Ranchers across a large part of the Intermountain and High Plains regions report alfalfa stands nipped by mid-spring frost. Alfalfa damage due to freezing temps isn't unusual but the mercury fell to record-low levels in some areas.

One rancher, who found the tops of most stems laid over, wondered if the plants would recover or if they needed to regrow from the crowns? The short answer is alfalfa's ability to recover depends on whether the plant terminals were killed.

Oklahoma State University (OSU) researchers say if plant terminals are killed by frost, it's best to cut or flash-graze the foliage already present to encourage new growth from crowns for later harvest. If most terminal buds look green and alive after 2-3 days, post-frost cutting isn't recommended. There may be some leaf loss, but stem regrowth will begin in about a week as warmer weather returns.

If nearly all terminal buds are killed, OSU data show regrowth begins from leaf buds and/or crown buds, depending on amount of foliar damage. If freezing kills most stems, regrowth will be from crown buds — usually 1-2 weeks later.

If only some top terminals are damaged, damaged stems still alive tend to inhibit growth of crown buds. As a result, recovery time before alfalfa would start growing again could be 2-3 weeks. Producers who cut or flash-graze damaged alfalfa in these situations encourage rapid crown bud growth and recovery.

One problem is there's likely not enough forage to pay for harvesting, though the hay quality and the recovery time resulting from removing the freeze-damaged forage would help offset some of the expense of taking a “short” harvest. It's unlikely frost during this time would have any drastic effect on stand life, assuming a vigorous stand with proper fertilization, good drainage, an adapted variety and proper fall management.

Any time forage is removed by grazing, take precautions to prevent cattle bloating.

For more on season-long alfalfa management, visit the OSU Web site at: www.alfalfa.okstate.edu/pub/harv943.htm#contents, or BEEF magazine's Web site for cow-calf production and management info — www.beefcowcalf.com.
Clint Peck

A small, hardy fly called a biting midge is suspected of helping spread vesicular stomatitis virus (VSV), which infects cattle, horses and sheep. The virus causes significant economic losses from sickness, quarantines and subsequent import/export restrictions.

Agricultural Research Service (ARS) microbiologist, Barbara Drolet, and her colleagues at the ARS Arthropod-Borne Animal Disease Research Laboratory in Laramie, WY, found VSV is capable of surviving and spreading through the blood-sucking midge, Culicoides sonorensis.

Without killing the midge, scientists had to show the virus ingested in a blood meal could survive in the insect's midgut, replicate and escape to infect other organs.

An artificial feeding system was used to feed the midges a viral meal and track the infections over time. They were able to prove VSV infects the midge's salivary glands and eggs and is shed in droppings.

After analyzing more than 1,600 whole-body sections of 144 insects, Drolet found three distinct pathways of VSV infection in the midges: digestive, circulatory and neural. These include horizontal transmission through biting, vertical transmission from adult midges to their offspring, and mechanical transmission where the virus excreted by infected midges can be passed to uninfected insects.
USDA-ARS news release

Biomedical research shows increasing the concentration of omega-3 unsaturated fatty acids in the human diet can enhance health. Flax seed is known to contain a very high level of these omega-3 fatty acids.

North Dakota State University scientists experimented to see if supplementing the finishing diet of cattle with flax could increase omega-3 content in beef. A total of 128 yearling heifers were allotted to four treatments: 1) control (no flax), 2) whole flax, 3) rolled flax, and 4) ground flax.

Flax was supplemented at 8% of the diet. At harvest, loin muscle sections were aged for 14 days. Following aging, samples were analyzed for fatty acid content of the phospholipids and neutral lipids.

Overall, flax supplementation resulted in a highly significant increase (P<0.0001) in phospholipid content of total omega-3 fatty acids. Processing flax (rolling or grinding) significantly increased phospholipid content of omega-3 fatty acids over whole flax, and grinding further increased them over rolling. Similar increases in omega-3 fatty acid content were observed in the neutral lipids.

The authors note these data suggest a portion of unsaturated fatty acids, including omega-3 fatty acids, escape biohydrogenation in the rumen and are absorbed in the small intestine. The results clearly indicate feeding flax can increase the omega-3 fatty acid concentration in fresh beef (Maddock et al. 2005. Midwestern Section ASAS. Abstract 110).
Michigan State University Spring 2005 Beef Cattle Research Update