Processing Grains: Is there any Bang for the Buck?

A common question posed by producers is "What is the proper way to feed grain - whole or processed?". Like many things in life, the answer is - it depends! The factors affecting this are the age (or weight) of the animal, the grain source and overall diet. Before getting to some useable rules of thumb, here is some background on why processing matters, and some general theory.

What is processing?

'Processing' means milling or rolling grain. It is also inferred by cracking, grinding, hammer-milling and so on. Generally, it can be assumed that processing adds about $10 per tonne to the diet cost, due to labour, power use and machinery upkeep.

Sheep are ruminant animals; they are designed to eat forages, fermenting them in the first of four stomach compartments known as the rumen. The rumen is not an acidic stomach as is ours…. It uses bacterial fermentation and requires a neutral pH, or a balance between acidity and alkalinity. To accomplish this, sheep excrete a buffer, (bicarbonate) from the salivary glands while chewing their cud. Thus, cud-chewing (rumination) promotes saliva production and rumen health. Chewing is good! So, coarser grains are better in most cases, as this promotes rumination and extends the amount of starch available over a longer period. This helps prevent acidosis - a condition to be avoided, where the rumen becomes acidic. In sheep, whole grains are sufficiently large to be ruminated and chewed, so they do not require processing, except in the following cases;

1. In small lambs (creep feed). Processing grains stimulates intake, as the smaller particle size is more palatable to lambs. For lambs less than 20 lbs. live weight, process all grains. For lambs less than 50-60 pounds, corn should be processed. Once they exceed this weight, all grains can be feed whole without compromising intake, and reaping the benefits of whole grain.
2. When energy needs to be available quickly in the rumen. For the rumen to use the soluble nitrogen in silages (especially alfalfa haylage), grains can be processed to speed the availability of energy to the rumen microbes so that they might utilize the silage nitrogen for protein production. There is debate as to whether this is necessary, but the approach has been used 'successfully' by dairy farmers in the past, and by some shepherds. Consult with your flock nutritionist before proceeding with this approach, as it is intentionally contrary to the above guidelines, and useful only in specific cases!

What's the Bottom line?

Avoid processing unless required. For most cases, this means processing only lamb rations. You don't need a mill to feed sheep, and feeding whole grains actually improves rumen health in your flock as compared to processed feeds.