Location: Livestock Behavior Research
Project Number: 5020-32000-014-081-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2026
End Date: Aug 31, 2028
Objective:
1. Analyze how milk allowance, weaning strategy (e.g., different gradual approaches), weaning duration, and housing conditions interact to influence calf welfare, behavior, and performance.
2. Characterize behavioral indicators and productivity impacts of cold stress in caged laying hens.
3. Investigate how hens’ social behavior contributes to the spread of northern fowl mites in cage-free housing systems.
Approach:
Objective 1. Studies in this theme will evaluate the effects of housing and weaning strategies on calf growth, behavior, health, and welfare. Individually and pair-housed calves will be compared, with emphasis on individually housed calves due to limited research on milk removal methods. Calves will be health scored twice daily, weighed weekly, and monitored for daily grain intake.
Weaning approaches will include: 1) dilution, where milk replacer solids are gradually reduced with increasing water inclusion until calves receive 100% water at final weaning; 2) meal frequency reduction, where calves transition from 2 milk feedings daily to 1 feeding over approximately 7 d; and 3) varying milk allowances (e.g., 6 vs 10 L/d), including step-down reductions in milk over several weeks.
The goal is to identify practical weaning strategies that optimize calf performance, rumen development, concentrate intake, and welfare while minimizing hunger and stress. Behavioral indicators such as vocalizations, cross-sucking, and non-nutritive sucking will be monitored using video surveillance. Saliva samples will assess cortisol as a stress indicator, blood samples will measure ßHBA as an indicator of rumen development, and novelty tests may be used to evaluate affective state during weaning.
Objective 2. We will house laying hens in 6 banks of cages where they will be assigned to control, warmed perch or standard perch treatments. At 36 weeks of age, we will reduce the room temperature to 10 °C or lower to induce cold stress, which will stimulate the warmed perch system to turn on. We will maintain these cold conditions for several weeks so that we can examine the impacts of cold stress and access to a warmed perch on egg production and egg quality. Using video recordings, we will examine hen behavior to identify early behavioral changes and perch use during cold stress. This work will provide information to help guide temperature management for laying hens, provide early indicators of cold stress, and provide information about the impacts of cold stress on egg production and egg quality.
Using video recordings of laying hens that are housed in cage-free floor pens and experimentally infested with northern fowl mites (NFM), we will characterize the relative mite infestation level of individual hens and then construct social networks for hens that have high mite loads at peak NFM infestation. All hens will be individually marked so that we can track how hen-hen interactions facilitate the spread of mites. Information from this project is expected to help producers develop early detection and intervention strategies for reducing NFM infestation levels.