The United States has the world's fourth largest cattle population. More than 970,000 farms raise beef cattle, contributing to a $71 billion retail value. Yet, farmers and feedlot operators spend millions of dollars every year feeding some cattle that don't grow efficiently. Simultaneously, when cattle are brought together in feedlots, they can be exposed to Bovine Respiratory Disease, leading to significant economic losses and reduced animal well-being. Now, with the help of two grants totaling more than $14 million from the National Institute of Food and Agriculture, part of the U.S. Department of Agriculture, research teams from the University of Missouri and Texas A&M University will combine their resources to battle these two problems.
"Currently, we have no highly effective tools to improve feed efficiency, which can lead to an increase in greenhouse gas emissions and demand for additional land to produce feed," said Jerry Taylor, Wurdack Chair in Animal Genomics in the MU College of Agriculture, Food and Natural Resources, and project director of a $5 million grant to study feed efficiency in cattle. "Historically, the only way we have improved the efficiency of cattle growth was by selectively breeding cattle that grew fast. While this reduced the time it took to bring an animal to market, it did not tackle the fundamental issue of improving the efficiency of converting nutrients from feed into beef. An animal that is efficient in converting nutrients into muscle will grow faster and emit less methane and manure in its lifetime, which also is beneficial for the environment."
With the new grants, Taylor and his colleagues will study the feed efficiency of cattle with several techniques, including using DNA-based models to predict genetic merit for feed efficiency. During the study, the researchers will genotype, or map the genes, of 8,000 cattle and identify how genetic differences affect feed intake and efficiency. The researchers also will identify the specific bacteria and microbes that reside in the animals' stomachs. These bacteria and microbes are a key factor in feed efficiency as they assist the animals in digesting the food.
"If we can identify and selectively breed the animals that have the best combination of genes for producing high-quality beef with the least amount of grain, their offspring could reduce environmental impacts and save producers millions of dollars," Taylor said. "Limiting the amount of feed used to produce beef could open farmland for other important crops, such as corn for ethanol, which could decrease dependency on fossil fuels and foreign oil."
The second grant, worth $9.2 million, will be led by James Womack, the W.P. Luse Endowed and Distinguished Professor in the College of Veterinary Medicine at Texas A&M University. Taylor will assist Womack in the study that will investigate Bovine Respiratory Disease (BRD), the most significant health problem of the U.S. beef and dairy industries. Cattle that are stricken with the disease typically stop eating, lose weight and require treatment, resulting in significant economic losses for farmers. Womack and his colleagues will identify the pathogens responsible for BRD and will use a DNA-based approach, which is similar to the approach being used in the feed efficiency study, to identify cattle that are resistant to the pathogens responsible for BRD. Selective breeding of resistant animals will lead to increased animal well-being and reduced production losses, the researchers said.
"These industries in the U.S. lose almost $700 million each year as a result of this complex disease," Womack said. "This includes more than 1 million animal deaths per year along with extensive sub-lethal illness and loss of productivity. The reduction of BRD will not only minimize economic losses, but also will improve animal health and welfare in these industries and reduce environmental and health risks associated with the use of antibiotics."
Both grants also have outreach and teaching components. A demonstration project involving several farms and commercial feedlots in the Midwest will evaluate the DNA diagnostics developed from the study to predict the feed efficiency of calves. Undergraduate, graduate and veterinary students will be involved in the research to learn about feed efficiency and disease resistance during the five-year projects. The research teams also will utilize cattle within industry feedlots for research and demonstration projects to show farmers' and feedlot producers how to implement procedures and practices that will improve feed efficiency and reduce the prevalence of BRD.