Western Meeting of Poultry

 Clinicians and Pathologists 

home

conferences

feedback

search

Hypoglycemia/Spiking Mortality Syndrome In Broiler Breeder Chicks

Dr. Sandra Stephens

Poultry Extension

University of Saskatchewan

History

Hypoglycemia/Spiking Mortality syndrome has been recognized in broiler chickens in Saskatchewan since 1994.  It was observed that mortality spikes in 12 – 14 day old chicks was occurring on a few farms for which no apparent reason for the deaths could be found.  It was noted that using a lighting program prevented the recurrence of the problem on these farms.

Symptoms

Chicks were observed to suffer from varying degrees of ataxia.  When walking they could be described as “drunk” chicks.  At times chicks appeared to be blind.  Some chicks displayed a mild to marked body tremor.  As the condition progressed chicks were found in lateral or sternal recumbency with one or both legs stretched out behind them.  Chicks went on to become comatose.  The chicks may or may not have had signs of diarrhea but orange mucoid droppings were observed in most cases.

Diagnostic findings

Few if any gross lesions were seen in these chicks.  Intestinal contents were observed on occasion to be more fluid than normal and orange mucoid material found in the distal small intestine.  The growth plates were usually found to be thickened.  Occasionally liver hemorrhage was seen.

Blood or plasma glucose levels ranged from 36 – 50 mg/dl (2.0 – 3.0mmol/L).  The normal range is 180 – 240 mg/dl (10 – 13 mmol/L)   (Fasting glucose = 150 mg/dl (8mmol/L)

Broiler Breeder Flock History

At 9 days of age the owner treated the flock with amprolium, suspecting a coccidia break to be the cause of increased mortality.  On day 10 the mortality was higher, (0.29%) and the owner started the birds on tetracycline.  On day 11 the mortality had increased to 1.07% and birds were submitted for necropsy.  Mortality peaked on Day 12 at 2.4%.

The owner indicated that he raised his breeder chicks on 22 hours of light until they were 3 to 4 weeks of age.  As well his starter ration had a higher energy level than what would be considered standard for breeder pullets.

Diagnostic Findings

Gross lesions were limited to the thymus glands that were very small and pale (histologically found to be normal), and the growth plates – which were thickened in most birds necropsied.

Feed was tested for, riboflavin, vitamin E, and ionophores all tested in the normal range.  A basic feed analysis was done and all elements were within expected values.  A mold screen was done on the feed and found to be negative.

Blood glucose levels of severely affected birds was found to be 25mg/dl as compared to that of apparently normal chicks with levels of 200mg/dl.

Discussion

This syndrome is usually reported in rapidly growing broiler chicks that are not being raised on an increasing lighting program.  The lighting program used in this breeder pullet flock was not what is considered standard for rearing breeder chicks – most flocks are put onto at least 12 hours of darkness per day by 3 days of age.  In addition the feed was more like a broiler starter ration than a breeder starter ration.  It would appear that in effect these chicks were being raised more like broilers than breeders and this may have contributed to the occurrence of this disease.

It was determined that the males from this hatch went to a farm that has a history of Hypoglycemia/Spiking Mortality and experienced a similar spike in mortality at approximately the same age.  This broiler farm has used a lighting and feeding program to control the occurrence of the condition on their farm for a number of years.  The broiler producer recognized the symptoms in his barn and admitted that he had made a management error.  It is unknown whether there is any vertical transmission of the causative agent(s) of this condition or an strain variability in susceptibility.  (The breeder male chicks arrived on the breeder farm on the same day but were from a different source than the females and were raised in a totally separate barn.  These males did not experience the same problems.)

The prognosis for this breeder flock’s productivity is probably not good as the sequel to hypoglycemia/spiking mortality in broiler flocks is extremely poor uniformity.  It is expected that the same poor uniformity will be seen in this flock. 

Top of Page

To send us your comments or questions regarding this web site, click here.
Last modified: 5/28/2009