NUTRITION ▶▶▶
Tackling ileitis by boosting immunity
The use of performance trace minerals to bolster the immune system can help swine producers reduce the losses associated with clinical and subclinical ileitis. Adopting resilient control solutions is becoming increasingly important as options for control become more restricted.
BY DR ZACH RAMBO AND DR CHRISTOF RAPP, ZINPRO CORPORATION I
leitis remains a widespread and financially significant problem, reducing growth rate and unit throughput and increasing mortality. It is becoming more of an issue as the global swine industry moves to reduce the use
of antibiotics. Ileitis is a widespread challenge, and treatment has usually revolved around vaccination and the use of antibiotics – but the use of antimicrobials is being removed from the control armoury. Ileitis is commonly seen as an issue in growers and finishers but is now increasingly seen in the late nursery phase as antibiotic restrictions are imposed.
Subclinical ileitis Subclinical ileitis is less well understood and recognised, of- ten being indistinguishable from other enteric challenges. Visible signs such as rough hair and gauntness are often not seen, but average daily gain will be affected, commonly reduced by between 10% and 37%. The cost of the disease to the industry is significant. About 40% of businesses report a level of clinical problems in the herd, and all will also be suffering the effects of unseen sub- clinical disease. As many as 50% of units will have subclinical issues and be largely unaware of it. They will simply see poorer performance and probably attrib- ute this to other causes. The cost of subclinical disease is esti- mated to be around € 3–11 per pig marketed. This soon mul- tiplies into significant sums when taken across a whole unit with several batches per year. To this morbidity effect can be added the costs of increased mortality and the costs of management disruption including reduced throughput, particularly in “all-in-all-out” systems. The cost of ileitis in swine herds can therefore be considerable,
28 ▶ PIG PROGRESS | Volume 37, No. 1, 2021
making control and reduced incidence a prime objective to improve efficiency.
Development of ileitis Ileitis develops as infection with Lawsonia intracellularis and has a significant impact on the small intestine. The infectious agent infiltrates the gut lining and suppresses the ability of the pig to mount a strong immune response and destroy spe- cific pathogens by reducing the activity of the part of the immune system known as T-cells. By suppressing the immune function, the bacteria can contin- ue to reproduce resulting in a thickening of the ileum, a con- dition often referred to as “garden hose gut”. This thickening of the ileum leads to malabsorption of nutrients, diarrhoea, reductions in feed intake and consequently a lower daily gain. Morbidity is common in subclinical situations, while mortality can occur in severe cases. Suppression of the im- mune system also compromises the pigs generally, making them more susceptible to secondary infections.
Reducing the incidence of ileitis One way to reduce the incidence of clinical and subclinical il- eitis is to take steps to ensure the animal’s immune system is robust and able to respond to the initial challenge to help prevent the disease becoming established. Trace elements have a significant role in the functioning of the immune
Figure 1 - Animals positive for Lawsonia intracellularis serum antibodies.
120 Zn sulphate 94 80 83 83 Performance mineral* 100 100
40
50
0 14 * Availa-Zn. 21 Days post inoculation 28
Serum antibody positive, %
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36
