scholarly journals Ovarian Follicle Growth during Lactation Determines the Reproductive Performance of Weaned Sows

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1012 ◽  
Author(s):  
Tania P. Lopes ◽  
Lorena Padilla ◽  
Alfonso Bolarin ◽  
Heriberto Rodriguez-Martinez ◽  
Jordi Roca

Factors causing variability in ovarian follicle size among weaned sows are not well known. This field study aimed to disclose influencing factors and evaluate if the differences at weaning were established during lactation. Ovaries were scanned using transrectal ultrasound. The first experiment was conducted over a year with 191 randomly chosen sows that were hierarchically grouped (p < 0.001) according to ovarian follicle diameter reached at weaning: Small (0.20–0.30 cm; n = 37), medium (0.31–0.39 cm; n = 75), and large (0.40-1.00 cm; n = 69). Sows with small follicles showed a higher incidence of post-weaning anestrus (p < 0.01), longer wean-to-estrus/ovulation intervals (p < 0.01) and farrowing smaller litters (p < 0.05). Ovaries with small follicles were more common among sows weaned in summer–autumn than in winter–spring (p < 0.01) and among sows of lower parity (1–3) (p < 0.05). In the second experiment, with 40 sows randomly chosen at farrowing, the ovaries were scanned at 7, 14, and 21 d post-partum. Sows showed great variability in ovarian follicular size during lactation with a consistent relationship between the three measurement times (r = 0.84, p < 0.01). Follicle size was smaller in sows nursing in summer–autumn than in winter–spring (p < 0.05). In conclusion, early lactation dictates the great variability in ovarian follicular diameter at weaning shown by sows. Sows with smaller follicles at weaning had longer intervals for estrus and ovulation and smaller litters at farrowing and they were in greater numbers among sows weaned during the summer and fall and among those with fewer previous farrowing.

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1979
Author(s):  
Tania P. Lopes ◽  
Lorena Padilla ◽  
Alfonso Bolarin ◽  
Heriberto Rodriguez-Martinez ◽  
Jordi Roca

The GnRH agonist buserelin (GnRH), used to synchronize ovulation in weaned sows, attains only 70–80% effectivity, owing to several reasons of ovarian origin. This study evaluated in particular whether mean ovarian follicle size at treatment and the season of weaning are among those influencing GnRH responsiveness. The experiment was carried out in a temperate-region farm with 352 sows of 1–6 parities weaned either in winter–spring (WS, 174 sows) or in summer–autumn (SA, 178 sows). The sows were randomized into two groups: GnRH (10 µg of buserelin acetate at 86 h after weaning, 172 sows) and control (180 sows). The ovaries were transrectally scanned from weaning to ovulation and the sows clustered according to their mean follicular size at treatment time: small (<0.5 cm in diameter), medium (0.5 to 0.64 cm) and large (0.65 to 1.09 cm). In total, 88.33% of the GnRH-treated sows ovulated, with 82% of them within the expected time window (120–132 h after weaning). In contrast, 95.45% of the unresponsive sows had small follicles at the time of treatment and were mostly weaned in SA (20.45%) than in WS (4.76%). In conclusion, the conspicuous presence of sows having small ovarian follicles at treatment time compromises the efficiency of the GnRH agonist buserelin to synchronize ovulation in weaned sows, which occurs more frequently in summer–autumn weaning.


1988 ◽  
Vol 47 (1) ◽  
pp. 53-57 ◽  
Author(s):  
J. C. Whittier ◽  
D. C. Clanton ◽  
G. H. Deutscher

AbstractAn experiment was conducted using medium-sized crossbred beef heifers to study how manipulation of weight gain in late gestation affected production. Forty heifers were fed individually to gain according to one of three regimens for an approximate 90 day period prior to parturition: (1) 1·2 kg gain per head per day for 45 days followed by no gains for 45 days; (2) 0·6 kg gain per head per day for the entire period; (3) no gain for the first 45 days followed by 1·2 kg gain per head per day for the last 45 days. Milk production was measured by weighing of calves before and after suckling at 30, 60, and 150 days post partum. Heifers were weighed, measured for heart girth and hip weight, and visually scored for condition at the start, middle and end of the feeding period to quantify growth and condition changes. Heifers that had a high rate of gain for a short time produced more milk in early lactation than heifers that gained at a slower rate for a longer time pre-partum (P < 0·05). Calf weaning weights and dam reproductive performance were unaffected (P < 0·05) by pre-partum weight gain. It is concluded from these results, that as long as the recommended weight gain is achieved during late gestation, the timing of the weight gain is not critical to sustain productivity.


2017 ◽  
Vol 103 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Karolina Skorupskaite ◽  
Jyothis T George ◽  
Johannes D Veldhuis ◽  
Richard A Anderson

Abstract Context Neurokinin B (NKB) is obligate for human puberty, but its role in adult female gonadotropin secretion and ovarian follicle growth is unknown. Objective To investigate antagonism of NKB on pulsatile gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion and ovarian follicle development in healthy women. Design Open investigation of the effects of a neurokinin-3 receptor (NK3R) antagonist (NK3Ra) vs a no-treatment control cycle. Setting Clinical research facility. Patients or other participants Healthy women with regular menses (n = 13). Intervention(s) NK3Ra MLE4901 40 mg taken orally twice daily from cycle day 5 to 6 for 7 days. Main outcome measure(s) LH secretion, ovarian follicle growth, and timing of ovulation. Results NK3Ra administration reduced basal LH secretion without a change in pulse frequency and delayed the LH surge by 7 days, the duration of treatment [mean cycle day ± standard error of the mean (SEM), 22 ± 1 days vs 15 ± 1 days in control cycles; P = 0.0006]. Follicle growth (mean diameter at the end of administration of NK3Ra administration ± SEM, 9.3 ± 0.4 mm vs 15.1 ± 0.9 mm in control cycles; P &lt; 0.0001) and rising estradiol concentrations (mean ± SEM, 166 ± 29 pmol/L vs 446 ± 86 pmol/L in control cycles; P &lt; 0.0001) were prevented. After treatment, follicle development resumed and normal preovulatory follicle diameter and estradiol concentrations were demonstrated. Postovulatory progesterone rise was similarly delayed (peak cycle day, 30 ± 2 vs 22 ± 1; P = 0.002) and cycle length was prolonged (35 ± 1 days vs 29 ± 1 days in control cycles; P = 0.0003) but luteal progesterone excretion was unaffected by the NK3Ra (LH surge day +7 mean urinary progesterone levels ± SEM, 58 ± 10 pmol/mol vs 48±7 pmol/mol creatinine in control cycles; nonsignificant). Conclusion These data demonstrate the involvement of NKB-NK3R signaling in the physiological regulation of GnRH/LH secretion, determining normal follicle development in women.


2020 ◽  
Vol 65 (No. 1) ◽  
pp. 8-17
Author(s):  
I Dogan ◽  
MB Toker ◽  
S Alcay ◽  
D Udum Kucuksen

This study is aimed at describing the ovarian follicular dynamics, corpora lutea and their hormonal control during early pregnancy in Saanen goats. The ovaries of pregnant goats (n = 10) were monitored daily for follicles (≥ 2 mm) and corpora lutea by transrectal ultrasound over the 35 days after mating. Blood samples were collected by jugular venipuncture at the time of ultrasonography and were analysed for the concentrations of oestradiol (E<sub>2</sub>) and progesterone (P<sub>4</sub>), inhibin, FSH (follicle-stimulating hormone) and LH (luteinizing hormone). The pattern of follicular growth was characterised by five (n = 2; 20 %), six (n = 5; 50 %) and seven (n = 3; 30 %) follicular waves during early pregnancy. The first corpora lutea (size 6.8 ± 0.4 mm, mean + SEM) were detected at 5.0 ± 0.3 days after the mating with a maximum diameter (12.2 ± 0.3 mm) observed on day 24.0 ± 1.1 of pregnancy. The dominant follicle diameter of waves 1 and 4, and the duration of waves 1–4 and 7 were maximal during the early pregnancy period (P &lt; 0.05). In addition, the inter-wave interval of the 5 waves was significantly (P &lt; 0.05) longer compared to the six and seven inter-wave intervals (7.0 ± 0.1, 5.8 ± 0.1 and 5.0 ± 0.2 days, respectively). Although the number of small and medium-sized follicles did not differ with the days post-breeding, the number of large-sized follicles in the same period significantly decreased between 16 and 26 days and was negatively correlated with the period of pregnancy (P &lt; 0.05). The plasma LH and E<sub>2</sub> concentrations were negatively correlated with the P<sub>4</sub> concentration. The inhibin concentrations were negatively correlated with FSH, but positively correlated with the number of large-sized follicles. These results indicate that ovarian follicular growth during the first 35 days of pregnancy in goats was characterised by a wave-like pattern and there was a close relationship between the number of FSH peaks and the number of follicular waves.


Rangifer ◽  
1992 ◽  
Vol 12 (3) ◽  
pp. 57 ◽  
Author(s):  
Rolf Langvatn

Morphometric studies of uteri, ovary weights, and follicle diameters were carried out to investigate possible methodological applications. Size and anatomical appearance of the uterus varied with age and phase in the estrous cycle, both in parous and nulliparous females. The uterus thus may provide valuable information on reproductive status for known-aged animals. Weight of ovaries increased in young, but declined in old females, showing significant covariance with body weight in young and prime ages. Ovary weights increased from low levels shortly after parturition to a maximum towards the end of the gestation period. Ovaries containing a corpus luteum were heavier than those without. Compared to ovary weights, mean diameter of largest ovarian follicle varied in an opposite pattern during the yearly cycle. Maximum follicle diameter was largest in non-ovulated females. Weight of ovaries and follicle size appear to be of limited value as criteria in analysis of reproductive status and performance.


2016 ◽  
Vol 28 (10) ◽  
pp. 1570 ◽  
Author(s):  
J. M. Connolly ◽  
M. T. Kane ◽  
L. R. Quinlan ◽  
P. Dockery ◽  
A. C. Hynes

Ovarian follicle culture is useful for elucidation of factors involved in the regulation of follicular function. We examined the effects of gas phase oxygen concentration, an oil overlay, serum type and medium supplementation with FSH, insulin–transferrin–selenium (ITS) and l-ascorbic acid on cultured preantral mouse follicle growth in a spherical, non-attached follicle culture system. Follicle growth in 5% oxygen was significantly (P < 0.01) inferior to growth in 20% oxygen in terms of follicle diameter. This was likely due to hypoxia, as evidenced by significantly (P < 0.05) increased follicle secretion of vascular endothelial growth factor (VEGF), a marker of cell hypoxia. Follicular growth was not (P > 0.05) affected by an oil overlay, ITS supplementation or serum type. Culture in medium with 5% mouse serum, 1 IU mL–1 FSH, 25 μg mL–1 l-ascorbic acid and 20% oxygen without an oil overlay supported the growth of follicles to a maximum diameter of 380 μm in 6 days. Compared with mature preovulatory mouse follicles in vivo that often have diameters >500 μm within the same time frame, in vitro-grown follicles clearly exhibit limited growth. Thus, adequate oxygenation is an essential factor in the process of optimising follicle growth.


2010 ◽  
Vol 22 (1) ◽  
pp. 246
Author(s):  
D. R. Faria ◽  
A. L. N. Boffe ◽  
S. F. Grossi ◽  
A. Gradela

The use of biotechnology, such as AI, embryo transfer, and hormonal protocols, have accelerated the genetic improvement in the equine specie, and inducers of ovulation, such as hCG, are important tools in implementing them. However, the repeated use of ovulation inducers can promote the development of antibodies and undermine their purpose. Thus, a synthetic GnRH, deslorelin, has been used. In this study, we compared the reproductive performance of 44 Mangalarga Marchador donor mares, aged between 5 and 21 years and with sound reproductive history after treatment with hCG or deslorelin. During estrus, mares were examined by transrectal ultrasonography every other day until a follicle of 30 mm in diameter was detected and then daily until detection of a >35-mm follicle and moderate uterine edema. At this time, mares were treated with either 2 mL of saline, i.m. as controls (CON = 16); 2500IU of hCG, i.v. (Chorulon, Intervet Inc., Millsboro, DE, USA; hCG = 14); or 2 mg mL-1 deslorelin in BRT vehicle (BET Pharm, Lexington, KY, USA), i.m. (DES = 14). After treatments, mares were examined at 12-h intervals until ovulation and were inseminated with fresh semen 12 h after ovulation. On Day 8, embryos were recovered and evaluated. All mares were ovulated, and follicle diameters were not different (P > 0.05) at the time of treatment (38 ± 0.029 v. 39 ± 0.029 v. 38 ± 0.029 mm). Embryo recovery was similar among groups (CON, 37.5%; hCG, 42.8%; DES, 50.0%, respectively). The interval from treatment to ovulation did not differ (P > 0.05) between hCG (1.43 +0.56 days) and DES mares (1.14 + 0.36 days), and both were less (P > 0.05) than for controls (CON, 2.94 + 0.77 days). The number of mares that ovulated per ovulation interval were as follows: <24 h = CON: 0%, hCG: 7.14%, and DES: 14.29%, respectively; from 24 to 48 h = 6.25%, 64.29%, and 78.57%; from 49 to 72 h = 37.5%, 28.57%, and 7.14%; >72 h = 56.25%, 0%, and 0%. Time to ovulation was negatively correlated (P < 0.05) with follicle diameter in CON (r = -0.50, P < 0.05) but not for hCG (r = 0.05) or DES (r = 0.022) and was positively correlated with embryo recovery for DES (r = 0.46, P < 0.10), but not hCG (r = 0.23) or CON (r = 0.09). Based on the results, we concluded that hCG and DES effectively synchronize the time of ovulation. Follicle size did not affect the time of ovulation in hCG- and DES-treated mares. We thank the Farm Water supply for the animals and drugs.


2006 ◽  
Vol 46 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Andrew A. Ponter ◽  
Anne-Emmanuelle Parsy ◽  
Marion Saadé ◽  
Jean-Paul Mialot ◽  
Christine Ficheux ◽  
...  

1981 ◽  
Vol 97 (3) ◽  
pp. 595-597 ◽  
Author(s):  
Surinder S. Bhalaru ◽  
J. S. Dhillon ◽  
M. S. Tiwana

SUMMARYStudies on the effect of body weight at calving on body-weight losses during early lactation and the post-partum reproductive performance of large, medium and small buffaloes revealed that the large buffaloes (weighing more than 550 kg at calving) lost most weight (45·9 kg) and the small buffaloes (weighing less than 475 kg at calving) least weight (4·9 kg) during the first 5 months of lactation. The body-weight loss was maximal in the 1st month of lactation. The reproductive performance (measured as conception rate, number of services per conception and service period) of small buffaloes was significantly (P < 0·05) better than the large buffaloes. These results indicate that body–weight losses during early lactation are affected by the body weight at calving and these losses play an important role in influencing the post-partum reproductive performance. It is therefore suggested that, to improve the reproductive performance, the feeding regimen of buffaloes during pregnancy and after calving should be such that body-weight losses after calving are small.


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