SelenoSource AF - Beef Cattle

Video 7:17 min

Supplementing Selenium in Beef Cattle

Introduction

Quality

Bioavailability

Profile
AF 2000
AF 600

Process

Dairy Cattle
Beef Cattle
Swine
Broiler Chickens
Chicken Breeders
Laying Hens
Market Turkeys
Turkey Breeders
Horses

Sources of Selenium

Selenium is found naturally in some feeds, although concentrations vary greatly by feedstuff and the region in which the feedstuff originated. Selenium may be supplemented in either the organic or inorganic form.
Organic selenium is composed largely of selenomethionine and selenocysteine, while inorganic selenium is simply a salt, usually sodium selenite or sodium selenate. Selenium-enriched yeast is an excellent source of organic selenium.

Bioavailability of Selenium Sources

Organic selenium is more bioavailable than inorganic selenium.
Inorganic selenium is reduced to un-absorbable elemental or inorganic selenides in the rumen.
Rumen bacteria take up more organic selenium than inorganic selenium, making bacterial selenomethionine and selenocysteine.
Limited data suggest that the true digestibility of selenium from feeds is between 40 and 65% for ruminants. Digestibility and absorption is 8 to 15% higher with organic selenium.

Selenium Status

The selenium status of an animal may be assessed by measuring the level of selenium in the milk, blood plasma or serum, whole blood, as well as blood or liver glutathione peroxidase activity.
Selenium and vitamin E work together as antioxidants, and thus proper supplementation of both is essential.
Period required to affect selenium status depend on ruminal environment and the source of selenium fed. This period ranges from 7 - 14 days in milk, 30 - 60 days for whole blood and plasma (serum) and 90 - 120 days for liver selenium and glutathionie peroxidase activity (GSH-Px).
Blood plasma or serum selenium content is a good indicator of changes in selenium supplementation. Whole blood, GSH-Px and liver selenium are better indicators of longer-term (90 - 120 days) supplementation.

Many natural feeds and forages contain inadequate selenium for beef cattle, making supplementation essential.

In order to avoid selenium deficiency symptoms such as some of those mentioned above, supplementation is critical. Selenium supplements may be derived from two basic sources.

Inorganic selenium salts (i.e., sodium selenite, sodium selenate)
Organic selenium yeast (SelenoSource AF)

SelenoSource AF is a more bioavailable source of selenium than inorganic selenium salts.
In the ruminant animal, rumen microbes reduce most inorganic selenium to a form of selenium that the animal cannot absorb, and thus is excreted. However, since SelenoSource AF is comprised largely of a selenium-containing amino acid (selenomethionine), it is utilized by the animal more efficiently.

SelenoSource AF is effectively transferred to the fetus as well as colostral and milk proteins.

Because SelenoSource AF is comprised largely of selenomethionine, this amino acid is used in making proteins in the animal. This is especially of benefit to pregnant and or nursing cows, as it ensures that calves get started right with enough selenium to prevent such problems mentioned above. Selenium salts, on the other hand, are not effectively transferred to the fetus, colostrum or milk. Consequently, calves born of cows consuming inorganic selenium are often selenium deficient.

SelenoSource AF is more effective than injectable selenium in maintaining selenium status.

Selenium injections are a short-term approach to fix a selenium-related problem. Additional handling and repetitive injections make feeding SelenoSource AF a more attractive alternative.