Alabama Beef Cattle Conference 2024

Title: Early life programming of the jejunum altered by maternal nutrition during gestation
Abstract: Although maternal nutrition’s role in fetal development is increasingly recognized, its impact on jejunum programming remains largely unexplored. This study examines how maternal vitamin and mineral (VTM) supplementation during gestation influences gene expression and biological pathways in the jejunum of neonatal calves. Fourteen crossbred Angus heifers were estrus-synchronized, bred with female-sexed semen, and assigned to either a basal diet (CON; n = 7) or the same diet plus VTM supplement (VTM; n = 7). Calves were euthanized 30 hours after birth for organ and tissue collection. A mid-jejunum subsample was freeze-dried and stored at -80°C before undergoing RNA isolation and sequencing. The study revealed that maternal VTM supplementation did not affect calf organ mass, including jejunum weight, but enhanced mitochondrial efficiency in the jejunum. Additionally, VTM supplementation significantly altered the gene expression profile, with 528 differentially expressed genes (DEGs) identified between VTM and CON calves. Key genes such as IGFBP2 and IGFBP6, associated with the insulin pathway and IGF transport, were upregulated in the VTM group. Pathway analysis identified significant roles in pancreatic secretion and immune response, with genes like PLCB1, SLC26A3, TNFSF18, and TNFRSF4 highlighted. These findings suggest that prenatal VTM supplementation influences gene expression related to jejunum function in neonatal calves, though the long-term implications require further study.

Title: Breeding beyond boundaries: enhancing livestock production with advanced reproductive technologies
Abstract: Advanced reproductive technologies have revolutionized livestock production by enhancing sustainability, reducing generation intervals, and optimizing the use of superior genetics. In vitro maturation (IVM) and in vitro fertilization (IVF) are key technologies in this domain, allowing for the maturation and fertilization of oocytes outside the body in a controlled laboratory environment. These oocytes, collected through follicle aspiration, can be matured and fertilized in large quantities, maximizing the genetic potential of valuable females. These technologies shorten generation intervals and significantly enhance genetic dissemination by enabling the transfer of multiple embryos to different recipients. Furthermore, IVF reduces the need for large quantities of semen, as a small amount can fertilize numerous oocytes, thereby maximizing the genetic contributions of valuable males. The primary objective of this research is to refine and enhance assisted reproductive technologies to make them more accessible to producers. The lab is testing the anti-estrogenic properties of a FDA-approved drug in horses, cattle, and pigs with the end goal of having higher quality and quantity embryos. This can hopefully provide some insight for optimizing protocols to improve outcomes, ensuring that these advanced techniques can be implemented more broadly within the livestock industry. By improving the efficiency and accessibility of IVM and IVF, we aim to empower producers with tools that enhance genetic progress, improve sustainability, and ultimately lead to more efficient and productive livestock systems.

Title: From Producer to Consumer: Sustainability in the United States Beef Industry
Abstract: The concept of sustainability in agriculture is a large focus for many production systems and subsequently the public. The animal production industry, specifically beef production, receives much of the blame for global warming and greenhouse gas emissions in the media cycle. While the beef industry actively works to mitigate its environmental impact and highlight the efforts of researchers and producers to reach sustainable goals, these efforts may go unnoticed in the media landscape. Multiple industry, university, and non-profit resources on sustainability initiatives are widely available, but a lot of them are tailored more toward internal users and industry partners. The focus of these thesis projects is to understand both the beef producer and consumer perspectives about sustainability in the industry. The first study investigates Alabama beef producers’ perspectives and awareness of sustainability practices in the industry. The purpose of the consumer survey is to better understand opinions on beef production and sustainability and the effectiveness of using infographics to educate and change negative or misinformed opinions about the beef industry. This combined research aims to fill a knowledge gap within agricultural communications specifically in the beef industry while also gaining a better understanding of sustainability within Alabama specifically.

Title: Exploring Differential Gene Expression and Pathways Associated with Pregnancy Outcomes in Beef Heifers
Abstract: Heifer fertility is a key factor in the success of beef production systems, as the reproductive performance of a heifer correlates with her stayability in the breeding herd. However, despite being reproductively mature and physically healthy, 5 to 15% of these heifers fail to conceive within a designated breeding season. The underlying physiological mechanisms preventing these heifers from achieving pregnancy remain elusive. Therefore, this study aimed to determine differentially expressed genes (DEGs) and biological pathways associated with pregnancy outcomes in beef heifers. Angus-Simmental crossbred heifers were subjected to an estrus synchronization and fixed-time artificial insemination (AI) program (7-day CO-Synch + CIDR) and blood samples were collected at the time of AI for isolation of Peripheral White Blood Cells (PWBCs). After pregnancy check, heifers were classified as pregnant (P) and non-pregnant (NP). Based on that, six animals per group were randomly selected for total RNA isolation from the PWBC samples, and RNA sequencing. The RNA-Seq data was analyzed for quality, with filtered reads aligned to the Bos taurus reference genome. DEGs were identified and subjected to a functional analysis using ShinyGO. Furthermore, the entire subset of expressed genes was subjected to a gene set enrichment analysis (GSEA). Our approach unveiled 230 DEGs, comprising 102 up and 128 downregulated genes in the NP group. The genes ADAMDEC1 and FBP1 were upregulated and have been associated with immune response. Functional analysis of DEGs retrieved allograft rejection, graft-versus-host disease, type I Diabetes Mellitus, insulin signaling pathway, and transcriptional misregulation of cancer. These pathways were confirmed by the GSEA. Downregulated genes included GZMB and BOLA-DQB, which are needed for proper cell targeting during immune response. This finding may provide a link between immune function and early pregnancy failure. However, the relationship between the immune system and pregnancy warrants further investigation. Our results shed light on the molecular mechanisms underlying reproductive performance in beef heifers and support previous studies associating immune function with pregnancy outcomes. These differentially expressed genes may be further explored as potential avenues for enhancing fertility in beef production systems.

Title: An Assessment of Yield and Quality of Stockpiled Bahiagrass in Central Alabama
Abstract: In the southeastern United States, cattle grazing programs play a vital role in livestock nutrition and production. Stockpiling, a common practice in this region, involves temporarily suspending grazing to allow the growth of a selected forage until frost. This practice ensures that there are enough mature grazing lands to support a crop of cattle, ideally for a month or more, closing the gap until cool-season forages are established. By extending the grazing period, stockpiling reduces the cost and labor associated with hay or silage feeding in cattle operations. Previous research indicates that bahiagrass tends to lose nutritive value as it matures. Bahiagrass was chosen for this study, as it is tolerant of poor soil and weather conditions. It also can withstand close grazing, which is ideal for the use of stockpiled forage. This study aims to evaluate the production and nutritional value of stockpiled bahiagrass at various stages of maturity and assess its potential to extend the grazing season by providing additional days of forage. Bahiagrass was harvested at two locations in central Alabama in Fall 2023 and will be harvested again this Fall 2024 at approximately 2-week intervals. Samples were collected using a quadrat and electric forage clippers. The samples will be analyzed in the Auburn University Nutrition laboratory to measure crude protein, total digestible nutrients and to calculate forage yield. This study assesses forage performance to lengthen the grazing season, particularly for cattle with low nutritional demands, thereby maximizing the use of grazing lands and reducing the need of producing hay or silage.

Title: Predicting the ground beef shelf life from the initial microbial community profile
Abstract: Food waste is a growing global issue that impacts consumers, producers, and environmental sustainability. Food insecurity is also an increasing issue, with an estimated 900 million people affected by severe food insecurity, globally, in 2022. Cattle producers are crucial to the food supply chain, providing affordable, high quality food products. However, many of those meat products that are produced tend to be discarded before they can be consumed. In 2024, an estimated one-fifth of the food that is produced globally will be wasted. One of the primary reasons for this elevated food waste at the consumer and retail level is the use of overly conservative sell-by and use-by dates on packages. These dates are an estimate of when the product will be too spoiled to sell or consume, though the products are generally still good days after. Consumers tend to believe that these dates are definitive markers of food safety of the product and will discard it according to those conservative dates. Therefore, it is important that these dates accurately express the product’s shelf life, so it is not discarded prematurely. Meat spoilage is driven by numerous factors, but the main factor is microbial activity. The bacteria that populate the surface of the meat break down the tissue and produce the chemical compounds that cause off-odors and flavors of spoiled meat, also including color changing, slime, and gas production. The goal of this research is to monitor the changes in microbial community structures over a 14-day shelf life and apply machine learning to generate a practical model of spoilage for predicting shelf life. Throughout the 14-day sampling, data was collected through colorimeter testing, lipid oxidation testing, microbial aerobic plate counts, and meat component analysis. We assess the overall microbial communities using amplicon sequencing methods and perform DNA extraction using the Illumina miSeq platform. We will then use a statistical assessment of the microbial taxonomies and see how they change over time. Following this, we will be able to construct a Random Forest regression machine learning algorithm to predict the data the product is considered microbiologically and sensory spoiled. The quality analysis results show that the product was microbiologically spoiled at day 6 of the experimental period, with spoilage being defined as a microbial aerobic plate count (APC) of 7 logCFU/g. Further evidence of spoilage included the HunterLab colorimeter data that demonstrated decreasing L* values as spoilage progressed, meaning the lightness of the cherry red color was becoming darker. Additionally, the redness values decreased throughout spoilage as oxidation occurred. The results from lipid oxidation also demonstrate spoilage as the values of mg/kg of malonaldehyde increase. As we continue our analysis, we expect the microbial communities involved to becomes less diverse as certain organisms tend to outcompete the others in the environment. This pattern will help with predicting the rate of product spoilage.