Effect of feeding level on luteal function and progesterone concentration in the vena cava during early pregnancy in gilts

Abstract

This study assessed the effect of feeding level on progesterone concentration in the caudal vena cava during early pregnancy in gilts. Twenty-four Landrace gilts were allocated to either a high (2.8±0.02) or a low (1.5±0.01 kg day⁻¹) feeding level at Day 0 of pregnancy. Serial blood samples were collected every 15 min for 3 h before and 3 h after feeding on Days 6 and 9 of pregnancy. Embryo survival and development as well as in vitro luteal progesterone production were assessed at Day 10 of pregnancy. Progesterone concentration in the vena cava was pulsatile with gilts on the high feeding level having more pulses compared with Low gilts on Day 9 of pregnancy (P<0.05). On Day 6 the number of pulses did not differ significantly between treatments; however, the average progesterone concentration in the vena cava tended to be higher in the gilts on the high feeding level (P<0.10). Embryo survival at Day 10 was 92±3% for High gilts compared with 77±3% for Low gilts (P<0.05). No difference in embryo development between the treatments was seen. There was no difference between treatments in in vitro secretion of progesterone by luteal tissue. In conclusion, a high plane of nutrition positively affects progesterone secretion by the ovaries in early pregnancy.

Influence of unilateral ovariectomy performed before ovulation on ovarian function, steroid hormone levels and development of porcine fetuses

“…[10] observed 13.0 ± 1.9 vs. 11.8 ± 0.9 CL and Athorn et al [4] 15.9 ± 0.8 vs. 15.7 ± 0.6 CL, respectively. However, uni-OVX immediately before ovulation significantly decreased the number of CL (10.9 ± 0.7) similarly to 9.5 ± 1.2 vs. 14.1 ± 1.2 in the study of Clark et al [2]. In our study, there was no influence of uni-OVX on CL weights.…”

“…Our results confirm previous data that the time point of uni-OVX influences ovarian follicle compensation. Ovariectomy long time [4,10] but not immediately before ovulation permits compensation of follicle recruitment [2,11]. In our study, uni-OVX 20 days before subsequent…”

“…Ovarian compensatory hypertrophy in pigs after unilateral ovariectomy (uni-OVX) has been studied already two centuries ago [1] and is still an interesting current model to study follicle selection and embryo survival [2][3][4]. Since the corpora lutea (CL) are a considerable source of progesterone (P4) in the pig to establish and, in some extent, to maintain pregnancy, their influence on embryo survival was analyzed, previously [4].…”

Within-litter variation in birth weight: impact of nutritional status in the sow

“…Sows receiving high ((2.8±0.02) kg/d) nutrient intake, compared with a low ((1.5±0.01) kg/d) nutrient intake, from Day 0 to Day 9 of pregnancy had higher embryonic survival at Day 10 of pregnancy ((92±3)% vs. (77±3)%) (Athorn et al, 2013), which may be due to higher concentrations of blood progesterone in response to adequate feed intake. Progesterone synthesis is likely to be impaired when dietary intake of nutrients (particularly amino acids) and energy is insufficient.…”

Dietary energy intake affects fetal survival and development during early and middle pregnancy in Large White and Meishan gilts

“…In general, P 4 synthesis-related proteins sense ovarian nutrient status, with the secretion of P 4 in the corpora lutea (CL) increasing when nutrients are abundant ( Athorn et al, 2011 , Athorn et al, 2013 ). The synthesis of luteal P 4 depends on cholesterol which is absorbed by the scavenger receptor-BI (SR-BI) and the low-density lipoprotein receptor (LDLR).…”