ASC-271: The Impact of Heat Stress and Fescue Toxicosis on Beef Cattle Reproduction

Tyler Purvis, Les Anderson, Darrh Bullock, Kevin Laurent, Jeff Lehmkuhler, Katherine VanValin | May. 19, 2025 (New)

Heat stress is a common problem facing beef-cattle producers throughout the United States, and in 2003 was estimated to cost the U.S. beef industry $369 million dollars annually. Heat stress occurs when an animal is creating and absorbing more heat than they can dissipate, which increases core temperature and physiological stress. Common symptoms of heat stress include increased respiration rates, panting, or standing in water such as ponds or puddles. Heat stress results in negative impacts on growth, health, and reproduction. Cattle can have reduced conception rates, growth rates, and milk production during the summer. During severe heat stress, conception rates can fall to 10%-20% or lower compared to 40%-60% conception rates observed in cooler months.

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ASC-270: Overview of the Mineral Nutrition of Yaks

Jeff Lehmkuhler, Katherine VanValin, Darrh Bullock, Les Anderson, Michelle Arnold | Feb. 12, 2025 (New)

Mineral nutrition is a critical aspect of livestock management, particularly for yaks grazing on the challenging terrains of the Qinghai-Tibetan Plateau or the diverse range conditions of North America. As these animals adapt to their environments, understanding their mineral requirements becomes vital for ensuring health, productivity, and overall well-being.

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ASC-267: Controlling the Calving Season

Les Anderson, Katherine VanValin, Darrh Bullock, Jeff Lehmkuhler, Kevin Laurent | Dec. 11, 2024 (New)

In 2017, the National Animal Health Monitoring System (NAHMS), a USDA source for cattle production statistics, reported that less than half of cow-calf herds across the country had a defined calving season. One reason is that most herds surveyed (85%) had fewer than 50 cows and therefore the cattle enterprise was likely not the primary source of income for these producers. Two common arguments against having a controlled breeding and calving season are, “I do not have anywhere to put the bull,” and “I like having a calf ready to sell whenever I need it throughout the year.”

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ASC-265: Estrus Synchronization Protocols for Beef Females

Les Anderson, Darrh Bullock, Kevin Laurent, Jeff Lehmkuhler, Katherine VanValin | Oct. 11, 2024 (New)

Artificial insemination (AI) can be an effective tool for beef producers to use to make faster genetic progress in the herd. Unlike the dairy industry where cattle are handled multiple times a day, incorporation of AI can be difficult because beef cattle are not handled often or easily. Decades ago, scientists began developing methods to control the expression of estrus to decrease the amount of labor and time required for AI. An understanding of estrus synchronization protocols can be beneficial to producers considering using AI in their genetic program.

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ASC-266: Reproduction in the Bull

Les Anderson, Darrh Bullock, Kevin Laurent, Jeff Lehmkuhler, Katherine VanValin | Oct. 11, 2024 (New)

The fertility of the herd bull is essential to a successful cow-calf operation. In many respects, it is more of a concern than the fertility of a single cow. Sub-fertile bulls create lower calving rates and can be responsible for poor herd-weaning weights: For every heat cycle a female fails to conceive, there is a corresponding decrease in calf weaning weight from 25 to 45 pounds because of a younger calf being weaned. It does not take long to realize that poor fertility or infertility of a bull can be extremely expensive to the cow-calf producer.

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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.

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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.

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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.

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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.

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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.