In pasture-based dairy farming, farms attempt to implement a "low-input or low-cost" strategy by making the best possible use of inexpensive pasture forage. This involves largely eliminating anything that incurs high production costs.
High individual animal yields are not pursued for cost reasons and cannot be achieved with exclusive pasture feeding. An important management criterion is aligning the calving of dairy cows with the vegetation period (seasonal calving). In grassland regions with short dormancy periods (Ireland, New Zealand, etc.), pasture-suitable cows predominantly calve in spring, i.e., shortly before the start of the vegetation period. In Austria's grassland regions, the vegetation period is significantly shorter in comparison. Furthermore, there are also differences regarding breeding preferences – on average, Austrian dairy cows are larger and heavier and achieve higher daily and annual milk yields. Since pasture feed intake is more limited compared to barn housing, at 15-20 kg dry matter per animal per day, high-performance animals on exclusive pasture feeding, especially at the beginning of lactation, mobilize significant body reserves. This can lead to metabolic stress and also to a decline in fertility and productive lifespan.
If a low-input, full-grazing system is pursued with the existing cow population in Austria during the vegetation period, then bringing forward the calving date to winter and targeted barn feeding during the first two months of lactation could offer advantages in terms of nutrient supply, milk production, and animal health. However, this strategy would entail a decrease in the proportion of pasture grass in the total annual ration and a significant increase in concentrate feed consumption and feed costs. The research project aims to investigate the effects of the calving date on milk yield, nutrient supply, and physiological, economic, and ecological parameters at the Moarhof organic teaching and research farm. It will provide further reliable insights into sustainable and energy-efficient dairy farming based on a low-input, full-grazing system.
Project goals:
If a "low-input, full-grazing" system is pursued with high-yielding (daily) cows during the growing season, then bringing forward the calving date to winter and targeted barn feeding during the first months of lactation could offer advantages in terms of nutrient supply, performance, and animal health. However, this strategy must be expected to result in a decrease in the proportion of pasture grass in the total annual ration and an increase in concentrate feed consumption and feed costs. This research project will investigate the effects of the calving date on milk yield, nutrient supply, and physiological, economic, and ecological parameters at the Moarhof organic teaching and research farm.
The following hypotheses will be tested in the project:
1.) High-yielding cows can be better fed during the barn period when calving in winter
(higher annual milk yield, more stable and higher milk solids content,
less loss of body condition at the start of lactation due to improved
nutrient supply)
2.) Spring calving allows for savings in concentrated feed and
an increase in the proportion of pasture grass in the annual ration (more cost-effective ration, but lower performance, lower
milk solids; effects on nutrient balance and economics)
3.) In the case of spring calving, a shorter lactation period is to be expected and the
cows must focus more on rebuilding their body condition during the dry period.
