Meet The Speakers

Ney is a professor of nutritional science and director of the Didactic Program in Dietetics at UW–Madison. Her research program addresses gastrointestinal physiology with a special interest in the dairy protein produced during cheesemaking, glycomacropeptide (GMP). Ney has pioneered the use of medical foods made with GMP for the dietary management of phenylketonuria (PKU), a rare genetic disease.

Talk summary: Results from STHI grant. We evaluated the anti-obesity effects of glycomacropeptide (GMP) in 13 obese, postmenopausal women. Participants consumed GMP supplements twice daily for one week and thrice daily for one week. Women completed a meal tolerance test (MTT) on day 1 (soy MTT) and day 7 (GMP MTT) of each week. During each MTT, subjects underwent measures of glucose homeostasis, satiety, and the fecal microbiome. GMP was highly acceptable. Glucose and insulin levels were no different. Postprandial area under the curve (AUC) glucagon was significantly lower, and the insulin-glucagon ratio was significantly higher with GMP compared with the soy MTT. Amylin was significantly higher with GMP vs soy and correlated with C-peptide and greater satiety. Ingestion of GMP supplements twice daily reduced Streptococcus. In conclusion, GMP increased amylin levels, improved glucose homeostasis, and altered the fecal microbiome. GMP might prove to be a helpful nutritional supplement in obese postmenopausal women.

Hasegawa is a postdoc in food science at UW–Madison and is mentored by food science associate professor Bradley Bolling. She got her PhD in food science at the University of California-Davis, where she mainly studied the impact of maternal obesity on infant metabolism and cognitive development. Hasegawa’s current projects investigate the anti-inflammatory properties of yogurt on obese population.

Talk summary: To understand the impact of yogurt consumption on chronic inflammation in people with obesity, we conducted a randomized controlled cross-over trial that included healthy women with BMI above 25 kg/m2. The dietary intervention consisted of two cycles of 4-week consumption of a low-fat dairy yogurt or non-dairy control food at 12 oz/day separated by a 4-week wash-out period (n=10/group). Dietary assessments and collection of fasting blood and fecal samples were conducted at the baseline and end of each dietary intervention. Plasma IL-10, an anti-inflammatory cytokine, was maintained by yogurt consumption, while the control food consumption reduced its level (p=0.043). Additionally, although yogurt consumption tended to reduce IL-6, the control food consumption had the opposite effect (p=0.063). The other inflammatory markers and fecal calprotectin did not vary between the interventions. Relative to a non-dairy control food, yogurt consumption maintained biomarkers consistent with lower chronic inflammation in healthy women with elevated BMI. 

Antunes is a graduate student in the Interdepartmental Graduate Program in Nutritional Sciences at UW–Madison and is mentored by nutritional sciences assistant professor Joseph Pierre. She developed her skills as a nutritional scientist through working as a nutritional counselor and getting a bachelor of nutrition from Universidade do Estado do Rio de Janeiro.

Talk summary: Obesity is a major contributor to morbidity and mortality worldwide. Among environmental factors, intestinal microbiome dysbiosis is strongly linked with obesity through association and causality studies. In the United States, over 280 million antibiotics are prescribed annually. The second most common antibiotic class, macrolides, remain necessary to treat infections but are unfortunately linked to long-term risk of metabolic syndrome and microbial disturbance. In the sterile mammalian intestine following birth, colostrum serves as an initial food source that delivers concentrated bioactive metabolites (e.g.-oligosaccharides, IgG) that facilitate optimal colonization of microbes including Lactobacillis, Bifidobacteria, and limit Enterococcus. Given these bacterial genera are indirectly targeted by macrolide antibiotics, we hypothesized that therapeutic treatment with colostrum would restore “eubiosis” following antibiotic-induced microbial depletion, leading to more normal community functions.  Our initial study evaluated the impact of colostrum therapy immediately following brief early life exposure to antibiotics, and we tracked metabolic phenotypes over the lifespan.

Larsen is a graduate student in food science at UW–Madison and is mentored by Center for Dairy Research scientist Rodrigo Ibáñez. Larsen's research is studying a possible new source of late gas formation in cheese. He is looking into what is causing this gas production and possible strategies to mitigate it, such as enzymes or adjunct cultures.

Talk summary: Biogenic amines (BA) are organic bases that are generally formed in fermented food products due to microbial activity, impacting organoleptic qualities and triggering allergic-like reactions upon consumption.  Strategies to prevent formation of BA in cheese include inhibiting growth of BA-producing bacteria and protecting BA-producing bacteria from oxidative stress.  Nisin is a bacteriocin produced by some strains of Lactococcus lactis (a common starter culture) which inhibits growth of Gram-positive bacteria.  ɑ-Tocopherol is an antioxidant naturally found in milk which has decreased production of BA in other food systems.  A cheese model system was supplemented with either 100 mg/kg nisin or 3 mg/L ɑ-tocopherol and ripened for 28 days at 10oC to evaluate formation of BA by Lentilactobacillus parabuchneri, a BA-producing bacteria.  Nisin reduced production of BA by 29%, while ɑ-tocopherol showed no effect.  These findings suggest the use of nisin-producing cultures may reduce incidence of BA in cheese.

Mohapatra is a postdoc in biological systems engineering at UW–Madison and is mentored by biological systems engineering professor Xuejun Pan. She received her PhD in fermentation technology from Biju Patnaik University in India.

Talk summary: In this study, we developed a facile and high-yield process to convert lactose into prebiotic galacto-oligosaccharides (GOS) with health-promoting properties. GOS was synthesized from lactose via acid-catalyzed glycosylation in concentrated sulfuric acid (64–84 % H2SO4). An optimal GOS yield (96%) was obtained 50% (w/w) initial lactose loading in 76 % H2SO4 after reaction at 70 °C for 20 min with minimal residual side products (e.g., galactose, glucose, anhydrosugars, and sugar degradation products). The synthesized GOS were a mixture of di-, tri-, and tetra-saccharides (47%, 25%, and 16%, respectively) and a small portion of larger oligosaccharides (DP up to 6 In vitro fermentation studies revealed GOS promoted the growth of selected Lactobacillus strains with comparable performance a commercial prebiotic GOS. Based on the invitro studies, selected probiotic Lactobacillus strains (Bifidobacterium bifidum -ATCC 29521 and Lactobacillus brevis- ATCC 8287) were experimented in 8-week-old mice models for their survival and persistence in the gut conditions with supplementation of the synthesized GOS and commercial GOS. While the survival of both the probiotics was similar for synthesized and commercial GOS, the persistence of L. brevis with supplementation of synthesized GOS was 8 and 3-fold higher at the 4th and 8th day, respectively, post termination of the probiotic in the feed system.

Chen is a graduate student in food science at UW–Madison and is mentored by food science assistant professor Tu-Anh Huynh. She studied food science at South China University of Technology and her project in the Huynh lab aims to discover novel antimicrobials from food fermentation microbiota.

Talk summary: Listeria monocytogenes is a leading cause of mortality among foodborne illnesses. Listeria is abundantly present in the natural and agricultural production environments, and frequently contaminates the human food production chain. Fermented foods harbor diverse and complex microbial communities that have been shown to exhibit antimicrobial activities. Among various fermented foods, cheese is exceptionally well studied for microbiota composition and diversity. Furthermore, on the surface of wooden boards used in cheese ripening, we found that Listeria was greatly inhibited. Thus, we hypothesize that the wooden cheese board microbiota is a source of natural antimicrobials against Listeria. We systematically isolated bacterial species from wooden boards used for different cheese types, and have thus far identified three species that inhibits Listeria: Serratia sp., Bacillus sp., and Lactococcus sp. Inhibition by Serratia sp. and Bacillus sp. occurs via secreted antimicrobial factors, and is specific towards Listeria. Work is in progress to identify those antimicrobials and their mechanisms of action.

Laporta is an assistant professor of animal and dairy sciences at UW–Madison. Her research investigates how autocrine, systemic, and environmental factors affect the regulation of mammary gland development and function. Additionally, she researches how these factors affect milk synthesis and composition.

Talk summary: In this presentation, I will describe the adverse outcomes of heat stress in dairy calves and discuss associations between environmental,  thermoregulatory, and productive calf-based indicators of heat stress in dairy calves exposed to a hot and humid climate in the Southeastern US region or a moderate continental climate in the Midwestern US region. I will also share new information on heat stress abatement mechanisms for dairy claves in these two climates. These data will inform scientists and producers on best-management practices to identify and mitigate heat stress in their calves. The Dairy Innovation Hub (short-term-high impact project) provided funding for data collection in the Midwest. 

Mantovani is an assistant professor of animal and dairy sciences at UW–Madison. His position is funded by the Dairy Innovation Hub. Mantovani's research is focused on understanding the functions and ecological interactions between anaerobic microbes that colonize the gastrointestinal tract of ruminants.

Talk summary: Mastitis is the most frequent inflammatory disease of the mammary gland in dairy cows, causing severe effects on animal health and significant economic losses to the dairy industry. Current therapies, based on antibiotics, can be inefficient due to the emergence of infections caused by environmental pathogens, the selection of antibiotic-resistant strains, and the capacity of some mastitis pathogens to form biofilms. Therefore, the development of new and effective approaches to control contagious or environmental mastitis could improve antibiotic stewardship in the Wisconsin dairy industry, potentially reducing the risk of antibiotic residues in milk, and the dissemination of pathogens and antibiotic resistance genes across the food chain. Here, we will address alternative therapeutic approaches based on bioactive peptides and anti-virulence compounds that could be used to develop novel antibiotic-free preparations or to boost the efficacy of traditional antibiotics used in intramammary formulations in dairy cattle. 

Pacheco is a graduate student in animal and dairy sciences at UW–Madison and is mentored by animal and dairy science assistant professor Francisco Peñagaricano. She has a BS in veterinary medicine from Federal University of Parana in Brazil.

Talk summary: Intensive selection in dairy cattle has been accompanied by an increase in inbreeding rate, which tends to impact performance traits, such as male fertility. Inbreeding can be quantified using runs of homozygosity (ROH) through genomic information. The goal of this study was to evaluate the association between ROH and bull fertility in Italian Brown Swiss cattle. Data consisted in 1,102 Italian Brown Swiss bulls with sire conception rate records and 567k SNPs spanning the entire genome. The association analysis between ROH and male fertility was performed comparing a subset of low-fertility vs. high-fertility bulls. Notably, ROH were more prevalent in low-fertility bulls. Four different ROH regions were significantly overrepresented in low-fertility bulls and these regions harbor genes related to male fertility. These findings suggest that inbreeding and increased homozygosity have a negative impact on male fertility, and quantification of ROH can be used to manage inbreeding in genomic selection programs.

Cavani is a postdoc in animal and dairy sciences and is mentored by animal and dairy sciences chair and professor Kent Weigel. She received her PhD in animal science from Sao Paulo University in Brazil.

Talk summary: Resilience can be defined as the capacity to maintain performance or bounce back to normal functioning after a perturbation. Using high-frequency data to analyze fluctuations in daily feeding intake can be a promising tool for identifying resilient dairy cows. Our goal was to develop new phenotypes based on consistency of daily dry matter intake (DMI) and estimate heritabilities and genetic correlations with residual feed intake (RFI) in Holstein cows. Consistency phenotypes were calculated based on the deviations from expected daily DMI for each cow during the feeding trial. Expected values were derived from parametric and non-parametric models. Overall, variance of deviations from expected daily DMI can be used as a phenotype for genetic analysis because it is heritable and appears to be genetically correlated with feed efficiency, indicating that cows with greater variation in daily DMI may be less efficient and less resilient.

Martinez Boggio is a postdoc in animal and dairy sciences and is mentored by animal and dairy sciences chair and professor Kent Weigel and animal and dairy science assistant professor Francisco Peñagaricano. He received his PhD in animal science from INRAE in France.

Talk summary: It is widely accepted that dairy cow performance is influenced by both host genome and rumen microbiome composition. The objectives of this study were to quantify the host-mediated effect through rumen microbiome on feed efficiency traits in lactating Holstein cows. Data consisted of feed efficiency records, SNP genotype data, and 16S rRNA rumen bacterial abundances from 435 mid-lactation Holstein cows from two research farms. We estimated the heritability of all microbial genera in the rumen, and we fitted several mixed models that included genomic and microbial genera to estimate their contribution on feed efficiency traits. The microbial genera showed a low to moderate heritability (h^2 from 0.15 to 0.75) and a low contribution on feed efficiency traits (from 0.11 to 0.15). These findings suggests that the rumen microbiome mediates part of the host genetic effects, and this can be used to improve genomic selection for complex traits.

Novo is a graduate student in animal and dairy sciences and is mentored by animal and dairy science assistant professor Francisco Peñagaricano. She has an MS in animal science from Federal University of Mato Grosso in Brazil.

Talk summary: It is widely accepted that dairy cow performance is influenced by both host genome and rumen microbiome composition. The objectives of this study were to quantify the host-mediated effect through rumen microbiome on feed efficiency traits in lactating Holstein cows. Data consisted of feed efficiency records, SNP genotype data, and 16S rRNA rumen bacterial abundances from 435 mid-lactation Holstein cows from two research farms. We estimated the heritability of all microbial genera in the rumen, and we fitted several mixed models that included genomic and microbial genera to estimate their contribution on feed efficiency traits. The microbial genera showed a low to moderate heritability (h^2 from 0.15 to 0.75) and a low contribution on feed efficiency traits (from 0.11 to 0.15). These findings suggests that the rumen microbiome mediates part of the host genetic effects, and this can be used to improve genomic selection for complex traits.