Publication Date
1993
Description
No significant differences were observed in dry matter (DM) intakes, rumen retention times or live weight gains of sheep fed lines of perennial ryegrass (Lolium perenne L,)selected for low (LS) or high (HS) leaf shear breaking load (LSBL). Rates of DM intake were 25% greater, and 18% fewer jaw movements per g DM eaten were required, for test meals of LS compared with HS, but these differences were not significant. The proportion of particles reduced to less than 1 mm during eating and ruminating did not differ significantly. The force required to shear a given dry weight of leaf into 1 mm particles (Index of Masticalory Load - IML) is a function of LSBL and the length:dry weight ratio. Under controlled-environment conditions, LS leaves had a 27% lower IML than HS. However, the tines in this study were grown under field conditions, and though the LSBL was 32% lower for LS leaves, they had a 37% greater length:dry weight ratio. Thus, IML was only 6% lower for LS, which may explain the relative similarity in feeding value for LS and HS ryegrass. LSBL alone is therefore not an appropriate basis on which to select for improved feeding value.
Citation
Inoue, T; Brookes, I M.; Barry, A. John T.N; and Hunt, W F., "Effect of Physical Resistance in Perennial Ryegrass Leaves on Feeding Value for Sheep" (2024). IGC Proceedings (1993-2023). 17.
https://uknowledge.uky.edu/igc/1993/session14/17
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Effect of Physical Resistance in Perennial Ryegrass Leaves on Feeding Value for Sheep
No significant differences were observed in dry matter (DM) intakes, rumen retention times or live weight gains of sheep fed lines of perennial ryegrass (Lolium perenne L,)selected for low (LS) or high (HS) leaf shear breaking load (LSBL). Rates of DM intake were 25% greater, and 18% fewer jaw movements per g DM eaten were required, for test meals of LS compared with HS, but these differences were not significant. The proportion of particles reduced to less than 1 mm during eating and ruminating did not differ significantly. The force required to shear a given dry weight of leaf into 1 mm particles (Index of Masticalory Load - IML) is a function of LSBL and the length:dry weight ratio. Under controlled-environment conditions, LS leaves had a 27% lower IML than HS. However, the tines in this study were grown under field conditions, and though the LSBL was 32% lower for LS leaves, they had a 37% greater length:dry weight ratio. Thus, IML was only 6% lower for LS, which may explain the relative similarity in feeding value for LS and HS ryegrass. LSBL alone is therefore not an appropriate basis on which to select for improved feeding value.
