Q. Do I need to do my own quality control on feed ingredients?
If you are purchasing large quantities of ingredients or even if you use custom premixes, it would be advisable to save samples for possible analysis. Each ingredient should be sampled upon delivery and be retained in a cool, dry location in an airtight container. If a problem arises, then the samples can be analyzed.
Q. How do I take a feed sample to assure that I get a good analysis?
For each batch of feed or for each ingredient, several (3 to 10) evenly distributed samples should be collected and mixed thoroughly. A one-pound subsample can be stored and submitted for analysis. Store the sample in an airtight container in a cool, dry location.
Q. What analysis should I have done on my grains and feeds?
Grains should be analyzed for test weight, moisture, and protein upon harvest. A my-cotoxin analysis should be conducted if a problem is suspected. Protein sources should be analyzed for protein, calcium, and phosphorus. A lysine analysis is desirable.
Q. Where can I get my feed analyzed?
There are several laboratories that do feed analyses. Contact your State Extension specialist for a current listing of laboratories in your area.
Q. What amount of analytical variation should I expect from a laboratory analysis?
An acceptable variation for most nutrients should be within 8 to 10% of the calculated value.
Q. I have read that limestone is added to soybean meal to improve its flowability. Is this true, and what should I do?
Yes, limestone and/or other materials are frequently added to soybean meal to improve its flowability. If limestone is used, the calcium content of the bean meal would affect how much additional dietary calcium would be needed in the final diet. Request from the manufacturer the compositional information on the product purchased.
Q. Does particle size of limestone affect pig performance?
Yes. Large particles of limestone will result in reduced digestibility and poor distribution in the mix. If the particle size for limestone is too fine, there may be a chemical binding of the calcium to other minerals in the digestive tract, which also lowers its availability. Dolomitic limestone contains magnesium, and there is a reduced availability of calcium from this limestone source.
Q. What is an "open" and a "closed" formula?
An open formula lists the percentage or amount per ton of all ingredients in the complete feed, premixes, or supplements. A closed formula does not identify precise concentrations of the feed ingredients, but lists the ingredients used for the formulation. Most commercial feeds use a closed-formula concept.