Viable Alternatives for Animal Protein Feeds

Dr. Maurice Eastridge and Dr. Bill Weiss, Dairy Nutrition Specialists, Ohio State University

In an attempt to reduce the risk of spreading Bovine Spongiform Encephalopathy (BSE; Mad Cow Disease) and to lower the associated human health risks, the Food and Drug Administration (FDA) has prohibited since 1997 the feeding of ruminant derived meat or meat and bone meal to ruminants. To further reduce these risks in the event that additional cases of BSE exist in the US, the FDA has proposed prohibiting the feeding of mammalian blood to ruminants (uncertainty remains whether the additional restriction will be only ruminant or all mammalian blood). These new rules will affect the availability and prices for protein sources fed to dairy cattle. These animal protein sources have primarily been targeted as sources of rumen undegraded protein (RUP) for lactating cows. Generally, a balance between corn-based (lower in lysine) and legume-based protein (lower in methionine) sources will provide a rather balanced supply of lysine and methionine to the small intestine for absorption. For Ohio, the grain byproducts listed in Table 1, especially brewers grains, corn gluten feed, corn gluten meal, soybean meal, and distillers grains, should be selected based on availability in local markets, price, and nutrients most limiting in the ration formulation. However, most of these grain byproducts are low in lysine and may not the best choice for meeting the amino acid requirements of dairy cows, especially with high corn silage rations. If additional RUP and energy are needed, whole-roasted soybeans should be considered. If additional RUP is needed for the high-producing cows, commercially available, high RUP soybean meal or fish meal may be economical alternatives. Rumen-protected amino acids should only be considered for very high-producing cows. If economically priced, feather meal can be used but is not a preferred feed for high-producing cows because of its lower digestibility of RUP and lower quality protein (low in methionine and tryptophan). For more information on pricing of feedstuffs, see the article titled "Fast Changing Feed Markets Bring Opportunities" in the January 2004 issue of the Buckeye Dairy News.

Table 1. Protein fractions in feed ingredients commonly available in Ohio.^1,2

¹Taken from NRC (2001).
²CP = crude protein, RUP = rumen undegradable protein, RUP Digest = digestibility of the RUP, Lys = lysine, and Met = methionine.