Beyond zinc oxide (ZnO):
how to raise robust piglets to successfully overcome the weaning challenges ?
Sustainable nutritional solutions for enhancing resilience against post-weaning stress
Challenges of early weaning
Early weaning practices and their impact on piglet development
Early weaning, a stressful start in modern pig farming
Modern pig farming is done on a large scale, focusing on efficiency and high production. This usually includes tightly controlled environments and practices designed to promote rapid growth.
One such practice is early weaning, where piglets are abruptly separated from their mothers and introduced to new surroundings, often mixing them with piglets from other litters or farms, causing considerable stress. Piglets are usually weaned as early as three to four weeks of age, a period when their immune system and microbiome are still developing.
Moreover, they must adapt to a new diet of solid, plant-based starter feed, which is a significant change from the highly digestible sow’s milk they are used to.
Weaning weakens
gut health
These challenges linked to weaning have a negative impact on piglet welfare, growth and health.
A major concern is the weakening of the intestinal barrier and the disruption of intestinal morphology. Additionally, the stress associated with weaning, combined with the sudden shift from milk to solid feed, can lead to decreased feed intake, hindering the adaptation of the intestinal flora to the new diet. This complicates digestion and nutrient absorption, resulting in increased osmotic pressure and reduced fluid absorption in the intestines, which raises the likelihood of diarrhea and dehydration.
Infection risk increases
production costs
Furthermore, since the immune system is not yet fully functional, piglets become more vulnerable to enteric bacterial infections, such as Enterotoxigenic Escherichia coli (ETEC), a common cause of post-weaning diarrhea (PWD).
Consequently, the pig industry often experiences financial losses shortly after weaning due to slower growth rates, increased mortality and higher treatment costs.
Zinc – an effective but highly controversial solution
From antibiotics to zinc oxide
Post-weaning diarrhea (PWD) has long been a major cause of economic losses in pig production, leading to the preventive use of antibiotics as growth promoters. However, the European Union prohibited this practice in 2006 due to concerns over antimicrobial resistance, paving the way for zinc oxide (ZnO) as an alternative. The attractiveness of ZnO lies in its affordability, wide availability in many EU countries, and its ability to be used in high doses as a trace element through premixing. High dietary levels of ZnO (2000-3000ppm) became common during the critical weaning phase and showed its value for supporting gut health through several mechanisms.
Firstly, ZnO proved to reduce intestinal permeability and improve intestinal barrier integrity through increased tight junction protein expression and a better villus height to crypt depth ratio, which are essential for nutrient absorption.
ZnO also promotes a healthy balance of intestinal microbiota, encouraging beneficial bacteria while inhibiting harmful pathogens. Furthermore, it boosts digestive enzyme activity, improving nutrient digestibility and growth performance in weaning piglets. As an antioxidant and immunomodulator, ZnO also supports overall well-being and immune function, and reduces inflammation.
The zinc shift: towards zero ZnO
Despite its advantages, ZnO has faced criticism for its environmental impact, particularly its contribution to soil and water pollution, and its potential role in promoting antimicrobial resistance. As a result, the European Commission announced plans to phase out high-dose ZnO as a therapeutic agent and growth promoter for pigs. As of 2022, ZnO can still be used as a feed additive, but only at a maximum dietary zinc limit of 150 ppm.
With this restriction in place, pig producers must seek alternative strategies to manage PWD and support pig health without relying on ZnO. Various nutritional options are now available to help young animals after weaning, focusing on maintaining a balanced intestinal flora and a healthy gut barrier to prevent diarrhea. Promoting intestinal health involves stimulating beneficial bacteria while inhibiting harmful ones, which can be achieved through feed additives that provide antibacterial effects or support the intestinal mucosa.
Stress and zinc deficiency drive endotoxin leakage
From ZnO ban to Endotoxins: piglets facing new health risks
As previously explained, ZnO has several positive effects on gut health. However, with the ZnO ban in place, these beneficial effects are no longer present, compromising the gut barrier.
A major consequence of zinc deficiency is the reduction of tight junction proteins, increasing intestinal permeability, which is even further aggravated by the stress associated with weaning itself. As a result, piglets become more vulnerable to gastrointestinal infections and endotoxin leakage, as the disruption of tight junction proteins allows pathogens and toxins to pass through the intestinal wall.
Endotoxins, which are toxic substances found in the outer membrane of Gram-negative bacteria, are typically derived from bacteria in the gastrointestinal tract, feed, and water. They are released when bacteria die or multiply, and can trigger strong immune responses that can lead to inflammation and various health issues.
⚠️ Once released into the bloodstream, endotoxins cause a strong inflammatory response that comes at a substantial cost by consuming energy and nutrients vital for growth and production.
This redirection of resources not only hinders overall growth, but also weakens the animal’s immune system, making it more susceptible to diseases. In addition, endotoxins can significantly trigger the development of various metabolic disorders.
Introducing EndoBan as alternative to ZnO
An effective gut barrier is crucial for gut health and prevents the entry of endotoxins into the bloodstream. Weaning can exert pressure on piglets’ digestive systems, causing increased permeability during the post-weaning phase and contributing to endotoxin leakage.
To address this, Nutrex has developed EndoBan®, a unique feed additive that stimulates LPS detoxification and removes endotoxins before they can translocate through the intestinal barrier. This product has shown to be an effective alternative to ZnO in a trial conducted on a Belgian farm with three-week-old Danbred x Piétrain piglets. The trial aimed to assess the impact of this additive on piglet growth performance compared to high levels of ZnO and to evaluate inflammatory parameters. EndoBan® was administered at a dose of 1000g/t of feed throughout the whole trial, while ZnO was provided at 1556g/t of feed only during the first 14 days.
EndoBan®: enhancing piglet growth and feed efficiency in post-weaning trials
The trial results revealed differences in performance between piglets supplemented with EndoBan® and those in the control and ZnO group (Figure 1).
By the end of the experiment, EndoBan piglets reached a final body weight of 21.3 kg, compared to 20.4 kg for the control group.
Additionally, daily feed intake was higher in the EndoBan® group (413.2 g/day) than in the control group (402.5 g/day), leading to an improved feed conversion (FC).
When comparing the EndoBan group to the ZnO group, both had similar final body weights, but the EndoBan group consumed less feed (413.2 g/day versus 430.6 g/day). This resulted in a better FCR for the EndoBan piglets, indicating more efficient feed utilization.
Figure 1. Effects of EndoBan and ZnO on body weight and feed conversion.
Reducing inflammation: the role of EndoBan® and ZnO in modulating immune responses
To assess the impact on inflammatory status, the gene expression of two key parameters involved in initiating inflammatory responses due to endotoxin leakage were analyzed: TLR-4 (Toll-like receptor 4) and NF-kB (Nuclear Factor Kappa B).
The TLR-4 receptor specifically recognizes and binds to endotoxins, triggering the activation of the NF-kB pathway and initiating an inflammatory response. At day 14, gene expression levels of both TLR-4 and NF-kB in the small intestines were downregulated in piglets fed diets supplemented with EndoBan and ZnO (Figure 2).
The comparable reduction in expression suggests that both supplements help decrease inflammation in the small intestine, which likely contributes to the improved growth performance observed in both groups. With less nutrients diverted to the immune system, more are available for growth.
Figure 2. Effects of EndoBan and ZnO on
pro-inflammatory parameters NF-kB and TLR-4
To conclude: Endoban, a promising strategy
In conclusion, early weaning presents piglets with significant challenges, including stress and reduced gut health, which can lead to PWD and economic losses for producers. Although ZnO has traditionally been an important solution for PWD, the ban on ZnO due to its environmental impact and risk of antibiotic resistance makes it necessary to explore alternative strategies to support pig health.
Trial results highlighted that EndoBan is a promising alternative to ZnO, achieving comparable growth while improving feed efficiency and reducing feed intake. Moreover, EndoBan achieved comparable reductions in inflammatory parameters in the small intestine (TLR-4 and NF-kB) as ZnO, making it an effective option for promoting intestinal health and preventing diarrhea in weaned piglets.
WHAT TO EXPECT FROM ENDOBAN !
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- EndoBan limits the leakage of endotoxins through the gut barrier
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- EndoBan prevents energy-consuming inflammatory responses
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- EndoBan improves growth, feed intake and feed conversion
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- EndoBan boosts the immune system
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- EndoBan provides a reliable alternative for ZnO
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