Effects of repetitive norgestomet treatments on pregnancy rates in cyclic and anestrous beef heifers

A. M. Ghallab, R. S. Ott, G. F. Cmarik, D. J. Kesler, Dan B Faulkner, J. E. Hixon

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Sixty-eight 12- to 14-month-old crossbred beef heifers averaging 285 kg were assigned at random to treated (n = 35) and control (n = 33) groups to evaluate the use of repetitive norgestomet treatments. Treated heifers received an ear implant containing 6 mg norgestomet on two occasions 16 days apart. Injections of 3 mg norgestomet and 5 mg estradiol valerate (EV) were given intramuscularly the same day as first implantation (Syncro-Mate-B). Implants were removed after eight days. Four bulls were then placed in each of two pastures containing half of the treated and half of the control heifers for 24 days after the time of the first implant removal. Progesterone concentrations from blood samples collected prior to the first treatment were used to determine reproductive status. The overall pregnancy rate 64 days after first implant removal for treated anestrous heifers (61%; 14 23) was similar (p > 0.25) to untreated (73%; 11 15) and treated (75%; 9 12) cyclic heifers, but higher (p < 0.1) than for untreated anestrous heifers (33%; 6 18). This treatment advantage resulted from an increased (p < 0.01) pregnancy rate after the second implant removal. In summary, repetitive norgestomet treatments enhanced pregnancy rate in anestrous heifers within a 24-day breeding season.

Original languageEnglish (US)
Pages (from-to)67-74
Number of pages8
JournalTheriogenology
Volume22
Issue number1
DOIs
StatePublished - 1984
Externally publishedYes

Fingerprint

norgestomet
Pregnancy Rate
pregnancy rate
beef cattle
heifers
estradiol valerate
Therapeutics
Breeding
Progesterone
Ear
Injections
estradiol
ears
breeding season
progesterone
bulls
crossbreds
pastures
injection
blood

Keywords

  • Beef heifers
  • norgestomet
  • synchronization
  • Syncro-Mate-B

ASJC Scopus subject areas

  • Animal Science and Zoology
  • veterinary(all)

Cite this

Effects of repetitive norgestomet treatments on pregnancy rates in cyclic and anestrous beef heifers. / Ghallab, A. M.; Ott, R. S.; Cmarik, G. F.; Kesler, D. J.; Faulkner, Dan B; Hixon, J. E.

In: Theriogenology, Vol. 22, No. 1, 1984, p. 67-74.

Research output: Contribution to journalArticle

Ghallab, A. M. ; Ott, R. S. ; Cmarik, G. F. ; Kesler, D. J. ; Faulkner, Dan B ; Hixon, J. E. / Effects of repetitive norgestomet treatments on pregnancy rates in cyclic and anestrous beef heifers. In: Theriogenology. 1984 ; Vol. 22, No. 1. pp. 67-74.
@article{4c80bb287eb84a23bc0c6e6209c1abdf,
title = "Effects of repetitive norgestomet treatments on pregnancy rates in cyclic and anestrous beef heifers",
abstract = "Sixty-eight 12- to 14-month-old crossbred beef heifers averaging 285 kg were assigned at random to treated (n = 35) and control (n = 33) groups to evaluate the use of repetitive norgestomet treatments. Treated heifers received an ear implant containing 6 mg norgestomet on two occasions 16 days apart. Injections of 3 mg norgestomet and 5 mg estradiol valerate (EV) were given intramuscularly the same day as first implantation (Syncro-Mate-B). Implants were removed after eight days. Four bulls were then placed in each of two pastures containing half of the treated and half of the control heifers for 24 days after the time of the first implant removal. Progesterone concentrations from blood samples collected prior to the first treatment were used to determine reproductive status. The overall pregnancy rate 64 days after first implant removal for treated anestrous heifers (61{\%}; 14 23) was similar (p > 0.25) to untreated (73{\%}; 11 15) and treated (75{\%}; 9 12) cyclic heifers, but higher (p < 0.1) than for untreated anestrous heifers (33{\%}; 6 18). This treatment advantage resulted from an increased (p < 0.01) pregnancy rate after the second implant removal. In summary, repetitive norgestomet treatments enhanced pregnancy rate in anestrous heifers within a 24-day breeding season.",
keywords = "Beef heifers, norgestomet, synchronization, Syncro-Mate-B",
author = "Ghallab, {A. M.} and Ott, {R. S.} and Cmarik, {G. F.} and Kesler, {D. J.} and Faulkner, {Dan B} and Hixon, {J. E.}",
year = "1984",
doi = "10.1016/0093-691X(84)90474-6",
language = "English (US)",
volume = "22",
pages = "67--74",
journal = "Theriogenology",
issn = "0093-691X",
publisher = "Elsevier Inc.",
number = "1",

}

TY - JOUR

T1 - Effects of repetitive norgestomet treatments on pregnancy rates in cyclic and anestrous beef heifers

AU - Ghallab, A. M.

AU - Ott, R. S.

AU - Cmarik, G. F.

AU - Kesler, D. J.

AU - Faulkner, Dan B

AU - Hixon, J. E.

PY - 1984

Y1 - 1984

N2 - Sixty-eight 12- to 14-month-old crossbred beef heifers averaging 285 kg were assigned at random to treated (n = 35) and control (n = 33) groups to evaluate the use of repetitive norgestomet treatments. Treated heifers received an ear implant containing 6 mg norgestomet on two occasions 16 days apart. Injections of 3 mg norgestomet and 5 mg estradiol valerate (EV) were given intramuscularly the same day as first implantation (Syncro-Mate-B). Implants were removed after eight days. Four bulls were then placed in each of two pastures containing half of the treated and half of the control heifers for 24 days after the time of the first implant removal. Progesterone concentrations from blood samples collected prior to the first treatment were used to determine reproductive status. The overall pregnancy rate 64 days after first implant removal for treated anestrous heifers (61%; 14 23) was similar (p > 0.25) to untreated (73%; 11 15) and treated (75%; 9 12) cyclic heifers, but higher (p < 0.1) than for untreated anestrous heifers (33%; 6 18). This treatment advantage resulted from an increased (p < 0.01) pregnancy rate after the second implant removal. In summary, repetitive norgestomet treatments enhanced pregnancy rate in anestrous heifers within a 24-day breeding season.

AB - Sixty-eight 12- to 14-month-old crossbred beef heifers averaging 285 kg were assigned at random to treated (n = 35) and control (n = 33) groups to evaluate the use of repetitive norgestomet treatments. Treated heifers received an ear implant containing 6 mg norgestomet on two occasions 16 days apart. Injections of 3 mg norgestomet and 5 mg estradiol valerate (EV) were given intramuscularly the same day as first implantation (Syncro-Mate-B). Implants were removed after eight days. Four bulls were then placed in each of two pastures containing half of the treated and half of the control heifers for 24 days after the time of the first implant removal. Progesterone concentrations from blood samples collected prior to the first treatment were used to determine reproductive status. The overall pregnancy rate 64 days after first implant removal for treated anestrous heifers (61%; 14 23) was similar (p > 0.25) to untreated (73%; 11 15) and treated (75%; 9 12) cyclic heifers, but higher (p < 0.1) than for untreated anestrous heifers (33%; 6 18). This treatment advantage resulted from an increased (p < 0.01) pregnancy rate after the second implant removal. In summary, repetitive norgestomet treatments enhanced pregnancy rate in anestrous heifers within a 24-day breeding season.

KW - Beef heifers

KW - norgestomet

KW - synchronization

KW - Syncro-Mate-B

UR - http://www.scopus.com/inward/record.url?scp=48549113993&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=48549113993&partnerID=8YFLogxK

U2 - 10.1016/0093-691X(84)90474-6

DO - 10.1016/0093-691X(84)90474-6

M3 - Article

AN - SCOPUS:48549113993

VL - 22

SP - 67

EP - 74

JO - Theriogenology

JF - Theriogenology

SN - 0093-691X

IS - 1

ER -