Kg Of Fat And Protein Corrected Milk Research Articles

Effect of management system and dietary seasonal variability on environmental efficiency and human net food supply of mountain dairy farming systems

Although mountain dairy cattle farming systems are pivotal for the economy, as well as for social and environmental aspects. They significantly contribute to the rural development which is currently strongly prioritized in the common EU agricultural policy, at the same time they are also increasingly criticized for having relatively high environmental impacts per kg of product, such as greenhouse gas emissions. Consequently, the aim of this study was to assess and compare the environmental efficiency of 2 common alpine dairy farming systems, with focus on the effects of grazing, considering the seasonal variability in feeding at individual cow level and farm management over a 3-year period. This study focuses on alpine farming systems but can be considered to represent well other topographically disadvantaged mountain areas. An intensively managed and globally dominating production system (high-input), aiming at high milk yield through relatively intensive feeding and the use of the high-yielding dual-purpose Simmental cattle, permanently confined in stables, was compared with a forage-based production system (low-input), based on seasonal grazing and the use of the autochthonous dual-purpose breed Tyrolean Grey. For the present analysis, a data set with information on feed intake and diet composition as well as animal productivity at individual cow level, and farm management data based on multiyear data recording was used. Four impact categories were quantified for 3 consecutive years: Global Warming Potential (GWP100), Acidification Potential (AP), Marine Eutrophication Potential (MEP), and Land Use (LU, m2yr and Pt, with the latter additionally considering the Soil Quality Index). Besides being attributed to 1 kg of fat and protein corrected milk (FPCM), these impact categories were also related to 1 m2 of on-farm area. Due to limited agronomic options beyond forage production and pasture use in alpine regions, net provision of protein was calculated for both farming systems to assess food supply and quantify the respective food-feed competition. Overall, the low-input farming system had greater environmental efficiency in terms of MEP per kg FPCM, as well as MEP and AP per m2 than the high-input system. LU was found to be consistently higher for the high-input than for the low-input system, the GWP100 per kg of FPCM was lower for the high-input system. Additionally, pasture access had a significant effect on the reduction of environmental impacts. Lastly, the net protein provision was slightly negative for the high-input system and marginally positive for the low-input system, indicating a lower food-feed competition for the latter. Future studies should also address the social and economic aspects of the farming systems, to offer a comprehensive overview of the 3 key factors necessary for achieving more sustainable farming systems, particularly in disadvantaged marginal regions such as mountain areas.

Environmental Performance of a Mixed Crop–Dairy Cattle Farm in Alexandria (Romania)

Agricultural specialization has increased considerably in Europe over the last decades, leading to the separation of crop and livestock production at both farm and regional levels. Such a transformation is often associated with higher environmental burdens due to excessive reliance on exogenous inputs and manure management issues. Reconnecting crop and livestock production via mixed farming systems (MFSs) could improve circularity and resilience, leading to reduced environmental impacts. The objective of this study was to evaluate the life cycle environmental performance of a commercial mixed crop–dairy cattle farm in Romania and to compare it against the corresponding specialized systems. The evaluation covered both dairy cattle production (milk and meat) and cash crops. Overall, the results show that the coupled system improves environmental performance by reducing the over-reliance on high-impact inputs like synthetic fertilizers and exogenous feed. The carbon footprint for the milk production of the studied system (1.17 kg CO2 eq.) per kg of fat- and protein-corrected milk (FPCM) was 10% lower than the mean value of common intensive milk production systems. The eutrophication impacts (2.52 × 10−4 kg P eq and 2.67 × 10−4 kg N eq./kg of FPCM) presented values of one order of magnitude less than their specialized counterparts. However, the impacts of the studied MFS, albeit lower than those for comparable specialized systems, still remain relatively high. In particular, methane emissions from enteric fermentation (0.54 kg CO2 eq./kg FPCM) were a major contributor to the carbon footprint. This highlighted the need to address the elevated emissions from enteric fermentation with better feed management, as well as improving and reinforcing the system’s self-sufficiency.

Impact of nitrate and 3-nitrooxypropanol on the carbon footprints of milk from cattle produced in confined-feeding systems across regions in the United States: A life cycle analysis

It is estimated that enteric methane (CH4) contributes about 70% of all livestock greenhouse gas (GHG) emissions. Several studies indicated that feed additives such as 3-nitrooxypropanol (3-NOP) and nitrate have great potential to reduce enteric emissions. The objective of this study was to determine the net effects of 3-NOP and nitrate on farmgate milk carbon footprint across various regions of the United States and to determine the variability of carbon footprint. A cradle-to-farmgate life cycle assessment was performed to determine regional and national carbon footprint to produce 1 kg of fat- and protein-corrected milk (FPCM). Records from 1,355 farms across 37 states included information on herd structure, milk production and composition, cattle diets, manure management, and farm energy. Enteric CH4, manure CH4, and nitrous oxide were calculated with either the widely used Intergovernmental Panel on Climate Change Tier 2 or region-specific equations available in the literature. Emissions were allocated between milk and meat using a biophysical allocation method. Impacts of nitrate and 3-NOP on baseline regional and national carbon footprint were accounted for using equations adjusted for dry matter intake and neutral detergent fiber. Uncertainty analysis of carbon footprint was performed using Monte Carlo simulations to capture variability due to inputs data. Overall, the milk carbon footprint for the baseline, nitrate, and 3-NOP scenarios were 1.14, 1.09 (4.8% reduction), and 1.01 (12% reduction) kg of CO2-equivalents (CO2-eq)/kg of FPCM across US regions. The greatest carbon footprint for the baseline scenario was in the Southeast (1.26 kg of CO2-eq/kg of FPCM) and lowest for the West region (1.02 kg of CO2-eq/kg of FPCM). Enteric CH4 reductions were 12.4 and 31.0% for the nitrate and 3-NOP scenarios, respectively. The uncertainty analysis showed that carbon footprint values ranged widely (0.88-1.52 and 0.56-1.84 kg of CO2-eq/kg of FPCM within 1 and 2 standard deviations, respectively), suggesting the importance of site-specific estimates of carbon footprint. Considering that 101 billion kilograms of milk was produced by the US dairy industry in 2020, the potential net reductions of GHG from the baseline 117 billion kilograms of CO2-eq were 5.6 and 13.9 billion kilograms of CO2-eq for the nitrate and 3-NOP scenarios, respectively.

How does soil carbon sequestration affect greenhouse gas emissions from a sheep farming system? Results of a life cycle assessment case study

A life cycle assessment (LCA) study of a transition from semiintensive to semi-extensive Mediterranean dairy sheep farm suggests that the latter has a strong potential for offsetting greenhouse gas (GHG) emissions through the soil C sequestration (Cseq) in permanent grasslands. The extensification process shows clear environmental advantage when emission intensity is referred to the area-based functional unit (FU). Several LCA studies reported that extensive livestock systems have greater GHG emissions per mass of product than intensive one, due to their lower productivity. However, these studies did not account for soil Cseq of temporary and permanent grasslands, that have a strong potential to partly mitigate the GHG balance of ruminant production systems. Our LCA study was carried out considering the transition from a semiintensive (SI) towards a semi-extensive (SE) production system, adopted in a dairy sheep farm located in North-Western Sardinia (Italy). Impact scope included enteric methane emissions, feed production, on-farm energy use and transportation, infrastructures as well as the potential C sink from soil Cseq compared to emission intensity. In order to provide a more comprehensive analysis, we used the following FUs: 1 kg of fat and protein corrected milk (FPCM) and 1 ha of utilised agricultural area (UAA). We observed that the extensification of production system determined contrasting environmental effects when using different FUs accounting for soil Cseq. When soil Cseq in emission intensity estimate was included, we observed slightly lower values of GHG emissions per kg of FPCM in the SI production system (from 3.37 to 3.12 kg CO2 equivalents – CO2-eq), whereas a greater variation we observed in the SE one (from 3.54 to 2.90 kg CO2-eq). Considering 1 ha of UAA as FU and including the soil Cseq, the emission intensity in SI moved from 6257 to 5793 kg CO2-eq, whereas values varied from 4020 to 3299 kg CO2-eq in SE. These results indicated that the emission intensity from semi-extensive Mediterranean dairy sheep farms can be considerably reduced through the soil Cseq, although its measurement is influenced by the models used in the estimation. Highlights - Extensification of dairy sheep systems provides an environmental benefit when soil C sequestration is considered. - Extensification of dairy sheep systems determines lower environmental impact per hectare of utilized agricultural area. - Enteric methane emissions are the main source of GHG emissions of the sheep milk life cycle. - Carbon sequestration in permanent grasslands can considerably contribute to climate change mitigation.

Environmental impacts of milk production and processing in the Eastern Alps: A “cradle-to-dairy gate” LCA approach

This study aimed to evaluate the environmental footprint and feed energy conversion ratio of Alpine dairy chains in the Eastern Alps, taking into account both the milk production and dairy processing phases, and to identify farm management features useful for targeting mitigation measures in the production phase. A cradle-to-farm gate Life Cycle Assessment model that included herd and manure management, on-farm feedstuff production and purchased feedstuffs and materials (dairy farm), and production inputs and dairy outputs (dairy processing) was applied to 75 farms (10 dairies). As functional units, we used 1 kg fat- and protein-corrected milk (FPCM) and 1 m2 of agricultural land, to account for production intensity and land managed by alpine farms, respectively. Impact categories (CML-IA and CED methods, background data from Ecoinvent database) assessed were global warming (GWP), GWP plus land-use change (GWP_LUC), acidification (AP) and eutrophication (EP) potentials, cumulative energy demand (CED) and land occupation (LO). Feed energy conversion ratio (whole diet - ECR; potentially human-edible portion of the diet - HeECR) was computed as the ratio between gross energy in feeds and that in milk. Mean ECR was 6.6 ± 0.5 MJ feed/MJ milk, of which only 8% derived from potentially human-edible feedstuffs. For 1 kg of FPCM at the dairy farm, GWP averaged 1.19 kg CO2-eq, GWP_LUC 1.31 kg CO2-eq, AP 17.3 g SO2-eq and EP 6.0 g PO4-eq (coefficients of variation, CV, ranged 17–21%), whereas mean CED was 2.7 MJ and LO 2.1 m2/y (CVs: 40–46%). When dairy processing was included, the impact values for 1 kg of dairy product were from 8 to 13 times greater than those obtained for 1 kg FPCM. Based on the outcomes of a principal component analysis, the farm management features most related to impacts and feed ratios were milk yield (MY, for the impacts per unit of milk and ECR), stocking rate (SR, for the impacts per unit of area), and percentages of concentrates (C, for GWP_LUC and HeECR). Step-wise analysis evidenced that strategies aiming to decrease the environmental footprint referred to milk and managed area at the same time and to improve the feed energy conversion ratios should include MY, SR and C jointly. These issues are particularly important for the sustainability of mountain farming systems, which need to create a virtuous link with local forage resources and the territory.

Effect of Feed Concentrate Intake on the Environmental Impact of Dairy Cows in an Alpine Mountain Region Including Soil Carbon Sequestration and Effect on Biodiversity

Several studies on the environmental impacts of livestock enterprises are based on the application of life cycle assessments (LCA). In Alpine regions, soil carbon sequestration can play an important role in reducing environmental impacts. However, there is no official methodology to calculate this possible reduction. Biodiversity plays an important role in the Alpine environment and is affected by human activities, such as cattle farming. Our aim was to estimate the carbon footprint (CF) of four different dairy production systems (different in breeds and feeding intensity) by using the LCA approach. The present study included 44 dairy Alpine farms located in the autonomous province of Bolzano in northern Italy. Half of the farms (n = 22) kept Alpine Grey and the other half (n = 22) Brown Swiss cattle. Within breeds, the farms were divided by the amount of concentrated feed per cow and day into high concentrate (HC) and low concentrate (LC). This resulted in 11 Alpine Grey low concentrate (AGLC) farms feeding an average amount of 3.0 kg concentrated feed/cow/day and 11 Alpine Grey high concentrate (AGHC) farms with an average amount of 6.3 kg concentrated feed/cow/day. Eleven farms kept Brown Swiss cows with an average amount of 3.7 kg concentrated feed/cow/day (BSLC) and another 11 farms feeding on average 7.6 kg concentrated feed/cow/day (BSHC). CF for the four systems was estimated using the LCA approach. The functional unit was 1 kg of fat and protein corrected milk (FPCM). Furthermore, two methodologies have been applied to estimate soil carbon sequestration and effect on biodiversity. The system with the lowest environmental impact in terms of CF was BSHC (1.14 kg CO2-eq/kg of FPCM), while the most impactful system was the AGLC group (1.55 kg CO2-eq/kg of FPCM). Including the CF reduction due to soil carbon sequestered from grassland, it decreased differently for the two applied methods. For all four systems, the main factor for CF was enteric emission, while the main pollutant was biogenic CH4. Conversely, AGLC had the lowest impact when the damage to biodiversity was considered (damage score = 0.41/kg of FPCM, damage to ecosystem diversity = 1.78 E-07 species*yr/kg FPCM). In comparison, BSHC had the greatest impact in terms of damage to biodiversity (damage score = 0.56/kg of FPCM, damage to ecosystem diversity = 2.49 E-07 species*yr/kg FPCM). This study indicates the importance of including soil carbon sequestration from grasslands and effects on biodiversity when calculating the environmental performance of dairy farms.

Dairy sheep carbon footprint and ReCiPe end-point study

Abstract Sheep milk production is an important livestock sector for the European Mediterranean countries including the regions of southern Italy. The main objective of this study was to investigate the carbon footprint and the related damages generated by dairy sheep farming by using a simplified LCA approach based on the ReCiPe End-point method. We used 1 kg of Fat and Protein Corrected Milk (FPCM) as functional unit (FU). The average flock size was about 400 animals and the average farm size was about 66 ha. In addition to milk all farms produced meat and wool. Therefore, we performed an economic allocation by dividing all inputs and outputs among milk and the other two co-products (meat and wool), based on farm financial statements. The CF impact determined by 1 kg of FPCM was 3.78 kg CO2-eq. The highest CF impact was mainly due to the enteric fermentation, producing biogenic CH4 as the prevalent chemical compound, followed by the production of meadow hay. Based on the ReCiPe End-point method the impact of 1 kg of FPCM from dairy sheep farming was 7.35 E-06 Disability Adjusted Life Years, whereas the Damage to Ecosystem Diversity was 3.29 E-07 Species*year and the value of the Damage to Resource Availability 0.025 $. In conclusion, the environmental management and sustainability of sheep farms should be constantly controlled with the aim of minimizing their impacts without compromising the competitiveness of this productive sector.

Effectiveness of climate change mitigation options considering the amount of meat produced in dairy systems

Many of the climate change mitigation options for dairy systems that aim at optimizing milk production imply a reduced output of meat from these systems. The objective of this study was to evaluate effectiveness of a number of mitigation strategies for dairy systems, taking into account compensation for changes in the amount of beef produced. Four commonly used mitigation strategies for dairy systems were evaluated using an LCA modelling approach: increasing the milk production per cow, extending the productive life span of cows, increasing the calving interval, and changing breed from Holstein Friesian to Jersey. The Dutch dairy system was taken as a case study. For each scenario, analyses were done in two steps. First, effects of the mitigation strategy on production of milk and carcass weight from the dairy system were calculated. Second, GHG emission intensities were calculated for three different functional units (FU): one kg of fat and protein corrected milk (FPCM), one kg of carcass weight (CW), and a fixed amount of milk and beef (i.e. 1 kg FPCM and 40 g CW). In the third FU, in case the amount of CW produced by the dairy system was lower than 40 g per kg FPCM, the remainder was compensated by CW produced in pure beef systems, assuming a GHG emission intensity of 30 kg CO2-eq. per kg CW for pure beef. Results showed a reduction in CW per kg FPCM from the dairy system in all four mitigation strategies. Considering GHG emissions per kg of FPCM only, the strategies reduced emissions by 0.2 to 18.1%. When considering emissions per kg of CW only, emissions were reduced by 12.5 to 48.9%. However, when we used a FU of 1 kg FPCM and 40 g CW, changes in emissions ranged from −0.2 to 3.8%. This was caused by the compensation of the lower CW production from dairy systems by CW from pure beef systems. Differences in emissions per kg FPCM and 40 g CW were smaller when the assumed emission intensity of pure beef was lower. We concluded that the mitigation strategies for dairy systems evaluated in this study were less effective for reduction of GHG emissions from production of milk and beef, when accounting for changes in the amount of beef produced. This study showed that the challenge of reducing GHG emissions of milk and beef production is interrelated. Hence, analyses of GHG emissions related to changes in production of milk and beef requires an integrated approach, beyond the system boundaries of the dairy farm.

Economic effect of reducing nitrogen and phosphorus mass balance on Wisconsin and Québec dairy farms

Our objective was to explore the trade-offs between economic performance (farm net income, FNI) and environmental outcomes (whole-farm P and N balances) of dairy farms in Wisconsin (WI; United States) and Québec (QC; Canada). An Excel-based linear program model (N-CyCLES; nutrient cycling: crops, livestock, environment, and soil) was developed to optimize feeding, cropping, and manure management as a single unit of management. In addition to FNI, P and N balances model outputs included (1) the mix of up to 9 home-grown and 17 purchased feeds for up to 5 animal groups, (2) the mix of up to 5 crop rotations in up to 5 land units and c) the mix of up to 7 fertilizers (solid and liquid manure and 5 commercial fertilizers) to allocate in each land unit. The model was parameterized with NRC nutritional guidelines and regional nutrient management planning rules. Simulations were conducted on a typical WI farm of 107 cows and 151 ha of cropland and, a Southern QC farm of 87 cows and 142 ha of cropland and all results were expressed per kg of fat- and protein-corrected milk (FPCM). In absence of constraints on P and N balances, maximum FNI was 0.12 and 0.11 $/kg of FPCM for WI and QC, respectively, with P and N balances of 1.05 and 14.29 g/kg of FPCM in WI but 0.60 and 15.70 g/kg of FPCM in QC. The achievable reduction (balance at maximum FNI minus balance when the simulation objective was to minimize P or N balance) was 0.31 and 0.54 g of P/kg of FPCM (29 and 89% reduction), but 2.37 and 3.31 g of N/kg of FPCM (17 and 24% reduction) in WI and QC, respectively. Among other factors, differences in animal unit per hectare and reliance on biological N fixation may have contributed to lower achievable reductions of whole-farm balances in WI compared with QC. Subsequent simulations to maximize FNI under increasing constraints on nutrient balances revealed that it was possible to reduce P balance, N balance, and both together by up to 33% without a substantial effect on FNI. Partial reduction in P balance reduced N balance (synergetic effect) in WI, but increased N balance (antagonistic effect) in QC. In contrast, reducing N balance increased P balance in both regions, albeit in different magnitudes. The regional comparison highlighted the importance of site-specific conditions on modeling outcomes. This study demonstrated that even when recommended guidelines are followed for herd nutrition and crop fertilization, the optimization of herd feeding, cropping, and manure spreading as a single unit of management may help identify management options that preserve FNI, while substantially reducing whole-farm nutrient balance.

Greenhouse gas balance of mountain dairy farms as affected by grassland carbon sequestration

Recent studies on milk production have often focused on environmental impacts analysed using the Life Cycle Assessment (LCA) approach. In grassland-based livestock systems, soil carbon sequestration might be a potential sink to mitigate greenhouse gas (GHG) balance. Nevertheless, there is no commonly shared methodology. In this work, the GHG emissions of small-scale mountain dairy farms were assessed using the LCA approach. Two functional units, kg of Fat and Protein Corrected Milk (FPCM) and Utilizable Agricultural Land (UAL), and two different emissions allocations methods, no allocation and physical allocation, which accounts for the co-product beef, were considered. Two groups of small-scale dairy farms were identified based on the Livestock Units (LU) reared: <30 LU (LLU) and >30 LU (HLU). Before considering soil carbon sequestration in LCA, performing no allocation methods, LLU farms tended to have higher GHG emission than HLU farms per kg of FPCM (1.94 vs. 1.59 kg CO2-eq/kg FPCM, P ≤ 0.10), whereas the situation was reversed upon considering the m2 of UAL as a functional unit (0.29 vs. 0.89 kg CO2-eq/m2, P ≤ 0.05). Conversely, considering physical allocation, the difference between the two groups became less noticeable. When the contribution from soil carbon sequestration was included in the LCA and no allocation method was performed, LLU farms registered higher values of GHG emission per kg of FPCM than HLU farms (1.38 vs. 1.10 kg CO2-eq/kg FPCM, P ≤ 0.05), and the situation was likewise reversed in this case upon considering the m2 of UAL as a functional unit (0.22 vs. 0.73 kg CO2-eq/m2, P ≤ 0.05). To highlight how the presence of grasslands is crucial for the carbon footprint of small-scale farms, this study also applied a simulation for increasing the forage self-sufficiency of farms to 100%. In this case, an average reduction of GHG emission per kg of FPCM of farms was estimated both with no allocation and with physical allocation, reaching 27.0% and 28.8%, respectively.

Global warming and mitigation potential of milk and meat production in Lombardy (Italy)

Lombardy is one of the most important Italian regions for livestock productions. It produces approximately 42% of Italian cow milk and an important part of Italian pork (40.6%) and beef (31.6%, including culled cows and veal meat). Moreover, Lombardy contributes for 11.5% to the Italian chicken meat production and for 7.53% to rabbit meat. The objective of the study was to estimate the total global warming potential (GWP) of milk and meat productions in Lombardy through a Life Cycle Assessment (LCA) approach and to evaluate the mitigation potential of milk and pork productions. The animal products considered were cow milk and meats from swine, cattle, chickens and rabbits, which represent the almost totality of meat produced in Lombardy. Milk productions and milk composition of Lombardy farms were obtained from the Italian Breeders Association recordings and converted into Fat and Protein Corrected Milk (FPCM). The total GWP of milk production at farm gate in Lombardy was calculated using the mean value of 1.37 kg CO2 eq./kg FPCM, obtained in previous LCA analyses on 102 dairy farms representative of farming systems in Lombardy. The functional unit was 1 kg of FPCM leaving the farm gate. Total meat production in Lombardy was obtained from official statistical data on slaughtered animals. For estimating GWP of meat production the results of previous LCA studies were used; the functional unit was 1 kg of live weight leaving the farm gate. The total GWP of cow milk production in Lombardy was 6.12 Mt CO2 eq.; the most part (90.8%) was generated by farms from lowland, 5.8% from mountains and 3.4% from hills. Results indicate that in Lombardy emission mitigation strategies have to be primarily applied to lowland farms. The total GWP of meat production in Lombardy was 8.5 Mt CO2 eq. Total GWP from milk and meat production in Lombardy was quantified in 14.6 Mt CO2 eq. The most contributing sectors to regional GWP from livestock are dairy and pork. Considering the protein content of animal products, it is noticeable that pork meat and milk had similar contributions to the total protein supply from milk and meat in Lombardy (42.2 vs 37.1% for milk and pork, respectively) but different impacts on GWP (41.9% vs 24.7%, respectively). Beef production gives a small contribution to protein supply but a high contribution to greenhouse gas emissions. Mitigation potentials were evaluated by applying to dairy and pork operations the GWP figures of actual farms of low impact. The results showed that the dissemination of already existing best farming practices could lead to approximately 22% reduction of Lombardy GWP for milk and 37% reduction for pork production. The regional multi-commodity analysis allows to evaluate the mitigation potential of technical measures within each sector as well as to identify mitigation strategies at a territorial level based on structural changes of livestock population.

Effect of dry period length on milk yield over multiple lactations

Shortening or omitting the dry period (DP) can improve the energy balance of dairy cows in early lactation through a decrease in milk yield after calving. Little is known about the effect of a short or no DP on milk yield over multiple lactations. Our objectives were (1) to assess the effect of DP length over multiple lactations on milk yield, and (2) to assess if the prediction of milk yield in response to DP length could be improved by including individual cow characteristics before calving. Lactation data (2007 to 2015) of 16 Dutch dairy farms that apply no or short DP were used to compute cumulative milk yield in the 60 d before calving (additional yield) and in the 305 d after calving (305-d yield), and the mean daily yield over the interval from 60 d before calving to 60 d before next calving (effective lactation yield). The DP categories were no (0 to 2 wk), short (3 to 5wk), standard (6 to 8 wk), and long (9 to 12 wk). The effect of current DP and previous DP on yields was analyzed with mixed models (n=1,420 lactations). The highest effective lactation yield of fat- and protein-corrected milk (FPCM) was observed for cows with a standard current DP (27.6kg per day); a daily decrease was observed of 0.6kg for a long DP, 1.0kg for a short DP, and 2.0kg for no DP. Previous DP did not significantly affect the effective lactation yield. Thus, cows can be managed with short or no DP over consecutive lactations without a change in quantity of milk losses. Cows that received no DP for consecutive lactations had a lower additional yield before calving (−172kg of FPCM), but a higher 305-d yield (+560kg of FPCM), compared with cows that received no DP for the first time. This could lessen the improvement of the energy balance in early lactation when no DP is applied a second time compared with the first time. For the second objective, a basic model was explored to predict effective lactation yield based on parity, DP length, and first-parity 305-d yield (n=2,866 lactations). The basic model was subsequently extended with data about recent yield, days open, and somatic cell count. Extending the model reduced the error of individual predictions by only 6%. Therefore, the basic model seems sufficient to predict the effect of DP length on effective lactation yield. Other individual cow characteristics can still be relevant, however, to make a practical and tailored decision about DP length.

Environmental assessment of small-scale dairy farms with multifunctionality in mountain areas

The aim of this study was to estimate the environmental impact of organic and conventional small-scale dairy farms in mountain areas. Sixteen farms rearing the dual-purpose Rendena breed were assessed for global warming potential, acidification and eutrophication impacts through the Life Cycle Assessment method in two scenarios: the Baseline Scenario based on the actual farm data and the Milk-Beef production system Scenario assuming that calves exceeding the culling rate were fattened directly on-farm. Three different emissions allocation methods were considered: No allocation; Physical allocation, which also accounted for the co-product beef; and Economic allocation, which also accounted for the ecosystem services provided by the farms and were estimated on the basis of agri-environmental payments. Furthermore, two functional units were used: fat and protein corrected milk (FPCM) and utilizable agricultural land (UAL). Within the Baseline Scenario and with FPCM as the functional unit, performing No allocation, the mean values obtained for the global warming potential, acidification and eutrophication were 1.43 kg CO2-eq/kg FPCM, 25.84 g SO2-eq/kg FPCM and 3.99 g PO43−-eq/kg FPCM, respectively. The organic farms had a significantly lower eutrophication impact than the conventional farms considering all three allocation methods. Conversely, if UAL was used as the functional unit, the mean values obtained for the global warming potential, acidification and eutrophication were 0.80 kg CO2-eq/m2, 14.28 g SO2-eq/m2 and 2.32 g PO43−-eq/m2, respectively. The Milk-Beef production system Scenario increased emissions per m2 of UAL, but it reduced the emissions apportioned to 1 kg of FPCM, with stronger trends in the organic farms because of the increased added value of the meat production. This study highlights how strengthening beef production in dual-purpose breeds reduced the emissions apportioned to milk and suggests an approach to acknowledge multi-functionality considering some of the ecosystem services provided by the farms.

Effective lactation yield: A measure to compare milk yield between cows with different dry period lengths

To compare milk yields between cows or management strategies, lactations are traditionally standardized to 305-d yields. The 305-d yield, however, gives no insight into the combined effect of additional milk yield before calving, decreased milk yield after calving, and a possible shorter calving interval in the case of a shortened dry period. We aimed to develop a measure that would enable the comparison of milk yield between cows with different dry period (DP) lengths. We assessed the importance of accounting for additional milk yield before calving and for differences in calving interval. The 305-d yield was compared with a 365-d yield, which included additional milk yield in the 60d before calving. Next, an effective lactation yield was computed, defined as the daily yield from 60d before calving to 60d before the next calving, to account for additional milk yield before calving and for differences in calving interval. Test-day records and drying-off dates of 15 commercial farms were used to compute the 305-d, 365-d, and effective lactation yields for individual cows. We analyzed 817 second-parity lactations preceded by no DP, a short DP (20 to 40d), or a conventional DP (49 to 90d). Compared with cows with a conventional DP, the 305-d yield of cows with no DP was 7.0kg of fat- and protein-corrected milk (FPCM) per day lower, and the 305-d yield of cows with a short DP was 2.3kg of FPCM per day lower. Including additional milk yield before calving in the 365-d yield reduced this difference to 3.4kg of FPCM per cow per day for cows with no DP and to 0.9kg of FPCM per cow per day for cows with a short DP. Compared with cows with a conventional DP, median days open were reduced by 25d for cows with no DP and by 18d for cows with a short DP. Accounting for these differences in calving interval in the effective lactation yield further decreased yield reductions for cows with no DP or a short DP by 0.3kg of FPCM per cow per day. At the herd level, estimated 365-d yield losses for cows with no DP or a short DP differed from effective lactation yield losses by 0.4 to −0.8kg FPCM per cow per day. Accounting for additional milk yield before calving had a major and consistent effect on yield comparisons of cows with different DP lengths. The effect of correcting for calving interval was more variable between farms and will especially be important when calving interval is affected by DP length.

Greenhouse gas emissions and land use from confinement dairy farms in the Guanzhong plain of China – using a life cycle assessment approach

The objective of this study were to quantify greenhouse gas (GHG) emissions and land use of milk production and evaluate the potential mitigation options at farm level in the Guanzhong plain, which is the main dairy farming region in China. The life cycle assessment methodology was used to analyse the GHG emissions of eight confinement dairy farms that covered different milk production levels, herd structures and diet compositions. The GHG emission per kg of fat and protein corrected milk (FPCM) ranged from 1.31 to 2.08 kg CO2 eq. after farm GHG emissions had been allocated to milk, meat and manure. Enteric methane and emissions related to feed production and manure management were the three major GHG emission sources from the eight farms and contributed 54%–60%, 21%–30% and 8%–10%, respectively, to total emissions. Land use per kg of FPCM was 1.81 m2 with the largest contribution from feed production. GHG emissions associated with the production of per kg of FPCM decreased with increasing herd milk productivity and herd feed efficiency. Sensitivity analyses showed that the GHG emissions were significantly affected by metric values of global warming potential (GWP), with increases of about 4% and 12% for the calculation based on the IPCC (2013) GWP values, compared to IPCC (2007) and IPCC (1996) values, respectively; and soybean meal from imported soybeans would increase GHG emissions per kg of FPCM significantly due to the emissions related to land use change. Lowering N-fertilizer use per ha for feed crop production, improving milk productivity and herd structure, and encouraging farmers to use manure for crop production are promising abatement strategies. Due to the low percentage of grass (average 14%) in the diet for dairy cows in the Guanzhong plain, replacing part of the concentrates with alfalfa hay would increase milk productivity and decrease GHG emissions per kg of FPCM.

Anaerobic digestion and milking frequency as mitigation strategies of the environmental burden in the milk production system

The aim of the study was to assess, through a cradle to farm gate Life Cycle Assessment, different mitigation strategies of the potential environmental impacts of milk production at farm level. The environmental performances of a conventional intensive dairy farm in Northern Italy (baseline scenario) were compared with the results obtained: from the introduction of the third daily milking and from the adoption of anaerobic digestion (AD) of animal slurry in a consortium AD plant. The AD plant, fed only with animal slurries coming also from nearby farms. Key parameters concerning on-farm activities (forage production, energy consumptions, agricultural machines maintenance, manure and livestock management), off-farm activities (production of fertilizers, pesticides, bedding materials, purchased forages, purchased concentrate feed, replacement animals, agricultural machines manufacturing, electricity, fuel) and transportation were considered. The functional unit was 1kg fat and protein corrected milk (FPCM) leaving the farm gate. The selected environmental impact categories were: global warming potential, acidification, eutrophication, photochemical oxidation and non-renewable energy use. The production of 1kg of FPCM caused, in the baseline scenario, the following environmental impact potentials: global warming potential 1.12kg CO2 eq; acidification 15.5g SO2 eq; eutrophication 5.62g PO43− eq; photochemical oxidation 0.87g C2H4 eq/kg FPCM; energy use 4.66MJeq. The increase of milking frequency improved environmental performances for all impact categories in comparison with the baseline scenario; in particular acidification and eutrophication potentials showed the largest reductions (−11 and −12%, respectively). In anaerobic digestion scenario, compared to the baseline one, most of the impact potentials were strongly reduced. In particular the most important advantages were in terms of acidification (−29%), global warming (−22%) and eutrophication potential (−18%). The AD of cow slurry is confirmed as an effective strategy to mitigate the environmental impact of milk production at farm level.

Carbon footprint of dairy goat milk production in New Zealand

The aim of this study was to assess the cradle-to-farm gate carbon footprint of indoor and outdoor dairy goat farming systems in New Zealand, identifying hotspots and discussing variability and methodology. Our study was based on the International Organization for Standardization standards for life cycle assessment, although only results for greenhouse gas emissions are presented. Two functional units were included: tonnes of CO2-equivalents (CO2e) per hectare (ha) and kilograms of CO2e per kilogram of fat- and protein-corrected milk (FPCM). The study covered 5 farms, 2 farming systems, and 3yr. Two methods for the calculation of enteric methane emissions were assessed. The Lassey method, as used in the New Zealand greenhouse gas inventory, provided a more robust estimate of emissions from enteric fermentation and was used in the final calculations. The alternative dry matter intake method was shown to overestimate emissions due to use of anecdotal assumptions around actual consumption of feed. Economic allocation was applied to milk and co-products. Scenario analysis was performed on the allocation method, nitrogen content of manure, manure management, and supplementary feed choice. The average carbon footprint for the indoor farms (n=3) was 11.05 t of CO2e/ha and 0.81kg of CO2e/kg of FPCM. For the outdoor farms (n=2), the average was 5.38 t of CO2e/ha and 1.03kg of CO2e/kg of FPCM. The average for all 5 farms was 8.78 t of CO2e/ha and 0.90kg of CO2e/kg of FPCM. The results showed relatively high variability due to differences in management practices between farms. The 5 farms covered 10% of the total dairy goat farms but may not be representative of an average farm. Methane from enteric fermentation was a major emission source. The use of supplementary feed was highly variable but an important contributor to the carbon footprint. Nitrous oxide can contribute up to 18% of emissions. Indoor goat farming systems produced milk with a significantly higher carbon footprint per area of land farmed compared with outdoor farming systems, although the 2 systems were not significantly different when results were expressed per kilogram of FPCM, at 0.81kg CO2e and 1.03kg CO2e per kg of FPCM, respectively. Both systems had footprints less than other reported dairy goat carbon footprints and on par with those for New Zealand dairy cows. The methodology used to determine enteric methane is important for an accurate and meaningful assessment. The choice of manure management system and supplementary feed can substantially affect the carbon footprint.

Environmental performances of Sardinian dairy sheep production systems at different input levels

Although sheep milk production is a significant sector for the European Mediterranean countries, it shows serious competitiveness gaps. Minimizing the ecological impacts of dairy sheep farming systems could represent a key factor for farmers to bridging the gaps in competitiveness of such systems and also obtaining public incentives. However, scarce is the knowledge about the environmental performance of Mediterranean dairy sheep farms. The main objectives of this paper were (i) to compare the environmental impacts of sheep milk production from three dairy farms in Sardinia (Italy), characterized by different input levels, and (ii) to identify the hotspots for improving the environmental performances of each farm, by using a Life Cycle Assessment (LCA) approach. The LCA was conducted using two different assessment methods: Carbon Footprint-IPCC and ReCiPe end-point. The analysis, conducted “from cradle to gate”, was based on the functional unit 1kg of Fat and Protein Corrected Milk (FPCM). The observed trends of the environmental performances of the studied farming systems were similar for both evaluation methods. The GHG emissions revealed a little range of variation (from 2.0 to 2.3kgCO2-eq per kg of FPCM) with differences between farming systems being not significant. The ReCiPe end-point analysis showed a larger range of values and environmental performances of the low-input farm were significantly different compared to the medium- and high-input farms. In general, enteric methane emissions, field operations, electricity and production of agricultural machineries were the most relevant processes in determining the overall environmental performances of farms.Future research will be dedicated to (i) explore and better define the environmental implications of the land use impact category in the Mediterranean sheep farming systems, and (ii) contribute to revising and improving the existing LCA dataset for Mediterranean farming systems.

Carbon footprint of milk produced at Italian buffalo farms

The carbon footprint (CF) of milk produced in six Italian Mediterranean Buffalo farms was estimated through a simplified Life Cycle Assessment. Functional unit was 1kg of fat and protein corrected milk (FPCM).The farms were characterized by high levels of inputs, as purchased feeds, chemical fertilizers and fossil fuels. Average cultivated area was 53.2ha; the forage system was based mainly on maize silage, immediately followed by Italian ryegrass and/or whole cereal silage. Average herd size was 360 and the average FPCM per lactating buffalo was 3563kg/year with an average milk fat and protein percentage of 8.24 and 4.57 respectively. The CF assessment was from cradle to farm gate. The greenhouse gases (GHG) that were taken into account were CH4 from enteric fermentations, CH4 from manure in the stable and in the tank; N2O from nitrification and denitrification processes in the manure before application into the soil and N2O produced after organic and synthetic fertilizer application; direct emissions of CO2 from the fossil fuels combustion within the farms and indirect emissions of CO2 deriving from production of electricity, off-farm feeds, synthetic fertilizers and other minor inputs. Carbon footprint of 1kg of FPCM was 3.75kg CO2eq. Main sources of GHG are enteric CH4 (45%) and indirect CO2eq (25%). Besides enteric CH4, the farm activity that gives the highest contribution to milk CF is on-farm feed production, with 34% on total greenhouse gas emissions (TGE). Carbon footprint with economic allocation (CFea) was estimated by considering the live-weight of males calves and culled cows: its value was 3.60kg CO2eq. If the economic value of the increase of the herd size is considered in the assessment, CFea decreases to 3.45 or 3.27kg CO2eq with an increase of 10% or 20% of the number of mature buffalos.

Assessing environmental impacts associated with freshwater consumption along the life cycle of animal products: the case of Dutch milk production in Noord-Brabant

The assessment of water footprints of a wide range of products has increased awareness on preserving freshwater as a resource. The water footprint of a product was originally defined by Hoekstra and Hung (2002) as the sum of the volumetric water use in terms of green, blue and grey water along the entire life cycle of a product and, as such, does not determine the environmental impact associated with freshwater use. Recently, several papers were published that describe building blocks that enable assessment of the site-specific environmental impact associated with freshwater use along the life cycle of a global food chain, such as the impact on human health (HH), ecosystem quality (EQ) or resource depletion (RD). We integrated this knowledge to enable an assessment of the environmental impact associated with freshwater use along the life cycle of milk production, as a case for a global food chain. Our approach innovatively combined knowledge about the main impact pathways of freshwater use in life cycle assessment (LCA), knowledge about site-specific freshwater impacts and knowledge about modelling of irrigation requirements of global feed crops to assess freshwater impacts along the life cycle of milk production. We evaluated a Dutch model farm situated on loamy sand in the province of Noord-Brabant, where grass and maize land is commonly irrigated. Production of 1 kg of fat-and-protein corrected milk (FPCM) on the model farm in Noord-Brabant required 66 L of consumptive water. About 76 % of this water was used for irrigation during roughage cultivation, 15 % for production of concentrates and 8 % for drinking and cleaning services. Consumptive water use related to production of purchased diesel, gas, electricity and fertiliser was negligible (i.e. total 1 %). Production of 1 kg of FPCM resulted in an impact on HH of 0.8 × 10−9 disability adjusted life years, on EQ of 12.9 × 10−3 m2 × year and on RD of 6.7 kJ. The impact of producing this kilogram of FPCM on RD, for example, was caused mainly by cultivation of concentrate ingredients, and appeared lower than the average impact on RD of production of 1 kg of broccoli in Spain. Integration of existing knowledge from diverse science fields enabled an assessment of freshwater impacts along the life cycle of a global food chain, such as Dutch milk production, and appeared useful to determine its environmental hotspots. Results from this case study support earlier findings that LCA needs to go beyond simple water volume accounting when the focus is on freshwater scarcity. The approach used, however, required high-resolution inventory global data (i.e. especially regarding crop yield, soil type and root depth), and demonstrated a trade-off between scientific quality of results and applicability of the assessment method.