File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Effects of dietary thyroid hormones on growth, plasma T3 and T4, and growth hormone in normal and hypothyroid chickens

TitleEffects of dietary thyroid hormones on growth, plasma T3 and T4, and growth hormone in normal and hypothyroid chickens
Authors
Issue Date1985
PublisherAcademic Press. The Journal's web site is located at http://www.elsevier.com/locate/ygcen
Citation
General And Comparative Endocrinology, 1985, v. 59 n. 1, p. 91-99 How to Cite?
AbstractCockerels and pullets fed with T3 or T4 for 2 weeks showed a decrease in both body weight gain and feed efficiency. The reduction in body weight gain and feed efficiency was dose related in cockerels where T3 or T4 were fed at 0.1, 1.0, and 10.0 ppm levels. T3 and T4 at 0.1 and 1.0 ppm had no significant effects on growth or feed efficiency in pullets, but the 10.0-ppm level of T3 and T4 caused a reduction of -55.24 and -28.18%, respectively, in body weight gain as compared with control birds. T3 was more active than T4 in reducing growth and was toxic when fed at 10.0 ppm both in cockerels and pullets. Both propylthiouracil (PTU)- and methimazole-treated cockerels showed a decrease in rates of gain. T3 and T4 at a dietary level of 0.1 ppm were equipotent in promoting growth in these PTU- and methimazole-treated cockerels, but 10.0 ppm caused a further reduction in body weight gain. Plasma T3 levels were found to be significantly higher in birds that were fed either T3 or T4. Plasma T4 levels were higher in T4-fed birds, but significantly lower in T3-fed birds as compared with controls. Both PTU- and methimazole-treated cockerels had significantly lower plasma T3 and T4 concentrations, but elevated plasma GH concentrations. Dietary T3 and T4 at 1.0 and 10.0 ppm, significantly lowered plasma GH concentrations. In summary, these results indicated that T3 was more active than T4 in reducing body weight gain in intact normal birds, but that they were equally potent in promoting growth in PTU- and methimazole-treated hypothyroid birds. Thyroid hormones (T3 and T4) are also more active in decreasing growth in intact cockerels than in pullets. It appears that there is some peripheral conversion from T4 and T3 has a negative feedback on plasma T4 concentrations. Since PTU-treated birds show elevated plasma GH concentrations, the decrease in body weight gain is probably due to the lowering of thyroid hormones rather than to an effect on pituitary GH release.
Persistent Identifierhttp://hdl.handle.net/10722/178441
ISSN
2015 Impact Factor: 2.667
2015 SCImago Journal Rankings: 1.245
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorLeung, FCen_US
dc.contributor.authorTaylor, JEen_US
dc.contributor.authorVan Iderstine, Aen_US
dc.date.accessioned2012-12-19T09:47:42Z-
dc.date.available2012-12-19T09:47:42Z-
dc.date.issued1985en_US
dc.identifier.citationGeneral And Comparative Endocrinology, 1985, v. 59 n. 1, p. 91-99en_US
dc.identifier.issn0016-6480en_US
dc.identifier.urihttp://hdl.handle.net/10722/178441-
dc.description.abstractCockerels and pullets fed with T3 or T4 for 2 weeks showed a decrease in both body weight gain and feed efficiency. The reduction in body weight gain and feed efficiency was dose related in cockerels where T3 or T4 were fed at 0.1, 1.0, and 10.0 ppm levels. T3 and T4 at 0.1 and 1.0 ppm had no significant effects on growth or feed efficiency in pullets, but the 10.0-ppm level of T3 and T4 caused a reduction of -55.24 and -28.18%, respectively, in body weight gain as compared with control birds. T3 was more active than T4 in reducing growth and was toxic when fed at 10.0 ppm both in cockerels and pullets. Both propylthiouracil (PTU)- and methimazole-treated cockerels showed a decrease in rates of gain. T3 and T4 at a dietary level of 0.1 ppm were equipotent in promoting growth in these PTU- and methimazole-treated cockerels, but 10.0 ppm caused a further reduction in body weight gain. Plasma T3 levels were found to be significantly higher in birds that were fed either T3 or T4. Plasma T4 levels were higher in T4-fed birds, but significantly lower in T3-fed birds as compared with controls. Both PTU- and methimazole-treated cockerels had significantly lower plasma T3 and T4 concentrations, but elevated plasma GH concentrations. Dietary T3 and T4 at 1.0 and 10.0 ppm, significantly lowered plasma GH concentrations. In summary, these results indicated that T3 was more active than T4 in reducing body weight gain in intact normal birds, but that they were equally potent in promoting growth in PTU- and methimazole-treated hypothyroid birds. Thyroid hormones (T3 and T4) are also more active in decreasing growth in intact cockerels than in pullets. It appears that there is some peripheral conversion from T4 and T3 has a negative feedback on plasma T4 concentrations. Since PTU-treated birds show elevated plasma GH concentrations, the decrease in body weight gain is probably due to the lowering of thyroid hormones rather than to an effect on pituitary GH release.en_US
dc.languageengen_US
dc.publisherAcademic Press. The Journal's web site is located at http://www.elsevier.com/locate/ygcenen_US
dc.relation.ispartofGeneral and Comparative Endocrinologyen_US
dc.subject.meshAnimalsen_US
dc.subject.meshBody Weight - Drug Effectsen_US
dc.subject.meshChickens - Physiologyen_US
dc.subject.meshDieten_US
dc.subject.meshFemaleen_US
dc.subject.meshGrowthen_US
dc.subject.meshGrowth Hormone - Blooden_US
dc.subject.meshHypothyroidism - Blood - Physiopathologyen_US
dc.subject.meshMaleen_US
dc.subject.meshMethimazole - Pharmacologyen_US
dc.subject.meshPropylthiouracil - Pharmacologyen_US
dc.subject.meshThyroxine - Blood - Pharmacologyen_US
dc.subject.meshTriiodothyronine - Blood - Pharmacologyen_US
dc.titleEffects of dietary thyroid hormones on growth, plasma T3 and T4, and growth hormone in normal and hypothyroid chickensen_US
dc.typeArticleen_US
dc.identifier.emailLeung, FC: fcleung@hkucc.hku.hken_US
dc.identifier.authorityLeung, FC=rp00731en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/0016-6480(85)90422-8-
dc.identifier.pmid4018556-
dc.identifier.scopuseid_2-s2.0-0022263069en_US
dc.identifier.volume59en_US
dc.identifier.issue1en_US
dc.identifier.spage91en_US
dc.identifier.epage99en_US
dc.identifier.isiWOS:A1985ALA3300011-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLeung, FC=7103078633en_US
dc.identifier.scopusauthoridTaylor, JE=7405405625en_US
dc.identifier.scopusauthoridVan Iderstine, A=6602377005en_US

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats