Source and feeding level of nitrogen on growth and carcass characteristics of beef steers fed grass as hay or silage1

Abstract Four hundred and thirty-two beef steers (346.3 ± 63.7 kg BW) were used to determine the effects of Zn source on feedlot cattle fed ractopamine hydrochloride. Cattle were blocked in groups of 54 by BW and housed in 48 pens containing 9 steers per pen. Pens within a weight block were randomly assigned to treatments in a 2 x 3 factorial arrangement, with factors being: 1) 0 or 30.1 mg of ractopamine HCl/kg DM fed during the final 29 days on feed; and 2) Zn source: 90 mg of supplemental Zn/kg DM from ZnSO4; Zn sulfate (67%) + Zn methionine (33%); and Zn from Zn hydroxychloride, fed through the entire feeding period. Cattle were fed a high concentrate finishing diet for 154 d and slaughtered at a commercial abattoir. Average daily gain, DMI, feed efficiency and carcass characteristics were determined after slaughter. Zinc source had no impact on live animal performance. Cattle fed ractopamine HCl had greater (P < 0.01) final BW, greater (P < 0.001) ADG, improved (P < 0.001) G:F, heavier (P < 0.01) HCW, and larger (P < 0.05) longissimus muscle compared to non-ractopamine supplemented steers. There was a Zn source by ractopamine interaction (P < 0.01) for dressing percentage. Cattle receiving ractopamine HCl with Zn hydroxychloride had a greater dressing percentage (P < 0.05) when compared to ractopamine HCl cattle fed other Zn sources. Cattle receiving ractopamine HCl with Zn sulfate had a lesser dressing percentage (P < 0.05) when compared to ractopamine HCl cattle fed other Zn sources. Additional Zn source by ractopamine HCl interactions were not significant. These data indicate that Zn source has minimal impacts on feedlot steer performance and carcass characteristics when supplemented to cattle receiving 0.0 or 30.1 mg of ractopamine HCl/kg DM.

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Effects of voluntary removal of ractopamine hydrochloride (Optaflexx) on live performance and carcass characteristics of beef steers

Translational Animal Science ◽

10.1093/tas/txab047 ◽

2021 ◽

Author(s):

P J Rincker ◽

J B Allen ◽

M Edmonds ◽

M S Brown ◽

J C Kube

Keyword(s):

Dry Matter ◽

Carcass Characteristics ◽

Carcass Weight ◽

Dry Matter Intake ◽

Beef Steers ◽

Live Performance ◽

Meet Residue ◽

Ractopamine Hydrochloride ◽

The Impact ◽

Linear Manner

Abstract There is a lack of consistency across the globe in how countries establish tissue ractopamine residue limits and which residue limits are applied to various tissues, particularly for edible noncarcass tissues. Therefore, some US beef slaughter organizations have recommended a 48-h voluntary removal of ractopamine before slaughter in order to meet residue requirements of specific export countries and maintain international trade. Our objective was to assess the impact of voluntary removal of ractopamine hydrochloride (Optaflexx®; Elanco, Greenfield, IN) up to 8 d before slaughter on growth performance and carcass characteristics. Crossbred beef steers (60 pens of 10 animals/pen) with an initial shrunk body weight (BW) of 611.8 ± 10 kg SEM were fed one of six treatments over 42 d. Treatments included a control that did not receive ractopamine, on-label use of ractopamine (0-d withdrawal), and 2, 4, 6, or 8 d of voluntary removal of ractopamine from feed before slaughter. The start of ractopamine feeding (30.1 mg/kg of diet dry matter for 32 d) was staggered so that blocks could be slaughtered on the same day. Dry matter intake was decreased by 0.5 kg/d when ractopamine was fed with a 0-d withdrawal (P = 0.04) compared to the control, but was not altered (P = 0.56) as the duration of ractopamine removal increased from 0 to 8 d. Final BW, total BW gain, and average daily BW gain were increased by feeding ractopamine with a 0-d withdrawal (P = 0.09) compared to the control, but these variables decreased in a linear manner (P = 0.10) as the duration of removal increased from 0 to 8 d. Gain efficiency was improved by 15% (P < 0.01) by feeding ractopamine with a 0-d withdrawal compared to the control, and gain efficiency decreased linearly (P = 0.06) as the duration of ractopamine removal increased. Approximately 2/3 of the increase in gain efficiency remained after 8 d of removal. Hot carcass weight was increased by 6 kg (P = 0.02) by feeding ractopamine with a 0-d withdrawal compared to the control. Measured carcass characteristics were not altered by ractopamine feeding or by removal before slaughter (P ≥ 0.24). The consequences of voluntary removal of ractopamine up to 8 d before slaughter were a linear decrease in live BW gain (0.64 kg/d), poorer gain efficiency, and numerically lighter carcass weight.

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357 Two-year study: Effect of backgrounding system on growing and finishing performance and carcass characteristics of beef steers

Journal of Animal Science ◽

10.2527/asasmw.2017.357 ◽

2017 ◽

Vol 95 (suppl_2) ◽

pp. 174-174

Author(s):

J. L. Cox ◽

K. Hales ◽

K. M. Ulmer ◽

R. J. Rasby ◽

S. D. Shackelford ◽

...

Keyword(s):

Carcass Characteristics ◽

Beef Steers

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Effect of encapsulated conjugated linoleic acid isomers on carcass composition of beef steers

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200021402 ◽

2007 ◽

Vol 2007 ◽

pp. 237-237

Author(s):

R.I. Richardson ◽

A.J. Fisher ◽

J.D. Wood ◽

K.J. Shingfield

Keyword(s):

Milk Fat ◽

Methyl Esters ◽

Carcass Characteristics ◽

Carcass Composition ◽

Beef Steers ◽

Early Lactation ◽

Current Experiment ◽

Energy Status ◽

Cla Isomers ◽

Fat Synthesis

Dietary supplements of a mixture of CLA isomers have been shown to reduce body fat accretion in mice and pigs with the trans-10, cis-12 isomer probably being responsible for the anti-lipogenic effects. The efficacy of calcium salts of a mixture of CLA methyl esters containing trans-10, cis-12, on milk fat synthesis, is relatively low (Bernal-Santos et al., 2003) and reported lack of effects on growth may be due to low efficacy and the short duration of CLA supplementation, during the last 32 or 60 days before slaughter, and the relatively low level of trans-10, cis-12 CLA fed. Shingfield et al (2004) demonstrated the potential of rumen protected supplements of a mixture of CLA isomers to reduce milk fat content and improve the energy status of dairy cows during early lactation. The current experiment used a lipid-encapsulated supplement containing equal amounts of cis-9, trans-11 and trans-10, cis-12 CLA methyl esters to study the effects on the performance and carcass characteristics of Limousin steers during a 100d finishing period.

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224 Impact of bunk management strategy on animal performance, carcass characteristics, and hydrogen sulfide gas concentrations in steers fed modified distillers grains with solubles

Journal of Animal Science ◽

10.1093/jas/skz122.231 ◽

2019 ◽

Vol 97 (Supplement_2) ◽

pp. 130-131

Author(s):

Leslie Lekatz ◽

Bryan Neville

Keyword(s):

Hydrogen Sulfide ◽

Carcass Characteristics ◽

Distillers Grains ◽

Beef Steers ◽

Adaptation Period ◽

Animal Performance ◽

Entire Study ◽

Distillers Grains With Solubles ◽

Carcass Characteristic ◽

Treatment Interaction

Abstract The objective of this study was to evaluate the impacts of bunk management on animal performance, carcass characteristic, and hydrogen sulfide gas concentrations in beef steers fed modified distillers grains with solubles (MDGS; DM basis). One hundred and thirty-nine steers (initial BW = 240 ± 5.17 kg) were allocated into 16 pens and assigned to one of two treatments: 1) Control-managed bunks: bunks devoid of feed prior to feeding; and 2) Long-managed bunks: bunks with approximately 2.54cm of feed remaining at the time feeding. Treatments were applied during a 28-d adaptation period, during which time, steers were adapted to a common finishing ration containing 25% MDGS (DM basis). Ruminal hydrogen sulfide gas was collected by rumenocentesis from two steers from each of three pens per treatment on d 0, 7, 14, and 28, which correspond to days of diet transition. Animal performance data were collected throughout the study and carcass characteristic data were collected when steers reached market weight. There were no differences (P < 0.13) in BW, ADG, or F:G between treatments during the adaptation period or throughout the entire study. Steers managed with long bunks had greater (P = 0.001) intake during adaptation; however, overall DMI was not different (P = 0.14) between treatments. Hydrogen sulfide gas concentrations were not affected by the day x treatment interaction (P = 0.30) but were affected by day (P = 0.003) with hydrogen sulfide concentrations increasing throughout adaptation. Hydrogen sulfide concentrations tended (P = 0.07) to be greater in steers with long-managed bunks vs. control-managed bunks. There were no differences (P > 0.53) in carcass characteristics. In summary, bunk management had no effect on performance or carcass characteristics and only tended to impact hydrogen sulfide gas concentrations.

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337 Effect of adding urea to finishing diets containing two different inclusions of distillers grains on steer performance and carcass characteristics

Journal of Animal Science ◽

10.1093/jas/skz122.239 ◽

2019 ◽

Vol 97 (Supplement_2) ◽

pp. 134-135

Author(s):

Bradley M Boyd ◽

James C MacDonald ◽

Matthew Luebbe ◽

Galen E Erickson

Keyword(s):

Fixed Effects ◽

Dry Matter ◽

Carcass Characteristics ◽

Distillers Grains ◽

Beef Steers ◽

Performance Measurements ◽

Minimal Impact ◽

Wet Distillers Grains ◽

Improved Performance ◽

Urea Inclusion

Abstract Crossbred beef steers (n = 384) were utilized to evaluate the effects of adding urea to a dry rolled corn based finishing diet containing low inclusions of wet distillers grains plus solubles (WDGS). Treatments were set up as a 2 × 4 factorial arrangement with factors consisting of WDGS inclusion at either 12 or 20% of diet dry matter (DM) and urea inclusion at either 0, 0.4, 0.8, 1.2% of diet DM. Cattle were blocked and stratified by initial body weight (BW) and assigned randomly to treatment. The heavy block of cattle were harvested after 160 d on feed (DOF) and the middle and light blocks of cattle were harvested after 179 DOF. The model include the fixed effects of weight block, WDGS inclusion, urea inclusion, and their interactions. There were no significant interactions (P > 0.12) observed between WDGS inclusion and urea inclusion in the diet; therefore, only main effects are discussed. Increasing inclusion of WDGS improved (P < 0.04) carcass adjusted ADG and G:F. Dry matter intake was reduced (P = 0.04) with increasing WDGS inclusions. Fat thickness was increased (P = 0.04) with increased WDGS inclusion; however, no other carcass characteristics were significantly affected by WDGS inclusion. Cubic effects of urea inclusion were observed (P < 0.05) for HCW, final BW, ADG, and DMI on a carcass adjusted and live BW basis; however, cubic effects with increasing urea inclusion are of minimal biological relevance. There were no linear or quadratic responses (P > 0.11) for increasing urea inclusion in the diet for performance measurements or carcass characteristics. Increasing WDGS inclusion in the diet improved performance. Added urea in the diet had minimal impact on performance, regardless of wet distillers grains plus solubles inclusion.

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Feedlot Performance and Carcass Characteristics of Beef Steers Grown and Finished under Different Nutrition and Management Programs

Journal of Animal Science ◽

10.2527/jas1982.5461115x ◽

1982 ◽

Vol 54 (6) ◽

pp. 1115-1119 ◽

Cited By ~ 11

Author(s):

K. W. Ridenour ◽

H. E. Kiesling ◽

G. P. Lofgreen ◽

D. M. Stiffler

Keyword(s):

Carcass Characteristics ◽

Beef Steers ◽

Feedlot Performance

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A COMPARISON OF THE METHOD OF ADMINISTRATION OF STILBESTROL ON GROWTH AND CARCASS CHARACTERISTICS OF BEEF STEERS

Journal of Animal Science ◽

10.1093/ansci/16.3.662 ◽

1957 ◽

Vol 16 (3) ◽

pp. 662-670 ◽

Cited By ~ 6

Author(s):

M. T. Clegg ◽

F. D. Carroll

Keyword(s):

Carcass Characteristics ◽

Beef Steers

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Effects of fibrolytic enzymes in corn or barley diets on performance and carcass characteristics of feedlot cattle

Canadian Journal of Animal Science ◽

10.4141/a97-050 ◽

1997 ◽

Vol 77 (4) ◽

pp. 645-653 ◽

Cited By ~ 50

Author(s):

K. A. Beauchemin ◽

S. D. M. Jones ◽

L. M. Rode ◽

V. J. H. Sewalt

Keyword(s):

Dry Matter ◽

Xylanase Activity ◽

Carcass Characteristics ◽

Feedlot Cattle ◽

Feed Additives ◽

Average Weight ◽

Beef Steers ◽

Feed Conversion ◽

Enzyme Preparations ◽

Fibrolytic Enzymes

A study was conducted to establish whether fibrolytic enzyme feed additives influence performance of feedlot cattle fed high grain diets, and to compare the effects of feeding diets of barley or corn on performance and carcass characteristics. Crossbred beef steers (408 kg) were offered high concentrate diets (95.1%, dry matter basis), consisting mainly of barley and barley silage or corn and corn silage. Concentrates were treated with either no enzyme or one of two enzyme mixtures. Calves were slaughtered after a 103- to 145-d feeding period at an average weight of 570 kg and 10.8 mm of backfat. Barley-fed calves grew faster (1.45 vs. 1.29 kg d−1), ate more dry matter (DM; 9.79 vs. 9.31 kg d−1), and converted DM to gain (6.85 vs. 7.35 kg DM kg−1gain) more efficiently compared with corn-fed calves (P < 0.001). Meat from barley-fed calves tended to be more highly marbled and was brighter in colour than meat from corn-fed calves, but diet had no effect on muscle score, rib eye area, or carcass leanness. Effect of enzymes differed for corn and barley diets; Enzyme 1, a preparation with higher xylanase activity than Enzyme 2, improved (P < 0.05) feed conversion ratio of barley diets by 11% over the finishing period, but enzyme treatments had no such effect for corn diets. Fibrolytic enzymes can be used to improve the digestibility of barley-based diets, but are not advantageous for corn diets. Further work is necessary to determine optimum formulation and level of application of enzyme preparations for use in barley diets. Further study of the differences in carcass characteristics of cattle fed barley or corn diets is warranted to substantiate the trends observed on this limited group of animals. Key words: Feedlot cattle, barley, corn, enzymes, cellulase, xylanase

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