‘Seed, feed and weed’ – the new approach to gut disorders

Enteric disorders in poultry are a major burden on the industry – but an innovative new approach could finally provide an answer. Olivia Cooper reports

Poor gut health is becoming a vicious circle for some poultry producers, leading to wet litter, sub-optimal growth rates and increased risk of infections. In most cases, antibiotics have been used to address the problem, but these are becoming increasingly regulated and do not provide a long-term solution.

Now, a collaboration between vets, nutrition and water specialists and avian health experts, appears to have found the answer. Known as “Seed, Feed and Weed”, the integrated solution revolves around colonising the gut with beneficial microflora, feeding them with acidified water to encourage growth, and weeding out harmful pathogens with mycotoxin blockers. The idea is to work with nature, breaking the destructive cycle and encouraging natural bird health.

And according to Richard Turner, director at St David’s poultry team in Exeter, trials prove that it is working (see box). “I really feel that at last we can see a way out of this problem,” he said at a recent conference organised by Datapoul, which helped fund the research. “Since 2000 (when antiobiotic growth promoters were effectively banned in the UK) enteric disorders have become a real problem and conventional therapy is failing.”

Stephen Collett, from the poultry research centre at Georgia University, said that growing antibiotic resistance – in both pathogens and consumers – meant the industry had to change its way of thinking. “By using antibiotics we have avoided addressing the real issue behind enteric disease.”

The problem stems from the natural avian anatomy, whereby food passes down the gut and back up again for redigestion, combined with the industry’s aim to maximise appetite and growth rates. “Stress compromises performance, and it is then much easier for bad bacteria to pass through the gut wall and into the body cavity.”

The most critical time is in the first five days of life, when a chick’s gut is developing and growing villi and microvilli – essential folds in the gut to aid nutrient absorption. Enzymes, crucial to the digestion process, attach to these villi, and any damage has a dramatic impact on gut performance.

“The faster food flows through the gut, the fewer nutrients are absorbed, and the more protein that passes out into the litter, resulting in problems like hock burn and foot pad dermatitis,” said Dr Collett.

Nutritionists had worked hard to produce balanced feed rations that would yield optimum growth and performance, said Sam Smyth, poultry nutritionist at Devenish Nutrition. But perfect, tailored nutrition would only improve performance once all the other limiting factors in a unit had been addressed.

“Early access of chicks to food is essential, as the longer the delay the greater the impact on health and ultimate growth,” he said. “Early intake is needed to kick start gut development and bolster the immune system – but all nutrients are interlinked. If you have an unbalanced diet, the birds will eat more to address the deficiency, which then causes an excess of the other constituents.”

The birds’ kidneys then have to work hard to excrete excess nutrients, causing increased water intake and wet, nutrient-rich litter. “It’s a vicious cycle if you have enteric problems, as the birds aren’t absorbing the food they eat, so they eat more to address the imbalance, which makes it even worse.”

Adding enzymes, organic acids, fatty acids, probiotics and fimbria blockers to the ration, along with whole grain to slow down the passage of food, all helped to improve digestion and bird health, said Mr Smyth.

And this year, fimbria blockers could be more valuable than ever, with the wet harvest increasing the risk of mycotoxins in feed. “There are a huge number of mycotoxin species, and we need a lot more research into the interactions between them,” said Dr Swamy Haladi, global technical manager of the mycotoxin team at Alltech.

In the UK, more than 60% of feed samples tested positive for DON (deoxynivalenol – produced by fusarium), with 45% carrying famonisins, and nearly 30% penicillium mycotoxins. “There are between one and five mycotoxin species present in 83% of samples tested – we are massively under-estimating the challenges.”

Mycotoxins kill off beneficial microflora in the gut, damage intestinal villi, reduce liveweight gain and depress the immune system, said Dr Haladi. “When fed mildly contaminated grain (2ppm of DON), the birds took three days longer to reach market weight. But when combined with Mycosorb (a mycotoxin binder), it almost completely eradicated the problem. However, you need an holistic approach – simply adding Mycosorb to feed won’t work as well as an integrated plan.”

And that is where the final strand of the project comes in. Often ignored by poultry producers, water is a colossal source of bacteria and nutrient imbalances. “A chicken is 75% water, and they consume twice as much water as feed,” said Kim de Vries, poultry vet at St David’s. Producers using boreholes were particularly at risk of contaminants, but even those on mains supply should test their water every six months, both at source and at the end of the drinker line.

“Limescale and biofilms can build up in the water tank, pipes and drinker lines, which provide an ideal environment for bacteria,” she said. Producers should test for bacteria, and use a sanitiser to clean the water and drinking lines. “Look at your water’s pH, hardness, dissolved solids and mineral content – all can interfere with medication and affect the type of sanitiser you should choose.”

For example, chlorine would not destroy biofilm or limescale; organic acids only removed limescale, and hydrogen peroxide only treated biofilms. “You need to rotate your sanitiser to target all areas.” However, adding buffered acids would improve bird health, by treating the water, reducing bacteria in the crop and slowing down the passage of food through the gut, she added.

By bringing these tools together, farmers were seeing a dramatic improvement in bird health and productivity, said Mr Turner. “We’ve trialled Seed, Feed and Weed in more than 20 crops on six farms – that’s 2.5m broilers. All farms have seen a significant improvement in litter quality, and the best financial result was a £15,000 jump in profits. They have all since rolled the system out across every house on their farms – it really does look exciting.”

* For more information contact St David’s Poultry Team on 01392 872 932.

PUT TO THE TEST ON FARM

Following trials with borehole water, Mr Turner wanted to see the impact of Seed, Feed and Weed on a farm with mains water. He chose a unit finishing 164,000 birds in five sheds, with a history of wet litter and a need to medicate for enteric disorders. The process was implemented in sheds two and three, albeit with a slight delay in shed three due to unforeseen circumstances.

“The quality of the litter was infinitely better – there was no smell, and it was considerably drier,” he said. All the houses were thinned at 33 days, with the birds in the control sheds weighing 1.83-1.86kg. Those in house three weighed 1.85kg, and in house two 1.95kg. The end crop weighed 2.48-2.51kg in the control sheds, with shed three at 2.53kg and shed two at 2.63kg.

Across the whole site, including the control sheds, feed conversion dropped from 1.74 in the previous crop to 1.64, with European Production Efficiency Factor (EPEF) rising from 291 to 351.

“The treatment cost with mains water averages 2p/bird, so the farmer needed 4.75p/sq m each week to pay for it,” said Mr Turner. “His previous crop averaged 88p/sq m a week, with a five-crop average of £1.05/sq m – but this trial group (including the three control sheds) yielded £1.16/sq m – that’s an 11p improvement, which goes straight to the bottom line.”

Capital costs to install the acid tanks and water infrastructure averaged about £2,000, depending on the site – but farmers could quickly recoup that through reduced bedding and medication costs. “And if you use a borehole, water costs will be reduced, too. However, it is important to address any underlying problems like Gumboro before moving on to this system – it’s not a silver bullet for all ills. Without doubt, it is paying in the field, and we’re now carrying out more trials to improve the data we’ve got.”