PMID- 7174549
OWN - NLM
STAT- MEDLINE
DCOM- 19830214
LR  - 20190512
IS  - 0021-8812 (Print)
IS  - 0021-8812 (Linking)
VI  - 55
IP  - 5
DP  - 1982 Nov
TI  - Trenbolone, estradiol-17 beta and estrone levels in plasma and tissues and live 
      weight gains of heifers implanted with trenbolone acetate.
PG  - 1048-56
AB  - Twenty-four heifers were allotted into three groups of eight heifers each and 
      designated control, long-term (LT) or short-term (ST). Animals in the latter two 
      groups were implanted in the ear with 300 mg trenbolone acetate (TBA) for 99 or 
      62 d, respectively. Four heifers in each group were subjected to liver and fat 
      biopsy 60 d after initiation of the experiment. At slaughter, which occurred 15 d 
      after retrieval of the implant, liver and fat were also collected. The implant 
      was analyzed for residual trenbolone (TBOH), and tissues were analyzed for TBOH 
      and estradiol-17 beta (E2 beta). Blood samples were taken weekly after 
      implantation and daily for 14 d before and after implantation. All heifers were 
      weighed weekly. The ST heifers gained faster (P less than .05) than the control 
      or the LT heifers, whereas the LT heifers gained similarly to the controls. 
      Plasma levels of TBOH rose to over 900 pg/ml in response to the implantation in 
      both treated groups, but stabilized at a lower level in the ST group than in the 
      LT group. In both groups plasma E2 beta rose to over 7.5 pg/ml in response to TBA 
      implantation; in fact, a regression analysis of E2 beta on TBOH in individual 
      cows showed that the two hormones varied directly. Fat and liver accumulated 
      substantial TBOH during implantation, but it cleared rapidly during the 15 d 
      withdrawal period. Indications from this experiment are that TBA has promise for 
      promoting rate of gain and efficiency of feed utilization in feedlot heifers. No 
      undesirable effects on carcass quality were detected. The drug cleared blood and 
      tissues rapidly after the implant was withdrawn. Further research is needed to 
      determine the most effective implantation schedule. It would be desirable to 
      determine whether a positive response to TBA will occur in animals being finished 
      predominantly on forages.
FAU - Henricks, D M
AU  - Henricks DM
FAU - Edwards, R L
AU  - Edwards RL
FAU - Champe, K A
AU  - Champe KA
FAU - Gettys, T W
AU  - Gettys TW
FAU - Skelley, G C Jr
AU  - Skelley GC Jr
FAU - Gimenez, T
AU  - Gimenez T
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - J Anim Sci
JT  - Journal of animal science
JID - 8003002
RN  - 0 (Anabolic Agents)
RN  - 0 (Drug Implants)
RN  - 0 (Estrenes)
RN  - 2DI9HA706A (Estrone)
RN  - 4TI98Z838E (Estradiol)
RN  - RUD5Y4SV0S (Trenbolone Acetate)
SB  - IM
MH  - Adipose Tissue/metabolism
MH  - Anabolic Agents/administration & dosage/*pharmacology
MH  - Animals
MH  - Body Weight/*drug effects
MH  - Cattle/*physiology
MH  - Drug Implants
MH  - Estradiol/*metabolism
MH  - Estrenes/*metabolism/*pharmacology
MH  - Estrone/*metabolism
MH  - Female
MH  - Liver/metabolism
MH  - Time Factors
MH  - Trenbolone Acetate/administration & dosage/analogs & 
      derivatives/*metabolism/*pharmacology
EDAT- 1982/11/01 00:00
MHDA- 2001/03/28 10:01
CRDT- 1982/11/01 00:00
PHST- 1982/11/01 00:00 [pubmed]
PHST- 2001/03/28 10:01 [medline]
PHST- 1982/11/01 00:00 [entrez]
AID - 10.2527/jas1982.5551048x [doi]
PST - ppublish
SO  - J Anim Sci. 1982 Nov;55(5):1048-56. doi: 10.2527/jas1982.5551048x.