximal tibiotasus but also can be in other bones as well
• influencing factors: rapid growth rate, intensive feeding, CA : P ratio, metabolic acidosis (excess chloride in the feed), copper deficient diet

Question 13

Cage layer fatigue (osteparalysis)

Answer 13

• laying hens
• Ca metabolism disorder
• death occurs from starvation and dehydration (birds can’t move)
• spontaneous bone fractures, thin eggshells
• amount of eggs produced is the same
• blood Ca is unchanged because Ca is mobilised from bones reserves
• predisposing factors: battery keeping of young layers, peak of egg production, Ca deficient diet
• stress increases vit C demand and vit C is needed for formation of collagen
• treatment: Ca and vit D, vit C supplementation

Question 14

Fatty liver haemorrhagic syndrome

Answer 14

• high producing laying hens
• disturbance in fat metabolism
• symptoms: significant drop (30-40%) in egg production, fat accumulation in hepatocytes and in the abdomen
• subcupsular haemorrhages and sudden death
• cause: intensified de novo lipid synthesis of the liver
• predisposing factors: CHs rich diet —> elevated insulin —> intensive lipid synthesis
• also high level of egg production —> elevated blood oestrogen conc -> increase of lipid synthesis
• birds kept in cages —> inhibition of catabolic hormones
• treatment: reduction of dietary starch level, replacemt by vegetable oils