Several experiments have been published into effects of dietary inclusion of small amounts of intact seaweed or seaweed components, beyond the common nutritional value. These effects include the use of seaweed as a prebiotic substance to influence micro biota in the digestive tract and for immunomodulation properties in pigs, to influence rumen fermentation. Seaweed can be used in animal diets in complete form, as a residue of bio processing, or as a source of bioactive components.
Sea Weed can be used in a pigs diet, but only at low levels and is a very good source for trace minerals once it has be washed, dried and ground. It is not a good source of protein or energy and if used in high levels will block the digestion of certain major feed ingredients.
Sorry to be the bearer of not such good news!!!! Though they are not as commonly used in pigs as in cattle, horses, goats or sheep, seaweeds may be used at low inclusion rate (<2%) to enhance pig health and pig meat quality.
Seaweed and seaweed extract are also thought to have potential prebiotic effects and to enhance immune functions in pigs. Seaweeds have therefor been assessed as potential antibiotics replacers in pigs. While many experiments have explored the effects of seaweed extract, we will only deal with intact seaweed as these only can be considered feed and not additive.
Second, the supplementation of laminarin and fucoidan extract increased the nutrient digestibility of the diets compared with the non-SWE diets. Little research has been conducted regarding the effects of SWE on digestibility or gut physiology in pigs. The increased digestibility may be due to the increase in the Lactobacilli spp. numbers observed with the SWE fed pigs. The SWE increased the numbers of lactic acid bacteria. These bacteria have an ability to produce a wide range of cell-associated polysaccharide depolymerises and glycosidase which may aid in nutrient digestion, and in particular will aid in the degradation of plant cell wall structural polysaccharides. It has also been reported that SWE may influence nutrient digestibility by maintaining the function and structure of the small intestine, leading to an increased digestive capacity of the gut (Reilly et al., 2008).
As well as being considered as a source of dietary fibre in monogastric nutrition, laminarin also have distinctive immunomodulatory characteristics. There is, however, considerable variation in the biochemical and solubility characteristics of ß-glucans and laminarin from ratio, a high index related to a greater resistance to intestinal disorders. A. nodosum added to well digestible diets did not enhance performances of piglets nor some gut health parameters and plasma oxidative status.
Mainly in young piglets, positive effects of seaweed components on some immunological parameters, gut morphology and gut health are observed. An important aspect is the extremely high variation in chemical composition within and between seaweed species. The digestibility of seaweed might be effected by processing and more specific the drying (heating).
Heat treatment is employed to dry certain plant products and to improve the quality of palliated feeds. Heat treatment can improves the nutritional value of seaweed meal and products by destroying the inhibitor which is naturally present, and by increasing the utilization of proteins and amino acids, fats, and carbohydrates present in the meal. Digestibility can be enhanced by heating and or partial "cooking" and thus the ME value is increased. There are several method available to improve digestibility and best know is cooking of food. There are many others like acid and alkaline treatment, ultrasound, enzymatic, micro wave, freezing . Most effective and common used is heat treatment or cooking food, you can eat cabbages raw but the nutrient content is low but after cooking the nutritional part is improved and include taste and flavour. We should also do not forget the influence of freezing as is now common. Increasing the nutritional value of seaweed for use in non-ruminants feed, especially pigs applicability of using brown edible seaweeds as a sole source of nutrition for the growth of lactic acid bacteria. Growth kinetics of lactic acid bacteria (LAB; Lactobacillus plantarum) was studied using three species of edible Irish brown seaweeds Himanthalia elongata, Laminaria digitata and Laminaria saccharina. As part of the screening process, growth of the LAB was carried out on raw and heat-treated forms of seaweeds. The seaweed species in their raw state could not support the growth of L. plantarum. Heat treatment resulted in almost 4 times increase in the total sugar content in L. digitata and L. saccharina broth which allowed the growth of L. plantarum for 24h after which the cell number started decreasing. In the case of algae it is all about the cell wall being disrupted resulting in an increase in digestibility of components. The resistance of the algal cell wall is generally a limiting factor for cell digestibility and species depended.
The digestive systems in pigs is in many ways similar to that of humans and a reason to have a closer look at its functions.
Easy degradable microalgae were found to have no cell wall (Dunaliella salina) or a protein-based cell wall without cellulose or hemicellulose (Chlamydomonas reinhardtii The cell degradation was 100% for D.salina and 70% for C.reinhardtii.
After pretreatment of N.salina a maximum of about 60%. Consequently, N.salina cell wall is resistant against enzymatic hydrolysis and degradability only improved by physical pre-treatment, roasted at 165°C for 150 min. After world war 2 and arround 1960 several scientist were resaying concerns about the ever growing world population and the impact it did have on planet Earth. The ever growing population would eventuality lead to a calamity. Micro algae were high on there list as alternative food supply than but never really made it because of digestibility. The cell wall of many of these microscopic cellular seaweed hard to crack and difficult to release the nutrients. Most used was freezing technique.
Use of seaweed because of iodine.
Seaweed are best known for their high organic iodine content and it has been shown that feeding pigs on seaweed (at 1.05 mg iodine /kg feed) could enhance tissues iodine content from 2.7 fold to 6.8 fold (Banoch et al., 2010; Dierick et al., 2009).
Entire seaweed fed during 76 days to 80 day-old pigs at 0.8% dietary inclusion were shown to increase IgA production in saliva and global immune function of pigs (Katayama et al., 2011).
In 2009 and 2010, seaweed were assessed in vitro and in vivo in order to establish their role on hindgut flora. Intact brown seaweed A. nodosum were included in basal diet at 2% shown to improve gut flora; it had depressive effect on E. coli and increased Lactobacillus : E. coli ratio, a high index related to a greater resistance to intestinal disorders.
The application of seaweed in animal diets and needs to be re-addressed.
Sows and piglets In young pigs, a number of experiments were performed to test the effects of intact seaweed or polysaccharides, e.g. laminarins and fucoidans, extracted from seaweed, on performance, gut health and immune status of different species.
Supplementing a diet with 2% dried iodine-rich intact marine seaweed (Ascophyllum nodosum) to weaned piglets had a reducing effect on the E. coli load in the stomach (P = 0.07) and small intestine (P < 0.05), while the lactobacilli/E. coli ratio was enhanced (P < 0.05) in the small intestine, indicating a beneficial shift in the microbial population (Dierick et al.,2009).
Under some conditions, humans lack iodine and it has been suggested that iodine status could be improved through milk and meat consumption. Providing iodine to animals in order to improve their products is feasible. However it was also found that inorganic iodine supply had no effect on pork meat iodine content. On the contrary only organic iodine is readily metabolized and was proven to be kept within muscles.
Researched as an alternative to in-feed antibiotics in pig diets (Gardiner et al., 2008; Reilly et al., 2008; Gahan et al., 2009). Because seaweeds are rich in indigestible polysaccharides and are a potential source of soluble dietary fibres. The most abundant polysaccharides in brown seaweeds are laminarin, fucoidan and alginic acid.
Lynch et al. (2010) showed that laminarin had antimicrobial properties while Deville et al. (2007) noted that laminarin can influence the adherence and the translocation of bacteria across the epithelial wall and seems to be a modulator of the intestinal metabolism by its effects on mucus composition, intestinal pH and short-chain fatty acid production, especially butyrate. Fucoidans are sulphated polysaccharides extracted from the cell wall of various species of brown seaweeds. Fucoidans have been shown to have antitumor, antiviral and antibacterial properties.