So you’ve identified forage species that are resilient in the pasture – but will the cows eat them?
That’s an important question for researchers working to build more resilient organic dairy pastures. A forage species may perform well agronomically, but if cows don’t find it appealing, its value in a grazing system may be limited.
Jessica St John, a PhD student working with Dr. Renée Bergeron at the University of Guelph, enlisted the help of 10 Holstein dairy cows to test the palatability of several promising forage species. Palatability can be assessed using measures of voluntary intake when a single feed is offered and through preference tests when animals are given a choice among feeds.
The results suggest that the dairy cows found all the forage mixes tested to be palatable – but they showed a preference for legume species.
This study complements research led by Marie-Noëlle Thivierge, who is testing multispecies forage mixtures in the field. She hopes to identify combinations that perform well under organic management while improving pasture resilience and contributing to greenhouse gas mitigation through carbon sequestration. Both studies are part of the OSC4 research activity, “Strategies to Enhance Pasture System Resilience and GHG Mitigation Potential in Organic Dairy Production.”
The cows chose legumes
St John’s palatability trials took place at the Ontario Dairy Research Centre at the University of Guelph.
“We tested the different forage functional groups: four legumes, five grasses and one non-legume forb species,” explains St John.
Although management of the fields and cows in this study was not certified organic, each of the forage species was grown as a monoculture using organic management practices.
Table 1. List of forages tested.
Forage Type | Common Name | Latin Name | Variety |
|---|---|---|---|
Legume | Alfalfa (AL) | Medicago sativa | Conventional Revived
(25% bare, 75% inoculated) |
Legume | Birdsfoot Trefoil (BT) | Lotus corniculatus | Leo (inoculated seed) |
Legume | Red Clover (RC) | Trifolium pratense | Organic GARANT (inoculated seed) |
Legume | White Clover (WC) | Trifolium repens | Common (bare seed) |
Grass | Festulolium (FE) | Festulolium braunii | Barfest |
Grass | Meadow Bromegrass (MB) | Bromus biebersteinii | Fleet |
Grass | Meadow Fescue (MF) | Schedonorus pratensis | Triumph |
Grass | Orchard Grass (OG) | Dactylis glomerata | High leaf ratio (HLR) |
Grass | Timothy (TI) | Phleum pratense | Organic Tenho |
Forb | Chicory (CH) | Cichorium intybus | Antler |
Forages were cut fresh each morning with a forage plot harvester, then sorted by hand to remove any plants other than the forage species being tested.
“We cut the forage samples between 6:30am and 7:30am and then fed the cows at 1:30pm. The preparation took a while!”
Forages were placed in the feed bunk in front of each of the 10 lactating Holstein cows. The fresh weight of the forages was taken before and after the 30-minutes feeding period to determine voluntary fresh forage intake. The researchers also determined the moisture content of each forage to calculate the equivalent dry matter intake.
When presented with individual forages, the cows appeared to prefer the legumes. They consumed more birdsfoot trefoil, white clover, red clover and alfalfa compared to the grass species both on a fresh and dry matter basis.
Interestingly, forage nutritive value was correlated with dry matter intake. Forages with higher concentrations of crude protein and calcium – characteristics associated with legumes in the study – were associated with higher dry matter intake, whereas forages with higher neutral detergent fibre (NDF) and acid detergent fibre (ADF) – characteristics associated with grasses in the study – were associated with lower dry matter intake.
The forb species, chicory, did not follow this pattern. Based on its nutritive value, chicory should have been attractive to the cows. however, intake was low. One possible explanation is that chicory contains bitter-tasting compounds, such as sesquiterpene lactones and tannins, which may have reduced its appeal.
Making informed choices
Palatability can be influenced by a range of factors intrinsic to the animal, the environment and the plants themselves. For example, nutritive value and bitter plant compounds may contribute to learned feeding behaviours, either through positive associations or negative post-ingestive nutrient feedback. Food neophobia – the tendency to avoid novel foods – can also influence palatability. An unfamiliar taste, smell or texture may initially make a forage less appealing.
The researchers observed this with their test subjects.
The cows selected for the study were naïve to pasture and had never consumed fresh forage. “We were nervous at first because there was very little to no interest,” St John explains. “They were used to getting their TMR (total mixed ration).”
To help the cows adjust to the unfamiliar foods, the researchers included an adaptation period before beginning the palatability trials. During the first two days, a mixture of all the forages was incorporated into the cows’ TMR to encourage exploration. The researchers noticed that after these initial two days, the cows became increasingly accepting of the fresh forage. Each forage species was then offered three times to each cow before the monitored palatability trials began.
In addition to learned experience, forage preference can be unique to each cow.
The researchers noted high variability for the consumption rate of species that cows consumed more of overall – the legume species. This suggests there may have been differences in preferences among individual cows.
“I think this highlights the importance of considering individual cow preferences in pastures as well,” says St John. “Providing variety could benefit individual cows within the herd.”
What happened when the forages were mixed?
The researchers next tested the cows’ intake of eight forage mixtures, simulating the diverse plant communities they might find on pastures selected for agronomic resilience.
Table 2. Target ratios of forages in mixtures (fresh matter basis).
Mix # | Ratio of Forages in Mixtures (%) |
|---|---|
1 | 50 WC/50 MF |
2 | 50 BT/50 MB |
3 | 50 AL/50 TI |
4 | 40 WC/30 MF/30 CH |
5 | 40 AL/ 30 TI/ 30 CH |
6 | 25 WC/ 25 BT/ 25 MF/ 25 OG |
7 | 25 WC/ 25 RC/ 25 MF/ 25 CH |
8 | 16.7 WC/ 16.7 BT/ 16.7 MF/ 16.7 MB/ 16.7 OG/ 16.7 CH |
The cows did not seem to have a preference for one mix over another, but they did do some sorting for their favorite species. In one case (Mix 5), cows sorted for alfalfa, consuming proportionately more than was present in the mixture of alfalfa, timothy and chicory. In another case (Mix 6), cows sorted for birdsfoot trefoil over white clover, meadow fescue and orchard grass.
Why sorting for legumes was not observed in all the mixtures remains a question. St John explains that it could be due, at least in part, to a limitation of the study protocol.
“It could have been a difficulty in sorting for some of the species. We didn’t chop them to consistent lengths. For example, white clover and red clover were smaller compared to alfalfa and birdsfoot trefoil.” The size and structure of the forage may have made some species easier to pick out than others.
Overall, the cows consumed a similar weight of each forage mix in the 30-minute feeding period. This may be because each mixture provided a good balance between legume and non-legume species contributing to similar palatability.
The dry matter intake of the forage mixtures was lower than the dry matter intake of individual legumes but slightly higher than intake of individual grasses or forb. “This is just anecdotal”, adds St John, “but it maybe suggests that mixing the forages [with legumes] has encouraged the dairy cows to consume more.”
The takeaway for dairy farmers
Selection of resilient pasture species must not only take into account the agronomic performance of the plants, but also their palatability.
St John’s results suggest that the dairy cows will consume the forage mixtures tested, although they appeared to find the legume species more palatable than the grass and forb species and sometimes sorted for individual legumes.
The results also suggest that individual cows may differ in their preferences. Providing a variety of forage functional groups and species could therefore be valuable in a multispecies pasture.
What’s next?
The palatability trials provide a useful first look at how dairy cows respond to these forage species. But the cows were fed under controlled conditions, not given the opportunity to choose among plants while grazing in a pasture.
“This study was conducted under conditions where dairy cows were presented with the fresh cut forages at the feed bunk. I think it would be really interesting to see what their behaviours would be on pasture with these forage mixtures,” says St John. “Individual preferences for dairy cows would be fun as well to look at. Just to notice the differences between cows and to see why they’re choosing the forage that they’re choosing.”
The next step is to take the research to the field and see how plant diversity, animal preference and grazing behaviour come together. This could provide further insight into designing more resilient organic dairy pasture systems.
About the researcher
You can find Jessica St John in Kemptville at her new position as Bilingual Livestock Specialist with the Ontario Ministry of Agriculture, Food and Agribusiness.
This project was completed with assistance from the following collaborators: Nicolas Devillers, Caroline Halde, Marie-Noëlle Thivierge, Kimberley Schneider and Trevor J. DeVries.
Stay tuned for more findings from this OSC4 research activity, including research on nitrogen excretion and efficiency, as well as enteric methane emissions in lactating dairy cows fed multispecies forage mixtures!
Published September 9, 2026
Organic Science Cluster 4 is an industry-led research and development endeavour co-managed by the Organic Federation of Canada and the Organic Agriculture Centre of Canada at Dalhousie University and supported by the AgriScience Program under Agriculture and Agri-Food Canada’s Sustainable Canadian Agricultural Partnership together with over 80 funding partners.
