Intake, Energy Expenditure and Methane Emissions of Grazing Dairy Cows at Two Pre-Grazing Herbage Masses
Open Access
- 1 January 2021
- journal article
- research article
- Published by Scientific Research Publishing, Inc. in Open Journal of Animal Sciences
- Vol. 11 (03), 440-457
- https://doi.org/10.4236/ojas.2021.113031
Abstract
A grazing experiment was undertaken to assess the effects of two levels of herbage mass (HM) on herbage DM intake (DMI), fat and protein corrected milk yield (FPCM), grazing behaviour, energy expenditure (HP), and methane emissions (CH4) of grazing dairy cows in spring. Treatments were a low HM (1447 kg DM/ha; LHM) or a high HM (1859 kg DM/ha; HHM). Pasture was composed mainly of cocksfoot (Dactylis glomerata) and lucerne (Medicago sativa), offered at a daily herbage allowance of 30 kg DM/cow, above 5 cm. Eight multiparous Holstein cows were used in a 2 × 2 Latin Square design in two 10-day periods. Despite the differences in pre-grazing HM between treatments, OM digestibility was not different (P = 0.28). Herbage mass did not affect DMI or FPCM. Grazing time was not different between treatments, but cows had a greater bite rate when grazing on LHM swards. However, HP did not differ between treatments. Daily methane emission (per cow), methane emission intensity (per kg FPCM) and methane yield (as percentage of gross energy intake) were not different. The lack of effect of the amount of pre-grazing HM on energy intake, confirms that the difference between HM treatments was beyond the limits that impose extra energy expenditure during grazing.Keywords
This publication has 37 references indexed in Scilit:
- Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in UruguayAnimals, 2012
- Effect of sward dry matter digestibility on methane production, ruminal fermentation, and microbial populations of zero-grazed beef cattleJournal of Animal Science, 2009
- Defoliation pattern, foraging behaviour and diet selection by lactating dairy cows in response to sward height and herbage allowance of a ryegrass‐dominated pastureGrass and Forage Science, 2003
- Persistence of differences between sheep in methane emission under generous grazing conditionsThe Journal of Agricultural Science, 2003
- Modelling covariance structure in the analysis of repeated measures dataStatistics in Medicine, 2000
- The effect of daily herbage allowance, herbage mass and animal factors upon herbage intake by grazing dairy cowsAnimal Research, 1996
- Effects of sward structure upon herbage intake by grazing dairy cowsAnimal Research, 1995
- An integrated methodology for studying short‐term grazing behaviour of cattleGrass and Forage Science, 1992
- The control of herbage intake in the grazing ruminantProceedings of the Nutrition Society, 1985
- Variations in herbage mass and digestibility, and the grazing behaviour and herbage intake of adult cattle and weaned calvesGrass and Forage Science, 1981