July 16, 2021

SSASAS: Kunkle Symposium

SSASAS: Kunkle Symposium

By: Dr. Emily Taylor
Use of Byproduct Feeds in Southeastern Beef Production Systems – Dr. Matthew Poore, North Carolina State University

Dr. Poore jump-started the SSASAS Kunkle Symposium to discuss byproduct feeds in the Southeastern beef production systems. There are many alternative feeds available and used for both cow/calf and stocker cattle in this region. Many considerations need to be made when utilizing these byproducts – stability of the supply chain, how to determine the value of the feed, do we need to all the nutrients available in that feed, are there associated effects, what is the handling cost, should we be worried about shrink, and is there potential for toxins, dust or other unintended consequences? In addition, classification of the feeds (waste materials, waste products, byproducts, and coproducts) may also influence when to use these alternatives.

An example was given using soyhull research that as feeding value is better understood, the market value of that feed will increase. One way to improve the understanding of a feed is using the Peterson Method. This method uses the TDN and CP levels relative to corn and soybean meal to identify a value for the feed. Dr. Poore then spent time reviewing the relative value and cost of common alternative feeds. While we see an increase in the use of the feeds due to increased nutritional value and lower prices, there is a potential for dramatic side effects when utilizing them. For instance, fermented sweet potato canner waste is very high nutritive value if used at low levels in a total mixed ration. However, it may cause severe dental erosion if fed free choice, resulting in reduced gains and tooth loss. Dr. Poore presented data showing how heavily sweet potato impacts cows teeth due to being very acidic. Also, culled cured sweet potatoes kept in cold storage can kill cows from acute pulmonary emphysema. Ultimately, the successful use of byproducts/waste products takes a high level of management and research to understand the best way for them to be utilized fully.

Cotton Byproduct Use in Southeastern Beef Cattle Diets: Quality, Intake, and Changes in Feed Characteristics – Dr. Kim Mullenix, Auburn University and Dr. Lawton Stewart, University of Georgia

Dr. Stewart began his presentation section discussing the history, research, changes, and recommendations of byproduct use by both he and Dr. Mullenix. There is an abundance of byproduct feeds that can be used for livestock from cotton production. 

Dr. Stewart reviewed the significant differences in the NRC and actual feed values for cotton byproducts. Byproduct quality is heavily dependent on breeding and the efficiency of harvesting and ginning. Dr.’s Stewart and Mullenix grouped their research into four categories: Whole cottonseed quality aspects, animal performance and whole cottonseed, grazing cotton residues, and gin trash – feeding and safety.

Dr. Mullenix presented a study that evaluated whole cottonseed intake. This research demonstrated greater consumption of ultra-low gossypol seed than seed derived from a more widely planted cotton variety in growing steers. Also, it previously was thought that gossypol had a negative impact on fertility in males. However, recent studies have shown that feeding up to 3.2 kg/hd/d over a 60-d period did not affect sperm quality. Quality characteristics were also evaluated in relation to protein degradability and heat-damaged whole cottonseed. A reduced protein value will be seen due to the Maillard reaction when the cotton seed gets wet.

Dr. Stewart then continued discussing the use of cotton stalks as an alternative feed. Animals were placed on pastures to graze the cotton harvest residual, and it was found as a viable alternative strategy when nutrients and feedstuffs may be limiting. Similar to grazing cotton stalks, gin trash remains a prevalent byproduct that can also be used to decrease the amount of hay fed during the winter. Ultimately, cattle operations can reduce feed costs while maintaining animal performance if cotton byproducts are better understood.

Rise of Craft Breweries and Distilleries Increase Beef Cattle Supplement Availability – Dr. Deidre Harmon, North Carolina State University and Dr. Jeffery Lehmkuhler, University of Lexington

Dr. Lehmkuhler began the presentation with a description of Bourbon and its standards of identity. Bourbon can differ in grain concentration depending on the distillery. Therefore, fermented mash from distilling will vary greatly. Dr. Lehmkuhler provided a quick review of the distilling process and its changes due to increased consumption. Within the industry, distilleries face many challenges: rapid increase in stillage, spatial concentration of distilleries, insufficient cattle production in distillery concentration areas, financial investment in dewatering systems, industrial waste, free or paid to take.

Nutrient waste as a result of large consumptions of distillery byproducts has become an increased challenge for producers. Dr. Lehmkuhler recommended a pit-style barn if a producer will feed large amounts of these high moisture mash feeds. He also listed a few considerations when providing stillage: pH is slightly acidic, which Dr. Poore previously discussed related to teeth decay, significant moisture intake = excretion volume, and dietary imbalances are possible. However, water replacement, locally available supplements, rare instances to be paid to take feedstuff, and fertilizer replacement from manure nutrients are a few positive opportunities when feeding stillage.

Dr. Harmon started her section of the presentation by giving an overview of the U.S. beer industry and identifying the significant increase in microbreweries within North Carolina. These microbreweries use a large variety of grains, and therefore a varied nutrient profile. Like the large bourbon distilleries, microbreweries provide an excellent source of protein (wet brewers grains) and offer a good supplement for forage-based diets. However, transport, storage, handling, and feeding can cause logistical concerns that need to be addressed before obtaining benefits.