Effects of thermal stress on calf welfare.

Cold and heat stress present welfare challenges for dairy calves. The consequences of thermal stress on biological functioning have been well documented, and many housing and management strategies have been evaluated to mitigate those detrimental impacts. In cold weather, mitigation strategies have largely focused on nutritional interventions or limiting heat loss with resources such as bedding or jackets.

Actively ventilating calf hutches using solar-powered fans: Effects on hutch microclimate and calf thermoregulation.

Although active ventilation via fans is an effective and widely adopted heat abatement method for use with adult dairy cattle, it has yet to be investigated in outdoor hutch-housed dairy calves despite most US calves being raised in such systems. We investigated a solar-powered fan system for outdoor calf hutches and its effect on hutch microclimate and calf thermoregulation. During summer, a 3 × 3 Latin square was replicated 4 times (n = 12 preweaning heifers) with 4-d exposure periods to minimally (CON; rear windows closed), passively (PASS; rear windows opened), or actively (ACT; solar-powered fan, activated at dry bulb temperature [T] > 21°C) ventilated hutch systems.

Untargeted Metabolomic Analysis of Lactation-Stage-Matched Human and Bovine Milk Samples at 2 Weeks Postnatal.

Epidemiological data demonstrate that bovine whole milk is often substituted for human milk during the first 12 months of life and may be associated with adverse infant outcomes. The objective of this study is to interrogate the human and bovine milk metabolome at 2 weeks of life to identify unique metabolites that may impact infant health outcomes. Human milk ( = 10) was collected at 2 weeks postpartum from normal-weight mothers (pre-pregnant BMI < 25 kg/m) that vaginally delivered term infants and were exclusively breastfeeding their infant for at least 2 months.

Amplifying local serotonin signaling prior to dry-off hastens mammary gland involution and redevelopment in dairy cows.

The monoamine serotonin (5-hydroxytryptamine, 5-HT) has been reported to inhibit milk protein gene expression and increase mammary epithelial cell (MEC) tight junction permeability after milk stasis. We hypothesized that increasing serotonin synthesis and signaling within the mammary epithelium before milk stasis would increase systemic and local involution markers, and downregulate the expression of milk protein and tight junction during involution, leading to more efficient tissue growth during the redevelopment phase. Herein, we examined the outcomes of increasing local mammary 5-HT synthesis before milk stasis on involution biomarkers, mammary gland microstructure, and gene and protein expression during the dry period.

Methods for detecting heat stress in hutch-housed dairy calves in a continental climate.

Dairy calves exposed to solar radiation, elevated ambient temperature, and humidity are at risk of impaired welfare and productivity. Initial detection of thermal discomfort requires determination of optimal heat stress indicators and thresholds. Such values have recently been established in calves in chronic, subtropical, and acute continental environments but not in continuous, temperate conditions.