Bovine Appetite Is Stimulated by Multi-Species Herbage Mixtures
Photo: Agroscope, Bloch O.
An optimum grassland botanical composition is a key element of the efficient feeding of ruminants. The fattening cattle in this trial clearly preferred a grass/clover/chicory mixture to pure ryegrass.
In the present-day context where climate change is the focus of debates, the farming sector and beef producers in particular face numerous challenges. In essence, the aim is to reduce the impact of production on global warming while respecting animal welfare. Grassland-based production systems represent a key component in meeting these challenges. The complementarity of forage species in grasslands is essential for securing grassland-based systems against climate vagaries; however, species that are particularly drought-resistant must at the same time be adapted to grazing and possess a worthwhile nutritional value as well as good ingestibility for ruminants. Chicory could qualify as one of these species. It was associated with a grass (perennial ryegrass) and two clover species (white and violet) to constitute the mixture forming part of this trial (Fig. 1). The aim of the trial was to compare the effect on fattening-cattle intake of the grass/clover/chicory mixture on the one hand and the perennial ryegrass monoculture on the other.
Intake measurements at the manger and on pasture
During eight cycles of two weeks each, the grass/clover/chicory mixture (ME) was evaluated in a mowing and grazing system compared to forage from grasslands with a perennial ryegrass (RG) monoculture. Two herds composed of six steers each – three Angus (AN) and three Limousins (LM) – were alternately fed the RG variant and the ME variant. During cycles 1–2 and 5–6, which took place in the stable, the mown forage was fed ad libitum to the animals and intake was measured individually using the electronic scale-mounted manger system. Intake was simultaneously estimated using a method based on the use of external markers (alkanes). The latter method was used to estimate intake during cycles 3–4 and 7–8, which took place on the pasture.
Greater appetite for the mixture
For the four cycles measured in the stable, average intake of the ‘ME variant’ forage was significantly greater, at 9.23 ± 0.85 kg DM/day versus 8.84 ± 0.82 kg DM/day for the RG variant (P < 0.01). The comparison of these values measured with scale-mounted mangers with those obtained via the markers (alkanes HC32-HC31) yields a good ratio (R2 = 0.71). The intake results over the eight cycles, illustrated in figure 2, are based on the data estimated from the alkanes. With an average daily intake of 8.28 ± 1.70 kg DM for ME and 7.88 ± 1.55 kg DM for RG, the effect of grassland botanical composition remains significant (P = 0.02). The effect of system (stable > pasture) is also significant (P = 0.03), whilst the effect of breed is not (P = 0.42). By contrast, for the cycles in the stable, the AN animals are distinguished by an intake of 0.64 kg DM more per day than the LM animals (P = 0.09).
Conclusions
- Whether mown and fed at the manger or consumed on pasture, forage from a mixture of grass, white clover, violet clover and chicory is ingested more readily than forage based on a ryegrass monoculture.
- This effect was seen for the two breeds studied. The latter differ from one another in terms of ingestion at the manger, which tends to be higher for Angus than for Limousin animals.
- Present at an average rate of 9% in the mixture, chicory appears to have been readily consumed, especially on pasture and by Angus cattle.
- The mixture is superior to pure ryegrass stands in several respects (Tab.1). Given its numerous advantages, the search for an optimum botanical composition of multi-species grasslands should be continued.
Bibliographical reference
Bovine Appetite Is Stimulated by Multi-Species Herbage Mixtures
