PMID- 1458872
OWN - NLM
STAT- MEDLINE
DCOM- 19930108
LR  - 20191028
IS  - 0739-7240 (Print)
IS  - 0739-7240 (Linking)
VI  - 9
IP  - 3
DP  - 1992 Jul
TI  - Is nutritional anestrus precipitated by subfunctional corpora lutea in beef cows?
PG  - 187-97
AB  - Thirty-four multiparous, lactating, cyclic beef cows which calved in moderate 
      body condition were used to determine effects of restricted nutrition on corpus 
      luteum (CL) development and endocrine status. At 78 d postpartum, six cows were 
      assigned to a control (CON) diet (26.0 Mcal ME), fed to increase bodyweight (BW) 
      and body condition score (BCS), and the remaining 28 cows were fed to lose BW and 
      BCS on a restricted (RES) diet (14.0 Mcal ME). Following a 40-d adjustment period 
      on respective diets, estrous cycles were synchronized and cows bled daily for 
      determination of progesterone (P4), luteinizing hormone (LH) and insulin (INS) 
      beginning at the synchronized estrus. Ultrasonography was used to determine the 
      ovulatory follicle and CL development. Control cows were maintained for one 
      estrous cycle and were ovariectomized on day 11 of their second cycle. Ten cows 
      on restricted diet (RES-C) continued to form a functional CL (P4 > 1.5 ng/ml at 
      day 10 of an estrous cycle) through as many as 5 cycles, after which observations 
      were discontinued. Fourteen cows on restricted diet (RES-A) were ovariectomized 
      on day 11 of a cycle when a CL was identified by ultrasonography, but was 
      subfunctional (P4 < 1.5 ng/ml on day 10 of that cycle). Four additional RES-A 
      cows which had subfunctional CL were not ovariectomized but were bled for an 
      additional 25 d. At ovariectomy, CL and ovarian weights were collected. Luteal 
      tissue was prepared for evaluation of P4 synthesis, LH responsiveness in vitro, 
      and for determination of P4 content and total LH receptors. Bodyweight and BCS 
      increased in CON cows; whereas, RES cows lost BW and BCS (P < .05). In the cycle 
      prior to ovariectomy, serum P4 and LH were not different in 18 RES-A cows which 
      developed subfunctional CL in comparison to CON cows. Four RES-A cows not 
      ovariectomized but bled for an additional 25 d neither exhibited estrus, 
      ovulated, nor had P4 concentrations greater than .3 ng/ml. Serum INS was lower in 
      RES-A cows during the cycle prior to ovariectomy than in CON cows (P < .05). 
      During the 11-d period prior to ovariectomy, mean serum P4 and INS were lower in 
      RES-A cows than in CON cows (P < .05); however, serum LH was not different. 
      Furthermore, CL and ovarian weights, P4 content of CL, secretion of P4 by luteal 
      tissue in response to LH in vitro and LH receptor number were not different 
      between CON and RES-A cows. In conclusion, nutritional anestrus may be preceded 
      by the formation of a CL with lower steroidogenic output in vivo. However, luteal 
      tissue, collected from RES-A cows, did not appear to be subfunctional during in 
      vitro incubation when substrate availability and gonadotropin support were equal 
      between diets.
FAU - Schrick, F N
AU  - Schrick FN
AD  - Department of Animal, Dairy and Veterinary Sciences, Clemson University, SC 
      29634.
FAU - Spitzer, J C
AU  - Spitzer JC
FAU - Gimenez, T
AU  - Gimenez T
FAU - Henricks, D M
AU  - Henricks DM
FAU - Jenkins, T C
AU  - Jenkins TC
FAU - Plyler, B B
AU  - Plyler BB
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PL  - United States
TA  - Domest Anim Endocrinol
JT  - Domestic animal endocrinology
JID - 8505191
RN  - 0 (Insulin)
RN  - 4G7DS2Q64Y (Progesterone)
RN  - 9002-67-9 (Luteinizing Hormone)
SB  - IM
MH  - Anestrus/*physiology
MH  - Animals
MH  - Cattle/blood/*physiology
MH  - Corpus Luteum/*physiology
MH  - Female
MH  - Food Deprivation/*physiology
MH  - Insulin/blood
MH  - Luteinizing Hormone/blood/physiology
MH  - Ovariectomy/veterinary
MH  - Progesterone/blood
EDAT- 1992/07/01 00:00
MHDA- 1992/07/01 00:01
CRDT- 1992/07/01 00:00
PHST- 1992/07/01 00:00 [pubmed]
PHST- 1992/07/01 00:01 [medline]
PHST- 1992/07/01 00:00 [entrez]
AID - 0739-7240(92)90032-S [pii]
AID - 10.1016/0739-7240(92)90032-s [doi]
PST - ppublish
SO  - Domest Anim Endocrinol. 1992 Jul;9(3):187-97. doi: 10.1016/0739-7240(92)90032-s.