 |
Brought to you by Kansas State University
College of Veterinary Medicine - Agricultural Practices Section
September 2007 |
 |
Contents:
K-State Bovine
Castration Survey
AVMA Food Supply
Veterinarian Maps
Factors
affecting feeder calf price in Arkansas
Testing with
PCR & Culture for Tritrichomonas foetus
Reproductive effects of leptospira vaccine and oxytetracycline
DNA paternity
identification in beef cattle
K-State
Bovine Castration Survey
Based on the number of steers reported annually by the USDA NASS there
are approximately 16 million bovine castrations performed in the US each
year; yet little is known about which methods of castration are most
commonly used in the industry. Since "Position Statements" on bovine
castration are currently being drafted by various organizations, we
believe that it would be helpful to establish benchmarks for the
profession identifying the most common methods of castration and how
these procedures are typically performed.
In order to evaluate Bovine Castration in the United States we invite
you to participate in a survey of beef and dairy practitioners conducted
by the Beef Cattle Institute (BCI) at Kansas State University. We expect
our online survey to take about 15 minutes. By completing the survey,
you will be giving us permission to use your anonymous responses in
written and oral reports, which may be published. This study is been
examined by the Institutional Review Board at Kansas State University
and deemed to be exempt from any further review (KSU IRB #4406). The
AABP Animal Welfare Committee has also had an opportunity to review and
comment on this survey prior to circulation.
To take the survey, please click
on the link below:
https://surveys.ksu.edu/TS?offeringId=73959
If you would like additional
information about this study or have questions before you participate,
please feel free to contact Dr. Hans Coetzee at the College of
Veterinary Medicine, Kansas State University, Manhattan KS 66506, by
email
(jcoetzee@vet.k-state.edu) , or by telephone at 785-532-6354 or
515-231-7688.
AVMA Food Supply
Veterinarian Maps
The American Veterinary Medical Association (AVMA) recently added a web
tool to visualize the number of food animal veterinarians in each
geographic region relative to the number of cattle in that area. The
site displays maps comparing USDA cattle inventory numbers by county to
the number of food supply veterinarians in each county. These maps can
be found at:
http://www.avma.org/fsvm/maps/default.asp
For more information on the potential shortage of food supply
veterinarians, look at the AVMA’s website (
www.avma.org ) and click on the Food
Supply Veterinary Medicine link.
Factors affecting
feeder calf price in Arkansas
Data were collected from 15 Arkansas livestock auctions to determine
factors affecting selling price. Data included how calves were sold
(single or groups), gender, breed or breed type, color, muscle
thickness, horn status, frame score, fill, body condition, age, health,
BW, and price. Data were randomly collected on 52,401 lots consisting of
105,542 calves. Selling prices for steers ($124.20 ± 0.07), bulls
($117.93 ± 0.12) and heifers ($112.81 ± 0.07) were different from each
other (P < 0.001). Hereford x Charolais feeder calves sold for the
highest price ($122.66 ± 0.14) and Longhorns sold for the lowest price
($74.52 ± 0.46). Yellow feeder cattle received the highest selling price
($96.47 ± 0.12), and spotted or striped feeder cattle received the
lowest ($83.84 ± 0.23). The selling price of singles was lower than the
selling price for those sold in groups of 6 or more ($117.26 ± 0.06 vs.
$122.61 ± 0.21; P < 0.001). For cattle classified as muscle scores 1, 2,
3, and 4, selling prices were $120.45 ± 0.05, $111.31 ± 0.09, $96.28 ±
0.44 and $82.21 ± 1.87, respectively. Polled feeder cattle sold for
$118.57 ± 0.05, and horned feeder cattle sold for $114.87 ± 0.14 (P <
0.001). Interactions (P < 0.001) were detected between frame score and
BW groups and muscle score and BW groups on the selling price of cattle.
A number of management and genetic factors affected selling price of
feeder cattle.
Barham, B.L., T.R. Troxel.
Factors affecting the selling price of
feeder cattle sold at Arkansas livestock auctions in 2005.
J. Anim Sci. 2007. Doi:10.2527/jas2007-0340.
Testing with PCR &
Culture for Tritrichomonas foetus
The sensitivity (Se) and specificity (Sp) of different testing schemes
were estimated for detecting Tritrichomonas foetus (T. foetus) in smegma
samples from experimentally infected bulls. Culture and polymerase chain
reaction (PCR) on smegma samples were evaluated alone and in parallel
testing. Mature dairy bulls (n=79) were intrapreputially inoculated with
T. foetus (n=19); Campylobacter (C.) fetus venerealis (n=13); both T.
foetus and C. fetus venerealis (n=11); Tetratrichomonas spp. (n=9); C.
fetus fetus (n=8); or were not inoculated (n=19). For each bull, smegma
samples were collected for 6 week post-inoculation and tested for T.
foetus by In Pouch TF® culture and PCR. Most T. foetus-inoculated bulls
became infected, according to culture (86.7%), PCR (90.0%), and both
tests together (93.3%). In T. foetus-inoculated bulls, both tests
combined in parallel on a single sample had a Se (78.3%) and Sp (98.5%)
similar to two cultures (Se 76.0%, Sp 98.5%) or two PCR (Se 78.0%, Sp
96.7%) sampled on consecutive weeks. The PCR on three consecutive weekly
samples (Se 85.0%, Sp 95.4%) and both tests applied in parallel on three
consecutive weekly samples (Se 87.5%, Sp 95.6%) were similar to the
current gold-standard of six weekly cultures (Se 86.7% and Sp 97.5%).
Both tests used in parallel six times had the highest Se (93.3%), with
similar Sp (92.5%). Tetratrichomonas spp. were only sporadically
detected by culture or PCR. In conclusion, we have proposed alternative
strategies for T. foetus diagnostics (for the AI industry), including a
combination of tests and repeat testing strategies that may reduce time
and cost for bull surveillance.
Cobo, ER, PH Favetto, VM Lane, A Friend, K VanHooser, J Mitchell, RH
BonDurant. Sensitivity and specificity
of culture and PCR of smegma samples of bulls experimentally infected
with Tritrichomonas foetus. 2007
Theriogenology 68(6) 853-860.
Reproductive
effects of leptospira vaccine and oxytetracycline
The objective of this field study was to determine whether a
commercially available monovalent Leptospira borgpetersenii serovar
hardjo type hardjo bovis vaccine coupled with systemic oxytetracycline
treatment to clear carriers would improve the reproductive performance
of beef cows. One thousand four hundred and forty six Angus cross-bred
beef cows in eight locations were randomly assigned to treatment and
control groups. Cows received two doses, 4 weeks apart, of a commercial
leptospira monovalent vaccine (n=741). Cows that received the vaccine
were also treated with 9mg/lb BW of oxytetracycline SC at the time of
the second injection of vaccine. Serum antibody titers and urine samples
were examined to detect presence of leptospira on farms prior to
treatments. Farms were categorized as positive or negative for
leptospira based on the presence of leptospiruric cows. Cows were
synchronized for fixed time artificial insemination (FTAI) and bulls
were introduced 14 days later to breed non-pregnant cows following FTAI.
Outcome measures evaluated were FTAI pregnancy rate and over-all
(season-long) pregnancy rate (based on rectal palpation) for treatment
and control group and for cows living in leptospira positive (N=1183)
and negative (n=264) farms. Data were analyzed with a statistical
software program (SAS Version 9.1 for Windows, SAS Institute, Cary, NC,
USA). General Linear Model was used to examine the effects of
vaccination on FTAI and over-all pregnancy rates. Variables included in
the model were treatment (yes or no), farms status for leptospira,
season (fall and spring), age (2, 3-6, >6 years) and body condition
score (<4, 5 and 6, >7). All possible interaction effects were also
tested. No significant differences in the FTAI pregnancy rate and
over-all pregnancy rate between treatment and control groups were
observed. The FTAI pregnancy rate for cows in the leptospira positive
farms was significantly less than the cows in the leptospira negative
farms [55.1% (651/1182) versus 61.7% (163/264)]. Among treatment groups,
there was no significant difference in the FTAI pregnancy rate for cows
in the leptospira positive and negative farms [55.4% (336/606) versus
59.3%(80/135)]. Similarly, among control groups, there was no
significant difference in the FTAI pregnancy rate for cows in the
leptospira positive and negative farms [54.8% (316/576) versus 63.6
(82/129)]. There were no significant differences in the over-all
pregnancy rate for leptospira positive and negative farms. The presence
of leptospira on the farm affected the FTAI pregnancy rate. The
monovalent leptospira vaccine coupled with oxytetracycline treatment did
not improve the reproductive performance in beef cows.
Kasimanickam, R, W. Whittier, J. Hall, J. Currin, K. Pelzer, B. Inman.
The effect of a monovalent leptospiral vaccine
and parenteral oxytetracycline treatment against Leptospira
borgpetersenii servor hardjo type hardjo on the reproductive performance
of beef cattle
– A field study.
2007 Theriogenology 68(3) 493-493.
DNA paternity identification in
beef cattle
The feasibility and economic value of DNA
paternity identification were investigated and illustrated using Nevada
beef cattle operations. A panel of 15 microsatellites was genotyped in
2,196 animals from 8 ranches with a total of 31,571 genotypes.
Probabilities of exclusion for each marker within ranch and across
ranches were computed. Joint probabilities of exclusion for the 15
microsatellites were also determined, resulting in values over 0.99 for
any individual ranch and across ranches. Dropping 1 or 2 microsatellites
with the lowest probabilities of exclusion resulted in joint
probabilities higher than 0.99 and with marginal reduction when compared
to the probabilities with 15 microsatellites. Formulae for benefit-cost
analysis for a DNA paternity identification program in beef cattle were
derived. Genotyping 15 microsatellites with 20 calves per sire resulted
in benefits of $1.71 and $2.44 per dollar invested at bull culling rates
of 0.20 and 0.30, respectively. The breakpoints for the program to be
profitable occurred when the ratio of the price of 1 kg of calf
liveweight over the cost of genotyping 1 microsatellite was higher than
1.1 for a bull culling rate of 0.30. Benefit-cost analysis was also
derived under incomplete DNA paternity identification using a lower
number of DNA-markers than necessary to achieve joint probabilities of
exclusion of 0.99. Approximately a 20% increase in benefit-cost ratio
was achieved using 10 versus 12 microsatellites with incomplete
paternity identification. The higher the number of bulls in the
operation, the lower the benefit-cost ratio of the paternity testing
program. Low probabilities of exclusion and a high number of bulls in
the beef operation reduced the benefit-cost ratio dramatically. DNA
paternity identification programs are feasible and may be profitable for
free range beef cattle operations.
Gomez-Raya, L., K. Priest, W. M. Rauw, M.
Okomo-Adhiambo, D. Thain, B. Bruce, A. Rink, R. C. Torrell, L. Grellman,
R. Narayanan, and C. W. Beattie The
value of DNA paternity identification in beef cattle: examples from
Nevada’s free range ranches.
2007 J. Anim Sci. published 18 September 2007, 10.2527/jas.2007-0068
___________________________________________________________________
Beef Research News is produced by the Agricultural Practices section at
Kansas State University. To modify your subscription to this service
please email Erin Evanson ( eevanson@vet.ksu.edu )
For more information please contact:
Brad White
Beef Production Medicine
Q211 Mosier Hall
Manhattan, KS 66506
bwhite@vet.ksu.edu
|