Studies on Effect of Lighting on “Sudden Death Syndrome” in Broiler Chickens

Broiler chicken flocks were studied to determine the mortality from sudden death syndrome occurring in the flocks. The difference in the incidence of the syndrome in pullets and cockerels, and the age at which the most birds are affected were also studied. The weight of sudden death syndrome birds was compared with the flock average and the effect of continuous lighting as opposed to intermittent lighting was examined.

The results suggest that; continuous lighting produces more sudden death syndrome deaths than intermittent lighting; that the incidence of sudden death syndrome is higher in cockerels than pullets; that the highest death rate occurred during the third and fourth weeks of life, and that sudden death syndrome birds on the average were heavier than the flock average.

     

Western Encephalomyelitis Virus Infection in “Indicator” Chickens in Southern Alberta

Sera from indicator chicken flocks situated in southern Alberta near Lethbridge were tested by the hemagglutination-inhibition (HI) technique for antibodies to Western, Eastern and St. Louis Encephalitis viruses during the summer and early fall of the four years 1964 to 1967.

One chicken in 1964, 90 in 1965 and five each in 1966 and 1967 were positive to Western encephalomyelitis (WE) virus by hemagglutination-inhibition tests. All of the positive sera were confirmed by neutralization test (NT) in infant mice. No antibodies to the Eastern and St. Louis viruses were detected.

Infection with WE virus was detected in each of the four years, indicating that WE virus is endemic to southern Alberta with a marked seasonal incidence occurring between the second week in August and the third week in September.

An improved technique for filtering sera is described.

     

On the Etiology of “Scotty Cramp” and “Splay” — Two Motoring Disorders Common in the Scottish Terrier Breed

The skull-cap, the meninges, and the dorsal surface of the cerebral cortex were inspected in 20 Scottish Terriers subjected to euthanasia because of severe Scotty Cramp, and in 1 Cocker Spaniel and 2 Scottish Terrier puppies sacrificed because of Splay (inability to stand on the hind legs).Apparent abnormalities observed in the 12 younger (6 weeks to 18 months old) Scotty Cramp animals were firm medial adhesion of the dura to the skull-cap (all animals), meningeal hemorrhage (10 animals), and bony jags on the inner side of the skull-cap making impressions in the underlying dura and cerebral cortex (8 animals).Similar bony irregularities causing durai and cortical impressions were observed in 5 out of 8 Scotty Cramp dogs belonging to a senior age group (3 to 11 years old). Meningeal hemorrhage was observed only in 1 animal belonging to this group, but consistent observations were scarified appearance of the dura along the midline and induration around superior cerebral veins medially in the cruciate sulcus.Meningeal hemorrhage and firm medial adhesion of the dura to the skull-cap were consistent observations in the Splay puppies (6 weeks to 3 months old).The possibility is discussed that the ultimate cause of Scotty Cramp and Splay may be abnormalities in the development of the parietal and frontal bones, of their interconnection, and of their relation to the underlying meninges. This in turn may exert mechanical, circulatory or other influences causing dysfunction of the cerebral motor cortex.