America’s Dairyland

I am honored and thrilled to join the Department of Dairy Science at the University of Wisconsin-Madison as an Assistant Professor and Extension Specialist in Animal Welfare. 

20180311_172208My goal for this role is to help the dairy industry remain sustainable in the long term. Understanding and promoting animal welfare is an essential part of achieving this goal. To this end, my applied research program will follow these broad themes:

  • Improving the fit between dairy animals and their environments: how do housing and management decisions affect physiology, behavior, and production?
  • Understanding the needs of dairy animals from a biological perspective: what behaviors are important for them to be able to express and what resources do they need?
  • Developing and validating tools: how do we evaluate animal welfare effectively on commercial operations? How can we use technology to help us monitor animal welfare?

I’m so excited for this opportunity in America’s Dairyland. I’m eager to learn more about the local industry, conduct applied research, and develop outreach programs that will promote best practices and help the Wisconsin industry adapt as our knowledge about animal welfare continues to grow.


Update: the UW-Madison College of Agricultural & Life Sciences published my new faculty profile here

Open-access paper on cattle motivation for roughage

Last week, we published a paper in PLoS ONE on the motivation of feedlot cattle for roughage. (This was the topic I presented at the 100th California Cattlemen’s Association, covered in a previous blog post). You can download the full text of the paper for free by clicking here.

Van Os, Jennifer M. C., Erin M. Mintline, Trevor J. DeVries, and Cassandra B. Tucker. 2018. Domestic cattle (Bos taurus taurus) are motivated to obtain forage and demonstrate contrafreeloading. PLoS ONE. doi:10.1371/journal.pone.0193109.

Free access to our paper on sampling for welfare assessments

We recently published a paper in the Journal of Dairy Science on sample sizes and cow-selection strategies for on-farm dairy welfare assessments. (This was the topic I presented at ADSA last summer, covered in a previous blog post). You can download the full text of the paper for free through March 7, 2018 by clicking here.

Van Os, Jennifer M. C., Christoph Winckler, Julia Trieb, Soraia V. Matarazzo, Terry W. Lehenbauer, John D. Champagne, and Cassandra B. Tucker. 2018. Reliability of sampling strategies for measuring dairy cattle welfare on commercial farms. Journal of Dairy Science 101:1495-1504. doi:10.3168/jds.2017-13611.

Brushing up on dairy farming

Last Saturday was the annual open house at the UBC Dairy Education & Research Centre. Despite the light rain, we got an estimated 870 visitors, many on bicycle! In addition to drinking free chocolate milk, our guests learned about dairy farming and research on animal welfare, reproduction, and nutrient management.

Along with UBC honors undergraduate student Savannah Goldstein and PhD student Ana Carolina Moncada, I talked with our visitors about grooming behavior and brush use by dairy cattle.

Previous research has shown that grooming is an important natural behavior for cattle. Grooming behavior includes licking or scratching themselves, licking each other to form and maintain social bonds, and rubbing against objects such as trees, fences, or other surfaces indoors. When cows are given access to brushes, they spend more time grooming themselves, especially on otherwise hard-to-reach spots such as around the tail. Most research has focused on adult cows, and an increasing number of farms invest in automated rotating mechanical brushes.

Non-rotating brushes for heifers

Savannah and I are currently conducting 2 experiments with weaned heifers about 5 months old. We are giving the heifers small, non-rotating grooming brushes, which are in fact scrub brushes from the hardware store costing $18-20 CAD ($14-16 USD) each.

For Savannah’s thesis project, we are evaluating the heifers’ preferences for brushes mounted on the wall of the lying area in their pen, which is an open space with deep sawdust bedding. We are comparing how much the heifers use brushes with different orientations and bristle stiffness levels: stiff (similar to a dandy brush for horses) vs. extra-stiff (like those on the rotating cow brushes).

In our other study, we are investigating whether mounting brushes inside the freestalls can encourage heifers to lie down correctly when they first move into that type of housing system. With freestall housing, the idea is for cows to lie down in a stall such that manure falls into the alley and doesn’t dirty the bedding. However, heifers and cows sometimes lie down backward or in the manure alley instead. So far our results show promise, and visiting McGill University undergraduate Jessica St-Pierre is considering trying this strategy on her family’s dairy farm in Quebec!

Open house JMV 170722

I set up the brushes with extra-stiff (black) and stiff (yellow) bristles for our visitors to feel and compare. The Lely automated rotating mechanical brush is in the background.

Open house 5023 brush lick 170722

One of my favorite friendly cows, 5023, wanted to check out the brushes too…

Open house 5023 brush head 170722

… So we mounted one on the fence for her and her buddies to investigate. Here, 5023 is getting in a good face rub!

Rotating brushes for cows

Ana, a PhD student and veterinarian from Colombia, is currently running a study with a rotating mechanical brush. She is investigating how mange, resulting from mite infestations, affects how much cows want to use the brush. Mites tend to dwell around the tailhead (where the tail meets the body), which is a difficult place for cows to reach and groom themselves. A mechanical brush can help cows relieve itchiness in that area of their body. To evaluate how important a resource – such as a brush – is to animals, we can ask them to pay a price. But the price involves performing a task or overcoming an obstacle instead of paying money. For her experiment, Ana has trained cows to push a gate to get access to the brush, and she can increase the “price” by adjusting the force needed for cows to open the gate.

Open house mehcanical brush 170722.png

Cow 4095 demonstrates how the mechanical brush can help her groom hard-to-reach areas such as her back

Check out this video clip I put together of some of the cows using the rotating brush in a variety of ways during the open house:

  • on the tailhead, where mange tends to occur
  • under the tail (a couple visitors joked it was like cow TP!)
  • on the head (doubling as a punching bag!)

Clear as mud?

Moisture can create muddy surfaces on pasture or in housing systems such as drylots and bedded packs. Dairy cattle show signs of increased stress in rainy and windy conditions, but previous research had not separated the effects of inclement weather from muddy ground conditions.

We housed pregnant cows and heifers in dirt-floored enclosures to evaluate the effects of muddy ground conditions on their lying behavior, dirtiness, and physiological responses.

Our results were hardly clear as mud! Rather, our cattle made it clear that they were reluctant to lie down on muddy surfaces. In fact, they often chose to lie down on the concrete floor in front of the feed trough instead, even though past research has shown that cows typically avoid lying on concrete. Previous studies have also found that it is important for cows to spend over half of their day lying down, but when the ground was muddier, our cattle spent more time standing up.

Our results show that – even in the absence of rain or wind – muddy ground surfaces have negative effects on the comfort and welfare of dairy cattle.

For our other findings, check out our paper in Journal of Dairy Science or listen to my 4-minute narrated slideshow explaining our study:

Jennifer M. Chen, Carolyn L. Stull, David N. Ledgerwood, and Cassandra B. Tucker. 2017. Muddy conditions reduce hygiene and lying time in dairy cattle and increase time spent on concrete. Journal of Dairy Science 100:2090-21036doi:10.3168/jds.2016-11972.

ADSA Pittsburgh

2017 ADSA poster

Last week I attended the 2017 American Dairy Science Association meeting in Pittsburgh, PA. I presented a poster on our project “Sampling strategies for dairy cow welfare assessments“, which is nearly ready to submit for publication.

During her M.Sc., Julia Trieb visited from Austria and collected about two dozen animal-based measures on 10 California drylot and freestall dairy operations. She restrained the cows in headlocks at the feed bunk to assess measures such as discharge and skin injuries, and released the cows one-by-one to watch them walk in order to score lameness.

Scoring all cows for so many measures can be time consuming, so we wanted to evaluate the accuracy of assessing a subsample of the pen.

We selected proportions ranging from 1/10 to 3/4 of the high-producing pen, and found that in our sample, we had to score at least 2/3 of the pen for all measures to be considered accurate.

We also compared different methods for selecting cows, and we found that choosing cows based on their position while locked at the feed bunk (i.e., pick 2, skip 1, pick 2, skip 1…) performed about the same as selecting cows randomly. Selecting cows based on their lockup position may be a more straightforward approach on farms that have headlocks.



UBC at the Western Canadian Dairy Seminar

I recently attended the 35th annual Western Canadian Dairy Seminar in Red Deer, Alberta. It was a big year, with over 900 attendees! I had a great time meeting producers and discussing their concerns about and ideas for improving cow comfort. I also chatted with some folks about thinking outside the box (but inside the litter box?) regarding cattle waste management. (Not to mention experiencing some “real” Canadian winter…!)

DFC 20170309

Here I am with UBC PhD students Heather Neave, Hanna Eriksson (both Animal Welfare Program), and Tracy Burnett (Reproduction Program) in the Dairy Farmers of Canada booth on International Women’s Day! (March 8, 2017)

About a dozen of us from UBC’s Animal Welfare and Reproduction programs represented the UBC Dairy Research & Education Centre. We created posters highlighting the take-home messages we’ve learned across some of our recent studies.

The topics presented by the Animal Welfare Program were:

  1. Colostrum management for calves
  2. Benefits of group housing for calves
  3. Transition cow management
  4. Outdoor access for lactating cows
WCDS booth dairy centre 2017

The UBC booth – click on the links above to see the pdfs of our posters!

Anne-Marieke Smid and I created the poster on outdoor access for lactating cows, which is based on her PhD work that is currently in progress. I recently posted some great photos from her study here.

The cows at UBC are normally housed indoors in a freestall barn with deep-bedded sand. Previous research has shown this to be the favorite indoor bedding type for cows. When Anne-Marieke gave the cows access to pasture, they spent 90% of the night outside.

However, giving cows access to pasture is not always feasible. Anne-Marieke also offered them access to outdoor packs with either sand or bark mulch covering the ground. So far, she has found that they spend about half of the night outdoors. She is now looking into how the amount of time they spend outside is influenced by weather conditions. Check out our poster for photos and graphs, or read Anne-Marieke’s interview with The Western Producer.

Who let the cows out?

My colleague Anne-Marieke Smid, a Ph.D. student in the UBC Animal Welfare Program, is nearing the end of a study she’s conducting. She is housing lactating cows in groups of 12 at a time. They have deep sand-bedded freestalls indoors and get access to an outdoor area.

In one of her previous studies, she gave cows access to a pasture overnight, but Anne-Marieke is also interested in understanding how cows respond to other types of outdoor options besides grass. In another study, she offered them an outdoor sand pack overnight. Now Anne-Marieke is providing cows with 24-hour access to a bark mulch pack, and she collected data in both summer and winter.

We’ve been working on a poster about these studies to present at the Western Canadian Dairy Seminar next month (March 7-10) in Red Deer, Alberta. If you’re going to be there, please come by the UBC Dairy Education & Research Centre booth to meet us and we’ll tell you all about it! (*Update: see here for a recap of the meeting!)

This morning, it was time for a new group of cows to go outdoors for the first time and get used to the bark mulch pack. Last week we got a great deal of snow and there was still quite a bit on the ground, but today was a warmer day. Check out the photos below to see what the cows thought!


Anne-Marieke released pairs of cows at a time from the barn


They started sniffing around to check out the snow…


…and the bark mulch pack


They had to figure out that there was an electric fence around the pack


As more cows came out…


…things started getting frisky!


Some of the cows started bucking…


…and kicking!…


…and even rearing! WOOOHOOO!!!! (my luckiest photo of the day)


Here are all 12 girls outside on the bark mulch pack. Don’t they look like kids at recess?