Spring is here and along with the improving weather, while I was attending the Petfood Forum in Kansas City it was obvious that everyone else also is feeling the need to get out and attend to business face to face.
My first impression on the attendance was the difficulty I had trying to find a place to park the car. Once inside it was obvious this event was well attended, and the exhibitors were in force and ready to talk.
We will be following up with information and articles on some of the interesting information gathered at the various booths in future additions, every possible topic if interest was covered by companies addressing all aspects of petfood production.
This issue is centered on cage/aviary birds with regards pet birds. What should a pet bird be fed? It is generally accepted that these animals should have a diet that has a combination of high-quality feeds, natural foods such as fresh fruit, veggies, seeding grasses, native flowers and green foods which are appropriate and safe for that species.
As a note the total bird feed industry for caged and outdoor birds is in the 5 to 6 billion dollar a year range. Basically, bird seed feeds are made up of seeds, nuts, fruits and vegetables where the individual ingredients are processed then combined in a mixer. Typical seeds used include sunflower, safflower, thistle, millet, peanuts, corn, milo, flax, rapeseed and others.
Health problems centre on unbalanced diets
Extruded bird feeds are growing and as noted above, the basis of these feeds is the same listed ingredients except there are ground and extruded into a small piece; much like is done for small diameter aquatic feeds. It is noted health problems with caged birds centre on unbalanced diets.
The benefit of compounded or extruded diets is the fact that they are complete in the nutritional values needed. The cooking process opens the nutritional value when using high temperature short time extrusion resulting in minimal nutrient loss, while eliminating germs greatly reducing the risk of infection in the birds. It is seen that these diets allow birds to eat less and have greatly reduced waste.
Research is supporting these diets with specific feeds for selected bird species. The feed compositions are advancing based on life stages, growing birds, adult birds and breeding birds for example.
Production of bird feeds varies, with many small extruders are available for the small operation but the technology exists to make small diameter pellets up towards 8 to 10 tons per hour or more asmentioned much like aquatic feed production.
The one difference is the colours usually added to these style feeds for effect and attraction for the birds. Larger piece feeds are made for the bigger pet birds such as parrots and mynah birds. Forming extrusion is also possible where the feed is not subjected to heat, but the process is used to push the feed formulation through the die to make the desired shape.
However, in most cased these feeds need to be elevated in moisture to allow the flow through these small holes. Therefore, drying or moisture reduction is needed but can be monitored to keep the heat down if desired with the correctly sized and designed dryer if you are concerned by heating the feed.
The full nutritional value
An area of concern when making small diameter feeds is the coefficient of variance (CV) in the feed mix. When making small diameter feeds that are not consumed in large volumes do require attention to detail, so the few pellets eaten have the full nutritional value.
A CV of five percent is considered a standard in the industry for feed mixers. The definition of CV is the standard deviation/mean x 100 to get in a percent basis. Standard deviation measures how far the average value is from the mean while CV measures the ratio of the SD to the mean.
These calculations give an indication that the smallest volume ingredient, normally the micro ingredients are mixed well and will appear in each pellet. Interested in testing mixer performance see an article on this topic by searching for “bookstore.ksre.ksu.edu/pubs/MF3393. pdf”, a Kansas State University publication on a method to test mixers.
It should be noted most preconditioners on extruders have a CV in the 5% to 10% range but there are models which approach 3% to 4%. These are great for adding final additions, normally liquids, and achieve a great mix prior to the extruder barrel.
Extruder operation is an art form
Process control is also a topic of interest, if you are going to the extent of having a great CV out of your mixer or conditioner it is expected you might wish to have total control on the process. Historically you were lucky if you had a great extruder operator as it was an art form.
Ok, being honest they had the intuition what to do but consistency between operators or shifts was lacking. Initial control was as simple as it gets, an indicator on the hand control valve giving an indication of how open or closed the valve might be.
Next was the same operation but a digital indicator showing the flow rates numerically. After this the switch to modern day controls include computers was rapid with the key being a known delivery rate of the dry feed mix as well as liquid additives with advanced flow meters.
Most systems are then controlled based on percentages of the dry flow rate. Everything is then easier to see and correct so that the production was more predicable over time. Industry standards changed and more verifications were needed.
Advancements included monitoring the conditioning cylinder with the exit of this device and the extruder barrel being critical control points. Temperature was the main interest to verify kill step on salmonella and other bacteria.
Down time is expensive
Advancements in technology allowed for moisture, density, product appearance and composition to be monitored and with feedback loops totally controlled at speeds man can’t compete with. Controls are not limited to the extruder as dryer, coaters and basically any machine in the plant can be set up for advanced monitoring and control.
The reasons for these advancements are many and not totally on product verification. Down time is expensive when you consider the product you did not make in that time period. Mis-manufactured feeds, fines, over dried or under dried product as well as over fortifying above the bag label is expensive when added up at the end of the year.
Another managed area is the start-up and shut-down waste as the ingredients are the most expensive part of feed manufacturing. Greatly reducing this by computer control or managing it to a minimal level is profitable. At a manageable level start up waste can be handled easily, if not then you need to move it around, dry it and regrind and add as rework.
As mentioned in a separate article closer to the back of this magazine, the Petfood Forum was full of exhibitors and all were centred on increasing the profitability of petfood producers. I am positive we all are not doing this for fun. We operate based on profits and we will strive to inform the latest and newest developments which allow for worthwhile topics to improve the producers bottom line.
Article contributed by Joe Kearns, Editor, International Petfood magazine.
