Animal Sciences Events
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Fall Graduate Student Seminar Series
November 7, 2022 @ 12:10 pm - 1:10 pm
Relationship Between Body Temperatures and Behaviors in Lactating Dairy Cows
Stress has many negative effects on dairy cows, such as reduced productivity and weakened immune system. These effects impact cow welfare and farm performance. Current methods of measuring stress in dairy cows can be invasive and labor intensive. Infrared thermography (IRT) may provide a solution to this problem. Body temperature has been used to measure stress in cows, and a higher temperature indicates a more stressed cow. Rectal temperature is typically used to measure body temperature, however IRT offers an easier, more automated way to obtain this measurement. “Relationships between body temperatures and behaviors in lactating dairy cows,” by Uddin et al. aimed to determine the relationship between IRT and behavioral measures of stress. They also aimed to determine if IRT measures are repeatable. Studying a group of cows over three months, they collected behavioral measures such as laterality index, flight speed, and chute score. For IRT, they took images of the eyes and forelimbs and found the maximum IRT of the designated regions. They found that the maximum IRT of the eyes, flight speed, waiting time, and laterality index were highly repeatable. Additionally, the data showed that higher limb and eye temperature as indicated by IRT was correlated with several stress behaviors, particularly a faster walking speed in forced lateralization tests and a shorter waiting time. While further studies are needed to support these results, IRT appears to be a promising method of determining if dairy cows are stressed on farms.
Estrogen Impacts the Appetite Stimulatory Effects of Inhaled Cannabis
Cannabis is the most widely used illicit substance globally. In this context, the majority of those who use cannabis, use it more than once a month, including some near-daily users. Importantly, medical cannabis is prescribed as an appetite stimulant, thus understanding the efficacy of its effects when dosed repeatedly and across genders is critical. Here, we characterized cannabis-induced appetite in male, female, and ovariectomized female mice exposed to daily cannabis vapor over a 10-day period. Results indicate that male and ovariectomized female mice demonstrate increased appetite over the majority of days within the manipulation period whereas intact female mice do not. Additionally, our data indicates that cannabis alters hypothalamic mRNA expression of key appetite regulatory signals in a gender specific fashion. Collectively these data suggest a regulatory role for estrogen in the control of cannabis-induced appetite and the central genetic mechanisms that contribute to this process. Moreover, this work provides important insights that can better guide the use of medicinal cannabis for appetite stimulation in male and female patients.