Evaluation of ractopamine hydrochloride (Optaflexx) on growth performance and carcass characteristics of finishing steers across different feeding durations1

2017 ◽  
Vol 95 (1) ◽  
pp. 485-498 ◽  
Author(s):  
C. J. Bittner ◽  
M. A. Greenquist ◽  
D. B. Burken ◽  
A. L. Shreck ◽  
J. C. MacDonald ◽  
...  
Keyword(s):  
Growth Performance ◽  
Carcass Characteristics ◽  
Finishing Steers ◽  
Ractopamine Hydrochloride

Evaluation of ractopamine hydrochloride (Optaflexx) on growth performance and carcass characteristics of finishing steers across different feeding durations

2017 ◽  
Vol 95 (1) ◽  
pp. 485
Author(s):  
C. J. Bittner ◽  
M. A. Greenquist ◽  
D. B. Burken ◽  
A. L. Shreck ◽  
J. C. MacDonald ◽  
...  
Keyword(s):  
Growth Performance ◽  
Carcass Characteristics ◽  
Finishing Steers ◽  
Ractopamine Hydrochloride

Effects of ractopamine hydrochloride on growth performance, carcass characteristics, and physiological response to different handling techniques1,2

2017 ◽  
Vol 95 (5) ◽  
pp. 1977-1992 ◽  
Author(s):  
J. A. Hagenmaier ◽  
C. D. Reinhardt ◽  
M. J. Ritter ◽  
M. S. Calvo-Lorenzo ◽  
G. J. Vogel ◽  
...  
Keyword(s):  
Growth Performance ◽  
Physiological Response ◽  
Carcass Characteristics ◽  
Ractopamine Hydrochloride

scholarly journals Effect of metabolizable protein intake on growth performance, carcass characteristics, and feeding behavior in finishing steers

2019 ◽  
Vol 3 (4) ◽  
pp. 1173-1181
Author(s):  
Leonardo G Sitorski ◽  
Marc L Bauer ◽  
Kendall C Swanson
Keyword(s):  
Feeding Behavior ◽  
Growth Performance ◽  
Carcass Characteristics ◽  
Feed Ratio ◽  
Marbling Score ◽  
Quadratic Effect ◽  
Metabolizable Protein ◽  
Finishing Steers ◽  
Fat Thickness ◽  
Time Eating

Abstract One-hundred thirty-two finishing steers (300 ± 2.7 kg body weight [BW]) predominately of Angus, Simmental, and Shorthorn breeding were used to study the effect of metabolizable protein (MP) intake on growth performance, carcass characteristics, and feeding behavior. Steers were stratified by initial BW across five pens and randomly assigned to one of four dietary treatments to supply an average of 626, 906, 1,209, and 1,444 g MP/d (n = 33 per treatment). Feed intake and feeding behavior were measured using radio frequency identification tags and the Insentec feeding system. For feeding behavior, a visit was defined as each time the Insentec system detected a steer at the feed bunk. A meal was defined as eating periods by intervals no longer than 7 min. Steers were fed until they reached an average BW of 598 ± 3.1 kg. Average daily gain (ADG) responded quadratically (P < 0.01) with ADG increasing in steers fed 906 g MP/d and plateauing thereafter. Dry-matter intake (DMI; kg) responded quadratically (P = 0.009) with DMI increasing with MP intake up to 1,209 g/d MP and decreasing thereafter. Gain to feed ratio (G:F) increased linearly (P = 0.04) and tended (P = 0.10) to respond quadratically, as G:F increased up to 906 g MP/d and plateaued thereafter. A quadratic response (P = 0.04 and P = 0.02, respectively) was observed for marbling score and 12th rib subcutaneous fat thickness with steers fed 1,209 g MP/d having the greatest marbling score and back fat thickness. A quadratic effect for visits and meals per day was observed (P < 0.01) with steers fed the 1,209 g MP/d treatment having the least visits and meals per day. In addition, time eating per visit responded quadratically (P = 0.05) with time increasing from 626 to 906 g MP/d. There was a linear increase (P ≤ 0.02) in time eating per meal and per day with increasing MP intake. A quadratic effect (P < 0.03) was observed for DMI per visit, meal, and minute with steers fed 1,209 g MP/d having the greatest DMI. In summary, steers fed 626 g MP/d had increased visits and meals per day. However, DMI per visit, meal, and minute were greater in steers fed 1,209 g MP/d. A day × treatment interaction (P < 0.001) was observed for plasma urea N as concentrations increased to a greater extent over time in the higher MP treatments than in the lower MP treatments. These data indicate that MP supply (from deficient to excess) influences growth performance, carcass characteristics, and feeding behavior of finishing steers.

scholarly journals Effects of ractopamine hydrochloride supplementation on feeding behavior, growth performance, and carcass characteristics of finishing steers1,2

2019 ◽  
Vol 3 (4) ◽  
pp. 1143-1152
Author(s):  
Ronald J Trotta ◽  
Kasey R Maddock Carlin ◽  
Kendall C Swanson
Keyword(s):  
Feeding Behavior ◽  
Growth Performance ◽  
Treatment Period ◽  
Radio Frequency Identification ◽  
Animal Health ◽  
Average Daily Gain ◽  
Carcass Characteristics ◽  
Eating Time ◽  
Total Period ◽  
Ractopamine Hydrochloride

Abstract Ractopamine hydrochloride (RAC) is a β-adrenergic agonist that functions as a repartitioning agent to improve muscling in feedlot cattle. Many studies have investigated the effects of RAC on growth performance and carcass characteristics; however, there is minimal information about the influence of RAC on feeding behavior. Sixty-nine steers (body weight [BW] = 364 ± 3.9 kg) predominately of Angus and Simmental breeding were subjected to a 126-d (n = 46) or 154-d (n = 23) feeding period and randomly assigned to one of two treatment groups: supplementation to provide 0 (CON; n = 34) or 267 ± 4.9 mg/d of RAC (n = 35). Ractopamine was provided as Optaflexx 45 at 0.024% of the diet (dry matter [DM] basis; Elanco Animal Health, Greenfield, IN). Dietary treatments were fed the final 42 d in the feed yard (treatment period). Feeding behavior and growth performance were measured using radio frequency identification tags and the Insentec feeding system. Following the final day of treatment, steers were slaughtered and carcass measurements were recorded. Data were analyzed using MIXED models in SAS. There were no differences in BW, average daily gain (ADG), DM intake (DMI), gain:feed ratio (G:F), or feeding behavior during the pretreatment period (P > 0.44). Ractopamine supplementation increased G:F during the treatment period (P = 0.02) and during the total period (P = 0.03) and tended to increase ADG during the treatment and total period (P ≤ 0.08). DMI was not affected during the treatment or total period (P > 0.67). Eating time per visit, per meal, and per day were decreased (P < 0.02) in steers supplemented with RAC during the treatment period. DMI per minute was increased (P = 0.02) in steers supplemented with RAC. Hot carcass weight, dressing percentage, and 12th rib fat were not influenced by RAC supplementation. Ractopamine supplementation decreased marbling (P = 0.008) and kidney, pelvic, and heart percentage (P = 0.04) and increased longissimus muscle area (P = 0.01). These data demonstrate that RAC supplementation for 42 d improves feed efficiency, increases the rate of DMI without altering DMI, and increases muscling in finishing cattle.

Effect of duration of restricted-feeding on nutrient excretion, animal performance, and carcass characteristics of Holstein × Zebu finishing steers

2020 ◽  
Vol 60 (4) ◽  
pp. 535
Author(s):  
F. A. S. Silva ◽  
S. C. Valadares Filho ◽  
L. A. Godoi ◽  
B. C. Silva ◽  
M. V. C. Pacheco ◽  
...  
Keyword(s):  
Growth Performance ◽  
Carcass Characteristics ◽  
Management Tool ◽  
Whole Body ◽  
Feed Ratio ◽  
Restricted Feeding ◽  
Period 2 ◽  
Finishing Steers ◽  
Ad Libitum ◽  
Ad Libitum Intake

Restricted-feeding may be a useful management tool available to reduce environmental impact in feedlots. Therefore, the objectives of the present study were to determine the effects of the duration of restricted-feeding on nitrogen (N) and phosphorus (P) excretion, growth performance and carcass characteristics of finishing steers. Twenty-five Holstein × Zebu steers (average initial bodyweight (BW) = 319 ± 16.2 kg; age = 19 ± 1 months) were used. Five steers were slaughtered to provide baseline empty BW (EBW) and empty body composition at Day 0. The remaining steers were randomly allotted to four groups of five steers, which were restricted to 85% ad libitum feed intake for either 0 (R0), 28 (R28), 42 (R42) or 84 (R84) days of an 84-day finishing period. All steers were fed a diet of 40% corn silage and 60% concentrate (DM basis) for 84 days. Total excretion of faeces and urine were collected during two periods: Days 25 to 27 (period 1) and Days 73 to 75 (period 2). The DM intake, average daily gain (ADG) and gain-to-feed ratio (G:F) were evaluated in three blocks, Days 0 to 28, Days 28 to 42 and Days 42 to 84. As expected, DM, N and P intakes were greater (P < 0.05) for R0 steers than R28, R42 and R84 steers when steers in R28, R42 and R84 treatments were restricted. When transitioned to ad libitum feeding, R28 and R42 steers had similar (P > 0.05) DM, N and P intakes compared with R0 steers. Faecal N and urinary P excretions did not differ (P ≥ 0.40) among restricted and ad libitum-fed steers in either period evaluated. However, greater (P < 0.05) faecal P excretions were observed in steers fed ad libitum intake in period 2 (R0). Phosphorus retention in period 2, and whole-body N retention were greatest (P < 0.05) in steers fed R28 and least (P < 0.05) in steers fed R84, steers fed R0 and steers fed R42 were intermediate and not different (P > 0.05). Final BW, overall ADG, G:F and carcass characteristics were not affected (P ≥ 0.11) by treatments. Restricted-feeding Holstein × Zebu steers to 85% of ad libitum intake for 84 days in the feedlot reduced DM intake and P excretion, without impairing steer growth performance or carcass characteristics. Nevertheless, it is important to highlight that the small sample size was one limitation of this present experiment.

Effects of ractopamine hydrochloride on growth performance, carcass characteristics, and physiological response to different handling techniques

2017 ◽  
Vol 95 (5) ◽  
pp. 1977 ◽  
Author(s):  
J. A. Hagenmaier ◽  
C. D. Reinhardt ◽  
M. J. Ritter ◽  
M. S. Calvo-Lorenzo ◽  
G. J. Vogel ◽  
...  
Keyword(s):  
Growth Performance ◽  
Physiological Response ◽  
Carcass Characteristics ◽  
Ractopamine Hydrochloride
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