Liliana Fadul-Pacheco, Michael Liou, Douglas J. Reinemann and Victor E. Cabrera
NMC Annual Meeting January 2021
Relationship Between Cow’s Social Interactions and Milk Performance: An
Exploratory Use of Social Network Analysis
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Introduction
• Social network analysis (SNA) explores complex relational patterns in communities and provides a description of the social relationships structure (Farine and Whitehead, 2015).
• Dairy cows are social animals
• Understanding their relationships or interactions could help improve management practices, performance and welfare.
• Domestic animals can have positive or negative social interactions (Rault, 2012).
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Introduction• Automatic milking systems (AMS)
environment provides a measure of social interaction in real-time, when cows go through a sort gate when moving from resting to feeding or milking areas.
• These time series data can be used to assess cows’ interactions.
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Objective• Perform an exploratory analysis using SNA to identify potential social relationships
between cows.
• Assess if there was an impact on milk production when the relationships among them is broken.
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Materials and Methods• Data from a commercial dairy farm during a 12-month period was used
• Each pen was fitted with a pre-selection sorting gate
4 pens with 1 DeLaval AMS/pen.
241 ± 36 milking cows
~60 cows/AMS
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Materials and Methods• Cow traffic and milk performance data were made available through the Dairy Brain
project at the University of Wisconsin (Cabrera et al., 2020).
Data on cow traffic:
• provided the time that each cow passes through the sorting gate.
Milk performance data:
• milk yield
• milking time
• lactation number
• days in milk
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Materials and Methods• To consider cow social relationship or affinities: affinity scores were calculated
depending on when cows passed through the sorting gate.
• All scores were normalized by the total time each pair of cows spent together in the pen.
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Wood’s lactation curve model Paired t-test analysis
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Materials and Methods
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Results
Example of the network representation of the social network of pen 1
Results
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Results
Without social affinity:
• Day-to-day variability in milk production in all pens increased by 3.5 times.
• Milk production tended to decrease
• Pen 3 had significant lower milk production: 0.66 kg/d per cow, P-value = 0.03
Results
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Results• Our results suggest that cows separated from
their best friend may produce less milk than cows who are paired with a best friend.
• We hypothesize that moving pairs of best friend cows into new pens could reduce daily variation and loss in milk production.
Results
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Conclusions• A better understanding of cows’ social relationship
structure could be beneficial to improve milk performance and cow welfare.
• Our results suggest that social interactions can impact milk production and likely welfare, even thought this was an exploratory study.
• More studies that promote understanding on social affinities among cows are needed.
Results
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Acknowledgments
This study was supported by the Food and Agriculture Cyberinformatics and Tools grant no. 2019-68017-29935/project accession no. 1019780 from the USDA National Institute of Food and Agriculture.