Abstract
The overall objectives of this thesis were to study the current situation on small-scale mountain dairy farms, differing in the breed used and the amount of concentrate supplementation, regarding the four pillars of sustainability. Studies were conducted at conventional dairy farms in South Tyrol, Northern Italy.
In the first assessment (Chapter 3), we investigated the effect of low vs. high concentrate supplementation in terms of animal welfare, health and reproductive performance in two different dairy cow breeds on small-scale mountain farms. 64 South Tyrolean dairy farms were evaluated by using an on-farm assessment for animal-based and resource-based welfare indicators, data from test day records, and a questionnaire for the farmer. Farms were divided into four groups: low input Tyrolean Grey (L-TG, 2.8 kg concentrate/cow and day), low input Brown Swiss (L-BS, 4.0 kg/cow and day), high input Tyrolean Grey (H-TG, 6.1 kg/cow and day), and high input Brown Swiss (H-BS, 8.7 kg/cow and day). The predominant husbandry system across all groups was tie-stall. The average energy-corrected milk yield increased with increasing concentrate level, with L- TG showing the lowest and H-BS showing the highest milk yield (4220 vs. 7675 kg/cow and year). Age at first calving was lowest in H-BS (30.8 months) when compared to all other systems, while numbers of lactations were higher in L-TG compared to H-BS (3.6 vs. 2.4). Feed efficiency (percentage of milk out of roughage) was significantly higher in L-TG and L-BS when compared to H-TG and H-BS (48.6, 43.3, 26.9 and 29.8%, respectively). When compared to the other systems L-BS showed poorer results for the welfare indicators lean cows, lesions and percentage of dirty animals.
The second study (Chapter 4) aimed to compare the economic situation of mountain dairy farms in South Tyrol that differ with respect to the amount of concentrates fed (low-input vs. high-input) and the breed used (Tyrolean Grey vs. Brown Swiss). The calculations show that low-input farms have lower variable costs but similar fixed costs and lower revenues compared to high-input farms. As a result, high-input farms are economically superior to low-input farms in terms of income per farm, per ha and per kg ECM. Regarding the breeds, farms using the local breed Tyrolean Grey can compete with with farms using the high-yielding breed Brown Swiss when subsidies are considered because of special payments for an endangered breed. The dominance of high-input farms can be explained with economies of scale and the milk to feed price ratio of about 1.8. Thus, the currently paid high milk price makes it economically worthwhile to produce as much milk as possible. The results thus point to the risk of intensification or abandonment of small mountain farms. In order to improve their economic situation and thus maintain small and low-input mountain dairy farms it might be an option to connect subsidies with the feeding strategy and farm structure, pay premiums for value-added milk products or use taxes for concentrated feed to support extensive farms.
The third study (Chapter 5) focused on the input of nutrients, which not only leads to unbalanced nutrient budgets on farm level but also to a lower contribution of net human food supply by using large amounts of human edible feedstuff. 64 dairy farms managed at differing concentrated feed intensity evels in South Tyrol were assessed. The farms were divided into four groups according to the amount of concentrated feed used (high [H] vs. low [L]) and the breed (Tyrolean Grey [TG] vs. Brown Swiss [BS]). Therefore the following groups were analyzed: H-BS with ⌀ 8.7, H-TG with ⌀ 6.1, L-BS with ⌀ 4.0 and L-TG with ⌀2.8kg concentrated feed per cow and day. All farms were located above 1000 m above sea level and had only permanent grassland without any cash crop cultivation. N budgets for H-BS, H-TG, L-BS and L-TG were 79.54, 50.81, 37.85 and 34.16 kg ha-1, respectively, with significantly higher values for H-BS compared to the other groups. Findings for P and K were also significantly higher for H-BS (12.8 and 43.96 kg ha-1, respectively) when compared to L-BS (3.10 and 8.86 kg ha-1) and L-TG (1.50 and 11.91
kg ha-1). The nutrient use efficiency, calculated as the proportion of input to output, for N and K was similar across all groups, while the farmland-related P-efficiency was significantly higher in L-BS and L-TG (91.3 and 98.5%, respectively) compared to H-BS and H-TG (73.0 and 72.4%, respectively). HeFCE for protein and energy was lowest for H-TG (0.99 and 2.38, respectively) compared to L-TG (1.54 and 3.73, respectively), with the decisive factor being the amount of concentrated feed per kg ECM produced (g DM/ kg ECM). Our studies show that dairy farms in South Tyrol produce under particularly difficult conditions. While intensity level and breed do not necessarily have an impact on animal welfare, our studies show that high-input farms have an economic advantage over low- input farms. In contrast, low-input farms score better on ecological and global social issues in terms of farm gate budgets and net contribution to human food supply. The pillars of sustainability cannot be seen separately, but influence each other in terms of synergies and trade-offs.