Enteric bacterial infections, like swine dysentery, salmonellosis, and ileitis can be isolated from most swine herds. In fact, a pork producer can find such bacteria almost anywhere in a pig barn by collecting a fecal sample and having it analyzed at a veterinary diagnostic lab. These bacteria often find their way into a herd from the comingling of pigs from multiple sites.
Adding stressors can take this already present bacteria from dormant to infectious leading to negative impacts on swine production. These stressors include weaning stress in the nursery, out-of-feed events where pigs are off of feed for six to 12 hours, or comingling stress.
Swine producers can reduce the severity of bacterial infections by supplementing their swine nutrition and feeding program with performance trace minerals like zinc. Zinc plays a role in helping a pig mount a rapid and robust immune response — which will improve performance and increase survivability, ultimately having a positive effect on a swine producers’ bottom line.
Signs and Economic Impact of Bacterial Infections
Whether it’s dysentery, salmonellosis or ileitis, the symptoms are going to look similar since they are all enteric bacteria. The primary symptoms focus around diarrhea. This will decrease feed intake or take pigs off of feed, which naturally reduces growth.
Producers may treat with an antibiotic to try to get ahead of the infection, increasing treatment costs. With some severe infections, we can even see an increase in mortality.
In the case of subclinical diseases, the infection will be present without showing any clinical signs but will still slow pig growth. In one study, subclinical ileitis reduced average daily gain by 59% and total bodyweight by 4.3 kg (9.48 pounds) compared to healthy pigs, resulting in a loss between $3 and $11 USD (2.65€ and 9.75€) per pig marketed.
Performance Trace Minerals Reduce Severity of Bacterial Challenges
Performance trace minerals won’t prevent an infection, but they can reduce the severity. Zinc from Availa®Zn will help pigs mount a more adequate immune response. Pigs may still develop diarrhea, but it will not be as severe or lead to a drastic increase in mortality.
Performance trace minerals help maintain feed intake during a disease challenge, which allows a pig to use more nutrients for immune function and growth. Driving feed intake will help maintain average daily gain, resulting in a pig growing to finishing body weight quicker.
In a Zinpro research study, in which a small number of pigs were challenged with swine dysentery, feeding ZINPRO® zinc methionine improved average daily feed intake by 0.47 kg (1.04 pounds), which resulted in an increase in survivability compared to pigs supplemented with zinc oxide.
In another study, feeding performance trace minerals decreased mortality and sick days in pigs facing a salmonellosis challenge compared to pigs fed zinc oxide. Mortality was reduced by 37.5% and sick days were reduced by 25%. This faster recovery from a bacterial infection resulted in a 100% increase in total gain and a 50% increase in total pork production, which ultimately had a $20.19 USD (17.56€) net return per pig to the producer’s bottom line.
Performance Trace Minerals Improve Antibody and T Cell Response
Feeding zinc from Availa-Zn also reduces gross lesions and gross lesion severity in pigs facing a Lawsonia intracellularis challenge due to a more rapid and robust immune response.
In a Zinpro research study, where pigs were given a subclinical Lawsonia intracellularis challenge and fed either Availa-Zn or zinc sulfate, 100% of the pigs fed Availa-Zn were serum antibody positive compared to just 83% of pigs fed zinc sulfate by day 28 post-inoculation. This means the pigs fed Availa-Zn had more antibodies present in their blood than pigs fed inorganic zinc.
Feeding Availa-Zn also resulted in a more rapid T-cell response, as pigs fed Availa-Zn had 85% more T-cells per infected crypts compared to pigs fed zinc sulfate at 21 days post-inoculation.
As a result of a more rapid and robust immune response, only 33% of pigs fed Availa-Zn had gross lesions at necropsy compared to 100% of pigs fed zinc sulfate at 28 days post-inoculation. Additionally, pigs fed Availa-Zn had 50% lower gross lesion scores at 21 days post-inoculation and 77% lower gross lesion scores at 28 days post-inoculation compared to pigs fed zinc sulfate.
Vaccine Response Enhanced with Performance Trace Minerals
Availa-Zn also improves vaccine response. When facing a clinical Lawsonia intracellularis challenge, pigs supplemented with Availa-Zn in combination with an ileitis vaccine had an average daily gain 13% higher than pigs fed zinc sulfate with the vaccine at 21 days post-inoculation. Additionally, mortality was 80% lower for pigs fed Availa-Zn.
Improve Commercial Production with Performance Trace Minerals
Dysentery, salmonellosis and Lawsonia intracellularis are present in pig barns but require a stressor in order to become a disease. While zinc from Availa-Zn can’t prevent infections from happening, feeding Availa-Zn can decrease the severity of the bacterial infection by helping pigs mount a more rapid and robust immune response. This will, in turn, improve commercial production factors and improve a pork producer’s bottom line.