Review: Perspective on high-performing dairy cows and herds

Milk and dairy products provide highly sustainable concentrations of essential amino acids and other required nutrients for humans; however, amount of milk currently produced per dairy cow globally is inadequate to meet future needs. Higher performing dairy cows and herds produce more milk with less environmental impact per kg than lower performing cows and herds. In 2018, 15.4% of the world\u27s dairy cows produced 45.4% of the world\u27s dairy cow milk, reflecting the global contribution of high-performing cows and herds. In high-performing herds, genomic evaluations are utilized for multiple trait selection, welfare is monitored by remote sensing, rations are formulated at micronutrient levels, health care is focused on prevention and reproduction is managed with precision. Higher performing herds require more inputs and generate more waste products per cow, thus innovations in environmental management on such farms are essential for lowering environmental impacts. Our focus is to provide perspectives on technologies and practices that contribute most to sustainable production of milk from high-performing dairy cows and herds

Activation of inflammatory responses in human U937 macrophages by particulate matter collected from dairy farms: an in vitro expression analysis of pro-inflammatory markers

Abstract Background The purpose of the present study was to investigate activation of inflammatory markers in human macrophages derived from the U937 cell line after exposure to particulate matter (PM) collected on dairy farms in California and to identify the most potent components of the PM. Methods PM from different dairies were collected and tested to induce an inflammatory response determined by the expression of various pro-inflammatory genes, such as Interleukin (IL)-8, in U937 derived macrophages. Gel shift and luciferase reporter assays were performed to examine the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Toll-like-receptor 4 (TLR4). Results Macrophage exposure to PM derived from dairy farms significantly activated expression of pro-inflammatory genes, including IL-8, cyclooxygenase 2 and Tumor necrosis factor-alpha, which are hallmarks of inflammation. Acute phase proteins, such as serum amyloid A and IL-6, were also significantly upregulated in macrophages treated with PM from dairies. Coarse PM fractions demonstrated more pro-inflammatory activity on an equal-dose basis than fine PM. Urban PM collected from the same region as the dairy farms was associated with a lower concentration of endotoxin and produced significantly less IL-8 expression compared to PM collected on the dairy farms. Conclusion The present study provides evidence that the endotoxin components of the particles collected on dairies play a major role in mediating an inflammatory response through activation of TLR4 and NF-κB signaling

Life cycle assessment of sheep meat and wool production in Northern California

A partial life cycle assessment (LCA) of a sheep production system in California was conducted to better understand the environmental impacts of sheep production in the United States. This cradle-to-farm-gate LCA analyzed emissions from sheep-lamb, stocker, and finishing stages of lamb production within the same market chain. Our objective was to calculate the carbon footprint associated with commercial sheep production in northern California and to compare the impact of allocation methods for 1 kg of live weight lamb (LWT), 1 kg cull adult (LWT), and 1 kg of greasy wool at the farm gate. Primary data was collected from on-farm records wherever possible and secondary data from published literature. Whole-system emissions totaled 474.7 Mt carbon dioxide equivalent (CO2e), of which 42.2% were from animal emissions, 52.6% from feed production and transport, and 5.2% due to animal transport and on-farm operations. Enteric methane was responsible for 34% of total emissions. The sheep–lamb, backgrounding, and feedlot phases were responsible for 86.1, 4.18, and 9.72%, of overall emissions, respectively. Emissions were allocated 100% to meat or between lamb, wool, and cull adult meat on a mass basis. The production system studied for this analysis focused on producing market lambs, with final live weights of 56.4 kg and carcass yield grade 2. Cull adults averaged 54.4 and 68 kg for ewes and rams, respectively, and whole-farm wool production was 2.05 Mt greasy wool. When all emissions were allocated to lamb production, carbon footprints were 28.6 kg CO2e/kg LWT. When emissions were allocated on a mass basis between lamb, wool, and cull adult meat, 65, 27, and 8% were allocated to lamb, cull adults, and wool, respectively. Carbon footprints were 19 kg CO2e/kg lamb, 8.0 kg CO2e/kg cull adult, and 2.5 CO2e/kg wool. These values highlight the importance of meat production to Californian sheep producers, compared with wool-focused systems found in Australia and the United Kingdom. Whilst lamb has a higher carbon footprint compared with beef regardless of allocation method, coproduct allocation methods also play a significant role in assigning environmental impacts. This analysis is a first step in assessing the overall impact of small ruminant supply chains in the country and identifying aspects that contribute to environmental impacts of production. The results provide baseline data on emissions from sheep production that may be useful in future efforts by the California lamb industry

A Case Study Assessment of the Carbon Footprint of Sheep Production Systems in California

•California is the nation's leading producer of market sheep •Most sheep in CA spend at least part of their life on rangeland, as part of a wide variety of diverse systems •The environmental impact of these systems is unknown •Life cycle assessment (LCA) and carbon footprint calculations can be used to measure the efficiency and environmental impacts of livestock production •California-specific LCAs have been conducted (e.g. Stackhouse-Lawson et al. (2012) for beef production and DeLonge(2016) for wool) •The environmental impact of sheep meat production in other countries has been studied, but not for the US •Reducing carbon footprint is highly correlated with increasing production efficiency and profitability •A case study based method will allow for the calculation and comparison of the carbon footprints of different production system types •Baseline resource use and carbon footprint data from different sectors of the California sheep industry would allow producers to assess current environmental impacts •This data would help producers improve production efficiency and reduce environmental impact while maintaining the health of native rangeland

Review: Modeling production and environmental impacts of small ruminants - Incorporation of existing ruminant modeling techniques, and future directions for research and extension

Mathematical models are a useful part of extension and researcher collaboration with producers and policymakers. Although many models of large ruminant production exist, with a wide variety of objectives and users, the range available to small ruminant producers is limited. This review summarizes the current state of models available to small ruminant research, identifies data gaps that could be filled to improve representation of current small ruminant production practices, and suggests a framework that could be used to develop a suite of models to improve small ruminant research at the research and consultant levels and research and teaching levels and to improve system-level assessment of environmental impacts

Tasked based assessment of dairy worker exposure to bioaerosols

Objective: The evaluation of dairy worker bioaerosol exposures among similar exposure groups (SEGs) to identify high risk tasks. The data is an important step in the development effective workplace intervention strategies to reduce bioaerosol exposure and health effects. Methods: Inhalable bioaerosol samples were collected in workers’ breathing zones (n=116) over entire work shifts using Button samplers loaded with PVC filters to measure organic dust, endotoxin (rFC assay), and 3-hyrdoxy fatty acids (3-OHFA), ergosterol and muramic acid (GC/MSMS). Ammonia was measured with ToxiRaes. To our knowledge this is the first study with combined 3-OHFA, muramic acid and ergosterol exposure analysis in dairies. SEGs were defined through observation of worker activities and location including: milking and parlor maintenance (33% of population), medical, maternity and calves (24%), mixed tasks (20%), re-bedding stalls (8%), other tasks (5%), feeding (4%), moving stock (3%) and maintenance (3%). Results: Participants were predominantly male (88%) Hispanics (91%) aged 25 to 40 years. Exposures to endotoxin (R2= 33.0% p<0.001), 3-OHFA (25.7% p<0.001), ammonia (18.0% p=0.008) and organic dust (13.9% p=0.022) differed significantly by SEG. 89% of workers had geometric mean endotoxin exposures that exceeded the recommended exposure limit (90 EU/m3), as did 12% of worker exposures to organic dust (2.5 mg/m3). The milking parlor, stock moving and mixed task SEGs had the greatest endotoxin and organic dust exposures. In contrast, the other task SEG, which included administration workers and facility managers, replaced the mixed tasks SEG for the greatest 3-OHFA exposures. The stock movers had the highest mean muramic acid and ammonia exposures. Conclusions: The finding that the majority of the dairy workers had endotoxin exposures that exceeded the recommended guideline indicates a need for a facility wide intervention strategy. Initial strategies should target milking, stock moving, other and mixed task SEGs which represented the greatest overexposure risk