Weaning piglets without antibiotics is currently the biggest challenge in producing healthy and efficient swine. The main challenge is starting too late and only looking at managing the weaned piglet, a balanced approach starting with the late pregnant sow is needed to succeed. This article highlights the main factors to consider efficient digestion, appropriate immune status and microbiome management when producing piglets with as little antimicrobials as possible.
Only a healthy sow can produce a large litter of even weight and good health. Then she has to provide them with sufficient milk to grow and develop vital systems such as a mature immune system. Providing enough milk is a physiological challenge for the sow, with her milk having approximately twice the energy (5.3 MJ GE/kg) and fat of cow’s milk (2.7 MJ/kg). Therefore, without a fit sow there can be no healthy piglets.
The sow’s contribution to piglet health goes further in the pre-weaning period. Piglets gastro-intestinal tract is only beginning to establish a microbiome of its own after birth. The sow contributes to this in two ways.
The sow has a developed immune system, so while she might appear healthy, she might still pass on harmful bacteria such as aggressive E. coli to her piglets. Considering the immature immune system of the piglets, only they may show disease which was passed on by the dam.
Piglets are weaned at unphysiologically early ages. Two systems are most affected, the gastro intestinal tract and the immune system. The gastro intestinal tract is affected by a change in microbiome, mechanical damage, and inflammation as reaction to the stresses (social, nutritional, handling) of weaning.
The effects are aggravated by the immature immune system which has not developed a full adaptive immune response and is therefore relying more on the innate immune response. Piglets are at a substantial risk of disease and translocation of pathogens from the intestinal tract at weaning.
Practices differ between countries, but wherever possible, piglets receive their first antibiotics (Colistin, Amoxycillin, CTC, Lincomycin, Tiamulin, Tylosin) already before weaning in an attempt to reduce potential pathogens. The damage to the desirable microbiome however makes piglets even more susceptible to those organisms that have widespread antibiotic tolerance such as Salmonella. In the US, antibiotic resistance in Salmonella has been reported at levels up to 78% for commonly used antibiotics.
After weaning, levels of zinc oxide of up to 2800ppm are used to manage intestinal health. This is working to a point; however, it makes absorption of crucial minerals such as iron very challenging for the treated piglets.
Even where legal, administering antibiotics to piglets has negative side effects and even zinc oxide has downsides (mineral absorption effect). There is no single solution how to replace one or two antibiotics and zinc oxide with a single component. Feed can help support piglets without antimicrobials in several ways.
It is possible to reduce the use of antibiotic and zinc oxide in piglets. However, there is no simple solution that can cover all risks to piglet’s health at young weaning ages and weights under 8kg. Ensuring acidification of the stomach content, a good digestibility of the feed, a primed immune system and modulation of the microbiome together however can maintain piglets’ health.