EFFECTS OF NEWCASTLE DISEASE VIRUS ON SOME REPRODUCTIVE PARAMETERS OF SHIKABROWN COCKS
EFFECTS OF NEWCASTLE DISEASE VIRUS ON SOME REPRODUCTIVE PARAMETERS OF SHIKABROWN COCKS
No Thumbnail Available
Date
2007-09
Authors
RWUAAN, JOSEPH SANKEY
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
vii
I am also very grateful to Mr. David Leo Kato who was always involved in the bleeding
of the cocks and setting the laboratory ready for the hemagglutination inhibition test.
I thank Mr. Musa Adejoh and Mallam Lawal Musa for the help they rendered in the
bleeding and weighing of the cocks.
I thank the former Head of Department of Veterinary Public Health and Preventive
Medicine, Professor I. Ajogi for making the room and facilities available for me to
keep the birds.
I also thank the Head of Department of Veterinary Surgery and Medicine, Professor A.B.
Ogunkoya for his interest and advice in this research work. The departmental generator
was always put on to enable me process the semen samples, to this I say thank you.
I thank all well wishers particularly my colleagues in the Department. I thank the Data
Processing Unit of Institute for Agricultural Research (IAR) and Dr. I.A. Adeyinka, the Head
of the Data Processing Unit of National Animal Production Research Institute (NAPRI) for
the analysis of my data.
Finally my profound thanks go to the Almighty God who has steered me through this work
and made sure it was concluded successfully.
viii
ABSTRACT
Fifty red and white Shikabrown cocks were purchased and fed on a diet of layers
mash with 18.0% crude protein, 95.6% dry matter, 17.1% crude fibre and 3.0%
nitrogen. The experiment took place betwen January and May, 2005.
Twenty‐five of the cocks were infected with 106.0EID50 of a velogenic Kudu strain
Newcastle disease virus while twenty‐five served as control. The cocks had their
packed cell volume, total protein, hemagglutination inhibition ND antibody titres
(HIT), semen characteristics, testosterone profiles and gonadal sperm reserves and
body and organ weights determined weekly for six weeks post infection. At six weeks
post‐infection, twenty control and twenty infected cocks were slaughtered. Their
internal organs were examined in situ and later removed and weighed; the
dimensions of the testes were also taken. The semen was evaluated for volume and
colour; and the latter was graded as: grade 1 = creamy; 2 = milky and 3 = watery.
There was no significant difference in the packed cell volume of the control and
infected red and white cocks. The values of the total protein did not show any
significant difference between the control and infected red and white cocks. The
antibody titres of the control red and white Shikabrown cocks were significantly
(P<0.05) lower than the antibody titres of the infected red and white cocks.
The cloacal temperatures and body weights did not show any significant difference
between the red and white cocks. The semen volume of infected red cocks showed a
general increase over that of the control red cocks. The semen volume of the control
white cocks was significantly higher than that of the infected white cocks. The white
ix
Shikabrown cocks had higher semen volume than the red Shikabrown cocks. The red
cocks had slightly better semen colour than the white cocks. The control white cocks
had better spermatozoa motility than the infected white cocks, while the infected red
cocks had better spermatozoa motility than the control cocks.
The spermatozoa concentration of the control white cocks was consistently better
than that of the infected white cocks. The spermatozoa concentration of the infected
cocks was lower than that of the control cocks. The white cocks had better
spermatozoa concentration than the red cocks.
The control white Shikabrown cocks had significantly (P<0.05) higher per cent live
spermatozoa than the infected white cocks. The infected red cocks had significantly
(P<0.05) lower per cent live spermatozoa than the control red cocks. The control
white cocks had significantly (P<0.05) higher per cent live spermatozoa than the
control red cocks.
The infected red and white Shikabrown cocks had higher percentage total spermatozoa
abnormalities than the control red and white cocks. The mean testosterone concentration
of the red and white cocks decreased post‐infection from week 1 to 6.
The gonadal sperm reserves of the control red and white cocks were not significantly
different but the gonadal sperm reserves of the control white cocks was significantly
(P<0.05) higher than the gonadal sperm reserves of the infected red and white cocks.
The total gonadal sperm reserves of the control white cocks was significantly (P<0.05)
higher than the total gonadal sperm reserves of the infected red and white cocks. The
left testicles of the control red and white cocks were significantly (P<0.05) heavier
than those of the infected red and white cocks.
x
The liver, spleen, thymus, heart and adrenal glands of the infected red Shikabrown
cocks were heavier than those of the control red Shikabrown, and white cocks and
infected white Shikabrown. The weights of the spleen and brain were not signifiantly
different in both the control and infected red and white cocks. The bursal weight of
the control white cocks was heavier than that of control red, infected red and
infected white cocks. The control red cocks had the heaviest adrenal glands. The
infected red cocks had the highest liver body weight ratio. The spleen body weight
ratio was the same for both control and infected red and white cocks. The control
white cocks had the least thymus body weight ratio. The infected red cocks had the
highest heart body weight ratio. The brain body weight ratio was the same for both
control and infected cocks. The control white cocks had a higher bursa body weight
ratio than the control red and infected red and white cocks. The infected red cocks
had the highest adrenal body weight ratio. Only one infected white cock showed
perivascular infiltration of lymphocytes and foci of glial cells.
It can be concluded that challenging the cocks with the velogenic Newcastle disease
virus led to the cocks having higher antibody titres which gave them more protection.
The infected red Shikabrown cocks had slightly higher antibody titres than the
infected white Shikabrown cocks hence they were more protected from the velogenic
Newcastle disease virus. The white cocks had better semen quality than the red cocks
but more prone to the Newcastle disease virus. In a Newcastle disease endemic
environment like Zaria farmers keeping Shikabrown chickens should adequately and
routinely vaccinate them against the disease.
Description
Department of Veterinary Surgery and Medicine
Faculty of Veterinary Medicine
Ahmadu Bello University
Zaria.
Keywords
EFFECTS,, NEWCASTLE,, DISEASE,, VIRUS,, REPRODUCTIVE,, PARAMETERS,, SHIKABROWN,, COCKS.