Foundation Scholars' Lectures and Discussion
2021 Production Division Foundation Scholar Winner, Jimena LaPorta
Title: Heat stress in the next generation: costs and opportunities for youngstock heat stress abatement
Global rising temperature is a considerable threat to livestock production and an impediment of animal welfare. In fact, the five warmest years on record occurred since 2015. While the impact of heat stress on lactating cattle has been extensively studied, it is evident that rising temperatures will impact increasing numbers of dairy cattle of all ages and lactation states. This seminar will highlight my novel body of work surrounding the consequences of heat stress exposure in young dairy cattle, including prenatal calves (in-utero), postnatal calves (pre-weaning), and growing heifers: all categories that are typically not considered for heat abatement on-farm. The seminar will be of interest to a variety of researchers in Dairy Science, as it will provide insights into the physiological and molecular mechanisms that might explain the negative phenotypic outcomes of heat stress exposure at different stages of development. My research largely focuses on unraveling the molecular signature of in-utero heat stress in mammary gland development and function and highlights the long-lasting and transgenerational effects of heat stress. Studies will be presented supporting the hypothesis that in-utero hyperthermia alters mammary developmental trajectory from fetal stages through the first lactation, resulting in decreased productivity for multiple lactations. Our data demonstrates that these long-lasting effects might be explained, in part, by alteration in the mammary gland methylation landscape. Carryover effects on the survival and productivity of the second generation are also observed, indicating a potential link between in-utero heat stress and gamete development. This seminar will also highlight our recent data on the provision of heat abatement to neonatal calves, highlighting evidence of improved milk and grain intakes that translate in enhanced growth and superior health. Similarly, studies will be described from pregnant nulliparous heifers, which are typically housed on pasture exposed to direct solar radiation. Lastly, the economics and profitability of cooling late-pregnant cows versus heat stress repercussions in the U.S. dairy sector will be discussed. Dry period heat stress leads to an estimated $810 million loss from reduced dam milk production. We approximated annual losses arising from in-utero heat stress at $600 million, factoring in milk loss across multiple lactations in both dam and daughter, reduced productive life, and additional heifer rearing costs. Consequently, the total annual economic loss if dry cows are exposed to heat stress during late gestation could reach $1.4 billion, comparable to estimates in lactating cows. Economic predictions with varying milk prices and heat stress days will be provided to discuss alternative scenarios for future milk markets and climate alterations. Our research highlights the importance of heat abatement strategies for dry-pregnant cows to ensure optimal generational productivity and showcases the benefits of cooling neonatal calves and growing heifers. Understanding the implications of heat stress at all life stages from a physiological, molecular, economic and welfare perspective will lead to the development of refined management practices and interventions to help overcome the long-lasting effects of climate change in the dairy industry.
2021 Dairy Foods Division Foundation Scholar Winner, Prateek Sharma
Title: Can material science approaches solve dairy industry problems?
This seminar would be of interest to a variety of researchers working in the areas of Dairy Foods manufacture and quality assurance. Dairy products can be manufactured in various structural forms e.g. liquid, semi-solids, and solids. For example, milk itself is a complex material and from the material-science point of view it is an emulsion wherein colloidal particles co-exist with a true solution. Similarly, yogurt, which is considered as a soft material (semi-solid), is formed from the milk after fermentation. Cheese, which is a rennet coagulated, casein rich fraction of milk, falls in the category of solid foods. Structurally, cheese is a complex network of proteins (caseins), in which fat globules, water, minerals, bacteria, and dissolved solutes, such as lactose, lactic acid, soluble salts, free amino acids, and peptides, are all interspersed. Structural origin of these diversified food textures is derived from the way that various food constituents are arranged to form a body or mass. Food material science helps in assessment of these structural arrangements of molecules at various length scale. My presentation will focus on the use of various material science approaches (rheology, diffusion, and phase transition) for solving critical issues that dairy industry faces.