Factors affecting estrus and ovulation time in weaned sows with induced ovulation by GnRH administration in different seasons

Pearodwong, Pachara; Tretipskul, Chanyuth; Soede, N.M.; Tummaruk, Padet

doi:10.1292/jvms.18-0429

Cited by 17 publications

(25 citation statements)

References 33 publications

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“…Both ovaries were examined, and the diameters of 4–8 large follicles in each ovary were measured. Ovulation time was defined as the time when a noticeable reduction in the number of follicles was observed minus 3 hr (Pearodwong et al., 2019). Follicles with diameter ≥ 15 mm that remained visible for 5 days were defined as cystic ovary (Castagna et al., 2004; Tummaruk & Kesdangsakonwut, 2012).…”

Section: Methodsmentioning

confidence: 99%

“…Both ovaries were examined, and the diameters of 4-8 large follicles in each ovary were measured. Ovulation time was defined as the time when a noticeable reduction in the number of follicles was observed minus 3 hr (Pearodwong et al, 2019).…”

Section: Determination Of Follicle Diameter and Timing Of Ovulationmentioning

confidence: 99%

“…Our previous study demonstrated that sows with low backfat thickness at weaning showed a delayed GnRH injection‐to‐ovulation interval (Pearodwong et al., 2019). Likewise, weaned sows with poor body condition scores showed a delayed oestrous‐to‐ovulation intervals (EOIs) (Pearodwong et al., 2019). However, the impact of low backfat thickness in spontaneously ovulating sows has not been investigated.…”

Section: Introductionmentioning

confidence: 99%

“…These parameters are indicators of the nutritional status of sows during their reproductive cycles (Maes et al, 2004). Our previous study demonstrated that sows with low backfat thickness at weaning showed a delayed GnRH injection-to-ovulation interval (Pearodwong et al, 2019). Likewise, weaned sows with poor body condition scores showed a delayed oestrous-to-ovulation intervals (EOIs) (Pearodwong et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

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Factors influencing pre‐ovulatory follicle diameter and weaning‐to‐ovulation interval in spontaneously ovulating sows in tropical environment

Pearodwong

Tretipskul²,

Panyathong

et al. 2020

Reprod Domestic Animals

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Follicle development and timing of ovulation are indicators of the reproductive performance of sows. The present study aimed to determine factors influencing preovulatory follicle diameter and weaning-to-ovulation interval (WOI) in spontaneously ovulating sows in tropical climates with special emphasis on breed, parity and backfat thickness at weaning. In total, 80 sows were included in the study. Follicle development was determined by using transrectal real-time B-mode ultrasonography every 6 hr after standing oestrus. Weaning-to-oestrous interval (WEI), oestrous-to-ovulation interval (EOI), WOI and the diameter of graafian follicles were investigated in relation to breed, parity number (1, 2-3 and 4-7) and backfat thickness (low, moderate and high) of sows. Overall, WEI, EOI, WOI and the pre-ovulatory follicle diameter

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Section: Methodsmentioning

confidence: 99%

Section: Determination Of Follicle Diameter and Timing Of Ovulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Factors influencing pre‐ovulatory follicle diameter and weaning‐to‐ovulation interval in spontaneously ovulating sows in tropical environment

Pearodwong

Tretipskul²,

Panyathong

et al. 2020

Reprod Domestic Animals

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“…Equine chorionic gonadotrophin (eCG ) alone or in combination with Human chorionic gonadotrophin (hCG) stimulates follicular growth and improves estrus and ovulation rates in sows and gilts [4,5] . Ovulation induction via the gonadorelin (GnRH) analog, buserelin after weaning shortens the interval between weaning and ovulation (WOI) and the interval between estrus and ovulation (EOI) in sows [6] . As a result, FTAI technology effectively improves the estrus and ovulation rates of sows and gilts, shortens the nonproductive days, reduces labor costs, improves production e ciency, and plays an important role in promoting the batch production of the pig industry.…”

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confidence: 99%

PMSG Pretreatment Before Fixed-Time Artificial Insemination Improves the Reproductive Performance in Replacement Gilts

Zhao

Chen

Qiaoli

et al. 2020

Preprint

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Background: Fixed-time artificial insemination (FTAI) uses exogenous reproductive hormones to regulate the sexual cycle of sows and realize the mating of pigs at a fixed-time without estrus identification. There is a great difference in litter size following FTAI, which may be due to the ovarian status before treatment. However, the specific underlying mechanism remains unclear.Results: We selected replacement gilts (n=104) and divided them into four groups: CON (n=35), EST (n=16), pregnant mare serum gonadotrophin (PMSG)-15D (n=26), and PMSG-20D (n=27). The PMSG-15D and PMSG-20D groups were pretreated with PMSG for 15 and 20 days, respectively. The four groups were then subjected to the same FTAI treatment. Pretreatment with PMSG causes ovulation in the gilts, to artificially promote an estrus cycle. At 42 hours after ALT feeding stopped, The follicular diameter of PMSG-15D group (2.94±0.24 mm) was significantly higher (P<0.05) than the other groups.，and the proportion of gilts with follicular diameter greater than 3 mm in the PMSG-15D group was significantly higher than that in the CON group (37.50% vs 5.88%). The maximum follicular diameter before ovulation in the PMSG-15D group (6.28±0.23 mm) was significantly larger (P<0.05) than that of the PMSG-20D group (5.98±0.59 mm) and EST group (5.60±0.47 mm), indicating that the follicular development of the PMSG-15D group was better than that of the other groups. The ovulation time of the PMSG-15D group was concentrated on the 25th to 26th day of FTAI. The ovulation rate was as high as 94.5% in the optimal insemination window period and was more suitable for FTAI. Compared with the CON (52.70±12.71 h) and the PMSG-20D (47.88±13.98 h) groups, the GnRH to ovulation interval (42.33±5.87 h) was significantly shortened in the PMSG-15D group. The level of follicle-stimulating hormone of gilts in the PMSG-15D group was more uniform and significantly lower than that in the CON group (P<0.01) at 42 h after Altrenogest feeding. The pregnancy rate (80.77%), total litter size (10.44±2.83), and live litter size (10.00±2.61) of the PMSG-15D group were higher than those of the other groups.Conclusions: We feasibly optimized FTAI using PMSG pretreatments. When the ovaries of replacement gilts were in the luteal stage owing to PMSG pretreatment for 15 days, the follicular development and reproductive performance of replacement gilts were significantly improved.

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Managing prolific sows in tropical environments

Tummaruk

Rensis

Kirkwood

2022

Molecular Reproduction Devel

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Litter size in modern sows has been dramatically improved in recent decades by genetic selection for highly prolific sows. In a tropical environment, the average total number of pigs born and number born alive are reported to be as high as 17.2 and 15.1 piglets per litter, respectively. Therefore, the new production target in many herds aims to achieve 30–40 pigs weaned per sow per year. Despite the improvements in litter size, the mean preweaning piglet mortality rate remains high, at between 10% and 20%, in major pig‐producing countries. A sufficient daily feed intake by lactating sows is important for high milk production as sow milk yield is the limiting factor for piglet growth rate. Heat stress, which can occur when the ambient temperatures rise above 25°C, is one of the major problems that decreases daily feed intake and compromises milk yield. Therefore, it is necessary to encourage high feed intakes to achieve high milk yields. However, even with high nutrient intakes, productivity can be constrained by intestinal barrier function, limiting digestive ability, and allowing potential pathogens and/or toxins to become systemic. This is more likely greater under tropical conditions because of heat stress, exacerbating sow fertility problems. Underpinning sow herd performance, including responses to environmental challenges, is the selection of appropriate gilts, for example, selection and management for early puberty, thus presumably selecting the more fertile gilts and the correct management of lactation to improve the number of weaned piglets are some of the key factors for future reproductive efficiency of the farm under tropical conditions.

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Factors affecting estrus and ovulation time in weaned sows with induced ovulation by GnRH administration in different seasons

Cited by 17 publications

References 33 publications

Factors influencing pre‐ovulatory follicle diameter and weaning‐to‐ovulation interval in spontaneously ovulating sows in tropical environment

Factors influencing pre‐ovulatory follicle diameter and weaning‐to‐ovulation interval in spontaneously ovulating sows in tropical environment

PMSG Pretreatment Before Fixed-Time Artificial Insemination Improves the Reproductive Performance in Replacement Gilts

Managing prolific sows in tropical environments

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