Effect of castration technique on beef calf performance, residual feed intake, and inflammatory response

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Effect of castration technique on beef calf performance, residual feed intake, and inflammatory response
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English
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Warnock, Trey
Thrift, Todd
Irsik, Max
Hersom, Matt
Maddock, Travis
Lamb, Cliff
Arthington, John
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University of Florida
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Gainesville, Fla.

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Effect of Castration Technique on Beef Calf Performance, Residual Feed
Intake, and Inflammatory Response

Trey Warnock1, Todd Thrift1, Max Irsik2, Matt Hersoni, Travis Maddock3, Cliff Lamb3,
John Arthington4


Method of castration utilized had minimal impact on average daily gain, feed efficiency, water intake,
residual feed intake or feeding frequency of beef calves castrated post weaning. Delaying castration and
utilization of banding techniques was not more favorable to surgical methods.


Summary
The objective of this experiment was to evaluate
the rate of growth, feed intake, water intake,
residual feed intake (RFI), and inflammatory
response of male beef calves during the feedlot
phase in response to different methods of
castration. Seventy-five beef calves (498 75
lb; 200 26 days of age) were placed in a
GrowSafe 4000 feed intake facility 7 d post-
weaning (15 calves/pen). Average daily gain
(ADG), daily feed intake (DFI), and daily water
intake (DWI) were recorded over an 84-d
period. Blood was collected post-castration on 6
d during the first 2 wk post castration to assess
inflammatory response. Calves were offered a
mixed diet total digestible nutrients (TDN) =
67.3% and crude protein (CP) = 12.2%, dry
matter (DM) = 89%) ad libitum. On day 0
calves were assigned to one of five treatments
(15 calves/treatment): 1) steers castrated
ii, ..,,~/i- prior to weaning at a mean age of 52
d (range 8-85 d; CON); 2) intact bulls that
remained intact for the entire 84 d experiment
(BULL); 3) bulls castrated by the Callicrate
Bander on d 0; 4) bulls castrated by the
Henderson Co,,i ,ig Tool on d 0 (HEN); and
5) bulls castrated ,,,..ii!iv utilizing an
emasculator on d 0 (SUR). Results indicate that
castration decreased ADG d 0 to 14, but not d 0
to 84. Daily feed intake and DWI were
unaffected by castration technique over the
entire experiment. Gain:Feed was not impacted
by castration technique; however, RFJ was
affected d 0 to 14 but not d 0 to 84. Acute phase


protein analyses indicated that surgical
castration elicited a short-term inflammatory
response, whereas banding elicited a delayed
response. It appears that calves castrated pre-
weaning were preferable in all measures of
performance, intake, and inflammatory
response. In this study, castration of weaned
bull calves averaging 500 lbs in weight did not
result in a long term decline in performance
regardless of method of castration utilized.

Introduction
It is customary for cow/calf operators to castrate
male beef calves prior to weaning. However,
some calves are not castrated until after
weaning. Several methods of castration are
available and the decision of which method to
utilize may be a function of the type and size of
the calf (Zweiacher et al., 1979). Larger and
older calves may have increased blood flow to
the testes increasing the risk of blood loss after
castration. This blood loss may be eliminated if
a bloodless means of castration is used.
However, these methods also have certain risks,
and may be problematic in terms of anaerobic
infections such as tetanus.

Several studies have demonstrated that male
beef calves endure an observable degree of pain
when castrated (Fisher et al., 1996; Ting et al.,
2003). This pain increases in acuteness and
duration as the calf s age, body weight, and


1Department of Animal Sciences, University of Florida, Gainesville, FL
2College of Veterinary Medicine, University of Florida, Gainesville, FL
3North Florida Research and Education Center, University of Florida, Marianna, FL
4Range Cattle Research and Education Center, University of Florida, Ona, FL










testicular size increases (Chase et al., 1995;
Stafford et al., 2002). All methods of castration
cause significant acute pain and distress;
however, surgical castration is suggested to be
more painful, initially evidenced by increased
plasma cortisol (Stafford et al., 2002). Pain and
inflammation may also affect the growth rate
and efficiency of beef calves (Fisher et al., 1997,
Ratcliff et al., 2005). If specific methods of
castration can be utilized to lessen the pain then
theoretically growth rate and efficiency may be
maximized.

Several studies have documented decreased
growth rate in castrated calves compared to
intact male calves but there has been minimal
research on the effect of castration on feed
efficiency (Brazle, 1992; Faulkner et al., 1992).
There have been no studies investigating the
effect of castration on residual feed intake (RFI)
and whether variation in RFI exists among
calves castrated by different methods. In
addition, there have been no studies evaluating
the effect of the Henderson Castrating Tool
(Stone Manufacturing and Supply Co., Inc.,
Kansas City, MO) on beef calf performance or
feed efficiency.

Materials and Methods
Animals and Treatments
Seventy-five male beef calves (498 + 75 lb)
were obtained from the University of Florida
Santa Fe Beef Unit (Alachua, FL) at weaning.
Calves were weaned for 7 d prior to transport
217 miles to the North Florida Research and
Education Center's (NFREC) GrowSafe feed
efficiency facility in Marianna, Florida. Calves
arrived at the NFREC in a single semi-load. The
arrival date was 22 d prior to the initiation of the
experiment. A pre-experimental period
(acclimation period) began on d -21 and lasted
until d 0 (day of castration). Calves were
stratified by breed, age, and weaning weight and
randomly allocated to one of five treatments (15
calves/treatment): 1) control steers (CON) were
castrated surgically prior to weaning at an
average age of 52 d (8-85 d); 2) intact bulls
(BULL); 3) bulls castrated by the Callicrate
Bander (No-Bull Enterprises, LLC, St. Francis,
KS; BAN); 4) bulls castrated using the
Henderson Castrating Tool (Stone Mfg &


Supply Co., Kansas City, MO; HEN); and 5)
bulls castrated surgically (SUR). The experiment
was comprised of two data collection periods,
post-castration period (d 0 14), and overall
period (d 0 84). Calves were randomly
assigned to one of five pens so that all
treatments were equally represented in all pens.

Calves were vaccinated prior to initiating the
experiment against IBR, BVD, BRSV, PI3
(Cattle Master Gold, Pfizer Animal Health),
blackleg (Ultra Choice 7, Pfizer Animal Health),
and treated for internal and external parasites
(Ivomec Epirnex, Merial). Over the entire
experiment calves exhibiting signs of respiratory
disease were recorded and treated with
Draxxin (tulathromycin, Pfizer Animal Health)
at label dose. Fifteen percent (n = 11) of calves
were treated for respiratory disease one time,
11% of all calves (n = 7; 58% re-treat) were re-
treated for respiratory disease and 1 calf was
treated a third time. Two CON calves were
treated once, one BULL calf was treated once
and three were treated twice, one BAN calf was
treated twice and one was treated a third time,
two HEN calves were treated twice, and one
SUR calf was treated once. These calves were
treated during the first 4 wk of the experiment
and after d 28 no cattle were treated during the
remainder of the experiment. All calves were
offered a mixed concentrate based diet (TDN =
67.3% and CP = 12.2%, DM = 89%) ad libitum.

Calves assigned to the BAN, HEN and SUR
treatments were castrated on d 0. Castration was
performed by trained technicians under the
supervision of a University of Florida
veterinarian. Calves were restrained in a chute
and castration was completed by the same
technician in the same manner for each calf for
each treatment group. All calves on all
treatments were vaccinated subcutaneously with
500 units of tetanus antitoxin on d 0.

For banded calves, the band was applied around
the scrotum proximal to the testes. The elastic
band was tightened by ratcheting until adequate
tension was applied, a metal grommet was then
crimped around the band to hold tension and
decrease blood flow to the scrotum and testes,










causing subsequent sloughing of the scrotum
and testes.

Henderson castrated calves were castrated by
incising the scrotum with a Newberry knife,
leaving an anterior and posterior flap. Testes
were exposed and removed by the Henderson
Castrating Tool. The castrating tool was
clamped on each spermatic cord individually
and rotated by a cordless drill approximately 20
rotations until the cord severed.

Surgically castrated calves were castrated by
incising the scrotum with a Newberry knife,
leaving an anterior and posterior flap. Testes
were exposed and spermatic cords were crimped
and severed with an emasculator.

Sampling and Analysis
Shrunk body weight (BW) were obtained on d 0,
14, and 84. In addition, full BW were recorded
on d 7, 28, 42, 56, and 70. All cattle were
weighed in the morning and at approximately
0700 h for each weigh date. On days that shrunk
BW were recorded, access to feed and water was
removed by 1900 h the previous evening.

Feed intake and water intake were recorded
using the GrowSafe system. Trips to the feed
bunk and head down feeding events were also
recorded by utilizing radio frequency
identification tags.

Blood samples were collected from a sub-
sample (n = 45) of the cattle at the beginning of
the experiment to investigate the acute phase
response resulting from castration. Three pens
(15 calves/pen) were sampled by blood
collection via jugular venipuncture on d 0, 2, 6,
9, 12 and 15. Plasma was extracted from blood
samples and analyzed for concentrations of
ceruloplasmin and haptoglobin.

The MIXED procedure of SAS was utilized to
perform statistical analyses. The model included
the main effects of treatment, pen, and day or
week when necessary. Animal within pen was
the random variable. Least square means are
reported with standard errors, means were
separated for comparison by PDIFF. All two-
way interactions found to be significant at


P <0.10 for a particular variable were included
in the model for that variable.

Results
Average Daily Gain
Castration of calves reduced (P = 0.06) average
daily gain (ADG) by an average of 76 percent
during the post castration period (day 0-14)
regardless of method utilized (Table 1). All
castrated calves gained less (P < 0.05) than
CON with BULL being intermediate and similar
(P = 0.23) to all other treatments.

Average daily gain over the entire experiment (d
0 to 84) was similar (mean = 1.94 lb/d; P = 0.42)
for all treatment groups indicating that castrated
calves were able to compensate and recover
from castration regardless of castration method.
Average daily gain was evaluated by period
from d 7 to 70 (data not shown). Banded calves
suffered a 50 percent reduction (P < 0.05) in
ADG compared to all other treatments.
However, ADG d 28 to 42, d 42 to 56, and d 56
to 70 was similar regardless of castration
method, indicating that at some point after d 28
and before d 42 all treatments began to gain
similarly. Ratcliff et al. (2005) reported that
weaned beef calves (462 + 32 lb) castrated
surgically tend to gain more (P < 0.10) than
banded calves in the 50 d after castration,
however no controls were present. Our results
indicate that all methods of castration reduce
ADG compared to control steers during the first
14 days after castration but by d 84 ADG was
similar regardless of castration technique. These
results imply that method of castration may not
impact ADG long term when castrating single
source weaned calves weighing around 500 lbs.

Feed and Water Intake
Daily feed intake from d 0 to 14 (post-castration
period) was similar (mean = 12.98; P = 0.80) for
treatment groups (Table 1).

Feed intake over the entire experiment (d 0 to
84) was analyzed by week (12 wk). Mean DFI
by wk (wk 1 to 12) was not impacted by
treatment (P = 0.92; Table 1). Fisher et al.
(1997) reported that castrated calves tend to eat
less (P < 0.05) than intact male calves early










post-castration and eat similar amounts 28 d
post-castration.

Feeding behavior was not impacted (P = 0.34)
by treatment early post-castration (Figure 1). All
treatments had decreased trips to the bunk on d -
1 and 0. This is attributed to the shrink period on
d -1 and the time spent out of the pen while
being processed on d 0. On d -1, 0, 1, and 2 all
treatments had similar number of trips to the
feed bunk. These results indicate that not only
was DFI by week not altered by castration
method, but feeding behavior was not impacted
by the stress of castration early post-castration.

Daily water intake was similar (mean = 9.6
gal/d; P > 0.10) among treatment groups from d
0 to 14 and d 0 84 (mean = 8.2 gal/d; Table 1).
These results indicate that the short term stress
of castration did not suppress water intake.

Feed Efficiency
Gain to feed ratio was similar among treatments
d 0 to 14 (mean = 0.03; P = 0.28; Table 1) and d
0 to 84 (mean = 0.09; P = 0.32). Residual feed
intake tended to be affected (P = 0.10) by
treatment during the post-castration period (d 0
to 14; Table 1). Control steers and BULL were
similar (P > 0.10) in RFI value, but lower (P <
0.05) than SUR. Calves that were castrated by
BAN and HEN were intermediate and similar (P
> 0.10) to CON, BULL, and SUR. These results
indicate that castration did induce a change in
efficiency, measured by RFI early post-
castration. There is a clear trend showing that
castration increased RFI, but the magnitude is
small and short in duration. Over the 84-d
experiment, RFI did not differ (P = 0.75) among
treatments, suggesting that in the long term,
castration does not negatively impact efficiency
as measured by RFI.


Stress Response
An interaction (P = 0.02) was detected between
treatment and day for plasma ceruloplasmin
concentration post-castration (Figure 2). All
treatments had similar (P > 0.10) plasma
ceruloplasmin concentrations on d 0. CON had
decreased (P < 0.05) plasma ceruloplasmin
concentrations compared to BULL and HEN on


d 2; BULL, HEN, and SUR on d 6 and 9; and
tended (P < 0.10) to be lower than BULL, HEN,
and SUR on d 12; and BULL, BAN, and SUR
on d 15. The delayed increase in plasma
ceruloplasmin concentrations in BAN compared
to CON suggests that BAN induced a delayed
inflammation response compared to surgical
methods of castration. The increased plasma
ceruloplasmin concentrations HEN and SUR
exhibited compared to CON indicates that there
is an acute inflammatory response early post-
castration in surgically castrated calves, however
it is decreased over time. HEN and SUR were
similar (P > 0.10) post-castration indicating that
neither surgical method was better at minimizing
a stress response.

An interaction (P = 0.0002) was detected
between treatment and day for plasma
haptoglobin concentration post-castration
(Figure 3). These data indicate that plasma
haptoglobin concentrations were greater in the
surgical methods early post-castration but were
not different from CON steers by d 9. Calves
that were BAN responded like CON until d 15
when BAN had greater plasma haptoglobin
concentration than CON and calves castrated
surgically, indicating the delayed inflammatory
response associated with banding calves. The
causative agent for increased plasma
haptoglobin concentration observed in intact
male calves in the current study remains to be
elucidated.

No one method induced a greater inflammatory
response early post-castration, these results may
be important from an animal welfare standpoint.
There are minimal differences in concentration
of plasma ceruloplasmin and haptoglobin among
castration methods and only slight numerical
differences compared to CON.




















































Literature Cited
Brazle. 1992. Kansas State Univ. Rep. of Prog. 651, Agric. Exp. Station.
Chase et al. 1995. J. Anim. Sci. 73:975.
Faulkner et al. 1992. J. Anim. Sci. 70:2970.
Fisher et al. 1996. J. Anim. Sci. 74:2336.
Fisher et al. 1997. J. Anim. Sci. 75:1041.
Ratcliff et al. 2005. Arkansas Animal Science Research Report. Fayetteville, AR. P 115.
Stafford et al. 2002. Research in Veterinary Science 73:61.
Ting et al. 2003. J. Anim. Sci. 81:1281.
Zweiacher et al. 1979. J. Anim. Sci. 49:5.










Table 1. Effect of castration technique on measures of performance, and intake in beef calves
Item Treatments'
ADG, lb/d CON BULL BAN HEN SUR S. E.2 P-value
d 0 to 14 1.60a 1.10ab 0.33b 0.53b 0.57b 0.33 0.06
d 0 to 84 2.0 2.1 1.8 1.9 1.9 0.13 0.42
Daily Feed Intake, lb/d
dO 0to 14 13.6 12.5 12.8 12.1 13.9 1.2 0.80
d 0 to 843 20.9 20.9 20.0 20.9 21.1 0.95 0.92
Daily Water Intake, gal/d
dO 0to 14 10.67 8.74 9.61 9.16 9.66 0.87 0.61
d 0 to 843 8.63 8.37 7.74 8.37 8.13 0.48 0.71
Gain:Feed
d 0 to 14 0.10 0.06 -0.06 0.03 0.02 0.05 0.29
d 0 to 84 0.10 0.10 0.09 0.09 0.09 0.005 0.39
Residual Feed Intake
d 0 to 14 -0.92a -0.88a 0.66ab -0.04ab 1.20b 0.66 0.09
d 0 to 84 -0.29 -0.48 -0.11 0.57 0.31 0.66 0.75
'CON = calves castrated pre-trial; BULL = intact male calves; BAN = calves banded on d 0; HEN = calves
surgically castrated with Henderson castration tool on d 0; SUR = calves surgically castrated with emasculators
ond0.
2Standard Error
3Data reported as average daily intake by week
a, b Means within same row with different superscripts differ P < 0.05.





9.0
8.0
7.8 0 T------- T T----
7.0
6CON
S5.0
BULL
S4.0
m BAN
3.0
.2.0 HEN
1.0 SUR

-1 0 1 2
Day


Figure 1. Effect of castration method on feeding behavior early post-castration.

















- ~ **..
-


60

! 50

40

30

S20

10

0


0 2 6 9 12 15
Day

Figure 2. Effect of the castration method x day interaction on plasma ceruloplasmin concentration post-
castration. Treatment x day: P = 0.02.


-CON
...... BULL

--- BAN
- HEN
- -SUR


0 2 6 9 12 15
Day



Figure 3. Effect of the castration method x day interaction on plasma haptoglobin concentration post-
castration. Treatment x day: P = 0.0002.


-CON
...... BULL

--- BAN
- HEN
- -SUR


0





o
<
I


/ I 1 I I




Full Text

PAGE 1

Summary The objective of this experiment was to evaluate the rate of growth, feed intake, water intake, residual feed intake (RFI), and inflammatory response of male beef calves during the feedlot phase in response to different methods of castration. Seventy five beef calves (498 75 lb; 200 26 days of age) were placed in a GrowSafe 4000 feed intake facility 7 d post weaning (15 calves/pen). Average daily gain (ADG), daily feed intake (DFI), and daily water intake (DWI) were recorded over an 84 d period. Blood was collected post castration on 6 d during the first 2 wk post castration to assess inflammatory response. Calves were offered a mixed diet total digestible nutrients (TDN ) = 67.3% and crude protein ( CP ) = 12.2%, dry matter ( DM ) = 89%) ad libitum. On day 0 calves were assigned to one of five trea tments (15 calves/treatment): 1) steers castrated surgically prior to weaning at a mean age of 52 d ( r ange=8 85 d; CON); 2) intact bulls that remained intact for the entire 84 d experiment (BULL); 3) bulls castrated by the Callicrate Bander on d 0; 4) bull s castrated by the Henderson Castrating Tool on d 0 (HEN) ; and 5) bulls castrated surgically utilizing an emasculator on d 0 (SUR). Results indicate that castration decreased ADG d 0 to 14, but not d 0 to 84. Daily feed intake and DWI were unaffected by castration technique over the entire experiment. Gain:Feed was not impacted by castration technique; however, RFI was affected d 0 to 14 but not d 0 to 84. Acute phase protein analyses indi cated that surgical castration elicited a short term inflammatory response, whereas banding elicited a delayed response. It appears that calves castrated pre weaning were preferable in all measures of performance, intake, and inflammatory response. In thi s study, castration of weaned bull calves averaging 500 lbs in weight did not result in a long term decline in performance regardless of method of castration utilized. Introduction It is customary for cow/calf operators to castrate male beef calves prior to weaning. However, some calves are not castrated until after weaning. Several methods of castration are available and the decision of which method to utilize may be a function of the type and size of the calf (Zweiacher et al., 1979). Larger and older ca lves may have increased blood flow to the testes increasing the risk of blood loss after castration. This blood loss may be eliminated if a bloodless means of castration is used. However, these methods also have certain risks, and may be problematic in ter ms of anaerobic infections such as tetanus. Several studies have demonstrated that male beef calves endure an observable degree of pain when castrated (Fisher et al., 1996; Ting et al., 2003). This pain increases in acuteness and e, body weight, and Effect of Castration Technique on Beef Calf Performance, Residual Feed Intake, and Inflammatory Response Trey Warnock 1 Todd Thrift 1 Max Irsik 2 Matt Herson 1 Travis Maddock 3 Cliff Lamb 3 John Arthington 4 Method of castration utilized had minimal impact on average daily gain, feed efficiency, water intake, residual feed intake or feeding frequency of beef calves castrated post weaning. Delaying castration and utilization of banding techniques was not more favorable to surgical methods. 1 Department of Animal Sciences, University of Florida, Gainesville, FL 2 College of Veterinary Medicine, University of Florida, Gainesville, FL 3 North Florida Research and Education Center, University of Florida, Marianna, FL 4 Range Cattle Research and Education Center, University of Florida, Ona, FL

PAGE 2

testicular size increases (Chase et al., 1995; Stafford et al., 2002). All methods of castration cause significant acute pain and distress; however, surgical castration is suggested to be more painful, initially evidenced by increase d plasma cortisol (Stafford et al., 2002). Pain and inflammation may also affect the growth rate and efficiency of beef calves (Fisher et al., 1997, Ratcliff et al., 2005). If specific methods of castration can be utilized to lessen the pain then theoretic ally growth rate and efficiency may be maximized. Several studies have documented decreased growth rate in castrated calves compared to intact male calves but there has been minimal research on the effect of castration on feed efficiency (Brazle, 1992; Fa ulkner et al., 1992). There have been no studies investigating the effect of castration on residual feed intake (RFI) and whether variation in RFI exists among calves castrated by different methods. In addition, there have been no studies evaluating the ef fect of the Henderson Castrating Tool (Stone Manufacturing and Supply Co., Inc., Kansas City, MO) on beef calf performance or feed efficiency. Materials and Methods Animals and Treatments Seventy five male beef calves (498 75 lb ) were obtained from the University of Florida Santa Fe Beef Unit (Alachua, FL) at weaning. Calves were weaned for 7 d prior to transport 217 miles to the North Florida Research and feed efficiency facility in Marianna, Florida. Calves arrived at the NFREC in a single semi load. The arrival date was 22 d prior to the initiation of the experiment. A pre experimental period (acclimation period) began on d 21 and lasted until d 0 (day of castration). Calves were stratified by breed, age, and weaning weight and randomly allocated to one of five treatments (15 calves/treatment): 1) control steers (CON) were castrated surgically prior to weaning at an average age of 52 d (8 85 d); 2) intact bulls (BULL); 3) bulls castrated by the Callicrate Bander (No Bull Enterprises, LLC, St. Francis, KS; BAN); 4) bulls castrated using the Henderson Castrating Tool (Stone Mfg & Supply Co., Kansas City, MO; HEN); and 5) bulls castrated surgically (SUR). The experiment was comprised of two data collection periods, post castration period (d 0 14), and overall period (d 0 84). Calves were randomly assigned to one of five pens so that all treatments were equally represented in all pens. Calves were vaccinated prior to initiating the experiment against IBR, BVD, BRSV, PI3 (Cattle Master Gold, Pfizer Animal Health), blackleg (Ultra Choice 7, Pfizer Animal Health), and treated for internal and external parasites (Ivomec Epirnex, Merial). Over the entire experiment calves exhibiting signs of respi ratory disease were recorded and treated with Draxxin (tulathromycin, Pfizer Animal Health) at label dose. Fifteen percent (n = 11) of calves were treated for respiratory disease one time, 11% of all calves (n = 7; 58% re treat) were re treated for respir atory disease and 1 calf was treated a third time. Two CON calves were treated once, one BULL calf was treated once and three were treated twice, one BAN calf was treated twice and one was treated a third time, two HEN calves were treated twice, and one SU R calf was treated once. These calves were treated during the first 4 wk of the experiment and after d 28 no cattle were treated during the remainder of the experiment. All calves were offered a mixed concentrate based diet (TDN = 67.3% and CP = 12.2%, DM = 89%) ad libitum. Calves assigned to the BAN, HEN and SUR treatments were castrated on d 0. Castration was performed by trained technicians under the supervision of a University of Florida veterinarian. Calves were restrained in a chute and castration w as completed by the same technician in the same manner for each calf for each treatment group. All calves on all treatments were vaccinated subcutaneously with 500 units of tetanus antitoxin on d 0. For banded calves, the band was applied around the scro tum proximal to the testes. The elastic band was tightened by ratcheting until adequate tension was applied, a metal grommet was then crimped around the band to hold tension and decrease blood flow to the scrotum and testes,

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causing subsequent sloughing of the scrotum and testes. Henderson castrated calves were castrated by incising the scrotum with a Newberry knife, leaving an anterior and posterior flap. Testes were exposed and removed by the Henderson Castrating Tool. The castrating tool was clamped on each spermatic cord individually and rotated by a cordless drill approximately 20 rotations until the cord severed. Surgically castrated calves were castrated by incising the scrotum with a Newberry knife, leaving an anterior and posterior flap. Testes w ere exposed and spermatic cords were crimped and severed with an emasculator. Sampling and Analysis Shrunk body weight ( BW ) were obtained on d 0, 14, and 84. In addition, full BW were recorded on d 7, 28, 42, 56, and 70. All cattle were weighed in the morning and at approximately 0700 h for each weigh date. On days that shrunk BW were recorded, access to feed and water was removed by 1900 h the previous evening. Feed intake and water intake were recorded using the GrowSafe system. Trips to the feed bunk and head down feeding events were also recorded by utilizing radio frequency identification tags. Blood samples were collected from a sub sample (n = 45) of the cattle at the beginni ng of the experiment to investigate the acute phase response resulting from castration. Three pens (15 calves/pen) were sampled by blood collection via jugular venipuncture on d 0, 2, 6, 9, 12 and 15. Plasma was extracted from blood samples and analyzed fo r concentrations of ceruloplasmin and haptoglobin. The MIXED procedure of SAS was utilized to perform statistical analyses. The model included the main effects of treatment, pen, and day or week when necessary. Animal within pen was the random variable. L east square means are reported with standard errors, means were separated for comparison by PDIFF. All two way interactions found to be significant at P <0.10 for a particular variable were included in the model for that variable. Results Average Daily Gain Castration of calves reduced ( P = 0.06) average daily gain ( ADG ) by an average of 76 percent during the post castration period (day 0 14) regardless of method utilized (Table 1). All castrated calves gained less ( P < 0.05) than CON with BULL being int ermediate and similar ( P = 0.23) to all other treatments. Average daily gain over the entire experiment (d 0 to 84) was similar ( m ean = 1.94 lb/d; P = 0.42) for all treatment groups indicating that castrated calves were able to compensate and recover from castration regardless of castration method. Average daily gain was evaluated by period from d 7 to 70 (data not shown). Banded calves suffered a 50 percent reduction ( P < 0.05) in ADG compared to all other treatments. However, ADG d 28 to 42, d 42 to 56 and d 56 to 70 was similar regardless of castration method, indicating that at some point after d 28 and before d 42 all treatments began to gain similarly. Ratcliff et al. (2005) reported that weaned beef calves (462 32 lb) castrated surgically tend t o gain more ( P < 0.10) than banded calves in the 50 d after castration, ho wever no controls were present. Our results indicate that all methods of castration reduce ADG compared to control steers during the first 14 days after castration but by d 84 ADG w as similar regardless of castration technique. These results imply that method of castration may not impact ADG long term when castrating single source weaned calves weighing around 500 lbs. Feed and Water Intake Daily feed intake from d 0 to 14 (post castration period) was similar ( m ean = 12.98; P = 0.80) for treatment groups (Table 1). Feed intake over the entire experiment (d 0 to 84) was analyzed by week (12 wk). Mean DFI by wk (wk 1 to 12) was not impacted by treatment ( P = 0.92; Table 1). F isher et al. (1997) reported that castrated calves tend to eat less ( P < 0.05) than intact male calves early

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post castration and eat similar amounts 28 d post castration. Feeding behavior was not impacted ( P = 0.34) by treatment early post castration (Fi gure 1). All treatments had decreased trips to the bunk on d 1 and 0. This is attributed to the shrink period on d 1 and the time spent out of the pen while being processed on d 0. On d 1, 0, 1, and 2 all treatments had similar number of trips to the fe ed bunk. These results indicate that not only was DFI by week not altered by castration method, but feeding behavior was not impacted by the stress of castration early post castration. Daily water intake was similar ( m ean = 9.6 gal/d; P > 0.10) among trea tment groups from d 0 to 14 and d 0 84 ( m ean = 8.2 gal/d; Table 1). These results indicate that the short term stress of castration did not suppress water intake. Feed Efficiency Gain to feed ratio was similar among treatments d 0 to 14 ( m ean = 0.03; P = 0.28; Table 1) and d 0 to 84 ( m ean = 0.09; P = 0.32). Residual feed intake tended to be affected ( P = 0.10) by treatment during the post castration period (d 0 to 14; Table 1). Control steers and BULL were similar ( P > 0.10) in RFI value, but lower ( P < 0.05) than SUR. Calves that were castrated by BAN and HEN were intermediate and similar ( P > 0.10) to CON, BULL, and SUR. These results indicate that castration did induce a change in efficiency, measured by RFI early post castration. There is a clear tren d showing that castration increased RFI, but the magnitude is small and short in duration. Over the 84 d experiment, RFI did not differ ( P = 0.75) among treatments, suggesting that in the long term, castration does not negatively impact efficiency as meas ured by RFI. Stress Response An interaction ( P = 0.02) was detected between treatment and day for plasma ceruloplasmin concentration post castration (Figure 2). All treatments had similar ( P > 0.10) plasma ceruloplasmin concentrations on d 0. CON had dec reased ( P < 0.05) plasma ceruloplasmin concentrations compared to BULL and HEN on d 2; BULL, HEN, and SUR on d 6 and 9; and tended ( P < 0.10) to be lower than BULL, HEN, and SUR on d 12; and BULL, BAN, and SUR on d 15. The delayed increase in plasma ceruloplasmin concentrations in BAN compared to CON suggests that BAN induced a delayed inflammation response compared to surgical methods of castration. The increased plasma ceruloplasmin concentrations HEN and SUR exhibited compared to CON indicates that there is an acute inflammatory response early post castration in surgically castrated calves, however it is decreased over time. HEN and SUR were similar ( P > 0.10) post castration indicating that neither surgical method was better at minimizing a stress response. An interaction ( P = 0.0002) was detected between treatment and day for plasma haptoglobin concentration post castration (Figure 3). These data indicate that plasma haptoglobin concentrations were greater in the surgical methods early post cast ration but were not different from CON steers by d 9. Calves that were BAN responded like CON until d 15 when BAN had greater plasma haptoglobin concentration than CON and calves castrated surgically, indicating the delayed inflammatory response associated with banding calves. The causative agent for increased plasma haptoglobin concentration observed in intact male calves in the current study remains to be elucidated. No one method induced a greater inflammatory response early post castration, these results may be important from an animal welfare standpoint. There are minimal differences in concentration of plasma ceruloplasmin and haptoglobin among castration methods a nd only slight numerical differences compared to CON.

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Literature Cited Brazle. 1992. Kansas State Univ. Rep. of Prog. 651, Agric. Exp. Station. Chase et al. 1995. J. Anim. Sci. 73:975. Faulkner et al. 1992. J. Anim. Sci. 70:2970. Fisher et al. 19 96. J. Anim. Sci. 74:2336. Fisher et al. 1997. J. Anim. Sci. 75:1041 Ratcliff et al. 2005. Arkansas Animal Science Research Report. Fayetteville, AR. P 115. Stafford et al. 2002. Research in Veterinary Science 73:61. Ting et al. 2003. J. Anim. Sci. 81:128 1. Zweiacher et al. 1979. J. Anim. Sci. 49:5.

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Table 1. Effect of castration technique on measures of performance, and intake in beef calves Item Treatments 1 ADG, lb/d CON BULL BAN HEN SUR S. E. 2 P value d 0 to 14 1.60 a 1.10 ab 0.33 b 0.53 b 0.57 b 0.33 0.06 d 0 to 84 2.0 2.1 1.8 1.9 1.9 0.13 0.42 Daily Feed Intake, lb/d d 0 to 14 13.6 12.5 12.8 12.1 13.9 1.2 0.80 d 0 to 84 3 20.9 20.9 20.0 20.9 21.1 0.95 0.92 Daily Water Intake, gal/d d 0 to 14 10.67 8.74 9.61 9.16 9.66 0.87 0.61 d 0 to 84 3 8.63 8.37 7.74 8.37 8.13 0.48 0.71 Gain:Feed d 0 to 14 0.10 0.06 0.06 0.03 0.02 0.05 0.29 d 0 to 84 0.10 0.10 0.09 0.09 0.09 0.005 0.39 Residual Feed Intake d 0 to 14 0.92 a 0.88 a 0.66 ab 0.04 ab 1.20 b 0.66 0.09 d 0 to 84 0.29 0.48 0.11 0.57 0.31 0.66 0.75 1 CON = calves castrated pre trial; BULL = intact male calves; BAN = calves banded on d 0; HEN = calves surgically castrated with Henderson castration tool on d 0; SUR = calves surgically castrated with emasculators on d 0. 2 Standard Error 3 Data reported as average daily intake by week a, b Means within same row with different superscripts differ P < 0.05. Figure 1. Effect of castration method on feeding behavior early post castration. Treatment effect: P =0.34

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Figure 2. Effect of the castration method x day interaction on plasma ceruloplasmin concentration post castration. Treatment x day: P = 0.02. Figure 3. Effect of the castration method x day interaction on plasma haptoglobin concentration post castration. Treatment x day: P = 0.0002.