Anima Books
books by holistic veterinarian Dr Christine King
The Highly Sensitive Dog
It pays to keep cows happy
In dairy cows, positive emotional states are reflected in
greater milk yield and udder health
In Chapter 10 of The Highly Sensitive Dog, 2nd edition, I talk about cultivating joy as a practical means of making life easier for these wonderful dogs. It's one of the more esoteric chapters in the book, as there is (as yet) relatively little hard science to back up my thesis in animals.
In another article in this series, titled Cultivate joy, I present a study which showed that horses read joy and fear on our faces and in our voices, and they respond accordingly.
Here's another fun one. It shows the practical value of positive emotional states in dairy cows:
The study
The researchers collected data from 37 commercial dairy herds in Romania, totaling 3,377 lactating (milking) cows.
Milking herd sizes ranged from 13 to 340 cows. Most of the cows were either Holstein-Friesian or Romanian Spotted breeds.
Housing systems varied: 26 farms used free-stall housing (cows are free to roam around in the barn) and the other 11 farms used tie-stall housing (cows are tethered in individual stalls), with variable use of pasture and outdoor loafing (resting, relaxing) areas.
Qualitative Behavior Assessment (QBA)
Using the Welfare Quality Assessment Protocol for Cattle, each cow's emotional expression was assessed twice, one month apart, and the scores averaged over the two visits.
Depending on farm size and structure, between one and eight observation points were selected to cover different functional areas (feeding, resting, milking) and capture behavioral diversity.
The QBA explores the individual cow's body language using 20 behavioral descriptors, each given a rating on a visual analog scale from 'absent' to 'dominant'. In alphabetical order, they included:
* active
* agitated
* apathetic
* bored
* calm
* content
* distressed
* fearful
* friendly
* frustrated
* happy
* indifferent
* inquisitive
* irritable
* lively
* playful
* positively occupied
* relaxed
* sociable
* uneasy
Positive Affect Index (PAI)
To capture the herd's overall emotional state, a Positive Affect Index was calculated using the individual scores for these six 'positive' descriptors:
1. Content
2. Happy
3. Inquisitive
4. Lively
5. Playful
6. Positively occupied
(If you've never seen an adult cow at play, it's well worth an internet search. If you've seen enough cat videos to last you a lifetime, try happy cows! ☺︎)
These descriptors were used because they most consistently represent genuine positive emotional states rather than neutral or context-dependent behaviors.
With the QBAs completed and the PAIs calculated (I've spared you that description — you're welcome ☺︎), the cow's and the herd's emotional states were compared with various indices of milk production and udder health. Here is what the researchers found.
Free-stalled cows are happier
Not suprisingly, the Positive Affect Index was significantly higher on the free-stall farms than on the farms that used the tie-stall approach.
Although there was a lot of variation among the farms, the PAI was generally positive on the free-stall farms (median: 0.30; range: –0.62 to 1.06) but it was generally negative on the tie-stall farms (median: –0.65; range: –1.88 to 1.09).
Free-stalled cows produce better milk
So, it should come as no surprise that the cows on the free-stall farms generally had higher milk yield and better milk quality than the cows on the tie-stall farms.
Compared with the tie-stall farms, cows on the free-stall farms averaged:
* 2.1 liters more milk per milking; with most dairies milking 2 or 3 times a day, that's an additional 4–6 liters of milk per cow, per day
* more protein, an additional 3.3 grams per liter (g/L) of milk
* more casein (a principal milk protein), an additional 2.1 g/L
* more lactose (milk sugar), an additional 0.7 g/L
* 14.5% lower differential somatic cell count
udder health
Somatic cells are the cow's own cells, as distinct from microbial cells (principally bacteria), that may be found in the milk.
They comprise cells that have harmlessly sloughed from the mammary gland and its ducts (epithelial cells), as well as cells of the immune system that are normally found in the mammary gland or that migrate from the bloodstream into the gland when the udder is inflamed (infected or injured).
The differential somatic cell count is the percentage of bovine cells in the milk that belong to the immune system (specifically, neutrophils and lymphocytes) rather than to the mammary gland and its ducts. The higher this count, the more inflammation in the mammary gland — i.e., mastitis.
Differential counts were high with both management systems, averaging 58% of somatic cells on the free-stall farms and 68% on the tie-stall farms. (That 10-point difference represents a relative reduction of 14.5% on the free-stall farms.)
But remember that all of these farms were commercial dairy operations, and almost all will have been conventional in their approach to animal care. Even in these economics- driven systems, happiness made a significant and tangible difference.
Even in these economics-driven systems,
happiness made a significant and tangible difference.
. . .
'Herd Happiness Index'
I couldn't help taking a leaf from Bhutan's book — specifically, its Gross National Happiness index — and couch the Positive Affect Index in similar terms for the title of this summary.
When the PAI was adjusted for the type of housing, in effect negating the influence of housing for statistical purposes, the following associations were revealed:
* milk yield and lactose were positively correlated with PAI — i.e., both went up as PAI went up
* total somatic cell count and differential count were negatively correlated with PAI — i.e., both went down as PAI went up
Collectively, the numbers reported in this paper are not earth-shaking (although I am rather impressed with the milk yield figures). However, they translate into real effects on a cow's health and productivity (milk yield and quality), and therefore on farm viability.
In short, it pays to keep cows happy! ☺
. . .
Click on the title to order The Highly Sensitive Dog, 2nd edn.