Past Events

The gut microbiota is a key regulator of the neuroimmune and neuroendocrine communication pathways of the brain-gut-microbiota axis. Disruption of the microbiome can lead to deterioration in gastrointestinal, neuroendocrine, immune functioning and may even contribute to the etiology and course of some psychiatric disorders. Some enteric gut bacteria, such as Lactobacillus species, have demonstrable beneficial effects on health and disease. Consequently, these organisms are used as probiotic supple-ments.

This thesis investigated the use of low-complexity, corn- and soybean meal-based diets in the nursery and as-sessed the effects of deoxynivalenol (DON) contamination and the effects of supplementation with immunomodulatory feed additives, such as a commercial anti-mycotoxin feed additive or fish oil on pig growth performance, gastrointestinal tract morphology, and immune system robustness. In the first week after weaning, both low and high DON-contaminated low-complexity diets resulted in reduced average daily gain and feed intake compared to pigs fed a high-complexity diet.

The presence of stressors such as disease or heat stress can lead to negative economic impacts in animal production by creating additional costs to producers for management and medication, weakened productive performance, or increased mortality. Genetic improvement for resistance traits is permanent and cumulative and, therefore, a viable solution for these issues in animal production systems. This thesis focuses on gastrointestinal parasite resistance, genetic resistance to scrapie, and heat tolerance in sheep.

This thesis investigated the impact of complete replacement of inorganic sources of supplementary trace minerals by organic sources in the diet of transition cows on cellular and humoral immunity of dams and neonate calves, colostrum characteristics, and oxidative balance, health and growth of calves. In cows, neu-trophil function was assessed in vitro by flow cytometry assays, and acquired immunity was evaluated by in vivo IgG responses to ovalbumin.

The overall objective of this thesis was to determine how milk yield at dry-off in AMS-milked cows, as affected by milking frequency and feed supplement allocation in the AMS, impacted udder health over the dry period, and how those factors might also affect milk production and cow behaviour before dry-off and in the next lactation.

The Summer Undergraduate Research Showcase happened the week of August 23-27, 2021. Watch the 14 students from across campus showcase their summer research projects in 3-5 minute videos, then attend the live Question & Answer sessions running August 25 and 26, 2021.

This thesis investigates the effects of increasing fat at the expense of lactose in milk replacer (MR) on growth, voluntary feed intake, feeding behaviour, and blood metabolites in Holstein calves. When investigating the effects high fat MR fed ad libitum, it was found that higher fat inclusion reduced voluntary MR intake without an evident effect on solid feed intake or growth. However, greater fat inclusion reduced hunger-related behaviours during the weaning period.

The ongoing shift from conventional cage to alternative housing for layers necessitates a deeper understanding of how commercial rearing systems impact physical development in pullets. My thesis examined the effect of three styles of rearing aviaries, differing in the opportunities for load-bearing exercise available during early life, and conventional rearing cages on musculoskeletal characteristics and proximate composition in two consecutive flocks of Lohmann Brown Lite (B) and Lohmann Select Leghorn Lite (W) laying hen pullets.