Forage intake, digestibility and performance of cattle, horses, sheep and goats grazing together on an improved heathland

Abstract

A mixed herd of five cows, five mares, 32 ewes and 32 goats was managed with their offspring during two consecutive years in a paddock (22.3 ha) with 76% of heathlands and 24% of improved pasture area, with the aim of studying their differences in ingestive behaviour and performance. Diet composition, dry matter intake (DMI) and digestibility (DMD) were estimated on three occasions using the alkane technique, and all animals were periodically weighed to calculate bodyweight (BW) changes per livestock unit (LU). Goats selected higher proportions of shrubs than the other herbivore species (P < 0.001). Overall, daily DMI was higher (P < 0.001) in equines (218 g/kg BW0.75) than in ruminants (174, 121 and 80 g/kg BW0.75 for cattle, goats and sheep, respectively), whereas DMD was lower (P < 0.001) in equines (569 g/kg DM) compared with ruminants (733–791 g/kg DM). During the first half of the grazing season (from late April to mid-July), dams’ BW changes per LU did not differ between species. However, during late summer–autumn lower (P < 0.001) BW losses per LU were observed in sheep and goats (–89 g/day) than in cattle (–534 g/day), being intermediate in horses (–254 g/day). For the overall grazing season, ewes and goats showed greater (P = 0.056) BW gains per LU (338 g/day) than cows and mares (178 g/day). Regarding the offspring, BW gains per LU were greater (P < 0.001) in lambs (3612 g/day) than in other species. Calves presented greater gains than kids (2647 vs 1909 g/day.LU), whereas foals showed intermediate gains (2385 g/day.LU). Therefore, under these conditions of partially improved heathlands, sheep was the most productive species. However, looking at the diet selection and digestibility, goats could complement sheep or cattle herds by achieving a more efficient utilisation of heathland vegetation, and increasing overall productivity per hectare. By contrast, horses, having high levels of grass intake, compete with cattle and sheep for pasture utilisation.

Comparison of feed intake, digestion and rumen function among domestic ruminant species grazing in upland vegetation communities

“…Recently, Osoro et al. (in press) in the same research farm in early‐spring, with cattle having an improved pasture availability between 8 and 10 cm, average intake values of 184 g DM/kg LW 0.75 /d, were observed. Feed intake values observed in cattle were 2 times higher than those observed in goats and sheep.…”

Comparative foraging behaviour and performance between cattle and horses grazing in heathlands with different proportions of improved pasture area

“…Large herbivores have replaced small ruminants in lessfavoured areas of Cantabrian Mountains in the NW of the Iberian Peninsula, dominated by heathlands, despite the more efficient use of this poor quality vegetation by sheep and goats (lower intake per metabolic weight, higher digestibility of selected diets, and higher performance because of their lower body size and absolute nutrient requirements) (Celaya et al 2008;Osoro et al 2017). In these plant communities, as in other shrublands, the limiting factor for livestock performance is not usually the amount of available phytomass, but its poor nutritive quality (Celaya et al 2011).…”

Forage selectivity by cattle and sheep co‐grazing swards differing in plant species diversity

“…Complex interactions between large herbivores and their particular environment strongly modify the feed selection of grazers. Two‐way animal–plant interactions have been described, in which each part is influenced by the other (Anderson, Fredrickson, & Estell, ; Dumont, Rook, Coran, & Röver, ; Maxwell, Moir, & Edwards, ; Osoro, Ferreira, García, Martínez, & Celaya, ). In addition to the effects of farm management, grazing pressure, stocking rate, available biomass, sward height, and social interactions among peers, the botanical composition could play a determinant role in the feed selection of domestic ruminants when grazing.…”