Furthermore, hydrolyzed fish proteins have proven to be even better sources of nutrition for weaning pigs and baby chicks. However, these benefits have not been available for Calf Milk replacements, mainly due to palatability/application issues and not because of nutritional value.
Numerous studies can be found going back several decades for the use of Fish Protein in Calf Milk replacers and they show that inclusion rates from 10-30 per cent are viable choices.
The lack of partial use is mainly a function of the lack of highly purified fish protein at cost effective prices and of course, a history of cheaply priced alternatives, but with grain & milk prices soaring, new manufacturing techniques which purify the fish/marine proteins are evolving.
Fish Protein Isolate (FPI) products are now available with superior amino acid profiles, zero fat content and at costs less than 50 per cent of milk protein sources. Some times referred to as Peptones, these protein chains have decades of research supporting their advanced status as an animal feed ingredients compared to numerous other proteins sources.
Raw fish used in traditional fishmeal products have a typical "Protein/Fat/Ash" profile. While this can vary and several percentage points for any given species, for the sake of discussion, lets consider typical herring or anchovy.
In order to produce a viable feed ingredient, three "processing/reduction objectives" must be achieved:
- Water Removal: for preservation purposes, and to reduce shipping cost. This is a costly & heat intensive process, thus destroying considerable portions of the nutritional value of the protein. Even in "LT" or low temperature meal, the process for removing water will denature the protein.
- Cooking: to break out free oil, and to preserve proteins. Simply put, the liquid oil can be released from the fish when temperature > 180F are reached for 20-40 minutes. And this cooking process changes the proteins from "raw flesh" to cook flesh where it can be further dried for storage.
- Fat/Oil Removal: for preservation purposes & formulation requirements. The cooking process starts the procedure and centrifuge finishes it such that up to 80 per cent of the fat/oil in the fish can be removed, but this still leaves about 20 per cent of the "Lipid Fat" as part of the protein fraction in fishmeal. Although extremely nutritional for numerous feed applications, this Lipid fraction has historical been considered a negative for Calf Milk replacers, mainly due to potential palatability/rancidity/storage issues.
New membrane manufacturing techniques improve all three of the above processes. By eliminating cooking, (removing oil without 'boiling'), and removing water with 50 per cent less energy input and most important --- a "Fat Free Protein Isolate" end product can be produced.
