Foraging dietary preferences

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The farmer's management plays a crucial role in guiding the expression of feeding preferences in pasture.

The feeding preference of ruminants refers to the tendency of animals to prioritize certain forage resources. Various factors influence the expression of feeding preferences in pasture. They are related to:

the animal: species, nutritional needs it seeks to meet, feeding experience, etc.
the vegetation structure: physical characteristics, taste, smell of the feed, plant maturity, spatial distribution, scarcity of so-called "preferred" resources in the pasture.

It is often assumed that it is better to offer young and homogeneous vegetation to herds, that is, the feeds that animals prefer. And the animal's breed is often credited with its ability to utilize coarse forages or difficult areas.

However, some farmers are aware that farming conditions are essential for herds to be adapted to their environment and to be motivated to consume the offered forages.

Understanding feeding preferences in pasture allows to:

Finish the paddocks, including the less palatable parts: gain grazing days, avoid leaving grass when it is lacking in winter or summer
Feed animals on so-called "poor" vegetation: meet high needs during bad seasons or on less palatable vegetation.
Limit refusals and bush encroachment : eat things animals would not normally eat (for example coarse grasses or shrubs).

Increase instantaneous stocking rate

Strip grazing technique and increasing animal numbers

Managing animals on large paddocks (> 30 hectares) is common but very often leads to overconsumption of certain so-called preferred areas.

Underlying process

Animals express less their feeding preferences due to "competition/stimulation" among individuals if the number of animals is increased on a reduced area. This can lead to consumption of less palatable resources such as coarse grasses.

In practice

The strip grazing technique is a solution to, among other things, homogenize the grazing impact on heterogeneous vegetation. This technique consists of dividing a paddock into smaller units by installing fences.

Design paddocks with diversified vegetation combining grassy areas and accessible foliage.

A fenced paddock must be functional for the animals (rest area, water…).

It is also possible to significantly increase the number of animals in the paddock, with an adapted duration of stay.

Direct grazing towards neglected areas

Focal points, herding, activity rhythms

In heterogeneous pastures, the least appreciated zones by animals tend to have tougher, strawy vegetation over time and are generally less palatable. Yet farmers often manage to effectively graze such areas.

Underlying process

Animal movement within a paddock is not only related to vegetation attractiveness depending on the time of day, but also by "attractive points" (water, shaded area in summer, sheltered area in winter…); or "repellents" (cold corridor, poorly bearing wet zone…).
It is possible to make animals eat atypical feeds by offering complementary vegetation in the grazing circuit that helps consume difficult-to-eat vegetation.
Shepherds create competition on the pasture among individuals and direct their impact on vegetation when they herd animals more or less tightly.

In practice

It is possible to manage grazing circuits by placing artificial focal points when significant underuse of a paddock portion is observed: watering points, salt blocks, paddock gate...
Respect animals' activity rhythms and adapt grazing time or hours according to the season.
Make vegetation accessible and attractive (for example, avoid that mulch residues or a fence prevent animals from moving).

Adapt supplementation to avoid demotivating the animal

Motivations related to hay or concentrate supply

Forages and feeds are distributed at pasture or at the trough, especially off-season or for animals with high needs, without always fully understanding the effects on actual pasture consumption. Animals seek different types of vegetation to meet their nutrients and fiber needs.

Underlying process

Distributed forages and feeds modify the rumen flora. The effect can be positive (appetizing, flora prepared to digest the ingested forage type) or negative (ballast, animal demotivation, loss of confidence in grazed resources).
Supplies rich in nitrogenous matter (oilcakes, alfalfa, etc.) promote cellulolytic microorganism activity, aid digestion, and stimulate consumption of overly cellulosic forages.
Large supplies of concentrates rich in starch or sugar can become problematic if the forage becomes too fibrous, which is common in pasture. Carbohydrate intake causes a drop in rumen pH, which disrupts digestion and reduces intake.
When initially filled, ruminants exacerbate their selective behavior at pasture by seeking the youngest parts of plants. This herd behavior reinforces the farmer's belief that his pastures are not very valuable. He adds hay and gradually loses confidence in the outside resources.

In practice

What is provided should not compete with what is sought outside, but rather stimulate (appetite stimulation). It should help improve digestive capacities (rumen flora, no overload).
Reduce starch supply as vegetation matures (or distribute in small amounts to stimulate the herd's appetite) and provide nitrogen supplements (nutritious hay, oilcakes, etc.) to facilitate fiber digestion.
Highly appreciated hay by animals after grazing causes waiting behavior, which reduces grazing activity during the last two hours. Average hay can be used if animals cannot be kept long enough at pasture, allowing them to sort at the trough before going out. Refusals are kept for the return. Poor-quality hay is preferred for the return from pasture "just in case...". Refusals permanently left at the bottom of troughs can also suffice. (According to Michel Meuret, Inra).

Develop feeding learning

Farming conditions are essential for herds to be adapted to their environment: feeding, immunity against parasites, climate, disturbances related to humans or wildlife, etc.

Underlying process

Animal behavior in farming is dictated by early experiences, feeding habits, social relationships within the herd, and memory of places and activity rhythms.
By promoting feeding learning, animals get used to consuming varied or coarse resources and develop larger rumens.

In practice

Keep young animals with experienced mothers
Create "school paddocks" containing a diversity of resources that animals will have to utilize later.
Plan pasture succession: ensure animals progressively discover new vegetation (for example, avoid designing paddocks without any woody plants if the next paddock contains many, and vice versa).

Autres fiches Pâtur’Ajuste

Sources

SCOPELA, with contributions from farmers. Technical sheet from the Pâtur’Ajuste network: Feeding preferences in pasture. September 2014. Available at: https://www.paturajuste.fr/parlons-technique/ressource/ressources-generiques/preferences-alimentaires-au-paturage