Mississippi Agricultural and Forestry Experiment Station

Animal and Dairy Sciences

The Department of Animal and Dairy Sciences provides research and assistance in livestock agriculture and companion animals. This constantly evolving field provides the world with food and fiber and has done so since domestication. Scientists in the department are nationally known for advances in animal production technology.

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A Balancing Act

A high priority among cattle producers is to ensure that livestock are comfortable; however, a cow’s inability to shed at the proper time may impact production performance. MAFES researcher, Dr. Trent Smith, recently discovered that cows that shed earlier in the season wean heavier calves. Read More

An Ample Diet

Pork, the most consumed meat in the world, is one of the most economical sources of animal protein for human consumption. Dr. Shengfa Liao, assistant professor in the Department of Animal and Dairy Sciences, grew up in a remote village in China when and where pork was a rare treat. As an Experiment Station researcher, he focuses on finding ways to enhance pork production by increasing feed efficiency for producers and improving animal welfare at the same time. Read More

Balanced Cows, Better Beef

The personality of livestock may seem secondary to productiveness, but research shows that the two may be connected. Cow temperament is correlated with how much money the cow brings in and how frequently it gets sick. Poor-tempered cattle are also known to produce less marbling and tougher beef. In an on-going study at the Brown Loam Research Station, researchers have studied the link between a cow’s temperament and performance. Dr. Rhonda Vann, research professor in the Department of Animal and Dairy Sciences and the Experiment Station, pioneered work on this front. Read More

Feeding on Fescue

Kentucky 31, a popular forage, is chosen for its drought tolerance and adaptability across climates; however, it has an unwanted host, an endophyte or fungus that lives inside the plant. This endophyte causes problems in beef cattle due to toxic chemicals found in the seed. The toxicity can restrict the cow's flow of blood to extremities, causing gangrene to occur in the foot and/or tail during the winter. During the summer, constricted blood flow to the surface of the animal interferes with its ability to regulate temperature, causing heat stress. "Our hypothesis was that if the animal is stressed from consuming endophyte-infected tall fescue, then the meat quality is going to be lower and the shelf life will be shorter," said Dr. Thu Dinh, assistant professor in the Department of Animal and Dairy Sciences and MAFES scientist. After testing the hypothesis, they found very little difference in the control group and the treatment group on lean color attributes and total bacterial count. Steaks from the treated steers did have a greater amount of oxymyoglobin, the compound that gives beef its bright red color. This indicates the muscle in endophyte-infected animals may have developed a protective mechanism against the toxicity. Read more

Go with the Flow

Two MAFES scientists, Dr. Caleb Lemley and Dr. Derris Devost-Burnett, are leading a team of researchers who are using biophotonics to study how maternal nutrient restriction affects calves. Lemley, an animal and dairy science assistant professor, focuses on the mother while Burnett focuses on the calves. The researchers evaluated the placentas, fetuses, and offspring of Angus and Brahman heifers sired by a Hereford bull. The team evaluated the placenta because it connects the mother to the fetus, studying how blood flow, in particular, can impact how nutrients the mother intakes reach the fetus. They sought to learn how maternal nutrient restriction affected the placenta's development. Lemley said understanding alterations of placental development during pregnancy will help producers to maximize fetal development in-utero, possibly decreasing the instances of calf morbidity and mortality. Burnett said, "While Lemley focuses on the maternal environment itself, I evaluate how that environment affects the growth of muscle and fat in the offspring." Thus far, the researchers have observed birth weight reduction and the development of less muscle fibers in offspring that were nutrient-restricted in-utero. Burnett said, "We hope research like this allows us to provide producers with data-based information that helps move the industry forward." Read more

Grass-fed

As consumer interests for forage-finished beef increases in the U.S., Mississippi Agricultural and Forestry Experiment Station scientists, Wes Schilling and Byron Williams, are studying different forages and the effects on beef quality and taste. Scientists conducted one study in the Experiment Station’s Prairie Research Unit, examining the quality of beef foraged on native grasses and bermudagrass. In a separate study, scientists compared grain-finished and forage-finished cattle. In both studies, researchers found that native warm-season grasses are acceptable forage for beef cattle during the stocker phase, producing a lean, high protein product with positive consumer acceptability. Read More

Healthy Mom, Happy Calf

Melatonin is a hormone our body naturally produces. Melatonin as a supplement is considered an antioxidant. While many people may take melatonin for a good night’s rest, researchers in the Mississippi Agricultural and Forestry Experiment Station are evaluating how melatonin supplements might help pregnant Holstein heifers give birth to healthier calves. Dr. Caleb Lemley, assistant professor in the Department of Animal and Dairy Sciences, along with two graduate and two undergraduate researchers, studied how melatonin supplementation affected blood flow between dam and calf during gestation. Read More

Increasing Fertility in Farm Animals

Fertility is the most essential factor controlling animal reproduction. Obtaining viable offspring depends on the ability of quality sperm and egg to generate a developmentally competent embryo. MAFES scientists identified biomolecular markers and mechanisms for determining the quality of sperm, eggs and embryos. Research results provided scientists with the molecular markers to predict semen and embryo quality.

Luminating Infections in Pregnant Mares

Infections are the leading cause of abortion, stillbirth and preterm delivery in mares. MAFES scientists have developed a new approach to understanding the infection process in pregnant mares by using biophotonic imaging and modified bacteria with luminescent characteristics. In other words, the technique allows researchers to capture real-time pictures of glowing bacteria as they spread through a mare’s body. The method allows scientists to track pathogens in a minimally invasive procedure.

Making artificial insemination of cows more effective

Animal scientist Jamie Larson, who specializes in cattle reproductive physiology, works with beef and dairy cattle to make artificial insemination more effective. Larson is experimenting with hormone treatments to determine if cows’ estrous cycles can be more closely synchronized, allowing them to be bred at about the same time. Cattle production would be more efficient if calves are about the same age and size. Scientists perform repetitive ultrasound at the Beef Unit to determine the effectiveness of their hormone protocol. Larson also works with fellow reproductive physiologist Caleb Lemley at the Bearden Dairy Research Center, monitoring cows to determine whether conditions in early gestation affect the health and future performance of calves. Researchers monitor cows 90 days before they give birth and follow the calves throughout their lives. Their goal is to identify ways to improve conditions in the womb to ultimately enhance calf health.

Marbling trumps thickness in steaks

Animal scientist Trent Smith examines the importance of marbling, streaks of fat within lean sections of meat. Marbling adds quality and flavor and increases the value of a cut of meat. At MSU’s Leveck Animal Research Center or South Farm, Smith studies two groups of 30 purebred Angus cattle. One group has the genes that influence marbling, while the other does not. His goal is to evaluate the cattle’s performance and analyze the impact of the marbling genes. A MAFES survey found that most consumers cited marbling as the most important attribute of rib-eye steak. Even if consumers were not willing to pay more for thick cuts, most said they would pay more for well-marbled steaks.

MSU Researchers Ask What Steak Eaters Crave

MAFES researchers recently conducted a study to gauge the public’s willingness to pay extra for thicker, heartier steaks.

The study found that most consumers did not highly value thickness. Only 23 percent of consumers listed thickness as the most important factor of a rib eye, making it only the third most important attribute. Thirty percent cited marbling as the most important attribute of rib eye, making it the most important factor tested. Thickness only defeated marbling for first place with the sirloin steaks.

The study found that even if consumers are not willing to pay more for thickness, most of them are willing to pay more for characteristics such as color and marbling. Read More

Protecting the Herd

As a molecular biologist, Dr. Florencia Meyer, a scientist in the Mississippi Agricultural and Forestry Experiment Station, hopes to unlock molecular secrets about the microbes that contribute to the cause of bovine respiratory disease. Bovine respiratory disease, or BRD, costs the cattle industry an estimated one billion dollars annually. The disease is usually caused by a combination of factors including stress, a viral infection, and bacteria present in the animal. Vaccines are used to prevent the disease and treatment options include antibiotics and stress management. Despite these options, however, BRD remains the number one health problem for the cattle industry, causing widespread illness, death, and production losses. While Meyer is currently studying three microbes at once, two of her recent publications centered on foundational research she has conducted on BoHV-1 alone. Most recently, the team ascribed a potential new gene for BoHV-1. "The project's findings will provide valuable information for the development of novel vaccine or pharmaceutical formulations that can help reduce the incidence of BRD and promote animal health, thus helping to ensure the safety and sustainability of the U.S. beef industry," she said. While the search for more answers continues, Meyer's research seeks to help establish better understanding of the multiple factors that affect this disease. Read more

Researchers Make 'Elusieve' Dreams Happen

Ground corn flour, soybean meal and distillers dried grains with solubles (DDGS) — a by-product from ethanol production — comprise more than 70 percent of swine and poultry diets. While these ingredients are important for livestock nutrition, they are high in fiber, which is not easily digested by swine and poultry. Feed producers needed a system to remove the fiber while maintaining vital nutrients. MAFES scientists developed a process called "Elusieve" that uses a combination of sieving and air classification to separate fiber from feeds. This technique sifts particles into four sizes and then blows them with air to remove fiber. They found that fiber separation increases starch content of ground corn flour by 3 percent and increases protein contents of DDGS and soybean meal. Read More

Safer Horse Transportation

There has been little research to measure the heat conditions in horse trailers during transport. MAFES scientists recently measured several temperature variables in a fully enclosed four-horse, ant-load trailer with and without animals. Scientists found that trailer temperatures during transport exceeded those recommended for animal housing, although the thermal environment was affected by vehicle speed, vent configuration and presence of animals. They found that temperature increased significantly in transport during relatively mild weather, which indicates that horses could suffer from heat stress during warmer weather. These results show the importance of closely monitoring heat conditions in trailers used to transport horses.

Understanding The Complexities of Reproduction

MAFES reproductive biologist Jean Feugang is trying to find out why some pregnancies are successful and others are not. Feugang, along with fellow scientists Peter Ryan and Scott Willard, are studying the reproductive stage that remains one of the most mysterious—the gap between sperm and egg development and embryo development. Specifically, the team hopes to understand what factors make one sperm successful while others fail and why some eggs take while others do not. Their research can provide invaluable insight into biological and cellular processes associated with sperm and egg behavior and interactions before early embryo development. They use nanotechnology to study reproductive issues at the most microscopic level. Using quantum dots—nanoparticles that are absorbed into sperm cells—they can track the cells’ movement along the reproductive tract. Much like putting a tiny camera into the body, this process shows researchers what is happening, when, and where in real time. The scientists are using swine for the study; however, their research has applications to all mammals, including humans. Developing noninvasive monitoring techniques for use after artificial insemination has the potential to improve breeding success rates. Using quantum-dot imaging in reproductive studies is a new approach, and MAFES scientists are laying the groundwork for future research in this area. Read More