No abstract

Paleopathologists have identified osteoporosis in ancient skeletons and modern physicians and scientists have identified risk factors for osteoporosis today, but they are not clearly linked, making it more difficult to clarify the causes of osteoporosis in the past. The evidence for osteoporosis in the remote past, its causes, and the management of this disease is reviewed in the light of evolving and improving diagnostic modalities, more precise definitions, and the recent rapid expansion of therapeutic options. While the specific effects of parity and lactation on the development of osteoporosis are still not entirely clear, duration of reproductive span and age at first pregnancy appear to be significant predisposing factors.

Observations made in a commerical broiler hatchery revealed that chicks hatched over a period of 48 hours. Chick mortality to 10 days of age was 3.2% for those hatched at the commencement of the hatch, 1.2% for those hatched at peak of hatch and 52.9% for those hatched at the end of hatching. Chicks hatched early were more prone to dehydration while late hatching chicks had a higher incidence of leg weakness. Chicks held for 48 hours in hatcher machines lost 12.5% to 21.7% of their hatching weight and 79.4% of the hatching weight of the yolk sac. Normal 10-day mortality from this hatchery in winter months was observed to be 2.4% but was reduced to 1.2% when staggered setting times of donor flocks was employed by removing chicks from the machines 3 hours after 100% hatch, but was increased to 5.6% by holding chicks in the hatchery in chick boxes for 24 hours at 70 degrees C.

Sixty-eight b r e e d e r c h i c k e n s , 4 to 12 m o n t h s of a g e , were taken from Australian flocks that had b e e n naturally infected with avirulent Newcastle d i s e a s e virus (NDV) a n d transported by air t o Malaysia. Nearly all t h e b r e e d e r s had haemagglutination inhibition antibodies t o NDV, a t titres of from 2 to 128. Thirty-two were inoculated intranasally with an Asian, velogenic, viscerotropic strain of NDV a n d all survived this challenge. Thirty-six were exposed to contact infection with t h e same velogenic NDV and 2 died of Newcastle d i s e a s e within 14 d a y s . T h e levels of haemagglutination inhibition antibodies a g a i n s t NDV i n c r e a s e d in t h e surviving b r e e d e r s after c h a l l e n g e , reaching 2048 or greater in a few birds. Velogenic NDV was isolated from a cloacal swab from one clinically normal b r e e d e r 10 d a y s after c h a l l e n g e by contact. Cloaca1 swabs t a k e n 7 t o 10 d a y s after c h a l l e n g e from a n o t h e r 23 b r e e d e r s yielded n o NDV.Twenty-four broilers, 7 w e e k s of age, were also transported from Australia to Malaysia. All lacked d e t e c t a b l e haemagglutination inhibition antibody to NDV a n d they were from a flock with no d e t e c t a b l e antibody to NDV. Twelve w e r e challenged with velogenic NDV intranasally a n d 12 were s u b j e c t e d to c o n t a c t c h a l l e n g e . All broilers d i e d of Newcastle disease within 13 d a y s .

An outbreak with mortality and acute nervous signs in ducks is reported. A haemagglutinating virus was recovered from dead and sick ducks that was neutralised by Newcastle disease antiserum. The virus was a thermostable paramyxovirus that was classified as a mesogenic Newcastle disease virus. The virus induced the infection in young ducklings following intramuscular inoculation.