Mississippi Agricultural and Forestry Experiment Station

Animal Production Systems

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.

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.

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.

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.

Swimming Upstream

MAFES scientists are helping producers in the heart of catfish country. Dr. David Wise and his staff at the Thad Cochran National Warmwater Aquaculture Center help producers find answers. Oftentimes, the question is an aquatic health issue that's impacting productivity and performance. Researchers have discovered ways to combat catfish anemia. They've also developed a vaccine that helps wipe out a disease common in catfish ponds. The work translates to dollars and cents for producers, and contributes to the industry's vitality.

Q&A with David Peebles

Poultry was a $3.2 billion dollar business in Mississippi in 2015. MAFES scientists conduct research that drives that industry forward. One such researcher is Dr. David Peebles. He's a MAFES scientist and professor in the Department of Poultry Science in the College of Agriculture and Life Sciences. He's called Mississippi State home for 28 years. Much of his research has been applied directly to the poultry industry while all of his students gain employment in their field of study. MAFES Discovers sat down with Peebles to discuss how his research role helps inform the poultry industry and discover how his academic appointment helps grow the poultry leaders of tomorrow.

Down the Line

730 million broilers were raised on Mississippi farms in 2015. MAFES researchers hope to discover more efficient, cost-effective ways to deliver feed to so many birds. That’s why Dr. Kelley Wamsley, MAFES researcher and assistant professor in the Department of Poultry Science, is studying how feed mill mechanics affect feed quality. Former MSU graduate student Ben Sellers conducted much of the research and Chris McDaniel, professor in the Department of Poultry Science, assisted on the projects.

A soldier in the fight

The black soldier fly, which turns agricultural waste into viable protein that can be used in feed for livestock such as chickens, may help fight food insecurity. John Schneider, Mississippi Agricultural and Forestry Experiment Station and professor of entomology in the Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, is evaluating how to integrate the insect into food production systems. According to Schneider, studies indicate that the insect is a high quality food source with no side effects. He hopes the research will help close the ecological loop, providing an efficient way to reduce agricultural waste and produce livestock feed.


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.

Feeding Pigs More with Less

Feed eats up two thirds of the total operation costs for pork producers. While measures like using feed additives and alternative feedstuffs and refining facility management may slightly reduce those costs, MAFES scientists search for ways to dramatically improve feed efficiency. MSU researcher, Shengfa Liao, is assessing the fundamental molecular and cellular mechanisms by which nutrients regulate swine muscle development and growth. Liao studies how dietary nutrients, such as amino acids and minerals, impact the expression of genes related to the muscle growth of pigs. After determining the gene regulatory network that controls muscle protein biosynthesis and degradation, new nutritional strategies could be developed to activate the pertinent gene network to enhance the pig’s ability to convert feed to muscle more efficiently, significantly reducing feed costs for pork producers.

Vaccine leads to better survival, bigger fish

MSU scientists have developed a vaccine and vaccine delivery system to protect catfish from commonly occurring bacteria that can cause death. During their first growing season, every catfish fingerling raised in the Mississippi Delta will be exposed to Edwardsiella ictaluri, the bacteria that causes enteric septicemia, or ESC. In research trials, vaccinated catfish have a relative percent survival rate above 90 percent. Vaccinated fish are also 20 percent larger than unvaccinated fish. MSU’s vaccine and delivery method were developed at the Thad Cochran Warmwater Aquaculture Center and received a provisional patent in 2013.

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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.

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.

Giving chicken hatchlings a boost

Chicken embryos are made up of water, protein, and fat. To get the energy they need to hatch, embryos must convert that protein and fat into carbohydrates. To help hatchlings retain protein and fat for growth, poultry scientist Wei Zhai is developing a procedure for injecting eggs with carbohydrates before they hatch. Zhai uses a commercial multi-egg injector to deliver uniform amounts of carbohydrates into each egg. Mississippi State is the only academic institution in North America to own this machine, which was donated by the pharmaceutical company Intelliject. Research indicates that injecting carbohydrates into eggs leads to good hatching and provides an early boost in body weight. MAFES scientists are now working to determine the most efficient amount of carbohydrates to inject into eggs. Other studies focus on whether injecting vitamins into eggs will help bone growth in chickens. Another benefit of injecting nutrients and vaccinations into eggs is that it alleviates bird stress by reducing the amount of handling they face after hatching

Finding the right diet for broilers

Poultry scientist Kelley Wamsley studies the nutritional content and manufacturing processes of poultry pellet feed. Since feed and feed manufacture represent about 60–70 percent of the total cost of raising a chicken, one small change could affect cost and performance. Wamsley’s research indicates that high-quality pellets are worth the price, especially for Mississippi poultry integrators who grow heavy broilers. These birds require a longer grow-out period, thus consume more feed. Research showed that poor-quality pellets result in poor performance. Pellet quality can deteriorate during transportation and as feed is distributed through grow-out houses, causing nutrients in the feed to segregate. High-quality pellets are more likely to stay intact and deliver a nutritionally complete diet. Wamsley also studies how alternative feed ingredients affect pellet manufacture and bird performance. As costs increase for corn, soybean meal, and other feed ingredients, there is a great need for high-quality, less-expensive alternative ingredients.

Using a natural feed source for catfish

MAFES scientists are looking for ways to lower costs while maintaining quality in Mississippi catfish production. Charles Mischke and David Wise, MAFES aquacultural researchers at the Thad Cochran National Warmwater Aquaculture Center in Stoneville, found that catfish can thrive for the first 6 weeks after hatching by feeding on naturally occurring zooplankton. They examined the growth and survival of newly hatched catfish fry not fed specially prepared commercial feed. Compared with fry that were fed a conventional diet, these fish suffered no ill effects in size or health. Fry not fed for 6 weeks ate zooplankton and other microscopic food organisms, which are abundant in ponds and high in protein and other nutrients. Reducing or eliminating fry feedings during the first few weeks can reduce the cost of fish production, saving producers at least $236 per acre.

Examining insects for nutrition and waste disposal

Imagine an insect that can eat nearly anything, control microbes, survive on water alone as an adult, and provide a good source of protein for animal feed. Entomologist John Schneider leads a team of scientists studying just such an insect: the black soldier fly. This insect could eliminate large amounts of agricultural waste while generating a valuable feed source. Black soldier fly larvae are 40–45 percent protein by dry weight. Harvested larvae can be dried and milled to create a high-protein meal for cattle, poultry, and fish consumption. These versatile, high-potential flies are not known disease carriers, do not bite or sting, and are not a nuisance species. Soldier fly larvae can eat almost anything—manure, cotton gin trash, and other agricultural by-products—without leaving behind any harmful fungi or microbial residue. With financial support from industry and visiting scholar Alfredo Llecha of Spain, MAFES researchers are designing a building with the optimum conditions for rearing black soldier flies.

Distillers' Grains as a Feed Supplement

Increased ethanol production also means increased stocks of the by-product distillers dried grains with solubles (DDGS), as well as increased interest in finding uses for the nutrient-rich grains. A MAFES study evaluated second-cycle Bovans White laying hens that were fed varying amounts of DDGS. Researchers looked at layer performance, egg characteristics and consumer acceptability. Results showed that DDGS could comprise up to one-third of a commercial layer diet without any significant detrimental effects on the production or egg characteristics of second-cycle hens. A similar study measured breast and thigh meat quality in broilers fed DDGS-supplemented diets. Overall, the diets yielded high-quality breast meat, and thigh meat quality was similar among diets containing up to 12 percent DDGS.

Identifying Destructive Invaders

Exotic insect species enter the United States through multiple routes, such as on wood shipping pallets, plant materials, and imported fruits and vegetables. The U.S. government sets trade restrictions to help prevent the introduction of nonnative pests, and its inspectors work at all borders to search for and confiscate materials carrying these insects. Some hidden pests do make it past inspection and move into U.S. crops. Once established, these pests can damage crops and native plant species, ultimately causing severe economic damage. Quick identification of invasive species is crucial to stopping their spread. The Mississippi Entomological Museum was recently designated as the Eastern Region Identification Center for the USDA’s Animal and Plant Health Inspection Service.

Do Cows Need to Shed?

In the subtropical climate of the Southeast, cows that fail to shed in a timely manner tend to show more signs of heat stress than their slick-coated herd mates. MAFES researchers found that on average, cows that shed their hair coats by the end of May weaned heavier calves than cows that take longer to shed. Hair coat shedding is a moderately heritable trait and should respond to selective breeding. Producers seeking to reduce shedding-related heat stress in their herds should evaluate their cows in late May and consider culling cows that shed little or not at all.

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.

Improved Grazing Systems for Cattle and Wildlife

MAFES scientists are evaluating cattle performance and environmental impacts of grazing based on native, warm-season grasses. These grasses once dominated the landscape but have been eliminated by conversion to agriculture and exotic forage grasses. Native grasses produce high biomass that is palatable and nutritious for livestock. These grasses also provide superior habitat for a variety of wildlife species, including bees and butterflies.

Treatments to Reduce Bacteria

Poor hatchability can occur due to eggshell bacterial contamination, which can be decreased by UV light or hydrogen peroxide. However, the antimicrobial effects of these two treatments combined are not known. MAFES scientists sought to determine if a greater bacterial reduction would occur using a combination of UV and hydrogen peroxide. Results indicated that the combined treatments further reduced bacterial contamination compared with each treatment individually.

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.

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.

MAFES Scientists Develop New Processing Technique

Technocatch, a poultry processing research company, recently teamed with processing company OK Foods and MAFES to develop an alternative to electric stunning and gas systems for processing chickens for consumption.

The new method, called LAPS (low-atmospheric pressure system), uses a vacuum system to reduce oxygen levels in a machine that can house up to 60 broilers per chamber. LAPS eventually renders the birds unconscious and then — borrowing a term coined by the USDA — "irreversibly stunned."

Initial testing for LAPS began in the Mississippi State poultry laboratory. LAPS received the American Humane Association (AHA) seal of approval, and the USDA officially stated it has "no objections to the system or its protocol." LAPS provides a humane method of processing poultry compared with the current methods employed.

Research Reveals Value of Selecting Calm Cattle

Recent research has demonstrated the value of cattle with calm temperaments and the price producers pay for keeping wilder animals in their herds. A 5-year MAFES study found that cows with poor temperaments could affect an entire herd and reduce producers’ bottom lines.

Findings from this research led scientists to conclude that producers should cull bad-tempered cows from their herds.

Researchers measured how a trio of cows behaved while enclosed in a 12-by-12-foot pen. They also studied the behavior of a single cow held in a chute similar to the ones used to hold bulls before they are released at rodeos.

In both cases, the cows’ behavior was measured after humans approached them. The research used laser technology to gauge how fast a cow traveled 6 feet after being released from a chute. For each part of the experiment, the cows were scored on a 5-point scale. A score of 1 described cows that were nonaggressive, docile, slow walking, easily approachable and not excited by humans. A score of 5 described cows that were very aggressive, excitable and out of control.

The pen scores and chute scores were nearly identical. Higher-scoring cows almost always ran out of the chutes at accelerated speeds.

The research found that anxious, aggressive cows — those with a pen score of 4 or 5 — present a host of problems. They become sick more often, have more difficulty gaining weight and damage farm equipment.

According to the study, cattle with high pen scores typically incur higher medical expenses than lower-scoring cattle. In addition, ill-tempered cattle typically bring in $5 or $6 less per hundred pounds of body weight than do calmer animals.

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.