As it is known, the use of antibiotics was banned as growth factor in animal fodder after the drawbacks of antibiotics for human and animal health were uncovered. These legal developments regarding antibiotics brought alternative fodder additives such as probiotics. Probiotics are biological products that contain live bacteria or yeast cultures and that are mixed in the form of powder, granules, liquid suspension, capsules and pellets in order to regulate stomach-intestine flora and fauna, to prevent the development of pathogen microorganisms and to increase benefiting from fodder. Although probiotics improve animal performance, there are some distinctions in their use. In fact, the fact that probiotics contain live organisms is the most important subject. Therefore, probiotics must not be considered in a way similar to the other fodder additives and must not be offered for trade. For the preservation period to be appropriate, probiotics must be stored in a fridge or a cool, dry place and they must be protected from direct sunlight. Factors such as humidity content, pH level, contact with air and storing conditions affect the liveliness of probiotics to a great extent. In the recent years, important progress has been made in fodder processing, packaging and product standardization but fodder processing has significant impact on the effectiveness of probiotics.
Probiotics that are used in animal feeding and the fodder industry
The probiotics that are used in animal feeding and fodder industry contain bacteria types such as Lactobacillus, Streptococcus and Bacillus and some mushroom or yeast types (Chart 1). The live cultures that are used probiotics have two basic forms: the first one of these is a vegetative form that are sensitive to heat and humidity. They are used in ruminant since they can be affected by stomach acid in those living beings that have one stomach and they lose their liveliness partially during pelletizing. The second one is a spore form that is naturally protected from strong stomach acid, antibiotics, heat and storing period. However, not all beneficial microorganisms have a spore form. The ability of these microorganisms to withstand different environmental conditions varies. Lactobacillus group microorganisms are extremely sensitive and they cannot endure the heat and pressure that emerges during pelletizing. There are also differences among types in terms of their endurance vis-a-vis various environmental conditions. As a matter of fact, it is reported that L. Plantarum has more endurance than L. Acidophilus. On the other hand, Bacillus group microorganisms are very stable and they can keep their liveliness during pelletizing because they have resistance to humidity, pressing and heat changes as they are in spore form. Maya and Streptpcoccuses are among Lactobacillus and Bacillus in terms of their abiility to remain alive during the pelletizing process.
We can sum up as follows the features that probiotics that are used in animal feeding must have...
Probiotic microorganisms:
The effects of the use of probiotics in feeding dairy cattle
In studies conducted by many researchers, it was found that probiotics have significant impact on the amount and contents of milk in dairy cattle as a result of the use of probiotics. The results of studies that consist of various rations and that were conducted by various researchers are given below.
In recent years, there has been a significant turn towards alternative growth factors as a result of the limitations placed on the use of antibiotics as a growth factor in animal feeding. Within this context, the use of probiotics in animal feeding as an alternative growth factor has become widespread. Probiotics support the balanced development of intestinal flora by lowering the number of pathogen microorganisms (coli and salmonella) thanks to competitive exclusion). Thus, important improvements in animal performance can be obtained through the use of probiotics. However, the fact that probiotics consist of live microorganisms causes them to be affected by the fodder processing techniques that are applied in the fodder industry. The most important fodder processing technique that can affect the liveliness of probiotics is pelletizing. As a matter of fact, the liveliness rate of probiotics of both bacterial and yeast origin drop to a great extent after pelletizing. In our country also many probiotics have been offered for use in the mixed fodder sector under various names. However, there is not sufficient research and information on the activities of the probiotics in question in prepared fodder. Therefore, it is not possible to see the expected increases in animal performance as a result of probiotic use. It is very important to know at what level the probiotics, which add costs to mixed fodder even though this is minimal, are affected by the processing techniques. It is known that techniques such as microcapsulation are used in minimizing these losses.
Knowing whether resistance of the probiotic to the heat that appears during pelletizing with various techniques has been ensured as well as the microbial source, concentration and the type of giving of the probiotic are very important in obtaining the expected increase in yield from probiotics when using probitoics in animal feeding and the fodder industry.
