Is There a Place for Fat in Beef Cow Diets?
by Dr. Cathy Bandyk, Cow/Calf Nutritionist, Quality Liquid Feeds
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In fact, recent research trials have suggested that low levels of supplemental dietary fat may offer all these benefits to the beef cowherd. The jury is still out on a number of key questions -- how much is needed? how important is type or source of fat? how does it work?? But the results of studies done at a number of universities are certainly promising enough to warrant consideration
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A Texas study (DeFries et al., 1998) used rice bran to increase dietary fat during early lactation from 3.7 to 5.2%. In contrast to the post-calving treatment in the Missouri study, the added fat increased pregnancy rates, measured 60 days into the breeding season, and also improved calf gains. Average gains for calves from cows receiving the additional fat were 90.3 lb, vs. 83.0, during the first 43 days; these numbers translate into ADG values of 2.1 and 1.9 lb/head.
A similar study was conducted in Wyoming (Whitney et al., 2000), with beef heifers receiving 0, 3, or 6% dietary fat from soy oil during the pre-breeding period. Again, all diets provided equal amounts of protein and energy. Heifers receiving the 3% added oil conceived 10 days earlier. It is possible that the 6% fat level was high enough to impair forage digestion, which could easily offset any other benefits.
A different hypothesis was tested in a trial conducted in Montana (Lammoglia et al., 1999). There, cows received additional dietary fat (4.7 % of dry matter intake) from safflower seeds during late gestation. They found that calves born to these mothers had increased cold tolerance.
Practical Applications
While there are adequate research results available to build a credible case for feeding some dietary fat to beef cows, a lot more work is needed before we can definitively outline the most effective supplementation strategies. In the meantime, a practical approach may be to provide additional fat during late gestation, and through early lactation until the start of breeding. However, since most cow/calf producers don't feed complete mixed rations to their cattle, practical delivery options are needed. It is also not clear how much fat needs to be provided in order to see performance benefits--although at the other end we do know that diets with more than 5% fat typically depress fiber digestion.
Liquid supplements offer a simple, convenient way to bring supplemental fat into the cowherd feeding program. These products are typically offered in lick wheel self-feeders, and can provide needed protein, energy, vitamins and minerals along with the fat. Other operations have found a good fit for liquid supplements as a top-dress, TMR additive, or big bale treatment. A recent review of the use of dietary fats as nutraceuticals for beef cattle (Williams and Stanko, Texas A&M, 1999) cited liquid supplements as a viable fat delivery option, noting that the oilseeds used in many of these research trials are not universally available or economically practical.
QLF and Land O'Lakes Farmland offers a variety of fat-containing supplements. A relatively new product, Beef Elite 20-8, is 20% protein and 8% fat. This supplement, which is also fortified with organic forms of key trace minerals, is designed for lick tank use. Energizer 36-16 can supply even higher concentrations of both protein and fat, and has also been used successfully in lick tank programs during reasonably mild weather conditions. These products, as well as other Energizers, such as 4-19 or 20-20, can also be included in bunk rations for cows, or used to treat baled or processed hay. Lower levels of supplemental fat are routinely included in pasture products such as QLF Super 34-3 and Pasture Plus 18-5.
