A division of the Chinese Academy of Science, the Dalian Institute of Chemical Physics, has come up with a new way of turning waste lobster and seafood shells into a high grade human and animal feedstuff that can control gut health.
It is a novel chitin oligosaccharide that can potentially replace the antibiotics that are still widely used in China. The use in pigs gave an increase in ADG of around 18% in early trials and this is way ahead of any other oligosaccharide trials.
Undoubtedly when antibiotics are used in a ‘normal’ feeding programme for young animals such as broilers or young post-weaned piglets, they can have very significant effects on growth performance, feed intake and feed conversion efficiency. They will also help to reduce mortality and morbidity levels for the whole farm. In Asia especially there have been few restrictions to the use of such on-farm antibiotic programmes.
Around the world at the time of writing (June 2012) there was a major drive to redress this situation with the withdrawal from use of antibiotic growth promoters (AGPs). The European Union began this with a new legislation in 2006 and more recently we have seen other countries beginning this process. Korea has been the first in Asia to begin the withdrawal of AGPs and Taiwan and the Philippines are also in detailed discussions working towards taking them out of use. China may also in the near future begin the process towards AGP free farming.
Alternatives to AGPs
Much detailed research has been completed over the last 15 years on the development of alternative applications and programmes and this has given us some effective pointers. We require systems that control the microflora in the gut lumen through the whole digestive system and which will prevent the colonisation of those gram negative bacterial serotypes that will either be pathogenic in action or at best which will generate toxins on the gut lining that will reduce the efficiency of digestion and hence growth. Most strains of E. coli and Salmonella organisms fall into these categories.
There is a very large array of micro-inclusion products that can also be used to enhance growth and feed efficiency. These include: acidulant blends, essential oils, immune-stimulants, probiotics and also prebiotics. This latter group of compounds can be particularly effective because they cover almost all of the functions of the other substances. An effective prebiotic is a molecule that can act as a good substrate in the gut for the growth of the beneficial bacteria and these are usually serotypes of lactobacillus and bifida type bacteria that effectively colonise the gut lining and keep the gut in a healthy condition. The prebiotic is hence stimulating a probiotic effect. What has also been determined more recently is, that prebiotics themselves can, if selected and developed carefully, act as strong immune-stimulants on the gut lining enterocytes and villus structures to enhance the enteric mucosal immune system which facilitates natural gut defence.What also happens when a prebiotic is applied, because of the enhanced lactobacillus flora, the level of acidity in the gut lumen increases due to the increased production of lactic acid, this in turn reduces the gut pH. Reduced pH in the gut lumen then has a very potent action in reducing the proliferation of gram negative bacteria and weakening bacterial cell replication.Prebiotics therefore can start a chain of biological actions in the gut wall and gut lumen that is extremely beneficial to the gut and general health status of the animal. If we select the molecules carefully we will significantly reduce the need for AGPs in livestock production.
The most favoured molecules as prebiotics in animal and human nutrition are the oligosaccharide molecules produced from a number of sources. These include manan-oligosaccharides, fructo-oligosaccharides, chitosan oligosaccharides, transgalacto-oligosaccharides and inulin, all of these have been used in livestock nutrition programmes. Some of them also have been researched widely to demonstrate their physiological actions and their ability to deliver some of the targets mentioned above.
A relatively novel oligosaccharide has been developed recently in China by a branch of the China Academy of Science at the Dalian Institute of Chemical Physics. This is an oligosaccharide structure derived from shrimp shells and the attached chemical moiety is a chitin molecule. The so-called COS (Chitosan Oligosaccharide) product has been the subject of a detailed research and development programme at the Dalian Institute to evaluate, in great detail, the immune functions, associated microbiological interactions and gut effects. The research techniques have also been directed at its antigenic binding characteristics and its ability to perform all of the things that we expect from a prebiotic molecule. The final stage of this research was its application in animal growth trials and although these are on-going the early results with growing broilers and young piglets have been very encouraging indeed with good growth responses. In Table 1 you can see the data from a trial carried out with post-weaned piglets. The NC and PC treatments are Negative Control and Positive Controls respectively and the 100, 200 and 400 treatments denote the inclusion level (ppm) of COS product applied. It can be seen that the COS treated piglets exhibited significantly improved lactobacillus development coupled with suppressed E.coli growth and this was reflected in significantly improved diarrhoea scores and the incidence of diarrhoea.
In Table 2 the given data is from an experiment carried out on 300 post-weaned piglets. The COS group grew 25% faster than the NC (Negative Control) group and 19% faster than the PC (Positive Control) group given an in-feed antibiotic. In addition the COS group expressed an FCR that was 3.3% better than the PC group.
The new COS products show great promise in terms of their ability to control the microflora in the gut of young growing pigs and poultry. The depth of science that has been utilised in this work has given a powerful knowledge based on the in-feed applications. Work on immune development and villus structure development has complemented the growth trial work illustrated above. Similar observations with broiler chickens have also been made.
It may be that these new molecules will prove effective AGP alternatives and if the results shown in Table 2 are substantiated in further commercial trials, then not only will the use of in-feed antibiotics be unnecessary but the COS products will be a very profitable tool for the progressive livestock farmers of today. The further spin-off from the application of prebiotics is that consumers are increasingly aware of these substances that are also used in many human health products and they are perceived as a very natural feeding technology. PP