Microbial management is recognized as a critical element for a successful crop. This is achieved through a combination of biosecurity measures, feed and water management and the application of microbial products. With the current low farm gate price impacting profitability, farmers search for ways to improve the cost efficiency of their operation. Applying products of lower unit cost , but also with lower efficiency, or delayin g the application of performing products may appear as a valid option. However, these approaches often lead to lower farm performance, and ultimately, lower profitability. For example, there is a dose response effect with the application of performing probiotics in feed (Figure 1). The same observation can be made with the application of water probiotics.
T he common on-farm brewing procedure aimed at increasing the number of bacteria before application to the pond may appear as cost saving. However , some key risks must be considered. Growth rate s of the different probiotic strains combined in a single product will vary with each strain. This means that when brewed, an original formulation will change during the brewing procedure. For a given product with 3 different strains it can be expected that one of the 3 strains may dominate. The expected benefit of this multi-strain product would then be lost. In addition, there may be overgrowth of non-intended strains that were present as contaminants at the beginning of brewing. The performance of a product depends upon the concentration and the composition, i.e. the strains of the bacterial species . Within a species such as Bacillus sutilis,, there exists major differences between strains regarding their optimal conditions for growth, but also production of enzymes or ability to outcompete pathogens such as Vibrio.
Examples of cost benefits will be presented.