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Research Service, USDA); “Broiler Hatchery” and “Chicken and Eggs” (National Agricultural Statistics Service, Agricultural Statistics Board, U.S.D.A.)© 2008 Primary Breeders Veterinary Association.
Articles may be reprinted with permission. For information and permission to reprint, contact Diane Baird, (706) 542-1904
Issue 101
September/October 2008
®
Published by the Department
of Population Health, University of Georgia
Editor: Dr Stephen Collett, Assistant Professor
Co-Editor: Dr Pedro Villegas, Professor
Department of Population Health
Phone (706) 542-1904
Fax (706) 542-5630
e-mail: dsbaird@uga.edu
Antigenic differences of NDV vaccines affect viral shedding
Patti J. Miller
Southeast Poultry Research Laboratory, Agricultural Research Services, United States Department of
Agriculture, 934 College Station Road, Athens, GA 30605, USA
Tables and figures reprinted from Vaccine, 25, Patti J. Miller, Daniel J. King, Claudio L. Afonso, and David L.
Suarez*, Antigenic differences among Newcastle disease viruses strains of different genotypes used in vaccine
formulation affect viral shedding after a virulent challenge, 7238-7246 (2007), with permission of Elsevier.
All Newcastle disease viruses (NDV) are of one serotype; therefore, any NDV used correctly as a vaccine should
induce antibodies able to prevent clinical signs and death from any NDV. The most common viruses used in the
U.S., as either live or inactivated vaccines, are B1 and LaSota strains. These strains were isolated in the 1940s
when virulent neurotropic viruses caused outbreaks with respiratory distress, nervous signs and paralysis in chick-
Contents
Antigenic differences of NDV vaccines affect viral shedding
Broiler
Live Production Cost
1-4
Excerpts. “Broiler Hatchery”
“Chicken and Eggs” and Turkey
Hatchery...
5
Broiler performance data
(Company) Previous month
6
Meetings, Seminars and Conventions
7
Average Company
Feed Cost/ton w/o color ($)
Feed cost /lb meat (c)
Days to 4.6 lbs
Chick cost / lb (c)
Vac-Med cost/lb (c)
WB & ½ parts condemn. Cost/lb
% mortality
Sq.Ft. @ placement
Lbs/sq. ft.
Downtime (days)
Data for week ending 23 August 2008
Page 1
331.70
30.06
42
5.03
0.10
0.22
3.92
0.83
7.01
14
ens with moderate mortality rates. Since the 1970s, the more virulent viscerotropic viruses have replaced the neurotropic
viruses as the predominant etiological agents of ND outbreaks causing respiratory disease, hemorrhages in multiple organs,
some neurological signs and high mortality rates.
When looking at NDV sequence information, two distinct classes can be seen in dendograms; class I and class II, with class
II being further divided into ten genotypes. The hemagglutinin-neuraminidase (HN) and fusion (F) are glycoproteins of
NDV that not only allow binding and fusion of the virus to the host cells to initiate a NDV infection, but also induce the production of antibodies in the host providing protection against disease. The NDV strains of greatest concern in the U.S. today
would likely be a virulent virus similar to the recent class II genotype V outbreak viruses, which are antigenically different
from the virulent viruses in class II genotype II like Texas GB that have not been isolated in the U. S. since the early 1970’s
(Table 1).
Table 1. Deduced hemagglutinin-neuraminidase (HN) and fusion (F) protein similarity between the vaccine strain
and the challenge NDV strain of CA02
Vaccine
Amino Acid similarity with challenge virus (%)
class/genotype
HN
F
100.0
100.0
Pigeon84
92.3
92.9
II/VIb
Ulster
90.7
89.7
II/I
B1
89.3
88.1
II/II
Alaska196
84.2
85.2
I/n/a
CA02
II/V
The objective of this study was to compare the protection induced in four week old SPF white Leghorn chickens by inactivated ND vaccines prepared with viruses of five different genotypes by measuring viral shed from vaccinates after a virulent
challenge, and to determine if using an improved vaccine strategy could reduce viral shedding, and presumably, the spreading of the virus and the consequent disease. We hypothesized that if birds were vaccinated with viruses that were more antigenically similar to the challenge strain that they would shed reduced amounts of challenge virus. We chose representative
NDVs from class I, and class II genotypes I, II, VIb and V. Twenty-one days after vaccination, serum antibody levels were
evaluated against each of the vaccine antigens using hemagglutination inhibition (HI) tests. Oropharyngeal and cloacal
swabs were taken before the birds were challenged and then on days two, four and nine post-challenge.
In this study, the vaccine homologous to the CA02 class II genotype V challenge virus induced the highest titers of HI antibodies using the CA02 as antigen when compared to the amounts induced by heterologous vaccines (Table 2). Improved
response as measured by a statistically significant decrease in the amount of challenge virus shed in oropharyngeal swabs
was also seen in the group vaccinated with the homologous vaccine (Figure 1). While all vaccines decreased the amount of
virus shed in cloacal swabs compared to the sham-vaccinated control birds, no significance was seen when comparing the
vaccines to each other. In addition, little significance could be discerned comparing the number of birds shedding in each
vaccine group compared to the controls and to each other.
Except for B1, which has been shown to perform poorly with its homologous antigen, each of the other vaccine groups gave
the highest HI titers when the antigen used in the assay was homologous to the vaccine antigen. The cross HI titers also
show that the HI titers can vary greatly depending on the antigen used for testing (Table 2).
Currently, the efficacy of ND vaccines does not include their ability to decrease shedding of the virulent virus after a challenge. However, in this study, inactivated vaccines formulated to be similar to the challenge virus induced better protection
in vaccinates as measured by the reduction in the shedding of virus. By formulating and incorporating ND vaccines with a
virus similar to the mostly likely outbreak virus, it may be feasible to induce an immune response that not only decreases
morbidity and mortality, but also reduces the amount of challenge virus in the environment and subsequent transmission.
Page 2Page 2
Table 2. Pre-challenge serology completed by micro-beta HIa and ELISA (IDEXX)
HI Antigens
Vaccine
B1
ELISA Antigen
Ulster
Pigeon84
AK196
CA02
133
30
40
96
3676c
612
586
146
306
411
3045
Pigeon84
348
281
562
182
190
2816
AK196
334
174
146
829
198
3269
CA02
761
538
485
463
794
3292
B1
291
Ulster
b
a
HI assays were completed with 4 HA units of each vaccine antigen to test pre-challenge serum of each vaccine
group and group geometric mean titers are presented. bHomologous responses noted by bold font. cELISA group
geometric mean titers are presented in the right column.
Figure 1. Virus isolation from oropharyngeal (oral) swabs collected on selected days after CA02 END virus challenge of all treatment groups at 21 days post-vaccination. A) Mean virus titers of oral swabs of all groups on all
sample days. All control animals were dead by day 6. B) Comparison of oral virus titers at 2 day post-challenge: *
indicates significant difference from Control and AK. C) Comparison of oral virus titers at 4 day post-challenge: *
indicates significant difference between Control, ** indicates significant difference between control and all other
treatments. Data (mean + SE) were analyzed by ANOVA followed by Tukey’s multiple comparison test. B1= B1,
UL=Ulster, PG =Pigeon84, AK =AK196, CA=CA02..
Page
Page
3 3
Excerpts from the latest USDA National Agricultural Statistics Service
(NASS) “Broiler Hatchery,” “Chicken and Eggs” and “Turkey Hatchery”
Report and Economic Research Service (ERS) “Livestock, Dairy and Poultry
Situation Outlook”
Chickens and Eggs
Released August 22, 2008, by NASS, Agricultural Statistics Board, USDA
July Egg Production Up Slightly
U.S. egg production totaled 7.60 billion during July
2008, up slightly from last year. Production included
6.49 billion table eggs, and 1.12 billion hatching eggs,
of which 1.05 billion were broiler-type and 64 million
were egg-type. The total number of layers during July
2008 averaged 336 million, down 1 percent from last
year. July egg production per 100 layers was 2,262
eggs, up 1 percent from July 2007. All layers in the
U.S. on August 1, 2008 totaled 335 million, down 2
percent from last year. The 335 million layers consisted of 277 million layers producing table or market
type eggs, 55.2 million layers producing broiler-type
hatching eggs, and 2.69 million layers producing eggtype hatching eggs. Rate of lay per day on August 1,
2008, averaged 72.5 eggs per 100 layers, up 1 percent
from August 1, 2007
Egg-Type Chicks Hatched Up 5 %
Egg-type chicks hatched during July 2008 totaled 37.9
million, up 5 percent from July 2007. Eggs in incubators totaled 33.0 million on August 1, 2008, up 2 percent from a year ago. Domestic placements of eggtype pullet chicks for future hatchery supply flocks by
leading breeders totaled 244 thousand during July
2008, up 33 percent from July 2007.
Broiler-Type Chicks Hatched Down 2%
Broiler-type chicks hatched during July 2008 totaled
807 million, down 2 percent from July 2007. Eggs in
incubators totaled 651 million on August 1, 2008,
down 3 percent from a year earlier. Leading breeders
placed 7.07 million broiler-type pullet chicks for future domestic hatchery supply flocks during July
2008, up 6 percent from July 2007.
cent from the eggs set the corresponding week a year
earlier. Average hatchability for chicks hatched during the week was 84 percent. Average hatchability is
calculated by dividing chicks hatched during the week
by eggs set three weeks earlier.
Broiler Chicks Placed Down 4 %
Broiler growers in the 19-State weekly program
placed 171 million chicks for meat production during
the week ending August 23, 2008. Placements were
down 4 percent from the comparable week a year earlier. Cumulative placements from December 30, 2007
through August 23, 2008 were 6.02 billion, up slightly
from the same period a year earlier
Turkey Hatchery
Released July 14, 2008, NASS, Agricultural Statistics Board, USDA
Eggs in Incubators on August 1 Down 5 % from Last Year
Turkey eggs in incubators on August 1, 2008, in the
United States totaled 31.9 million, down 5 percent
from August 1, 2007. Eggs in incubators were down
3 percent from the July 1, 2008 total of 32.8 million
eggs. Regional changes from the previous year were:
East North Central down 7 percent, West North Central down 4 percent, North and South Atlantic down 3
percent, and South Central and West down 8 percent.
Poults Hatched In July Up 1 % from Last Year
Turkey poults hatched during July 2008, in the United
States totaled 27.5 million, up 1 percent from July
2007. Poults hatched were up 5 percent from June
2008 total of 26.2 million poults. Regional changes
from the previous year were: East North Central up
slightly, West North Central down 3 percent, North
and South Atlantic up 4 percent, and South Central
and West up 3 percent.
Net Poults Placed In July Down 2 % from Last Year
Broiler Hatchery
Released August 27, 2008, by NASS, Agricultural Statistics Board, USDA.
Broiler-Type Eggs Set In 19 Selected States Down 4 %
Commercial hatcheries in the 19-State weekly program set 207 million eggs in incubators during the
week ending August 23, 2008. This was down 4 per-
The 26.8 million net poults placed during July 2008 in
the United States were down 2 percent from the number placed during the same month a year earlier. Net
placements were up 5 percent from the June 2008 total
of 25.6 million.
Page
Page
4 4
Current Month Charts
Broiler Performance Data
Average
Region
Live Production Cost
Feed Cost/ton w/o color ($)
Feed cost /lb meat (c)
Days to 4.6 lbs
Chick cost / lb (c)
Vac-Med cost/lb (c)
WB & ½ parts condemn. Cost/lb
% mortality
Sq.Ft. @ placement
Lbs/sq. ft.
Downtime (days)
SW
Midwest
Southeast
Mid-Atlantic
S-Central
Company
340.65
30.69
43
5.00
0.05
0.22
4.08
0.79
7.17
14
314.90
28.20
41
4.83
0.04
0.23
4.19
0.80
7.09
11
334.25
29.97
41
5.14
0.08
0.15
3.54
0.83
6.91
16
326.54
30.71
41
4.52
0.11
0.23
3.94
0.91
7.23
16
334.16
30.77
42
4.86
0.05
0.22
3.97
0.83
7.28
12
331.70
30.06
42
5.03
0.10
0.22
3.92
0.83
7.01
Broiler Whole Bird
Region
Condemnation
% Septox
% Airsac
% I.P.
% Leukosis
% Bruises
% Other
% Total
% ½ parts condemns
14
Average
SW
Midwest
Southeast
Mid-Atlantic
S-Central
Company
0.158
0.025
0.010
0.000
0.009
0.006
0.209
0.292
0.234
0.050
0.021
0.000
0.001
0.002
0.309
0.286
0.083
0.051
0.004
0.000
0.003
0.006
0.147
0.199
0.125
0.066
0.043
0.004
0.002
0.006
0.246
0.372
0.080
0.032
0.023
0.000
0.002
0.006
0.143
0.419
0.130
0.046
0.021
0.001
0.004
0.005
0.239
0.244
Data for week ending 23 August, 2008
Previous Month Charts
Broiler Performance Data
Live Production Cost
Feed Cost/ton w/o color ($)
Feed cost /lb meat (c)
Days to 4.6 lbs
Chick cost / lb (c)
Vac-Med cost/lb (c)
WB & ½ parts condemn. Cost/lb
% mortality
Sq.Ft. @ placement
Lbs/sq. ft.
Downtime (days)
Region
SW
296.31
41
29.37
3.93
0.10
0.11
4.71
0.87
8.22
7
Midwest
290.66
41
26.22
4.81
0.05
0.35
4.90
0.79
7.03
11
Broiler Whole Bird
Condemnation
% Septox
% Airsac
% I.P.
% Leukosis
% Bruises
% Other
% Total
% ½ parts condemns
Data for week ending 26 July 2008
Southeast
282.02
25.85
41
5.13
0.08
0.17
3.93
0.84
6.76
16
Mid-Atlantic
278.39
27.32
40
4.05
0.10
0.26
4.77
1.26
5.98
14
S-Central
290.86
28.66
41
3.85
0.03
0.11
3.50
0.84
8.47
7
Region
Average
Company
286.69
27.20
41
4.48
0.07
0.20
4.20
0.93
7.15
11
Average
SW
Midwest
Southeast
Mid-Atlantic
S-Central
Company
0.087
0.015
0.013
0.000
0.001
0.003
0.118
0.140
0.320
0.042
0.030
0.001
0.002
0.000
0.395
0.596
0.075
0.115
0.004
0.000
0.007
0.004
0.206
0.218
0.187
0.074
0.022
0.019
0.001
0.002
0.305
0.416
0.071
0.026
0.011
0.000
0.002
0.005
0.114
0.161
0.135
0.050
0.016
0.004
0.002
0.003
0.211
0.317
Page 5
Meetings, Seminars and Conventions
2008
September
September 16-18: Combined Northeastern Conference on Avian Diseases (NECAD) / Pennsylvania
Poultry Sales and Service Conference
(PSSC) at the Penn State Conference
Center Hotel, State College, Pa. Contact
Bill Pierson tel 540-231-7823
2008
October
October 6, 2008 - October 8, 2008 -National Meeting on Poultry Health
& Processing 43rd National Meeting
on Poultry Health and Processing October 6 - 8, 2008 Clarion Resort Fontainebleau Hotel Ocean City, Maryland
2009
January
2009
April
April 5-8: The 7th International Symposium on Avian Influenza, The University of Georgia Center for Continuing Education, Athens, Georgia, USA.:
Online registration begins on August 1,
2008at: http://
www.georgiacenter.uga.edu/
conferences/2009/Apr/05/avian.phtml
For additional information
www.georgiacenter.uga.edu/
conferences/
ai.symposium@ars.usda.gov USDAARS, Southeast Poultry Research Laboratory, 934 College Station Road, Athens, Georgia 30605 USA. Phone: 706546-3434; FAX 706-546-3161
2010
April
April 20-23: VIV Europe 2010,
Utrecht, The Netherlands. Contact:
XNU Exhibitions Europe B.V, P.O.
Box 8800, 3503 RV Utrecht, The Netherlands, Fax: +31 302-952-809; Website:
www.viv.net
January 28-30: International Poultry Expo 2009, Georgia World Congress Center, Atlanta, Georgia. Contact:
US Poultry & Egg Association, 1530
Cooledge Road, Tucker, Georgia 300847804. Phone: +1-770-493-9401; Fax:
+1-770-493-9257; Email: expogeneralinfo@poultryegg.org.
Website: www.poultryegg.org
The University of Georgia is committed to the principle of
affirmative action and shall not discriminate against
otherwise qualified persons on the basis of race, color,
religion, national origin, sex, age, physical or mental
handicap, disability, or veteran's status in its recruit­ment,
admissions, employment, facility and program accessibility,
or services.
2009
March
Reminder
All previous issues of the
Poultry informed Professional are archived on our
website www.avian.uga.edu
under the Online Documents
and The Poultry Informed
Professional links.
March 23-25: 58th Western Poultry
Diseases Conference. Holiday Inn
Capitol Plaza, Sacramento, CA, USA.
Contact Conference and Event Services,
University of California, Davis. Phone
530-752-0198 Fax 530-752-5791 e-mail
confandeventsvcs@ucdavis.edu Website
conferences.ucdavis.edu/wpdc
Page 6