Cow Under a Hot Tin Roof (Heat Stress & Heat Abatement Strategies)

Transcription

1 Cow Under a Hot Tin Roof (Heat Stress & Heat Abatement Strategies) PRO START TRAINING June 16, 2017 R. Tom Bass, II, DVM, PhD Renaissance Nutrition, Inc.

2 Overview Heat stress facts and figures Current and future effects of heat stress on: Milk production Herd health Reproduction Heat abatement bottlenecks & opportunities Facilities /management Nutrition

3 How Do Cows Exchange Heat? Conduction (heating soup on an electric stove) Direct transfer of heat between surfaces Radiation (why you don t leave a dog or child in a hot car) Primary means of gaining heat when in direct sunlight Convection (using your Koster tester) Air flow, fans! Evaporation (why you re cold when you get out of the pool) Panting, sweating Enhanced by air flow

4 The significance of heat stress is often underappreciated

5 Effects of Heat Stress by the Numbers 3 Fahrenheit Potential cow body temp. after 20 minutes in holding pen 4 Pounds of milk production lost for each 1 F in body temp. above normal; also months of year w/above avg SCCs 6-16% DMI loss among heat-stressed cows 68 Updated THI where dairy cows begin to experience production losses from heat stress (old THI was 72) 4,500 BTUs produced/cow/hour at 65 lb milk with air temps. > 80 F (about like a 1500W hair dryer blowing continuously on high setting!) 1,000 BTUs removed from a cow for every 1 pound of water evaporated off her back 73 $ lost per cow annually in PA as a result of heat stress ( $40 million) 810,000,000 Potential annual $$ loss to the US Dairy Industry if no dry cow cooling were done

6 Updated THI for Lactating Dairy Cows (Zimbleman & Collier, 2011) Milk Losses: ~ 2 lb ~ 6 lb ~ 8+ lb VERY, VERY BAD!

7 Cow Cooling Priority List (edited from John Smith, KSU) 1. Provide adequate drinking water 2. Provide shade 3. Reduce parlor walking distance 4. Reduce time in the oven (a.k.a.- holding pen) - <45 min-1 hr per milking 5. Improve ventilation 6. Add holding area (and exit lane) cooling 7. Cool all dry cows 8. Cool fresh/early lactation cows 9. Cool mid- and late lactation cows

8 How Do Cows Say They re Hot? Rectal temperatures higher than F Breathing rate greater than 70 per minute Increased standing time, water trough loitering, etc. DMI drop of 10% or more in hot weather Decreased cud chewing Production drop of 10% or more in hot weather (typically, the higher they are, the farther they may fall) Increased death rate (assoc. with min. daily THI>70 or max. daily THI >80)

9 Ever See Cows Doing This??

10 How about this??

11 Effects on milk production Dependent Upon: Heat abatement Level of production Humidity and night cooling Herd demographics Novelty and tolerance??? Secondary heat-related contributors

12 Peak Milk Production by Lactation and Month /1 2/1 3/1 4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1 12/1 Test Dates Peak Milk L1 Peak Milk L2 Peak L3+ lbs of Milk Per Cow Slide courtesy of Dr. Bruce Clark, Monsanto Dairy Business

13 Effects on Reproduction Reduced activity and duration of estrus Reduced follicular development and growth Reduced oocyte quality Reduced semen quality and bull fertility Reduced conception rates Increased multiple ovulations and twinning incidence Increased early embryonic death Decreased uterine blood flow LOWERED PREG RATE Each 0.9 F in uterine temp. conception rate by 12.8% Residual effects may last 60+ days beyond the heat stress period.

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15 Effects of Increasing THI on EED Pregnancy loss rates for different maximum daily temperature-humidity indices (THI) during days 21 to 30 of gestation (adapted from Garcia-Ispierto et al., 2006).

16 90-day non-return rate (%) < 10,000 lb 10,000-20,000 lb > 20,000 lb

17 Where is the herd located?

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19 Where is the herd located?

20 Hot Weather Repro Strategies Get virgin heifers bred Use inexpensive semen Use higher ECR bulls GnRH at time of AI? Employ embryo transfer More use of TAI programs PG-3-G presynch?? Kansas data, 2012

21 Heat Stress-Repro Summary Comments NO geography is immune Effects are dose & duration dependent Better heat abatement = less impact Less heat stress = faster rebound More lameness = slower rebound May be more negatively affected than milk production When do all those cows finally get bred and then calve?

22 What time of year do we see the greatest problem with lame cows? 4 yr WI study: 2 mo. lag between peak temp. and peak development of claw horn lesions 2005 FL study: peak occurrence in Aug, Sept It is not uncommon to observe a high incidence of foot problems subsequent to a hot summer dairy farmers and herdsmen routinely complain about an increase in lameness during the months of August, September and October. - Jose Santos, DVM, UC-Davis

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24 HEAT STRESS Interaction of Fall Lameness Risk Factors Other factors: Low BCS Calving Infection Leg & Hoof Conformation NUTRITION FLOOR SURFACE, SLOPE & STANDING TIME (CONCRETE & COW COMFORT)

25 Cow comfort is the most important factor determining prevalence of lameness in a dairy herd Nigel Cook, BVSc, MRCVS UWSVM Source: 2006 AABP Proceedings

26 Number of Lameness Cases Effect of Standing Time on Number of Lameness Cases % Time Standing Galindo and Broom, 1994

27 Cud Chewing Decreases in Hot Cows Source: M Haan, PSU. Data from a Southeastern Pennsylvania 100-cow tie stall herd from July 7 through October 15, 2016.

28 Commonly Observed Problems 1. Improper fan placement Location, angle, height, direction Improper fan selection

29 Fan Considerations Target air flow: 5-7 mph ( fpm) Each foot of fan diameter covers 8-10 feet of cow area (linear distance) Work with prevailing wind, not against it Usually the best fan option for cooling cows (box or basket fans)

30 Source: C. Gooch, Cornell U.

31 Source: C. Gooch, Cornell U.

32 HVLS Fans Higher initial cost, lower operating cost diameter, $3K-5K per fan Difficult to install where needed (over cows) Air flow: mph No data to suggest newer blade designs are an improvement Double-sided air flow? Better than nothing, but better options probably exist Good for bird control Fan Options

33 Cow Cooling?

34 Cow Cooling? Source: Kammel, et al, 2003 Desired air flow is 500+ fpm. Are the HVLS fans doing the job?

35 Cow Cooling? Desired air flow is 500+ fpm. Are the HVLS fans doing the job?

36 Cow Cooling? From 04 & 05 study in Georgia (Worley and Bernard, PAS, 2008) that compared HVLS fans & high press. foggers vs. 36 fans & high press. foggers over the free stalls & feed alley: HVLS-cooled cows were hotter HVLS fans generated lower air speeds ( mph) vs. 36 fans ( mph) in feeding and resting areas

37 Other Fan Facts Output (cfm s) is important 48 fans typically double the output of 36 fans Efficiency is probably more important Compare ratings generated by independent testing facility (e.g. BESS Lab at U. of IL) Advantages in operating efficiency (more cfm/watt) can add up to substantial cost savings over the life of the fan Can realistically expect $300-$750 net savings per fan over an 8 year life span

38 Clean the Fans!!! Dust/dirt on fan guards and louvers can performance by 40%.

39 Commonly Observed Problems 2. Inadequate system maintenance Dirty fans Inoperable fans Leaky spray nozzles Broken water lines 3. Insufficient system use Curtains up vs. down Fans not on Sprinklers not on

40 Commonly Observed Problems 4. Improper prioritization of heat abatement measures Fans vs. water Lactating cows vs. dry cows Barn vs. holding pen What is the proper order or prioritization??

41 Prioritization of heat abatement efforts 1. Holding pen 2. Transition cows 3. Dry cows 4. Early lactation cows 5. Mid, late lactation cows

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45 Holding Pen PPV System Utilize outside air, but lower velocity More uniform air distribution Water can still be incorporated More effective???

46 Do You Want to Cool Cows or Cool Air? Evaporative air cooling works best with low humidity 90º F and 50% RH: temp. by 12º F 90º F and 80% RH: temp. by 2º F Cool the air in dry climates, cool the cow in humid climates 1 pound water evaporated = 1000 BTU heat transferred (lost) Mister = cooled air Sprinkler/soaker = COOLED COWS What about conductive cooling?

47 Is Water Necessary to Cool Cows? KSU: THI = 80 (88º F and 57% RH) Attempting to cool cows with fans alone actually increased body temperatures! To effectively cool cows, combine: 1. Frequent wetting (conduction), with 2. Moving air (convection), to enhance EVAPORATION

48 Body temperature ( F) Hourly Temperature Data 7/7/08 to 7/10/ Fans F&S 1 F&S 2 Source: J. Currin, VMRCVM.

49 How do you effectively cool cows in the eastern US? Soak the cow to the skin, blow air over the cow to dry her off, repeat Low pressure (20 psi) soaker system Large droplets Edstrom controller to vary frequency Fans, fans, fans Orient barns east-west; 4-rows better than 6 Respiratory rates are a good proxy for body temperature >80 breaths per minute equates with body temps. 103 F

50 Misted Cows + Poor Air Flow = Potential Problems Source: Monsanto Dairy Business

51 Wet the Cow Down, Blow Air Over the Cow, Repeat Greater frequency = better cow cooling Temperature Sprinkler Cycle (1 min. on-time/cycle; ½-4 gpm flow rate) F 15 minutes F 10 minutes > 85 F 5 minutes Cows should be dried (or nearly so) each cycle

52 Feedline Soaker System Costs (2015, per John Sheets, Elanco) Edstrom Controller: $ Nozzles: $7-8 each Solenoids: 1 - $37, $80, 2 - $125 Pressure reducers: 1 - $75, $250, 2 - $350 Pipe & angle iron: $3/ft. System components (above): $3/ft. Labor for Installation: $3/ft. Total cost: approx. $9/ft.

53 Water- The Magic in a Cow Cooling System (J. Smith, KSU) Source: Monsanto Dairy Business

54 Water- The Magic in a Cow Cooling System (J. Smith, KSU) Source: Monsanto Dairy Business

55 Water- The Magic in a Cow Cooling System (J. Smith, KSU)

56 What about tie stall barns? Tunnel ventilation Evaporative cooling pads Conductive cooling?? Soakers???

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59 When Dry Cows Get Heat Stressed May calve 2-3 weeks early 3-5 days early is typical Reduced calf birth weight (8-15%), vigor, and survivability Calves produce significantly less milk once they begin lactating (Montiero, et al, 2013) Compromised immune function Increased retained placentas Decreased colostral quality and/or quantity (?) Reduced dry matter intake (8-22%) DECREASED MILK PRODUCTION

60 When Dry Cows Get Heat Stressed Florida Study (1982) Shaded Cows: 87.5 lb calf birth wt. 14,898 lb 305-d milk UNshaded Cows: 80.7 lb calf birth wt. 13,113 lb 305-d milk Israel Study (1988) Cooled Cows: 95.2 lb calf birth wt lb 150-d milk UNcooled Cows: 89.5 lb calf birth wt lb 150-d milk Failure to properly cool dry cows has recently (2016) been estimated to cost the US dairy industry $810 million annually.

61 Recent Research on Cooling Dry Cows Study Cooling Method (duration) Days Milk Measured Cows Cooled Cows NOT Cooled Cooling Advantage Mexico, 2006 California, 2006 Florida, 2008 Florida, 2009 Israel, Milk (lb/day) ---- Fans & water mist (D) Fans & shade to existing feed bunk sprinklers (PF) Fans & sprinklers (D) Fans & sprinklers (D) Feed bunk fans & foggers (D) Compiled by H. Dann, Miner Inst.

62 Effects of Dry Cow Cooling on Milk Production Source: S. Tao, UFL

63 What about calves born to heat-stressed cows?? Lower birth weights Compromised immune function Reduced IgG absorption efficiency Lower cellular immunity Greater pre-pubertal and 1 st lactation culling risk Lower fertility? PRODUCE 10 LB LESS MILK PER DAY DURING THEIR FIRST LACTATION

64 Heat Abatement Ideas for Calves Shade Water (intake can double from 70 to 90 F) Ventilation

65 Reflective Hutch Covers (

66 Commonly Observed Problems 5. Water issues with feed line soakers Mounting height, nozzle direction Excessive system pressure Insufficient water supply

67 Commonly Observed Problems 6. Insufficient drinking water availability

68 Water Recommendations 1. Provide a minimum of 2 water sources per group - At least 3 trough space per cow - 2 waterers per 100 cow increment (Gordie Jones) 2. Aim for a water depth of Provide 2 of linear trough space per cow per half parlor turn in return alley 4. Cleanliness is crucial! 5. Ensure water supply exceeds maximum water demand Can cows drink through straws? 6. No sippee cups or beef cow waterers in freestall barns 7. Two-foot holes

69 Commonly Observed Problems 7. Facility limitations Improper barn orientation (N-S vs E-W) Solid and/or low sidewalls (eave height) Lack of shade Tie stall barns Dysfunctional tunnel ventilated barns Improper or inadequate floor slope Insufficient electrical or lagoon capacity

70 Shade Critical to reduce cows radiational heat gain Don t forget feed bunks and waterers (Shaded resting area + unshaded feed bunk = decreased DMI) Orient freestall barns east-west Don t forget pastured (and dry lot) cattle Provide 60 ft. 2 per cow Orient pasture shade structures north-south Why the difference?

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73 Orient Freestall Barns East-West Source: Joe Harner, KSU

74 Source: Joe Harner, KSU Not North-South

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80 Ventilation- Design for it Barn Specs 4/12 roof pitch 4-row cooler than 6-row 14 min. sidewall (eave) height, 16 preferred Ridge vent width: 3 per 10 ft. of barn width 3 min. eave width All controls automated (timers, thermostats) Open(able) gables Open-fronted stalls Use topography to your advantage Avoid wind shadows Enhance air flow w/fans day AND night!

81 Economics of Heat Abatement Per 100 milking cows, assume: 5 lb milk lost per cow per day for 60 days due to controllable heat stress $15/cwt ($20/cwt) milk $4500 ($6000) lost income from reduced milk yield Impact on reproduction, milk components, and herd health not even factored in Break-even level of production loss is 3-4% Cow cooling will pay for itself in the first summer. Brian Perkins

82 Heat stress summary Hot cows: Freshen with more problems and/or poorer start-ups Experience more lameness Are more difficult to get pregnant & keep pregnant Are less productive & persistent Are more prone to metabolic and infectious disease ARE LESS PROFITABLE YOU LIVE WITH THE NEGATIVE EFFECTS FOR AT LEAST SIX MONTHS, if not year-round Winter to early spring is the time of year to improve your dairy s heat abatement measures!!!

83 Ration Additives for Hot Weather Yeast/yeast culture Benefits to rumen function & health AO Fungal extracts (Fiber-Force) Increased milk production in 6 of 14 trials Decreased rectal temps. in 4 of 12 trials OmniGen-AF? Several recent trials showing reduced body temps. or improved milk production in treated, heat-stressed cows DCAD elevators (Alka-products, Sweetlyte) Sources of Na+ and K+ that raise ration DCAD Elevated Zinc? May help w/ leaky gut syndrome, which is theorized to be a component of the detrimental effects of heat stress Rumensin What does it do and how does that align with the metabolism of heat-stressed cattle? Chromium (RenChrome) Several trials showing increased milk production & DMI Enhances glucose utilization, which is prioritized in heatstressed cows Niacin? data is varied; some evidence for increased sweating, fewer increases in milk production Betaine? Recent GA study (2016) showed pre-fresh feeding led to better start-ups in hot weather NUTRITIONAL STRATEGIES SHOULD BE SECONDARY TO FACILITY-RELATED HEAT ABATEMENT CONSIDERATIONS!!!

84 Effects of Feeding YC in the Summer Location Rations DMI (lb/day) Milk (lb/day) Feed Efficiency CA, 2010 Control YC GA, 2007 Control a 1.5 a YC b 1.6 b SD, 2004 Control a YC b IL, 2000 Control (Jerseys) YC a, b P 0.10 Slide adapted from J. Santos, 2012

85 Effects of Feeding YC in the Summer Average increase of 2.7 lb FCM across these 9 trials. C. Harms, 2013, Diamond V

86 Location Effects of Feeding Chromium to Heat-Stressed Dairy Cattle Chromium Suppl. DMI (lb/day) Milk (lb/day) Feed Efficiency Saudi Arabia, 2004 Control 43.0 a 65.7 a 1.53 (mid-lact.) Cr yeast Cr (4 mg) 46.7 b 73.1 b 1.56 Saudi Arabia, 2009 Control 49.0 a 71.5 a 1.46 (prefr-early lact.) organic Cr Cr (6 mg) 55.4 b 81.8 b 1.48 China, 2009 Control 38.8 a 53.5 a 1.38 (early lact.) Cr picolinate Cr (7 or 11 mg) 40.0 b 56.4 b 1.41 Iran, 2010 Control (early lact.) Cr-met Cr (6 mg) PA, USA, 2013 Control 62.8 a 96.6 a 1.54 (prefr-early lact.) Cr prop Cr (8 mg) 67.7 b b 1.56 a, b P 0.05

87 Rationale for Higher DCAD in Hot Weather Panting: causes cow s blood to become more acidic, increases K + loss, more drooling Less cud chewing: less salivary buffer produced Increased sweating: loss of more Na + and K + Increased urination (resulting from increased drinking): additional K + losses Encourages increased butterfat production

88 Summary of DCAD Research (Lactating Cows) Elevating DCAD: Increases dry matter intake (2-7* lb) Increases milk production (2½-12* lb) Increases blood bicarbonate (buffer) concentrations Works best when Na + and K + are both used Works for both early* and mid-lactation cows Target: + 25 to +30 DCAD in hot weather

89 Mineral Sources to Increase DCAD K + potassium carbonate (DCAD Plus ) Na + sodium bicarbonate ( bicarb, baking soda), sodium sequicarbonate Why? Raises rumen ph Increases blood bicarbonate concentration Why not salt (NaCl) or KCl??

90 Nutritional Summary (adapted from Dr. Jose Santos, UFL) Feed cows more frequently during periods of heat stress Feed the highest quality (highest NDFd) forage available Minimizes the need for high-starch feeds Ration NDF should be a minimum of 31-33%; (min. undf of 8.75%??) When forage quality is a problem, replace part of the starch with a highly digestible NDF source Formulate diets with a moderate concentration of CP Determine the MP needs of the cows and formulate based on MP and essential amino acids Keep RDP at ~10-11% of the diet DM; monitor MUNs Keep Rumensin in the ration if at all possible Feed biotin +/- chelated trace mins for better foot health

91 Nutritional Summary (adapted from Dr. Jose Santos, UFL) Feed moderate to high (up to 5% of the diet DM) fat diets, but avoid excessive amounts of unsat. fatty acids Increase Na + and K + Add 1 to 1.2% of the total ration as sodium bicarbonate to increase the total Na + up to % Increase the K + content up to % with DCAD Plus Ration DCAD should be between +25 and +35 meq Mg + should be 0.36 to 0.4% in high K + diets Incorporate live yeast or yeast culture into the ration Improves production of fat-corrected milk Improves feed efficiency Reduces the risk of rumen acidosis

92 Thank You! Any Questions???