The foundations of a successful transition period for sows: a holistic approach

It is essential to minimize stress at all levels, as stress can reduce the secretion of prolactin and oxytocin, thereby decreasing uterine contractions and the secretion of colostrum and milk. Stress can also cause behavioral disturbances in the sow, such as nervousness and aggression. These behaviors can result in a higher number of crushed piglets or even piglet rejection. Furthermore, chronic or repeated stress reduces the immune response, compromising the animals’ health.

The transition period coincides with a change in housing from the gestation room to the lactation room, which generally involves moving from group housing to individual housing. Sows must be moved with extreme calm and care. To this end, the functional design of the aisles and adequate lighting are essential.  Furthermore, to ensure prior adaptation to the new conditions, it is crucial to make the housing change well in advance of farrowing.

The optimal comfort temperature for sows is between 18 and 22 °C, with an ideal relative humidity of 60–75%, to prevent heat stress, which could prolong farrowing and reduce feed intake as well as colostrum and milk production. On the other hand, newborn piglets require a micro-climate with temperatures between 34 and 38 °C during the first hours and days of life. To achieve maximum energy efficiency, it is essential to have good thermal insulation in the barns, as well as a ventilation system that maintains good air quality without creating drafts on the animals. Additionally, cooling systems are necessary, especially in warmer climates. It is also essential to provide optimal space per animal and a functional design for the farrowing room, including a heated resting area for the piglets.

The use of free-range farrowing pens allows for the sow’s unrestricted movement, which reduces her stress levels and improves her intestinal motility through exercise. In such systems, an increase in nesting behavior has been observed (Peltoniemi et al. 2021), along with a reduction in farrowing duration and the number of stillborn piglets. Although higher perinatal piglet mortality due to crushing has been observed, a balance can be achieved by implementing partial confinement of the sow during the first few days around farrowing.

During the transition phase, the sow should be in optimal body condition, and obesity should be avoided. It is possible that adipose tissue stores fat-soluble steroids, such as progesterone, which would delay its reduction prior to farrowing, weakening uterine contractions and hindering colostrum secretion (Björkman et al., 2020). Elevated postpartum progesterone levels can inhibit lactogenesis and reduce milk yields (de Passille et al., 1993). Likewise, it is recommended to avoid sows with excessively poor body condition, as they will not be able to successfully navigate this period and their subsequent fertility will be compromised.

It is imperative to prevent constipation in sows, as this complicates the expulsion of piglets, prolonging farrowing. Furthermore, reduced intestinal motility can lead to increased bacterial growth (dysbiosis), which results in an excessive release of endotoxins and high levels of oxidative stress, triggering a local inflammatory reaction in the intestine. It is important to note that endotoxins can be absorbed from the intestine and affect the normal endocrine changes associated with farrowing (Martineau et al., 1992). Regular use of the Agrifirm fecal scoring system enables objective assessment of fecal quality in sows and facilitates the implementation of appropriate corrective measures.

The traditional gestation period for sows (114 days) has increased with new lines of hyperprolific sows, with gestations in practice ranging from 113 to 121 days in duration. Pharmacological induction of farrowing is carried out by administering prostaglandins, and farrowing occurs between 20 and 36 hours after administration. Synchronizing farrowing can facilitate birth assistance and the handling of piglets for adoptions and colostrum feeding. However, their premature use can result in reduced birth weight, lung function, and vitality, which may reduce colostrum production and the piglets’ survival rate.

Oxytocin is used in prolonged births, in the absence of piglets in the birth canal, to induce uterine contractions and facilitate the expulsion of the piglets. However, an excessive dose can cause excessive uterine contractions and delay farrowing, increasing the risk of hypoxia and stillbirths.

Colostrum is only available for 24 hours, and its concentration of Immunoglobulin G (IgG) decreases rapidly after the onset of farrowing (Le Dividich et al., 2017). During the first days of life, piglets exhibit high levels of trypsin inhibitor activity in the gastrointestinal tract, which prevents the degradation of maternal Ig present in colostrum, thereby enabling its absorption in the intestine (Markowska-Daniel et al., 2010). However, this absorption capacity gradually decreases until 24–36 hours after birth, at which point physiological intestinal closure occurs, thereby preventing further absorption (Rooke and Bland 2002). Colostrum intake has a positive correlation with plasma IgG levels in piglets at 24 hours of age and at weaning (Devillers et al., 2011) – and, for this reason, it is essential to ensure an optimal colostrum intake of 250 ml per piglet (Ferrari et al., 2014). Failure to rapidly ingest an adequate amount of colostrum is considered one of the main causes of pre-weaning mortality (Quesnel et al., 2012), and this also compromises survival and health status after weaning. The implementation of management techniques, such as ‘split suckling’, is essential to promote proper colostrum intake from the mother.

During the short transition period, the sow’s nutritional requirements undergo significant changes. In the final phase of gestation, the sow has higher requirements to ensure significant fetal and mammary growth, as well as colostrum production. The farrowing process requires a great deal of energy, and, subsequently, milk production generates high nutritional demands. If feed intake or composition is inadequate, the sow will mobilize body reserves to ensure fetal and reproductive tract growth (Theil et al., 2022). On many farms, to facilitate handling and management, sows switch from a gestation diet with low energy and protein and a higher fiber content to a lactation diet with higher energy and protein and a lower fiber content upon entering the farrowing pen. To optimize results, we recommend using a transition diet. Fiber is very important in the transition diet: incorporating higher levels of soluble fiber, such as sugar, beet pulp, along with other insoluble fibers, reduces the risk of constipation, shortens the duration of labor (Oliviero et al., 2010), and provides sustained energy after meals (Serena et al., 2009).

The use of highly digestible protein sources ensures optimal fetal growth and maximizes colostrum and milk production, while preventing unwanted fermentation. The inclusion of specialty soy products like HP-270 in transition diets has been shown to improve piglet birth weight and litter uniformity, as well as increase the quantity and quality of colostrum produced by the sows. To meet the demands of farrowing and colostrum production, energy levels and fat inclusion in the diet must be increased compared to gestation feed.

The formulation of the transition feed should promote calcium homeostasis, as this is essential for maintaining the contractile activity of smooth muscle and uterine contractions, as well as colostrum production. Maintain adequate calcium levels and a low electrolyte balance during the peripartum period to generate a relatively acidic blood pH that increases free calcium levels, thereby reducing stillbirths and the risk of urinary tract infections.

This is an aspect that requires special attention, as it has a significant impact on outcomes. It is of utmost importance to use feeding curves tailored to the individual needs of each sow, avoiding excessive restrictions on feed intake to prevent constipation and/or nutrient deficiencies. Feeding sows higher amounts of feed during the transition period reduces the duration of farrowing and the number of stillborn piglets, and improves colostrum production. However, excessively high amounts affect farrowing negatively (Feyera et al., 2021).

Feeding sows no later than 3 hours before the onset of farrowing reduces the duration of farrowing, the need for manual assistance, and the number of stillborn piglets (Feyera et al., 2018). Increasing the frequency of daily feedings leads to higher feed intake, which helps improve production performance and increases piglet survival rates. During warm seasons, it is recommended to adjust feeding schedules to avoid the hottest hours of the day and to maximize feed intake. Automatic electronic feeding systems maximize feeding frequency, intake, and feed efficiency, while reducing manual labor. Although this represents a significant investment, it is highly cost-effective.

In addition to the measures mentioned, Agrifirm offers the option of supplementing sows’ diets with functional ingredients, which helps improve the performance of the sow and her offspring.

• C-Vita is a unique combination of active medium-chain fatty acids (MCFAs) that stimulate immunity in sows and their offspring. C-Vita increases both the quantity and quality of colostrum, while also increasing neutrophil viability (De Vos et al., 2021). This strategy improves the health of sows and their piglets, increasing their survival rates and performance.
• Vitanox is a carefully selected blend of natural polyphenols with high antioxidant power. These polyphenols neutralize reactive oxygen species (ROS) formed during oxidative stress in the intestinal lumen, protecting intestinal cells from intracellular oxidation and preserving the integrity of the intestinal barrier. This prevents the translocation of pathogens, endotoxins, and toxins from the intestinal lumen into the bloodstream, reducing metabolic disorders and improving health status and production performance.
• The addition of a mycotoxin and endotoxin adsorbent with proven in vitro and in vivo efficacy, such as Vitafix Spectrum, significantly reduces the adverse effects of mycotoxins. Furthermore, this adsorbent captures endotoxins in the gastrointestinal tract, preventing their local action on the gastrointestinal mucosa and their absorption into the bloodstream, thereby reducing their systemic effects.