Use of a β-Agonist to Alter Fat and Muscle Deposition in Steers1

Ricks, Catherine A.; Dalrymple, R. H.; Baker, P.K.; Ingle, D. L.

doi:10.2527/jas1984.5951247x

Cited by 275 publications

(127 citation statements)

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“…These effects were subsequently confirmed in swine (Ricks et al 1984a), steers (Ricks et al 1984b) and lambs (Baker et al 1984) and have since undergone intense scrutiny and experimental testing by the swine industry (Anderson et al 1987; Bergen et al Hancock et al 1987; Merkel et al 1987; Veenhuizen et al 1987; Watkins et al 1989).…”

Section: T6mentioning

confidence: 91%

The effect of feeding the beta-adrenergic agonist ractopamine on the behaviour of market-weight pigs

Schaefer¹,

Jones²,

Tong³

et al. 1992

Can. J. Anim. Sci.

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. The effect of feeding the beta-adrenergic agonist ractopamine on the behaviour of market-weight pigs. Can. J. Anim. Sci. 72: [15][16][17][18][19][20][21]. A total of 86 ad libitum fed Lacombe bred barrows and gilts weighing on average 90 kg were used to determine the effect of feeding ractopamine on anirnal behaviour. Four treatment groups consisted of a control (N : 22) and three levels of ractopamine (10 ppm (N : 15), 15 ppm (N : 24) and 20 ppm (N --25) in the diet). The pigs received the ractopamine treatments for 5-6 wk prior to behavioural observations. There was little effect of ractopamine on behaviour. The ractopamine-fed pigs were observed to lie down in a group more frequently (P : 0'06) and to walk around their pen less frequently (P : 0.01). No abnormal, stereotyped, agonistic or aggressive behaviour was induced by the ractopamine. The data from the present study suggest that ractopamine, added to the diet ofmarket-weight pigs at levels reported, does not cause marked changes in behaviour. (Jones , 1987.Clearly, reducing fat and increasing lean seem Can. J. Anim. (Mar. 1992) desirable in order to provide a leaner pork product as currently demanded by today's consumer (Wood 1987 Ethograms used in the current study were based on those proposed by Jensen (1980Jensen ( , 1982 and McGlone (1985)

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Section: T6mentioning

confidence: 91%

The effect of feeding the beta-adrenergic agonist ractopamine on the behaviour of market-weight pigs

Schaefer¹,

Jones²,

Tong³

et al. 1992

Can. J. Anim. Sci.

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“…Two major approaches may be proposed for enhancement of lipolysis. First, it should be possible to stimulate directly fat cell f-adrenoceptors with fi-adrenoceptor agonists (Ricks et al, 1984). The use of a non-specific fi-adrenoceptor agonist (e.g.…”

Section: Introductionmentioning

confidence: 99%

Lipomobilizing effects of procaterol and yohimbine in the conscious dog: comparison of endocrinological, metabolic and cardiovascular effects

Valet¹,

Taouis²,

Tran³

et al. 1989

British J Pharmacology

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provoked an equivalent increase in plasma non-esterified fatty acids (+ 100%). Procaterol, but not yohimbine, induced hyperglycaemia (+ 120%). Plasma insulin was weakly enhanced by yohimbine (+ 120%) as compared to the increase given by procaterol (+ 500%). 4 Both drugs stimulated sympathetic nervous system activity, as indicated by the increased plasma noradrenaline concentration, but only yohimbine increased the plasma adrenaline level. 5 Cardiovascular measurements indicated that procaterol strongly enhances heart rate and transiently decreases mean blood pressure. Yohimbine exhibits a weaker effect on heart rate and slightly increases mean blood pressure. 6 The present work clearly indicates that lipid mobilization is enhanced during fasting in the dog by selective fl2-adrenoceptor stimulation or by Cc2-adrenoceptor blockade. This enhanced lipolytic effect may result either from a direct action of the drugs on the adrenoceptors of fat cells or from an activation of the sympathetic nervous system. Procaterol suffers major limitations since it strongly increases heart rate, immunoreactive insulin and glycaemia. On the other hand, yohimbine induces only minor modifications both in cardiovascular and endocrinological parameters.

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“…Ractopamine (RAC) is a ß-adrenergic agonist (ß-agonist) which at repartitioning doses has been found to increase muscle growth and decrease fat deposition in different animal species (Baker et al, 1984;Mersmann, 1998;Mills and Spurlock, 2003;Ricks et al, 1984;Sillence, 2004;Watkins et al, 1990). In pigs and cattle treated during the final period of the finishing improved feed efficiency, heavier carcass weights, and higher dressing percentages have been documented (Gu et al, 1991a,b; Laudert et al, 2005a,b; Poletto et al, 2009;See et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Physiopathological changes related to the use of ractopamine in swine: Clinical and pathological investigations

Catalano¹,

Odore²,

Amedeo³

et al. 2012

Livestock Science

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The aim of the study was to investigate clinical and pathological modifications induced by treatment with different doses of the β2-agonist ractopamine (RAC) in pigs. Thirty-two eight-month-old LandracexLarge White pigs (mean weight, 102.8 ±6.7 kg) were treated with 0, 10 (R10), 20 (R20) and 40 (R40) mg/kg/diet of RAC for the last 35 days before slaughtering. Before and after treatment body weight was recorded, blood samples were collected for complete blood count and thyroid hormone concentration analysis, and cardiac instrumental evaluation was performed. At slaughtering, tissue samples were collected for histopathological examination. None of the animals showed any signs of clinical disease during the study period. Treatment did not induce any statistically significant difference in complete blood counts (P>0.05) among groups.A significant (Pb0.05) decrease in feed consumption was observed between R10 and R40 treated animals. A significant (Pb0.01) increase in ventricular internal dimensions and left ventricular mass was observed in R20; a significant reduction in thyroid weight (Pb0.05) was observed in the animals receiving the highest-dose treatment (R40). Urethral hyperplasia and metaplasia, and prostate hyperplasia and a significant (Pb0.05) reduction in circulating triiodothyronine levels were found in overall treated animals. Taken together, these data suggest that RAC treatment in pigs induces adaptative non-neoplastic urethral and prostatic disorders of growth and a reduction in thyroid hormone concentrations. Nevertheless, additional research on a larger group of animals is needed to define the biomolecular mechanisms underlying the observed lesions, in order to improve the surveillance tools to identify illegal treatments. IntroductionRactopamine (RAC) is a ß-adrenergic agonist (ß-agonist) which at repartitioning doses has been found to increase muscle growth and decrease fat deposition in different animal species (Baker et al., 1984;Mersmann, 1998;Mills and Spurlock, 2003;Ricks et al., 1984;Sillence, 2004;Watkins et al., 1990). In pigs and cattle treated during the final period of the finishing improved feed efficiency, heavier carcass weights, and higher dressing percentages have been documented (Gu et al., 1991a,b; Laudert et al., 2005a,b; Poletto et al., 2009;See et al., 2004).The dosage required to induce "anabolic" effects is generally 10-20 times higher than that indicated for therapeutic purposes. At elevated doses, certain β2-agonists such as clenbuterol can cause morphological, histological and/or biochemical changes in various organs of exposed animals (Biolatti et al., 1994;Sillence et al., 1993). In vivo, β-adrenergic agonists may induce secondary events caused by hormonal or physiological responses of several tissues, involving especially endocrine and cardio-respiratory organs.In pigs, treatment during the finishing with repartitioning doses of β-agonists has been associated with modifications of vascular microcirculation characterized by ulcerative lesions of the distal extremities...

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Use of a β-Agonist to Alter Fat and Muscle Deposition in Steers1

Cited by 275 publications

References 0 publications

The effect of feeding the beta-adrenergic agonist ractopamine on the behaviour of market-weight pigs

The effect of feeding the beta-adrenergic agonist ractopamine on the behaviour of market-weight pigs

Lipomobilizing effects of procaterol and yohimbine in the conscious dog: comparison of endocrinological, metabolic and cardiovascular effects

Physiopathological changes related to the use of ractopamine in swine: Clinical and pathological investigations

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