College of Agriculture & Natural Resources

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The collections in this community comprise faculty research works, as well as graduate theses and dissertations.

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Subject: search.filters.subject.dairy

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Now showing 1 - 6 of 6
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    Enhanced Biogas Production of Cassava Wastewater Using Zeolite and Biochar Additives and Manure Co-Digestion
    (MDPI, 2020-01-19) Achi, Chibueze G.; Hassanein, Amro; Lansing, Stephanie
    Currently, there are challenges with proper disposal of cassava processing wastewater, and a need for sustainable energy in the cassava industry. This study investigated the impact of co-digestion of cassava wastewater (CW) with livestock manure (poultry litter (PL) and dairy manure (DM)), and porous adsorbents (biochar (B-Char) and zeolite (ZEO)) on energy production and treatment efficiency. Batch anaerobic digestion experiments were conducted, with 16 treatments of CW combined with manure and/or porous adsorbents using triplicate reactors for 48 days. The results showed that CW combined with ZEO (3 g/g total solids (TS)) produced the highest cumulative CH4 (653 mL CH4/g VS), while CW:PL (1:1) produced the most CH4 on a mass basis (17.9 mL CH4/g substrate). The largest reduction in lag phase was observed in the mixture containing CW (1:1), PL (1:1), and B-Char (3 g/g TS), yielding 400 mL CH4/g volatile solids (VS) after 15 days of digestion, which was 84.8% of the total cumulative CH4 from the 48-day trial. Co-digesting CW with ZEO, B-Char, or PL provided the necessary buffer needed for digestion of CW, which improved the process stability and resulted in a significant reduction in chemical oxygen demand (COD). Co-digestion could provide a sustainable strategy for treating and valorizing CW. Scale-up calculations showed that a CW input of 1000–2000 L/d co-digested with PL (1:1) could produce 9403 m3 CH4/yr using a 50 m3 digester, equivalent to 373,327 MJ/yr or 24.9 tons of firewood/year. This system would have a profit of $5642/yr and a $47,805 net present value.
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    Immune response after intramammary challenge with Streptococcus uberis mastitis for cows fed OmniGen-AF® during mid-lactation
    (2021) Fischer, Amanda; Kohn, Richard; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Mastitis is one of the costliest diseases in the dairy cattle industry. Environmental pathogens, such as Streptococcus uberis (Strep. uberis), are the most prevalent causes of mastitis infections, while contagious pathogen mastitis has declined in incidences due to improvement in management protocols. Antimicrobials and antibiotics are the primary therapies currently utilized in the dairy industry to treat mastitis. However, the concern for antibiotic overuse and potential bacterial resistance due to improper use of these therapies has steered research in exploration of alternatives to antibiotics or other strategies. One potential alternative is supplementation of an immunomodulatory feed additive to daily cattle total mixed rations (TMR). A current immunomodulator is OmniGen-AF ® (OMN) produced by Phibro Animal Health Corporation (Teaneck, NJ) and has been explored being fed to lactating dairy cattle by previous research groups. OmniGen- AF ® has been reported to improve initial innate immune response during infection. However, it is unknown how OMN influences the innate immune system in vivo to a S. uberis mastitis infection. The ability of OMN to modulate immune function during an environmental mastitis infection was tested compared to control groups. Cows fed OmniGen-AF® and challenged with Strep. uberis had numerically higher least squared mean Log somatic cell count compared to the control group that was not fed OMN and challenged with Strep. uberis. OMN fed cows displayed numerically higher average daily feed intake and fluid milk yield values compared to the control group. Further analysis of milk and blood samples using immunoassays to monitor the effects OMN has on cytokine and cortisol levels throughout mastitis infection is needed to determine innate immune response. In conclusion, OmniGen-AF® has the potential as an immunomodulator that improves innate immune system activity with continuous supplementation in the diet to prevention of dairy cattle environmental mastitis.
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    Revenue Insurance Now Available For Dairy Producers
    (2018-10) Kuykendall, Olivia; Goeringer, Paul
    USDA recently approved a financial risk management program for farmers who are vulnerable to dairy price fluctuations. The Dairy Revenue Protection program is buy-in insurance that covers a percentage of a producer’s expected quarterly revenue. Coverage is quarterly and the price depends on either the class or component of the milk products and the desired percentage of coverage. More information on the program, eligibility, limitations, pricing, where and how to buy can be found in this publication.
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    In Vitro Study of an Orange Oil Derived Alternative to Antibiotics in the Treatment of Bovine Mastitis
    (2015) Federman, Cassandra Skye; Biswas, Debabrata; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Bovine mastitis is a costly disease in the U.S. dairy industry. Its major causative agent Staphylococcus aureus is often unresponsive to antibiotic therapy. Our first study examined terpeneless, cold-pressed Valencia (CPV) orange oil as a possible alternative to antibiotic therapy in the treatment of S. aureus associated bovine mastitis. Orange oil showed significant inhibition of S. aureus growth and invasion of bovine epithelial mammary cells, but only modest reductions in pre-formed biofilms, which contribute to persistence of S. aureus infections. Our second study examined major components of terpeneless, CPV orange oil. Of four major compounds tested, only citral and linalool had significant inhibitory effects on S. aureus growth. In addition, they were capable of reducing pre-formed biofilms as well as association and invasion to bovine epithelial mammary cells. Part of this inhibition was due to downregulation of virulence and biofilm genes.
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    Campylobacter spp. in bulk tank milk and milk filters from US dairy farms
    (2015) Del Collo, Laura P; Biswas, Debabrata; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Campylobacter spp. are a common cause of foodborne outbreaks associated with raw or unpasteurized milk, and Campylobacter spp. have also been detected on most dairies in the US. An estimate of the prevalence of thermophilic Campylobacter spp. in bulk tank milk (BTM) on US dairy operations was determined as part of the National Animal Health Monitoring System’s Dairy 2014 study. Campylobacter spp. were detected in the BTM and milk filters from 34.2% of the 234 dairies. Isolates were obtained from 18.4% of the dairies. C. jejuni was the most frequently isolated species, and this species is also the most common cause of human infection. When resistance to a panel of nine antimicrobials was tested, 68.4% of C. jejuni isolates were resistant to tetracycline. This survey suggests that BTM from US dairies can be contaminated with pathogenic Campylobacter spp., and the consumption of unpasteurized, raw milk represents a human health risk.
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    On-Farm Dry Matter Analysis to Improve Feed Delivery Precision on Dairy Farms
    (2011) French, Karin R.; Kohn, Richard A; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Uncertainty in dairy ration content impacts feed efficiency, milk production, expenses, and environmental losses. When measuring silage by weight, unknown changes in dry matter (DM) may change the total mixed ration. The objective of this study was to measure variation in silage DM on selected farms and evaluate an electronic method of on-farm DM analysis. Of 31 Maryland farms surveyed, 63% reported DM analysis by an on-farm method, 83% by any method including laboratory measurement. Eight producers performed DM analysis daily for 21 days using a Farmex 1210 Electronic Silage Tester (on-farm) and they recorded precipitation; matching samples were analyzed for DM in a laboratory after oven drying ("standard" method, 55°C followed by 100°C) and by using a Farmex 1210 (laboratory). The standard deviation of mean silage DM varied from 0.72% to 3.33% DM, depending on farm. The electronic method compared poorly to standard DM analysis for most farms.