|Vallet, Jeffrey - Jeff|
Submitted to: Biology of Reproduction Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2001
Publication Date: 12/20/2001
Citation: Vallet, J.L., Klemcke, H.G., Christenson, R.K. 2001. Progesterone treatment on days 2 and 3 of pregnancy decreases uterine capacity and increases placental efficiency in swine [abstract]. Biology of Reproduction. 64(Supplement 1):284. (Abstract No. 453) Interpretive Summary:
Technical Abstract: Progesterone treatment of gilts on day 2 and 3 and estrogen treatment on day 12 and 13 of pregnancy advanced conceptus development. In this experiment, the effects of progesterone and estrogen treatment on subsequent hematocrit (HT), placental weight (PW), fetal weight (FW), placental efficiency (PE) and uterine capacity (UC) were determined. Gilts were unilaterally hysterectomized-ovariectomized on day 160 of age, making litter size a measure of UC. They were then artificially inseminated at estrus and were either untreated (n=20, C), treated with estradiol valerate (E, 5 mg/day, im, n=14) on days 11 and 12 of pregnancy or treated with progesterone (P; 200 mg/day; i.m.; n=23) on day 2 and 3 of pregnancy. Gilts were slaughtered on day 103 to 107 and a blood sample was collected from each fetus for measurement of HT. Fetal and placental weights, UC and the number of CL were recorded. CL number did not differ between treatments (14.6+/-0.7, 13.2+/-0.8 and 13.3+/-0.6 for C, E and P, respectively). UC was less (p=0.053) in P (5.6+/-0.4) than C (6.9+/-0.5) and E (6.2+/-0.6) treated gilts. PE (FW:PW ratio) was greater (p<0.05) in P (4.64+/-0.11) than C (4.28+/-0.11) and E (4.28+/-0.14) treated gilts. Also, FW adjusted by using PW as a covariate (another measure of PE) was greater (p<0.01) in P (926+/-19) than C (848+/-21) and E (840+/-25) treated gilts. These results indicate that P treatment decreased UC and increased PE. Although P treatment decreases uterine capacity, it could be useful in increasing the size of the piglet.