The return to estrus

Apart from the number of piglets born alive and weaned, the number of litters per sow per year is an important characteristic of sow performance

Background on the challenge

To increase the number of litters per sow per year, pig producers aim to inseminate the sow at the first estrus after weaning. Success is measured by a low rate of sows returning to estrus. For successful insemination, the physiological condition of the sow needs to be in a state to a) facilitate fertilization of the mature egg b) prepare the uterus for embryo implantation and c) maintain pregnancy after successful fertilization.

The implication for the industry

Sows returning to estrus result in an economic loss by reducing the number of litters per sow per year. Besides, even culling rates of sows that might not yet have achieved their optimal performance increase. A high rate of sows returning to estrus, therefore, disrupts the smooth running and the financial status of a sow farm. It is important to minimize the rate of return to estrus through good management, proper sow nutrition, insemination practice, and preparation of the sow for the next breeding cycle.

  • fast time to action

  • reduces the return to estrus

  • supports implantation and placentation

Panbonis® is a complementary feed that contains a standardized level of 1,25 dihydroxycholecalciferol-glycosides (1,25(OH)2D3-gly) from dried and ground Solanum glaucophyllum leaves. 1,25(OH)2D3-gly can only be absorbed after the sugar molecule is released from 1,25(OH)2D3 by specific enzymes that are present in the intestine. This is a gradual process, ensuring a slow release of the bioactive component. Once it is absorbed, it does not need additional activation steps, like vitamin D3 or 25-hydroxycholecalciferol (25(OH)D3) do, which means that Panbonis® can directly support the animal even in periods when specific activation enzymes in liver and kidney are limited.

Supplementing sow diets during gestation and lactation with Panbonis® supports implantation and placentation and reduces the return to estrus.

  • Supports the crucial role of vitamin D3

  • 100% Natural

  • GMO-free

  • Standardized content of the active ingredient

  • Gradually absorbed from the intestine

  • Considered a complementary feed in the EU

  • High processing and storage stability

Mode of action

To become active, vitamin D3 needs to undergo a two-step activation. The first step happens in the liver and the second in the kidney to deliver the bioactive form 1,25-dihydroxycholecalciferol (1,25(OH)2D3). 1,25(OH)2D3 binds to the vitamin D3 receptor (VDR) to exert its action in the body. Besides the classical functions of vitamin D3 on mineral metabolism, there are also non-classical functions such as effects on fertility. It has been observed that 1,25(OH)2D3 is important for implantation and placentation. There is also evidence that 1,25(OH)2D3 plays a role in immune modulation during pregnancy and influences oocyte quality. These are factors that are important to increase chances of successful insemination and maintain pregnancy, which all play a role in reducing the number of sows returning to estrus.

Trial results

Return to estrus in a field trial with Panbonis® given during gestation and lactation (8 Farms, ca. 6400 sows per treatment). Data are shown as mean ± SD

Reduced rate of return to estrus and reduced variability

Treatment Control 100 g/t Panbonis®
Return to estrus (%) 3.5 ± 2.5 2.7 ± 1.0

Additional trials on uterus involution and sow fertility are ongoing.

Our solution Panbonis®
  • fast time to action
  • reduces the return to estrus
  • supports implantation and placentation