Effect of Ractopamine on the Optimum Dietary Phosphorus Regimen for Pigs

dc.contributor.author Lutz, T.
dc.contributor.author Stahly, T.
dc.date 2018-02-13T00:03:30.000
dc.date.accessioned 2020-07-02T07:01:28Z
dc.date.available 2020-07-02T07:01:28Z
dc.date.copyright Wed Jan 01 00:00:00 UTC 2003
dc.date.embargo 2012-08-14
dc.date.issued 2003-01-01
dc.description.abstract <p>Ten replications of individually penned gilts from a high-lean strain were used to determine the effect of ractopamine (RAC) on the optimum dietary available phosphorus (AP) regimen. At 70 kg body weight, pigs were randomly allotted to a corn-soybean meal basal diet (.08% AP) adequate in all nutrients except AP. The basal diet was supplemented with mono-dicalcium phosphate to create six AP concentrations (.08, .13, .18, .23, .28, .33%) and ractopamine HCl to create two RAC concentrations (0 and 20 ppm). A constant Ca/AP ratio of 2.5:1 was maintained in each diet. BW gain and feed intake were recorded weekly for 5 weeks, and total urine output was collected via urinary catheter the last 2 days of each 7-day period. After this 5-week collection period pigs remained on their diets until they achieved a body weight of 114 kg and were then slaughtered keeping the ham and loin for subsequent dissection and bone removal.</p> <p>In pigs growing from 70 to 114 kg BW dietary AP additions resulted in improved (P<.01) daily BW gain, but did not alter carcass or ham-loin muscle content. Dietary AP additions also linearly improved (P<.01) bone integrity as observed by ham-loin bone content and femur and fifth vertebra weight and mineral content. RAC improved (P<.01) BW gain (+125 g), gain/feed ratio (+64 g/kg), and carcass and ham-loin muscle (+3.4%, +5.6% ) content. RAC reduced (P<.05) the ham-loin bone content and femur and fifth vertebra weight and mineral content, but the amount of additional bone or bone mineral accrued per unit of added dietary AP was linear and independent of RAC. Because of their greater muscle accretion capacity, thus P demand, pigs fed RAC from 70 to 114 kg BW needed an additional .03% AP to maintain the same femur mineral content as the non-RAC pig.</p> <p>Over the five periods, RAC lowered P content of BW gain (4.66 vs. 4.05 g/kg) and urinary P excretion (219 vs. 67 mg/d) independent of dietary AP. The magnitude of change in BW gain and P content of BW gain was reduced in later periods of growth. Dietary AP additions improved (P<.01) P accretion and P content of BW gain. To achieve maximum BW gain, the amount of AP needed was not altered by RAC. To achieve the same P content of BW gain, an indicator of the adequacy of the bone mineral content of gain, an additional .06% to .02% AP was needed in the RAC pigs depending on length of ractopamine feeding. Based on these data, RAC does not alter the amount of AP needed to optimize rate and efficiency of BW gain but does increase the AP needed to maintain P content of body growth equivalent to non-RAC pigs.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/swinereports_2002/10/
dc.identifier.articleid 1003
dc.identifier.contextkey 3212408
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath swinereports_2002/10
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/91313
dc.language.iso en
dc.relation.ispartofseries Animal Science Research Reports
dc.relation.ispartofseries ASL R1796
dc.source.bitstream archive/lib.dr.iastate.edu/swinereports_2002/10/asl_1796.pdf|||Fri Jan 14 18:03:37 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Animal Sciences
dc.subject.keywords ASL R1796
dc.title Effect of Ractopamine on the Optimum Dietary Phosphorus Regimen for Pigs
dc.type article
dc.type.genre nutrition
dspace.entity.type Publication
relation.isSeriesOfPublication 7f3839b7-b833-4418-a6fa-adda2b23950a
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