Handling Sand-laden Manure

Transcription

1 Handling Sand-laden Manure Wesley C. Wright, P.E. October 22, 2015

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3 Free Stall Bedding Cows rest 10 or more hours per day Proper bedding should: Provide comfort Conform to cow s body Resist compaction and provide traction Maintain a low moisture content Inhibit bacterial growth

4 Bacteria in Bedding Inhibiting bacterial growth is crucial to cow cleanliness, udder health, and ultimately milk quality Major pathogens causing mastitis: Strep. Uberis Strep. Dysgalactiae Coag. Neg. Staphs. Coliforms Staph. aureus Strep. ag Mycoplasma Environmental Contagious

5 Bedding Bacteria Levels Minimal Risk Less than 300,000 cfu/g Moderate Risk 300,000 to 1,000,000 cfu/g High Risk Greater than 1,000,000 cfu/g

6 Organic Bedding Dried Manure solids Paper Straw Peanut Hulls Sawdust Shavings Crop Residue

7 Inorganic Bedding Gypsum Limestone Screenings Sand

8 Pros/Cons of Organic Bedding Pros: Readily available Low cost Absorbs moisture Cons: Supports growth of environmental mastitis pathogens Research has found <24 hours >1,000,000 cfu/g (high risk)

9 Pros/Cons of Inorganic Bedding Pros: Increases traction Inert Drains moisture Cons: Gypsum- could elevate H 2 S levels in manure slurry Limestone- prone to packing Sand- abrasive to equipment

10 Sand makes Good Bedding It s comfortable Provides excellent traction Limits bacterial growth Does not cause hock abrasions Can be recycled Easy to maintain in the Free Stall Barn

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27 Free Stall Barn Flush System

28 Free Stall Barn Flush System Targets Flush Velocity - >5 feet/second Flush Depth inches Contact time seconds Controlled by Flush rate - gallons/minute Flush Time seconds Slope of alleys Length and width of the alleys

29 Alley Length (ft) Alley Slope %

30 Alley Length (ft) Alley Slope %

31 Alley Length (ft) Alley Slope %

32 Alley Length (ft) Alley Slope %

33 Alley Length (ft) Alley Slope %

34 Alley Length (ft) Alley Slope %

35 Why recycle sand from sand-laden manure?

36 Why recycle sand? Scenario 300 Cows / Free stalls 30 lbs./day sand per free stall 3,300,000 lbs./year sand 1650 tons 70 tandem truck loads $600 per load for certified mason s sand $42,000 per year Over 10 years $420,000 1 inch of sand over 7 acres Fill a >2,000,000 gallon lagoon

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38 Recycling Sand Separation Lane

39 Sand Separation Lane Separation based on Density Water and manure - ~60 lbs. / cubic foot Sand - ~120 lbs. / cubic foot Dilution and Suspension High Velocity Flush Reduce the Velocity IF done correctly, sand settles and manure moves on in the flush.

40 Sand Separation Lane Recommended Targets: At least 150 feet in length Slope % Recommended Width feet Flush velocity at the end of the lane 1-2 feet/second Uniform grade sand - ~0.5 mm

41 Case Study Little River Dairy

42 Problems Free Stall Barn flush not getting the alleys clean Deposition in the Gravity Trench causing overflow No separation in the Sand Lane

43 Solution Free Stall Barn Flush

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45 Solution Gravity Trench

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48 Solution Sand Separation Lane

49 Sand Separation Lane Target Slope %

50 Target Sand Separation Lane

51 Sand Separation Lane Target Recommended Width feet

52 Target Sand Separation Lane

53 Sand Separation Lane Target Velocity at the end of the lane 1-2 feet/second

54 Target Sand Separation Lane

55 Sand Separation Lane Target Uniform grade of sand ~0.5 mm

56 Target Sand Separation Lane

57 Adjusting the Sand Lane Iteration 1 April 2014

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61 Adjusting the Sand Lane Iteration 2 June 2014

62 Long sweep 90 ⁰ 30 inch wide Flare throat with 3 energy disrupter blocks

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73 ASTM Range for Coarse Sand New Recycled Sand Old Sand New Sand 0.7 % Passing Sand Grain Size (mm)

74 % Organic Matter /9/2014 4/11/2014 4/14/2014 4/16/2014 6/13/2014 6/23/2014 6/25/2014 7/2/2014 7/9/2014 7/16/2014 7/28/2014

75 Recycled Sand Quality October 7, 2015 Sample 0.51% organic matter Milk - Somatic Cell Counts Indicator of cows immune response to pathogenic bacteria Monthly average over the last year 133,000 Normal - 100,000 US limit - 750,000

76 Remember Free Stall Barn Flush Slope - 3% Velocity - >5 feet/second Depth inches Contact time seconds Sand Separation Lane Velocity at end of lane feet/second Uniform grade sand - ~0.5 mm (Certified Mason s Sand)

77 Questions?