01/04/2015: Ruminants: Feed formulation and nutrition focus

by Elena Forbes, Azeus Machinery co ltd, China
 

First published in Milling and Grain,February 2015

The main feedstuffs fed to cattle include: grass, hay, grain, silage and total mixed ration. There are in fact, many types of feeds that can be fed to cattle, for example, crumbles, meals, coarse mix and pellets made from raw material such as corn, wheat, soybean.

In this article, Elena Forbes of Azeus Machinery takes a closer look at the processes involved in creating a good quality pellet. With the global demand for cattle feed ever increasing, the need to produce high quality and nutritionally balanced feed has become an essential issue in the feed market. 

What are the advantages of pelleted cattle feed?

Raisers have been using pellets for decades to feed their cattle. Compared with other kinds of feed-stuff, a good quality pellet actually offers a lot of benefits to the raisers such as decreased eating periods, improved palatability, less segregation in the feed and reduced waste. 
First of all, pelleted feeds take up significantly less storage space, particularly in the case of pelleted hay products. A ton of baled hay can take up 200 to 330 cubic feet of storage space in a barn; a ton of hay pellets or cubes requires only 60 to 70 cubic feet. 

Secondly, compared to other types of feed, they are very low in dust. “Compete” pelleted feeds can include not only grains, but also vitamins and other supplements. Manufacturers have created many types of pelleted mixes to suit all sorts of cattle, no matter their activities.

 
Almost no commercial feed ration is left untouched by the pelleting process - sift through a prepared sweet feed with your fingers, and you’ll discover a smattering of pellets mixed in with the oats and corn and other grains. That pellet generally contains a vitamin/mineral supplement for the ration, bound up with a fibre source such as dehydrated alfalfa.

Moreover, cattle consume feed pellets more readily and rapidly when compared to other forms of cattle food. Furthermore, the pellets produce less waste as mentioned above making it a very economical method to feed dairy animals as well. 

This is especially important for small raisers for whom every penny counts. Similarly, the waste reduction also helps raisers a lot during the droughts because they will have to spend less amount of money feeding cattle. Pellets also improve the palatability of the cattle feed.

Finally, it is always good to feed pelleted concentrates to the cattle. There is nothing wrong in doing so; rather it is a beneficial and fruitful method of feeding cattle.

Demand for cattle feed pellets in the global market place

With the increasing awareness among people towards safety and quality of beef choosing high quality and nutritionally well-balanced feed is essential in order to promote cattle feeding standards.

Cattle feed pellets being made from corn, wheat bran, rice, sorghum, and beans, appears to be the obvious choice, as it decreases feed wastage, has high bulk density and better material handling characteristics.

Pelleted cattle feed prevents selective feeding on preferable ingredients in a formulation. Since all ingredients have been moulded together, cattle must eat a balanced formulation, minimising waste and improving feed conversion.

Capitalising on the growth trend in the global cattle feed pellet market, some leading companies are rushing into the development and manufacturing of feed pellets. The increasing demand for cattle feed pellets is prompting the global players to turn their attention to feed pellet products in order to meet growing needs.  

The cattle feed pelleting process: a comprehensive overview 

Stage one: cattle feed grinding
Material is held in the grinding chamber until it is reduced to the size of the openings in the screen. The number and size of hammers on a rotating shaft, arrangement, sharpness, the speed of rotation, wear patterns, and clearance at the tip relative to the screen or striking plate are essential variables relating to grinding capacity and the appearance of the product. Impact grinding is most efficient with dry, low-fat ingredients, although many other materials may be reduced in size by proper screen selection and regulated intake. 

Stage two: cattle feed mixing
Feed mixing may include all possible combinations of solids and liquids. Mixing is recognised as an empirical unit operation, which means that it is more of an art than a science and must be learned by experience. 

Three mechanisms are involved in the feed mixing process:
a. The transfer of groups of adjacent particles from one location in the mass to another
b. Diffusion distribution of particles over a freshly developed surface
c. Shear slipping of particles between others in the mass.

Stage three: cattle feed pelleting
The goal in any feed pelleting operation is to produce good quality pellets while simultaneously maintaining an acceptable production rate at minimum cost.
There are many factors being involved in making a good pellet, such as material density, source of supply, ingredient quality, protein content, temperature, moisture, die specifications and pellet mill operation. 

Incoming raw material flows into the feeder and (when conditioning is required) is delivered uniformly into the conditioner for the controlled addition of steam and/or liquids. From the conditioner, the feed is discharged over a permanent magnet and into a feed spout leading to the pellet die. Inter-elevator flights in the die cover feed the material evenly to each of the 2 rolls. Feed distributor flights distribute the material across the face of the die. Friction drive rolls force the material through holes in the dies as the die revolves. Cut-off knives mounted on the swing cover cut the pellets as they are extruded from the die. The pellets fall through the discharge opening in the swing door.

Stage four: cattle feed pellet cooling
The purpose of cooling is to remove heat and moisture after the pelleting process. A pellet is in its most fragile state as it leaves the die. It has been formed but is a soft plastic, easily deformed product at this time. Every endeavor should be made to handle this product as gently as possible until it is cooled, dried and hardened. From a system standpoint, the pellet should drop directly from the pellet mill into the cooler, since any type of mechanical handling will generate fines.

Stage five: pellet crushing
Crushing is an important part in the feed pellet line. By crushing, large feed pellets can be divided into different particle sizes in the certain range. Crushing has a direct impact on both the cost and the nutrition of feed pellets.

Cooled pellets may be ground on corrugated rolls and the resulting product sifted into various sizes of granules. The specifications of cattle feed pellets are usually as follows:
Diameter: 3-5mm
Length:15-20mm

Read the magazine HERE.

 

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