A commercial feedlot study utilizing 1,737 crossbred heifers (initial BW 690 lb) compared the effect of two implant strategies [Synovex ONE Feedlot (day 0) or Synovex Choice (day 0) followed by Synovex Plus (day 95)] on performance and carcass characteristics. No differences were observed in carcass weight, final body weight, or gain, but heifers implanted with Synovex ONE Feedlot had slightly greater feed conversion and greater intake than heifers implanted using Synovex Choice/Synovex Plus. Heifers implanted with Synovex Choice/Synovex Plus had lower marbling score and yield grade, higher dressing percentage, and greater loin muscle area compared to heifers implanted with Synovex ONE Feedlot. Cattle implanted with Synovex ONE Feedlot showed a tendency for better quality grading compared to heifers implanted with Synovex Choice/Synovex Plus. These data suggest that implanting heifers with Synovex ONE Feedlot gives comparable growth to heifers implanted with Synovex Choice followed by Synovex Plus, with some changes in fatness when fed equal days

Bundy, Sheri

Cleale, Ralph M.

Cooper, Robert J.

Erickson, Galen E.

Jordon, D. J., Jordon

Schumacher, Elizabeth A.

Scott, Tony L.

Sides, Gary

English

DigitalCommons@University of Nebraska

University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnNebraska Beef Cattle Reports Animal Science Department2019A Comparison of Synovex ONE® Alone to SynovexChoice® Followed by Synovex Plus® as ImplantStrategies for Finishing HeifersElizabeth A. SchumacherUniversity of Nebraska - Lincoln, eschumacher6@unl.eduGalen E. EricksonUniversity of Nebraska - Lincoln, gerickson4@unl.eduD. J. Jordon JordonRobert J. CooperTony L. ScottSee next page for additional authorsFollow this and additional works at: http://digitalcommons.unl.edu/animalscinbcrPart of the Large or Food Animal and Equine Medicine Commons, Meat Science Commons, andthe Veterinary Preventive Medicine, Epidemiology, and Public Health CommonsThis Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It hasbeen accepted for inclusion in Nebraska Beef Cattle Reports by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln.Schumacher, Elizabeth A.; Erickson, Galen E.; Jordon, D. J. Jordon; Cooper, Robert J.; Scott, Tony L.; Bundy, Sheri; Sides, Gary; andCleale, Ralph M., "A Comparison of Synovex ONE® Alone to Synovex Choice® Followed by Synovex Plus® as Implant Strategies forFinishing Heifers" (2019). Nebraska Beef Cattle Reports. 1025.http://digitalcommons.unl.edu/animalscinbcr/1025AuthorsElizabeth A. Schumacher, Galen E. Erickson, D. J. Jordon Jordon, Robert J. Cooper, Tony L. Scott, SheriBundy, Gary Sides, and Ralph M. ClealeThis article is available at DigitalCommons@University of Nebraska - Lincoln: http://digitalcommons.unl.edu/animalscinbcr/102576 · 2019 Nebraska Beef Cattle Report©  The Board Regents of the University of  Nebraska. All rights reserved.in one event. At initial processing, heifers received Inforce 3 (Zoetis), One Shot BVD (Zoetis), albendazole (Valbazen, Zoetis), doramectin (Dectomax, Zoetis), and an implant based on the assigned treatment. Also at processing, heifers were pregnancy checked using rectal ultrasound and if bred, were administered dinoprost trometh-amine (Lutalyse HighCon, Zoetis) or both Lutalyse HighCon and dexamethasone to abort. Heifers that were aborted were not removed from the study. Re- implanting occurred between 93 and 95 days after initial processing for heifers assigned to the CH+ strategy. Heifers assigned to the ONE strategy were not processed after initial processing. Heifers were fed an average of 182 days.Three intermediate diets were used to step up heifers onto a finishing diet containing 59.46% corn (dry rolled, high moisture, or a blend), 30% wet or modified distillers grains plus solubles (DGS), 3% alfalfa hay, 5% corn stalks, 2.5% supplement meal, 0.04% micro- ingredients on a dry matter (DM basis). All ration formulation changes were the same relative to days on feed for all cattle throughout the trial. Initial BW was defines as individual BW at processing, shrunk 4.0%. Final BW was collected at time of shipping using weights collected on the truck, then taking average pen weight shrunk 4.0% to adjust for gut fill. Cattle were harvested at a commercial facility on four dates and individual carcass data were collected. Individual hot carcass weight (HCW) was collected at slaughter. Following a 24 hr chill, 12th- rib fat depth, longissimus muscle (LM) area, marbling scores, USDA quality grade (QG), and USDA yield grade (YG) were collected.Statistical analysis of performance and carcass data were conducted using the Mixed procedure of SAS (9.3, SAS Institute Inc, Cary, NC). Pen was the experimental unit. Treatment and block were considered fixed effects. All performance and carcass data were analyzed with initial BW as a covariant because of a very small yet sig-implant strategy with an implant given upon arrival and a terminal implant given later is common. The level of trenbolone ac-etate (TBA) and estradiol (E) or the estradi-ol analog estradiol benzoate (EB) provided in those implants determine the strength of the implant, with the highest concentration of TBA or E typically found in the termi-nal implant. Re- implanting cattle requires handling animals a second time. A single implant able to cover the entire feeding period may be appealing to producers that want to minimize labor costs or reduce handling. Synovex ONE Feedlot is a single implant that is coated with a polymer film that delivers a slow release of TBA and EB. This allows the implant to remain active up to 200 days. The objective of this study was to evaluate the effects of implanting heifers with Synovex ONE Feedlot compared to a dual implant strategy of Synovex Choice followed by Synovex Plus on finishing heif-er performance and carcass characteristics.ProcedureCrossbred heifers (n = 1737) weighing 690 lb of initial body weight (BW) were fed at a commercial feedyard in central NE (Ford Farms, Cairo, NE). Heifers were sourced from sale barns located in NE, KS, and OK. The study was designed as a randomized complete block design with blocking factor being arrival date and initial weight of the cattle and pen was replica-tion. Treatments were (1) implanting with Synovex ONE Feedlot (200 mg of TBA + 28 mg EB; ONE) at initial processing and (2) implanting with Synovex Choice (100 mg TBA + 14 mg EB) at initial processing followed by Synovex Plus 95 days later (200 mg TBA + 28 mg EB; CH+). Heifers were randomly allotted to pen (n = 24) based on a BW randomization using pay weight. There were 12 replications started on trial over 9 dates. Treatments were assigned to pens within replication using a random number generator. Heifers were processed, weighed, and assigned to pen and treatment Elizabeth A. SchumacherGalen E. EricksonD. J. JordonRobert J. CooperTony L. ScottSheri BundyGary SidesRalph M. ClealeSummary with ImplicationsA commercial feedlot study utilizing 1,737 crossbred heifers (initial BW 690 lb) compared the effect of two implant strategies [Synovex ONE Feedlot (day 0) or Synovex Choice (day 0) followed by Synovex Plus (day 95)] on performance and carcass character-istics. No differences were observed in carcass weight, final body weight, or gain, but heifers implanted with Synovex ONE Feedlot had slightly greater feed conversion and greater intake than heifers implanted using Synovex Choice/Synovex Plus. Heifers implanted with Synovex Choice/Synovex Plus had lower marbling score and yield grade, higher dress-ing percentage, and greater loin muscle area compared to heifers implanted with Synovex ONE Feedlot. Cattle implanted with Synovex ONE Feedlot showed a tendency for better quality grading compared to heifers implant-ed with Synovex Choice/Synovex Plus. These data suggest that implanting heifers with Sy-novex ONE Feedlot gives comparable growth to heifers implanted with Synovex Choice followed by Synovex Plus, with some changes in fatness when fed equal days.IntroductionThe use of growth- promoting implants in both steers and heifers improves growth performance and lean meat yield when compared to unimplanted cattle. There are many different implant strategies common in the industry. With increased incentive to feed cattle to heavier weights, a dual- A Comparison of Synovex ONE® Alone to Synovex Choice®  Followed by Synovex Plus® as Implant Strategies for Finishing Heifers2019 Nebraska Beef Cattle Report · 77 nificant difference between treatments for initial BW. Quality grade and yield grade distributions and morbidity and mortality data were analyzed using the Glimmix procedure of SAS. Treatment differences were significant at an α value equal to or less than 0.05.ResultsHeifers implanted using the ONE strat-egy had a tendency for greater (P = 0.09) DMI than those implanted with the CH+ strategy (Table 1) with heifers implanted us-ing the CH+ strategy having significantly (P < 0.01) lower DMI in the final 85 days fol-lowing re- implanting. No differences were observed between treatments for carcass- adjusted final BW, live final BW, live ADG, and carcass- adjusted ADG (P ≥ 0.13). Heif-ers implanted using the CH+ strategy had lower (P < 0.01) F:G on a carcass- adjusted basis compared to those implanted with the ONE strategy, but similar (P = 0.10) F:G on a live basis. All heifers had similar (P = 0.11) HCW. Cattle implanted using the ONE strategy had greater (P ≤ 0.01) marbling score and calculated YG than those implanted using the CH+ strategy. Heifers implanted with the CH+ strategy had greater (P ≤ 0.02) dressing percentage and LM area than heifers implanted with the ONE strategy. Treatments had similar (P = 0.15) 12th rib fat thickness.A tendency (P = 0.06) for a difference in QG distribution between treatments was observed (Table 2). Heifers implanted using the ONE strategy showed a tendency (P = 0.06) for greater percent of carcasses grading Prime and a greater (P = 0.02) per-cent of carcasses grading in the upper 2/3 of Choice. Furthermore, heifers implanted with the ONE strategy had a lower (P = 0.05) percent of carcasses grading in the lower 1/3 of Choice and a lower (P < 0.01) percent carcasses grading Select compared to cattle implanted with the CH+ strate-gy. The USDA Yield Grade distributions tended (P = 0.09) to be different between the two implant strategy treatments. Treat-ments did not differ (P ≥ 0.11) in percent YG1 or YG2 carcasses but those implanted with the CH+ strategy had numerically greater percent YG1 and YG2 carcasses. Heifers implanted using the CH+ strategy had greater (P < 0.01) percent YG3 car-casses while those implanted with the ONE Table 1. The effect of using one slow- release implant compared to a dual implant strategy on heifers fed 182 dItemTreatment1SEM P- ValueONE CH+No. of heifers (pens) 869 (12) 868 (12) - - Initial BW, lb 690 691 0.5 0.08DMI, lb/d 23.6 23.3 0.11 0.09Initial 96 d, lb/d3 21.8 22.1 0.16 0.34Final 85 d, lb/d3 25.7 24.8 0.17 <0.01Live PerformanceFinal BW, lb2 1367 1366 3.1 0.90ADG, lb/d 3.74 3.74 0.016 0.97F:G 6.33 6.25 0.030 0.10Carcass- adjusted performanceFinal BW, lb4 1362 1371 3.6 0.13ADG, lb 3.72 3.76 0.019 0.13F:G 6.37 6.21 0.028 <0.01Carcass characteristicsHCW, lb 846.0 851.8 2.19 0.11Dressing Percentage, % 61.9 62.3 0.001 0.02Marbling score 534.7 508.4 4.45 <0.01LM area, in2 13.2 13.6 0.07 <0.0112th- rib fat thickness, in 0.772 0.750 0.01 0.15Calculated Yield Grade 3.92 3.76 0.04 <0.011ONE = Synovex One Feedlot on d 0; CH+ = Synovex Choice on d 0 and Synovex Plus on d 95.2Final BW is the average pen weight shrunk 4.0%. Subsequent ADG and G:F are calculated from shrunk final BW.3These DMI figures are from before and after re- implanting dates for the CH+ treatment.4Calculated as HCW divided by the mean dressing percentage of 62.13%. Subsequent ADG and G:F calculated using carcass- adjusted final BW.Table 2. A comparison of the distribution of quality grade and calculated yield grade between heifers implanted with two different strategiesItemTreatment1SEM P- ValueONE CH+USDA Quality Grade, % - 0.06Prime 8.40 5.79 0.90 0.06Upper 2/3 Choice 47.81 41.79 1.56 0.02Low Choice 35.37 39.15 1.21 0.05Select 8.42 13.27 0.71 <0.01USDA Yield Grade, % - 0.091 1.61 2.45 0.53 0.292 11.51 14.52 1.21 0.113 39.23 47.00 1.44 <0.014 38.48 29.11 2.38 <0.015 9.16 6.91 1.10 0.171ONE = Synovex One Feedlot on d 0; CH+ = Synovex Choice on d 0 and Synovex Plus on d 95.78 · 2019 Nebraska Beef Cattle Reportcan improve operational efficiency with minimal effect on performance.Elizabeth A. Schumacher, graduate studentGalen E. Erickson, professorD. J. Jordon, Cattlemens Nutrition ServicesRobert J. Cooper, Cattlemens Nutrition ServicesTony L. Scott, Cattlemens Nutrition ServicesSheri Bundy, Cattlemens Nutrition ServicesGary Sides, ZoetisRalph M. Cleale, Zoetisstrategy, resulting in slightly poorer feed conversion. Treatments had similar carcass weights and 12th rib fat thickness, but heifers implanted with the ONE strategy showed higher marbling scores and yield grade with lower dressing percentage and smaller loin muscle area. Heifers implanted with the ONE strategy showed an improve-ment in quality grade over heifers implant-ed with the CH+ strategy but had a higher percent yield grade 4 than cattle implanted with the CH+ strategy. No differences were observed between treatments in morbid-ity or mortality. These data suggest that utilizing Synovex ONE Feedlot in heifers strategy had greater (P < 0.01) percent YG4 carcasses. Treatments were not different (P = 0.17) in percent YG5 carcasses but heifers implanted with the ONE strategy had numerically greater percent YG5 carcasses. No differences (P ≥ 0.38) were observed between treatments for percent morbidity or mortality.ConclusionWhen fed to the same number of days, heifers implanted with the ONE strategy had greater intake but similar final weight and gain to heifers implanted with the CH+ 

A
Comparison of Synovex ONE® Alone to Synovex Choice®
Followed by Synovex Plus® as Implant Strategies for Finishing Heifers

UNL | Libraries

University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln
Nebraska Beef Cattle Reports Animal Science Department
2019
A Comparison of Synovex ONE® Alone to Synovex
Choice® Followed by Synovex Plus® as Implant
Strategies for Finishing Heifers
Elizabeth A. Schumacher
University of Nebraska - Lincoln, eschumacher6@unl.edu
Galen E. Erickson
University of Nebraska - Lincoln, gerickson4@unl.edu
D. J. Jordon Jordon
Robert J. Cooper
Tony L. Scott
See next page for additional authors
Follow this and additional works at: http://digitalcommons.unl.edu/animalscinbcr
Part of the Large or Food Animal and Equine Medicine Commons, Meat Science Commons, and
the Veterinary Preventive Medicine, Epidemiology, and Public Health Commons
This Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It has
been accepted for inclusion in Nebraska Beef Cattle Reports by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln.
Schumacher, Elizabeth A.; Erickson, Galen E.; Jordon, D. J. Jordon; Cooper, Robert J.; Scott, Tony L.; Bundy, Sheri; Sides, Gary; and
Cleale, Ralph M., "A Comparison of Synovex ONE® Alone to Synovex Choice® Followed by Synovex Plus® as Implant Strategies for
Finishing Heifers" (2019). Nebraska Beef Cattle Reports. 1025.
http://digitalcommons.unl.edu/animalscinbcr/1025
Authors
Elizabeth A. Schumacher, Galen E. Erickson, D. J. Jordon Jordon, Robert J. Cooper, Tony L. Scott, Sheri
Bundy, Gary Sides, and Ralph M. Cleale
This article is available at DigitalCommons@University of Nebraska - Lincoln: http://digitalcommons.unl.edu/animalscinbcr/1025
76 · 2019 Nebraska Beef Cattle Report
©  The Board Regents of the University of  
Nebraska. All rights reserved.
in one event. At initial processing, heifers 
received Inforce 3 (Zoetis), One Shot BVD 
(Zoetis), albendazole (Valbazen, Zoetis), 
doramectin (Dectomax, Zoetis), and an 
implant based on the assigned treatment. 
Also at processing, heifers were pregnancy 
checked using rectal ultrasound and if bred, 
were administered dinoprost trometh-
amine (Lutalyse HighCon, Zoetis) or both 
Lutalyse HighCon and dexamethasone to 
abort. Heifers that were aborted were not 
removed from the study. Re- implanting 
occurred between 93 and 95 days after 
initial processing for heifers assigned to the 
CH+ strategy. Heifers assigned to the ONE 
strategy were not processed after initial 
processing. Heifers were fed an average of 
182 days.
Three intermediate diets were used 
to step up heifers onto a finishing diet 
containing 59.46% corn (dry rolled, high 
moisture, or a blend), 30% wet or modified 
distillers grains plus solubles (DGS), 3% 
alfalfa hay, 5% corn stalks, 2.5% supplement 
meal, 0.04% micro- ingredients on a dry 
matter (DM basis). All ration formulation 
changes were the same relative to days 
on feed for all cattle throughout the trial. 
Initial BW was defines as individual BW 
at processing, shrunk 4.0%. Final BW was 
collected at time of shipping using weights 
collected on the truck, then taking average 
pen weight shrunk 4.0% to adjust for gut 
fill. Cattle were harvested at a commercial 
facility on four dates and individual carcass 
data were collected. Individual hot carcass 
weight (HCW) was collected at slaughter. 
Following a 24 hr chill, 12th- rib fat depth, 
longissimus muscle (LM) area, marbling 
scores, USDA quality grade (QG), and 
USDA yield grade (YG) were collected.
Statistical analysis of performance and 
carcass data were conducted using the 
Mixed procedure of SAS (9.3, SAS Institute 
Inc, Cary, NC). Pen was the experimental 
unit. Treatment and block were considered 
fixed effects. All performance and carcass 
data were analyzed with initial BW as a 
covariant because of a very small yet sig-
implant strategy with an implant given 
upon arrival and a terminal implant given 
later is common. The level of trenbolone ac-
etate (TBA) and estradiol (E) or the estradi-
ol analog estradiol benzoate (EB) provided 
in those implants determine the strength of 
the implant, with the highest concentration 
of TBA or E typically found in the termi-
nal implant. Re- implanting cattle requires 
handling animals a second time. A single 
implant able to cover the entire feeding 
period may be appealing to producers that 
want to minimize labor costs or reduce 
handling. Synovex ONE Feedlot is a single 
implant that is coated with a polymer film 
that delivers a slow release of TBA and EB. 
This allows the implant to remain active up 
to 200 days. The objective of this study was 
to evaluate the effects of implanting heifers 
with Synovex ONE Feedlot compared to 
a dual implant strategy of Synovex Choice 
followed by Synovex Plus on finishing heif-
er performance and carcass characteristics.
Procedure
Crossbred heifers (n = 1737) weighing 
690 lb of initial body weight (BW) were 
fed at a commercial feedyard in central 
NE (Ford Farms, Cairo, NE). Heifers were 
sourced from sale barns located in NE, 
KS, and OK. The study was designed as a 
randomized complete block design with 
blocking factor being arrival date and initial 
weight of the cattle and pen was replica-
tion. Treatments were (1) implanting with 
Synovex ONE Feedlot (200 mg of TBA + 
28 mg EB; ONE) at initial processing and 
(2) implanting with Synovex Choice (100 
mg TBA + 14 mg EB) at initial processing 
followed by Synovex Plus 95 days later (200 
mg TBA + 28 mg EB; CH+). Heifers were 
randomly allotted to pen (n = 24) based 
on a BW randomization using pay weight. 
There were 12 replications started on trial 
over 9 dates. Treatments were assigned to 
pens within replication using a random 
number generator. Heifers were processed, 
weighed, and assigned to pen and treatment 
Elizabeth A. Schumacher
Galen E. Erickson
D. J. Jordon
Robert J. Cooper
Tony L. Scott
Sheri Bundy
Gary Sides
Ralph M. Cleale
Summary with Implications
A commercial feedlot study utilizing 
1,737 crossbred heifers (initial BW 690 lb) 
compared the effect of two implant strategies 
[Synovex ONE Feedlot (day 0) or Synovex 
Choice (day 0) followed by Synovex Plus (day 
95)] on performance and carcass character-
istics. No differences were observed in carcass 
weight, final body weight, or gain, but heifers 
implanted with Synovex ONE Feedlot had 
slightly greater feed conversion and greater 
intake than heifers implanted using Synovex 
Choice/Synovex Plus. Heifers implanted with 
Synovex Choice/Synovex Plus had lower 
marbling score and yield grade, higher dress-
ing percentage, and greater loin muscle area 
compared to heifers implanted with Synovex 
ONE Feedlot. Cattle implanted with Synovex 
ONE Feedlot showed a tendency for better 
quality grading compared to heifers implant-
ed with Synovex Choice/Synovex Plus. These 
data suggest that implanting heifers with Sy-
novex ONE Feedlot gives comparable growth 
to heifers implanted with Synovex Choice 
followed by Synovex Plus, with some changes 
in fatness when fed equal days.
Introduction
The use of growth- promoting implants 
in both steers and heifers improves growth 
performance and lean meat yield when 
compared to unimplanted cattle. There are 
many different implant strategies common 
in the industry. With increased incentive 
to feed cattle to heavier weights, a dual- 
A Comparison of Synovex ONE® Alone to Synovex Choice®  
Followed by Synovex Plus® as Implant Strategies for Finishing Heifers
2019 Nebraska Beef Cattle Report · 77 
nificant difference between treatments for 
initial BW. Quality grade and yield grade 
distributions and morbidity and mortality 
data were analyzed using the Glimmix 
procedure of SAS. Treatment differences 
were significant at an α value equal to or 
less than 0.05.
Results
Heifers implanted using the ONE strat-
egy had a tendency for greater (P = 0.09) 
DMI than those implanted with the CH+ 
strategy (Table 1) with heifers implanted us-
ing the CH+ strategy having significantly (P 
< 0.01) lower DMI in the final 85 days fol-
lowing re- implanting. No differences were 
observed between treatments for carcass- 
adjusted final BW, live final BW, live ADG, 
and carcass- adjusted ADG (P ≥ 0.13). Heif-
ers implanted using the CH+ strategy had 
lower (P < 0.01) F:G on a carcass- adjusted 
basis compared to those implanted with 
the ONE strategy, but similar (P = 0.10) 
F:G on a live basis. All heifers had similar 
(P = 0.11) HCW. Cattle implanted using 
the ONE strategy had greater (P ≤ 0.01) 
marbling score and calculated YG than 
those implanted using the CH+ strategy. 
Heifers implanted with the CH+ strategy 
had greater (P ≤ 0.02) dressing percentage 
and LM area than heifers implanted with 
the ONE strategy. Treatments had similar 
(P = 0.15) 12th rib fat thickness.
A tendency (P = 0.06) for a difference 
in QG distribution between treatments 
was observed (Table 2). Heifers implanted 
using the ONE strategy showed a tendency 
(P = 0.06) for greater percent of carcasses 
grading Prime and a greater (P = 0.02) per-
cent of carcasses grading in the upper 2/3 
of Choice. Furthermore, heifers implanted 
with the ONE strategy had a lower (P = 
0.05) percent of carcasses grading in the 
lower 1/3 of Choice and a lower (P < 0.01) 
percent carcasses grading Select compared 
to cattle implanted with the CH+ strate-
gy. The USDA Yield Grade distributions 
tended (P = 0.09) to be different between 
the two implant strategy treatments. Treat-
ments did not differ (P ≥ 0.11) in percent 
YG1 or YG2 carcasses but those implanted 
with the CH+ strategy had numerically 
greater percent YG1 and YG2 carcasses. 
Heifers implanted using the CH+ strategy 
had greater (P < 0.01) percent YG3 car-
casses while those implanted with the ONE 
Table 1. The effect of using one slow- release implant compared to a dual implant strategy on heifers 
fed 182 d
Item
Treatment1
SEM P- ValueONE CH+
No. of heifers (pens) 869 (12) 868 (12) - - 
Initial BW, lb 690 691 0.5 0.08
DMI, lb/d 23.6 23.3 0.11 0.09
Initial 96 d, lb/d3 21.8 22.1 0.16 0.34
Final 85 d, lb/d3 25.7 24.8 0.17 <0.01
Live Performance
Final BW, lb2 1367 1366 3.1 0.90
ADG, lb/d 3.74 3.74 0.016 0.97
F:G 6.33 6.25 0.030 0.10
Carcass- adjusted performance
Final BW, lb4 1362 1371 3.6 0.13
ADG, lb 3.72 3.76 0.019 0.13
F:G 6.37 6.21 0.028 <0.01
Carcass characteristics
HCW, lb 846.0 851.8 2.19 0.11
Dressing Percentage, % 61.9 62.3 0.001 0.02
Marbling score 534.7 508.4 4.45 <0.01
LM area, in2 13.2 13.6 0.07 <0.01
12th- rib fat thickness, in 0.772 0.750 0.01 0.15
Calculated Yield Grade 3.92 3.76 0.04 <0.01
1ONE = Synovex One Feedlot on d 0; CH+ = Synovex Choice on d 0 and Synovex Plus on d 95.
2Final BW is the average pen weight shrunk 4.0%. Subsequent ADG and G:F are calculated from shrunk final BW.
3These DMI figures are from before and after re- implanting dates for the CH+ treatment.
4Calculated as HCW divided by the mean dressing percentage of 62.13%. Subsequent ADG and G:F calculated using carcass- 
adjusted final BW.
Table 2. A comparison of the distribution of quality grade and calculated yield grade between heifers 
implanted with two different strategies
Item
Treatment1
SEM P- ValueONE CH+
USDA Quality Grade, % - 0.06
Prime 8.40 5.79 0.90 0.06
Upper 2/3 Choice 47.81 41.79 1.56 0.02
Low Choice 35.37 39.15 1.21 0.05
Select 8.42 13.27 0.71 <0.01
USDA Yield Grade, % - 0.09
1 1.61 2.45 0.53 0.29
2 11.51 14.52 1.21 0.11
3 39.23 47.00 1.44 <0.01
4 38.48 29.11 2.38 <0.01
5 9.16 6.91 1.10 0.17
1ONE = Synovex One Feedlot on d 0; CH+ = Synovex Choice on d 0 and Synovex Plus on d 95.
78 · 2019 Nebraska Beef Cattle Report
can improve operational efficiency with 
minimal effect on performance.
Elizabeth A. Schumacher, graduate student
Galen E. Erickson, professor
D. J. Jordon, Cattlemens Nutrition Services
Robert J. Cooper, Cattlemens Nutrition 
Services
Tony L. Scott, Cattlemens Nutrition 
Services
Sheri Bundy, Cattlemens Nutrition Services
Gary Sides, Zoetis
Ralph M. Cleale, Zoetis
strategy, resulting in slightly poorer feed 
conversion. Treatments had similar carcass 
weights and 12th rib fat thickness, but 
heifers implanted with the ONE strategy 
showed higher marbling scores and yield 
grade with lower dressing percentage and 
smaller loin muscle area. Heifers implanted 
with the ONE strategy showed an improve-
ment in quality grade over heifers implant-
ed with the CH+ strategy but had a higher 
percent yield grade 4 than cattle implanted 
with the CH+ strategy. No differences were 
observed between treatments in morbid-
ity or mortality. These data suggest that 
utilizing Synovex ONE Feedlot in heifers 
strategy had greater (P < 0.01) percent YG4 
carcasses. Treatments were not different (P 
= 0.17) in percent YG5 carcasses but heifers 
implanted with the ONE strategy had 
numerically greater percent YG5 carcasses. 
No differences (P ≥ 0.38) were observed 
between treatments for percent morbidity 
or mortality.
Conclusion
When fed to the same number of days, 
heifers implanted with the ONE strategy 
had greater intake but similar final weight 
and gain to heifers implanted with the CH+ 


https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=2055&context=animalscinbcr

A Comparison of Synovex ONE® Alone to Synovex Choice® Followed by Synovex Plus® as Implant Strategies for Finishing Heifers

Abstract

Similar works

Full text

Available Versions

DigitalCommons@University of Nebraska

UNL | Libraries