Numbered Publications by Jeff Lehmkuhler
ASC-263: Converting from Year-round to Controlled Calving
Les Anderson, Darrh Bullock, Ben Crites, Kevin Laurent, Jeff Lehmkuhler, Katherine VanValin | Jul. 19, 2024 (New)
In the United States more than half (55%) of all beef cow-calf operations do not have a defined calving season. Typically, in these operations, bulls are not removed from the herd and remain with the cows the entire year. This "uncontrolled breeding" results in cows calving over several months or, in some cases, cows calving every month. Calving year-round presents many challenges in herd management and decreases productivity. In some cases, producers have an off-the-farm job and limited time can be left to dedicate to the cowherd. In these scenarios, it is crucial to maximize time and labor efficiency.
ASC-264: Artificial Insemination in Beef Cattle
Les Anderson, Darrh Bullock, Kevin Laurent, Jeff Lehmkuhler, Katherine VanValin | Jul. 19, 2024 (New)
Successful artificial insemination (AI) breeding programs depend on adequate facilities, good herd health programs, sound nutritional management, using experienced and well-trained technicians, high fertility semen, and the ability to observe or synchronize a fertile estrus. Most problems and(or) failures in AI programs are associated with poor nutritional development in replacement heifers, inadequate body condition of cows at and after calving, failure to identify or control estrus in females, and/or failure to breed them at the proper time. Rarely is infertility the result of poor-quality semen or technician error.
ASC-261: Going Green: Ten Fundamentals of Greenhouse Gas Emissions for Beef Systems
David Harmon, Jeff Lehmkuhler | Feb. 13, 2024 (New)
Global warming has become a key focus of all agricultural sectors during the late 2010s and early 2020s. Discussion on identifying and increasing adoption of sustainable practices, shifting from gasoline to electric automotive engines, and producing alternative sources of energy continually permeate the airwaves. These various proposals are accompanied with new terminology and concepts that may not be fully defined for the audience. As a livestock producer, it is important to know and understand how new legislation for limiting greenhouse gas emissions in the agricultural sector could be directed toward the farm gate.
ASC-258: Minerals Matter for Beef Cattle
Michelle Arnold, Kevin Laurent, Jeff Lehmkuhler, Katherine VanValin | Nov. 20, 2023 (New)
Minerals are an essential nutrient for beef cattle. If minerals are not consumed in the diet, deficiencies can occur. At the same time, overconsumption of certain minerals can result in toxicity. Providing the proper balance of each mineral without overconsumption is necessary for optimal performance, as minerals are essential for supporting growth, reproduction, lactation, and health.
ASC-259: Reproduction in Female Yaks
Les Anderson, Jeff Lehmkuhler, Mary McCarty, Katherine VanValin | Oct. 26, 2023 (New)
The yak (Bos grunniens) is a unique domestic animal. These animals were developed in the extreme environment of the Himalayas, where food resources can be extremely limiting. The yak provides food (meat and milk), fiber (hair), and are beasts of burden (used for pack, transportation, plowing, etc.) for the local populations. The number of yaks in the world is limited, creating a need to understand and control reproduction in the yak to improve genetic diversity.
ASC-260: Controlling Reproduction in Female Yaks
Les Anderson, Jeff Lehmkuhler, Mary McCarty, Katherine VanValin | Oct. 26, 2023 (New)
The yak (bos grunniens) is a member of the bovine family and plays a vital role in the life of the people of the Himalayan region (China, Mongolia, India, Nepal, etc). The Himalayas is an especially harsh region with long, cold winters and sparse vegetation for most of the year. As with all bovine, nutrient availability, both quality and quantity of available foodstuffs, and current status of body reserves or degree of fat stored in the body dictate the ability of the cow to conceive during a breeding season. Even though conception rate (probability of conception at a single estrus event), is high (70+%), pregnancy rate (probability of conception at the end of a breeding season) is typically only 40%-60% in their natural environments because a high proportion of female yaks fail to have an estrus during the breeding window. Understanding the major factor reducing pregnancy rate is important to creating and implementing management protocols to improve the reproductive ability of female yaks.
ID-275: Practical Corn Silage Harvest and Storage Guide for Cattle Producers
Donna Amaral-Phillips, Chad Lee, Jeff Lehmkuhler, Nick Roy | Sep. 27, 2023 (New)
Corn silage is often referred to as the "king of forages" and for good reason. With adequate and timely rainfall and normal environmental temperatures during the growing season, corn silage can yield 20 to 25 (or more) tons as fed per acre. Even in years with limited soil moisture, this crop can provide needed forage when harvested and stored properly although whole plant yield and/or grain content is often reduced.
ID-273: Match-a-Yak: a Tool to Minimize Inbreeding in North American Yaks
Les Anderson, Darrh Bullock, Ted Kalbfleisch, Jeff Lehmkuhler, Mary McCarty | Sep. 25, 2023 (New)
The domesticated yak (Bos grunniens) arrived in North America in the late 1890s. A few animals were imported into Canada and North American zoos and became the foundation of the North American genetic pool. Research was conducted in Alaska hybridizing them with Highland cattle in the early 1900s. A handful of yaks were imported into the United States in the early 1900s and again later in the 1980s. However, the genetic diversity of the North American yak is limited, necessitating a need to manage breeding programs to reduce inbreeding.
ASC-255: A Guide to Body Condition Scoring Yaks
Les Anderson, Jeff Lehmkuhler, Mary McCarty | May. 1, 2023 (New)
Having issues with cows breeding back and raising a calf every year? Are your heifers taking longer to reach puberty than you think they should? Are some calves born weak and not able to stand quickly? Reproduction is closely associated with body-fat stores and muscling. Fat cells produce a hormone, leptin, that plays a role in the hormonal cascade regulating reproduction. Learning how to assess body reserves or condition as a management tool can help improve your reproductive efficiency and farm profitability.
ID-217: Forage-Related Disorders in Cattle: Nitrate Poisoning
Michelle Arnold, Jeff Lehmkuhler, Megan Romano, Ray Smith | Oct. 24, 2022 (Minor Revision)
Nitrates are natural constituents of all plants. Under normal conditions, plants take up nitrate through their roots and transport it to the leaves for use in photosynthesis. However, photosynthesis decreases under adverse environmental conditions (e.g., drought; leaf damage due to disease, hail, frost, insects, or herbicides; cool and cloudy weather; and other plant stressors). When photosynthesis is reduced, nitrate transportation to the leaves slows also. Potentially toxic nitrate concentrations can remain in the lower stalks and stems.
