Bioconversion of whey permeate (WP) to value-added compounds and materials is a key prerequisite to eliminating the burden of this waste stream on the dairy industry, and in turn, safeguarding water and soil quality, whilst enhancing the economics of dairy operations. The central thrust of the proposed study is to convert WP at 12-liter bioreactor scale to 2,3-butanediol (2,3BD)–a versatile chemical with numerous industrial applications. We have isolated, sequenced and characterized a strain of Enterobacter hormaechei that produces 42 g/L 2,3BD on lactose as the sole carbon source. In the proposed study, we will demonstrate the use of lactose-rich WP to produce similar titer of 2,3BD in batch fermentation. Additionally, we will use fed-batch fermentation to increase 2,3BD titer to 55 – 60 g/L. In an effort to pave the way for potential commercial scale application of this strain of E. hormaechei to produce 2,3BD in WP, we will de-risk such an effort by inactivating major antibiotic resistance genes in the genome of this organism. The proposed study will provide multifaceted training in fermentation science, analytical chemistry and synthetic biology for a postdoctoral fellow. The results are expected to forge a roadmap for future efforts to convert WP to 2,3BD at pilot scale. Additionally, it is anticipated that the findings will engender similar efforts to de-risk other microorganisms that produce high concentrations of different important compounds, albeit with inherent risks associated with the spread of antibiotic resistance or virulence genes.

The Dairy Task Force 2.0 recommended creating the Dairy Innovation Hub (recommendation #2) to address an urgent need for research and innovation to maintain a sustainable competitive advantage of Wisconsin dairies. In addition, recommendation #26 calls for new, unique, impactful ideas to be explored which could provide significant benefits to the dairy industry by leveraging the cross-disciplinary expertise within the UW system. This cross-disciplinary research effort focuses on the nutritional regulation of reproductive function. Specifically, we will investigate an economic dietary strategy to modulate placenta development during the first month after insemination in order to reduce or prevent pregnancy loss. This period was selected as more than 50% of pregnancy losses occur at this time, which places reproductive failure as the second most reported reason for involuntary culling in the US. Aim 1 will determine if essential amino acid supplementation in lactating dairy cows during the first month of pregnancy rescues a high pregnancy loss phenotype due to impaired placental development and function. Aim 2 Will elucidate the mechanisms by which essential amino acids regulate placental function in vitro. Results from this research could not only improve reproductive outcomes and reduce involuntary culling, but it will also reduce production costs, which will contribute to the sustainability of dairy farms.

The dairy industry produces approximately 190 million tons of whey per year as a byproduct, often causing environmental concerns due to improper disposal. The lactose in whey is a valuable resource that can be further utilized instead of being disposed of or solely processed into powders for exportation. Simultaneously, the market is experiencing escalating demands for low-calorie sweeteners, such as tagatose, and health-enhancing prebiotics. This project will transform whey into tagatose and prebiotics. The major objectives include 1) identifying and elucidating efficient isomerization processes to convert the galactose, derived from lactose in whey, into tagatose; 2) developing a sustainable process for the production of prebiotic galacto-oligosaccharides (GOS) utilizing whey permeate; and 3) assess the economic viability and environmental impact of this innovative process through TEA and LCA. The methods involve a combination of lab-scale experiments, a range of analytical work, and rigorous data analytics. The ultimate goal of this project is to develop a scalable, cost-effective, and environmentally friendly method for tagatose and GOS production from whey, establishing a win-win situation for both the dairy and food industries. The impacts will be multifaceted: reducing environmental pollution from whey waste, adding economic value to a byproduct, bring a form of economic development to farm business and community sections, and offering health-beneficial ingredients to consumers. Xiaolei Shi and Jarryd Featherman are also CO-PIs on this project.

Probiotics are commonly used as a prophylactic treatment of various gut disorders. However, gastrointestinal survival of probiotics is highly variable among individuals. Approaches to boost and optimize intestinal survival are therefore much welcomed and could even boost probiotic efficacy in the clinic. Whey protein phospholipid concentrate (WPPC) is an underutilized dairy stream, harboring glycoproteins that could be used to promote intestinal survival of probiotics. WPPC-derived glycoproteins possess glycan sites that can specifically bind to probiotics surface receptors, thereby improving their viability and their attachment to epithelial cells, which is corroborated by our exciting preliminary data. In this study, we will use Limosilactobacillus reuteri (L. reuteri)
as our probiotic test species. Select strains bind intestinal mucins and are established probiotics based on their ability to modulate the immune system, to increase the intestinal barrier function, and to have antimicrobial activity against notorious pathogens. We hypothesize that the formation of WPPC-L. reuteri complexes improves survival in both the food matrix and in the gastrointestinal tract. To test our hypothesis, we will pursue the following aims: 1) to increase the purity of WPPC glycoproteins to promote the formation of WPPC-L. reuteri complexes; 2) to determine the binding efficacy of glycoproteins to complex with L. reuteri strains and to establish the extent by which probiotic survival in yogurt is impacted; 3) to determine gastrointestinal survival of the probiotic
complexed ± WPPC. The expected outcome of our research is that its successful completion will have delivered a next-generation dairy food by leveraging underutilized materials in the dairy stream, which will improve WPPC marketability and increase profits for dairy farmers and processors. Jan-Peter van Pijkeren is collaborating on this work.

Diarrhea is one of the primary causes of mortality in neonatal dairy calves and results in financial losses to dairy farmers. Factors associated with birth seasons such as temperature, crowding and housing conditions, humidity, pathogen distribution, and hygiene conditions also affect the risk of neonatal calves developing diarrhea. Despite the efforts to characterize the changes in the gut microbiome of dairy calves during the pre-weaning period, no study has compared the microbiota of healthy and diarrheic animals using both next-generation sequencing and culturomics approaches or evaluated the influence of seasonal changes in the fecal microbiome of healthy and diarrheic dairy calves. Here we aim to expand the current knowledge regarding the establishment of different microbial groups in the GIT in early life, which could help dairy farmers design more efficient intervention strategies to manage microbial colonization of neonatal calves. We will use Next-Gen Sequencing and culturomics approaches to evaluate differences in the intestinal microbiota of healthy and diarrheic calves in winter and summer periods and will select bacteria with health-promoting activities from healthy animals to develop synthetic microbial consortia with enhanced capacity to convert milk oligosaccharides to short chain fatty acids, particularly butyric acid.

Wisconsin is the second-largest dairy producer in the US, but the industry is facing challenges, including climate change and changes in dietary patterns. US climate policies, including carbon pricing, are complex due to variations between states and the federal government. While the US aims for zero emissions by 2050, different states may have differing policies. Wisconsin lacks carbon pricing, but the Wisconsin Climate Action Report and the Senate Bill 70 on WI’s budget, call for a thorough analysis of carbon pricing within the state. Additionally, there is a societal shift towards plant-based diets, partly to mitigate greenhouse gas emissions. The consequences of dietary shifts on the dairy industry depend on the policies implemented by governments. Therefore, this study aims to explore two key questions: 1) How does state-level carbon pricing heterogeneity compared to national uniform carbon pricing impact the dairy industry? 2) How do dietary changes affect dairy production considering various climate policies? The study utilizes a subnational version of the Global Change Analysis Model (GCAM), specifically the GCAM-USA model to address the questions. Multiple scenarios will be designed to project the combined impact of policies and dietary patterns on the dairy industry from 2020 to 2050. The results will provide insights into the alternative future of the dairy industry and the mechanisms driving changes at both the national and state levels, aiding institutional and individual climate mitigation plans, decision-making, and public advocacy for sustainable policies.

Research suggests that Rumen protected choline (RPC) may positively affect offspring growth, health, and well-being. RPC is typically fed to gestating dairy cows for three weeks prepartum. In utero choline exposure is an intervention which aims to enhance tissue growth and performance in a growing fetus. Currently the optimal timing, duration, and dose of in utero choline exposure is unclear. The objective of this project is to evaluate the effects of in utero choline exposure on growth, feed efficiency, and Carcass quality in Angus x Holstein cattle.

Publication in Journal of Animal Science – June 2023

White and her post-doc France are investigating hepatic carbon flux during the transition to lactation, a critical period for health and productivity, and the onset of metabolic disorders. This project aims to offer a better understanding of the etiology, onset, progression, and genetic predisposition to metabolic disorders, such as ketosis and fatty liver, in cattle.

White and her postdoc Arshad are exploring the factors that contribute to the nutrient use for feed efficiency. The ultimate goal is to understand nutrient use efficiency at cellular and whole-animal level to improve feed efficiency and reduce methane emissions in dairy cows.

Establishing alfalfa by interseeding into a high-yielding corn silage companion crop can increase yields and profitability of forage production on dairy farms. Additionally, this practice reduces the risk of nutrient and soil loss due to living cover being present in fields, both during and after corn production. Adoption was previously hampered by unreliable survival of alfalfa underneath corn. Recent research has identified that annual grasses, alfalfa foliar diseases and potato leafhoppers are the primary reasons for poor alfalfa establishment. While research in Wisconsin has identified pesticide treatments for ensuring good establishment, added cost and negative impacts from extensive agrichemical use deters adoption. Knowledge of thresholds where pesticides benefit establishment are not known. We propose to determine what levels of annual grass weeds, potato leafhoppers, and alfalfa foliar injury reduce establishment of interseeded alfalfa. Experiments will be conducted at Arlington, Prairie du Sac and Lancaster research stations where a wide range of pest levels will be imposed. Relationships between alfalfa survival and pest levels will be determined and validates across six on farm demonstrations. Results will be disseminated to stakeholders to improve pest management and adoption of this practice. At the conclusion of the study, we will survey stakeholders and producers to determine the impact of this project and identify additional obstacles that prevent adoption of this system on Wisconsin dairy farms. This project will aid the adoption of more sustainable forage production practices that will limit environmental impacts while enhancing farm productivity and profitability.

Publication in Agronomy for Sustainable Development – August 2021