scholarly journals Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs1

2017 ◽  
Vol 1 (4) ◽  
pp. 533-558 ◽  
Author(s):  
M. J. Ritter ◽  
A. K. Johnson ◽  
M. E. Benjamin ◽  
S. N. Carr ◽  
M. Ellis ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Feed Efficiency ◽  
Early Research ◽  
Adrenergic Agonist ◽  
Dosage Range ◽  
Welfare Indicators ◽  
Trade Name ◽  
Stress Responsiveness ◽  
Ractopamine Hydrochloride ◽  
The U.S

Abstract This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a β-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed.

scholarly journals 401 Effect of zinc source and ractopamine hydrochloride on the growth performance and carcass characteristics of steers fed in confinement to harvest

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 160-160
Author(s):  
John Wagner ◽  
William T Nelson ◽  
Terry Engle ◽  
Jerry Spears ◽  
Jeff Heldt ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Average Daily Gain ◽  
Carcass Characteristics ◽  
Feedlot Cattle ◽  
Beef Steers ◽  
Live Animal ◽  
Zinc Source ◽  
Dressing Percentage ◽  
Ractopamine Hydrochloride ◽  
Daily Gain

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.

What Drug Are You Prescribing?

PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 636-637
Author(s):  
Harold Jacobziner
Keyword(s):  
Trade Name ◽  
Food And Drugs Administration ◽  
The U.S

There is at present much interest over the new regulations of the U.S. Food and Drugs Administration, requiring that the generic names shall accompany the trade name of drugs in advertisements and trade literature. This raises the question as to whether the same parallel requirement might not be imposed by editors in papers concerned with drugs. Often only the generic name appears in the title, especially if the article deals with some unfavorable aspect of the drug.

scholarly journals Effects of various ractopamine hydrochloride withdrawal periods on performance, health, and carcass characteristics in yearling steers

2019 ◽  
Vol 4 (1) ◽  
pp. 67-74
Author(s):  
Tony C Bryant ◽  
Josh I Szasz ◽  
Lois F G Pringle ◽  
Eddie Crispe ◽  
K Shawn Blood ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Dry Matter ◽  
Block Design ◽  
Average Daily Gain ◽  
Carcass Characteristics ◽  
Average Dose ◽  
Withdrawal Period ◽  
Feedlot Performance ◽  
Dressing Percentage ◽  
Ractopamine Hydrochloride

Abstract Ractopamine hydrochloride (RAC) is a β-adrenergic agonist approved for feeding during the last 28 to 42 d prior to cattle slaughter to improve feedlot performance and carcass characteristics. Three thousand crossbred yearling steers (527 ± 2.4 kg; AVG ± SD) were used in two periods to evaluate the effects of various RAC withdrawal times on feedlot performance, health, and carcass characteristics. In Period 1, 6 blocks of 30 pens totaling 1,500 steers were utilized, which was repeated for Period 2. In a randomized complete block design, cattle were assigned to 1 of 5 treatments consisting of 1) No RAC fed (CON), 2) 12-h RAC withdrawal (12-hRAC), 3) 2-d RAC withdrawal (2-dRAC), 4) 4-d RAC withdrawal (4-dRAC), and 5) 7-d RAC withdrawal (7-dRAC). Cattle were fed for a total of 62 d, and applicable treatments were supplemented with 30.0 ppm (dry matter basis) of RAC (average dose = 322 mg per steer per day) for 33 d at the end of the feeding period, corresponding to their respective withdrawal times. Initial body weight (BW) displayed a quadratic curve, with 2-dRAC and 4-dRAC withdrawal periods having the greatest BW. Accordingly, dry matter intake (DMI) responded quadratically (P = 0.034), with 2-dRAC and 4-dRAC treatments demonstrating the greatest DMI. No significant treatment differences (P ≥ 0.641) were observed in final live BW, average daily gain (ADG), or feed efficiency. Alternatively, when using a common dressing percentage to calculate live BW, cattle on RAC treatments exhibited 7.6 kg additional live BW (P < 0.001) compared to CON cattle. Furthermore, carcass-adjusted ADG and feed efficiency did not differ (P > 0.10) between RAC treatments but were improved compared to the CON treatment (P ≤ 0.002). Hot carcass weight (HCW) was on average 4.9 kg greater (P < 0.001) for RAC treatments vs. CON, and no differences were detected (P > 0.10) among RAC treatments. Within RAC treatments, carcass cutability responded quadratically (P ≤ 0.005) to withdrawal period, with the 2-dRAC and 4-dRAC treatments containing more Yield Grade 4 and 5 and fewer Yield Grade 1 and 2 carcasses than the other RAC treatments. On the basis of the results of this experiment, feeding RAC improves dressing percentage, HCW, and carcass-adjusted BW, ADG, and feed efficiency. Furthermore, extending the RAC withdrawal period to 7 d does not have a significant impact on cattle performance or health and has minimal effects on carcass characteristics.

Effects of a beta-adrenergic agonist (L-644,969) on performance and carcass traits of growing lambs in a cold environment

2000 ◽  
Vol 80 (3) ◽  
pp. 459-465 ◽  
Author(s):  
Y. Z. Li ◽  
R. J. Christopherson ◽  
B. T. Li ◽  
J. A. Moibi
Keyword(s):  
Nitrogen Balance ◽  
Feed Efficiency ◽  
Control Diet ◽  
Carcass Traits ◽  
Beta Agonist ◽  
Cold Environment ◽  
Adrenergic Agonist ◽  
Muscle Weight ◽  
Beta Adrenergic ◽  
Beta Adrenergic Agonist

A 2 × 2 factorial experiment was conducted to study the effects of the beta-adrenergic agonist L-644,969 (BAA, supplied at 0.28 vs. 0 mg kg−0.75 d−1) on growth performance, carcass traits and nitrogen balance of lambs at two environmental temperatures (0°C vs. 20 °C). Sixteen Suffolk-Cross wether lambs (30.2 ± 2.06 kg BW) were randomly divided into four groups and exposed to each of four experimental treatments (20 °C with control diet; 20 °C with BAA-supplemented diet; 0 °C with control diet; and 0 °C with BAA-supplemented diet) for 5 wk. The collection period for nitrogen balance was 4 d during the 4th week of treatment. The low temperature decreased efficiency of feed utilization and increased backfat thickness by 20.8% (P < 0.01) and 35.1% (P < 0.05), respectively. L-644,969, on the other hand, increased daily gain, feed efficiency and hot carcass weight by 22.5% (P < 0.05), 17.2% (P < 0.05) and 9.6% (P < 0.05,) respectively. Dressing percentage (P < 0.01), biceps femoris weight (P < 0.01) and rib eye area (P < 0.01) were also increased, but abdominal fat expressed as a percentage of liveweight (P < 0.05) was significantly decreased by BAA treatment. The improved weight gain, muscle weight and ribeye area in response to BAA, and in the absence of an increase in total nitrogen retention, indicate that the responses are due to nutrient repartitioning. Temperature did not impair the nutrient repartitioning effect of BAA, but feed efficiency may be more improved by BAA for the animals in the cold environment. Key words: Performance, carcass traits, beta-agonist, temperature, lambs

scholarly journals Effects of differing withdrawal times from ractopamine hydrochloride on residue concentrations of beef muscle, adipose tissue, rendered tallow, and large intestine

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242673
Author(s):  
Haley E. Davis ◽  
Ifigenia Geornaras ◽  
Valerie Lindstrom ◽  
Jacqueline M. Chaparro ◽  
Mahesh N. Nair ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Large Intestine ◽  
Limit Of Detection ◽  
Zero Tolerance ◽  
Beta Agonist ◽  
Target Tissue ◽  
Management Protocol ◽  
Limit Of Quantitation ◽  
Ractopamine Hydrochloride ◽  
The U.S

Ractopamine hydrochloride (RAC) is a beta-agonist approved by the U.S. Food and Drug Administration (FDA) as a medicated feed ingredient for cattle during the final days of finishing to improve feed efficiency and growth. Maximum residue limits and U.S. FDA residue tolerances for target tissues have defined management practices around RAC usage in the U.S. However, many countries have adopted zero tolerance policies and testing of off-target tissues, presenting a major challenge for international export. Therefore, the objective this study was to determine the necessary withdrawal time among cattle group-fed RAC to achieve residue concentrations below tolerance levels in muscle and off-target tissues. Specifically, both total and parent RAC residues were quantified in muscle, adipose tissue, rendered tallow, and large intestines from animals group-fed RAC and subjected to withdrawal 2, 4, or 7 days before harvest. Ractopamine (parent and total) residues were below the assay limit of detection (< 0.12 ng/g) in all muscle and adipose tissue samples from animals in control groups (no RAC). However, RAC residues were detectable, but below the limit of quantitation, in 40% of tallow and 17% of large intestine samples from control animals. As expected, mean RAC residue concentrations in muscle, adipose tissue, and large intestine samples decreased (P < 0.05) as the RAC withdrawal duration (days) was extended. Irrespective of RAC withdrawal duration, mean parent RAC residue concentrations in muscle, adipose tissue, and large intestine ranged from 0.33 to 0.76 ng/g, 0.16 to 0.26 ng/g, 3.97 to 7.44 ng/g, respectively and all tallow samples were > 0.14 ng/g (detectable but below the limit of quantitation). Results of this study provide a baseline for the development of management protocol recommendations associated with withdrawal following group-feeding of RAC to beef cattle in countries that allow RAC use and intend to export to global markets which may be subject to zero tolerance policies and off-target tissue testing.

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