Managing Heat Stress in the SE. Dr. Stephanie H. Ward Dairy Extension Specialist North Carolina State University

Transcription

1 Managing Heat Stress in the SE Dr. Stephanie H. Ward Dairy Extension Specialist North Carolina State University

2 Stand up! Meet two new people Ask their name and where they are from A quiz will follow

3 Heat stress results from: High temp High humidity No air movement Direct sunlight

4 Energetics Fecal Loss Urinary and Gas loss Heat Increment Production (Milk Yield) Gross Energy Digestible Energy Metabolizable Energy Net Energy Energy from feedstuffs Energy available to the cow Energy used by the cow Maintenance

5 Thermoneutral Zone (TNZ) TNZ is temperature where heat loss is minimized and energy can be used for production Milk yields TNZ for cows 5 to 20ºC 40 to 68ºF THI = 62

6 Heat Abatement

7 Fans Don t cool the air, move it over the cow faster Evaporative cooling Wet the cow or wet the air Use fans to cool Shade Prevent heat from direct sunlight Options for conventional and grass based dairies Heat Abatement

8 SQMI Farm Data Farm Survey Questions related to heat abatement and milk quality Season Fan availability/use criteria Evaporative cooling/use criteria Feeding and nutrition

9 SQMI Farm Data SCC was lowest when fans were available in housing and parlor Highest when only available in housing Fan Availability Fan Availability Housing Parlor Parlor + Housing

10 SQMI Farm Data Criteria used to turn fans on (temperature, visual observation, or always on/off) did not affect SCC Temperature criteria did Temperature ON/OFF 0 Temperature < >80 OBS

11 SQMI Farm Data Using evaporative cooling did reduce SCC Criteria for use did not Evaporative Cooling 0 Evaporative Cooling None Misters Soakers Other

12 SQMI Farm Data Temperature on/off did affect SCC Temperature ON/OFF Temperature < >85

13 Heat Abatement Mechanical heat abatement is necessary to reduce temperature non-evaporative and evaporative cooling Nutritional changes can help offset loss in production

14 #SquadGoals Goal #1: Maintain nutrient intake Goal #2: Encourage water intake Goal #3: Maintain BCS

15 Heat Stress and DMI NRC (1989) predicts: 10%* decline in DMI when AT increases from 68 to 95ºF NRC (2001) predicts: 8%* decline in DMI when AT increases from 68 to 95ºF Industry says up to 20% decrease in DMI *Based on 1300lb cow producing 60lbs FCM

16 Goal # 1 Maintain Nutrient Intake Increasing feed offered can help Offering more feed at PM than AM may encourage intake Remember heat increment? Offer more fiber can increase heat of digestion Change ration profile 50% Forage/50% Concentrate Use best quality forages in high producing cows Maximize digestibility of the ration

17 Item Goal #1 Maintain Nutrient Intake Added Hay Environment Control Low Medium High Effect DMI, lb/d Cool L** Hot L* Hot- adjusted L W** Milk, lb/d Cool L Hot Q* Hot- adjusted L W* Cows fed increasing NDF (Bermudagrass Hay) decreased DMI during hot and cool weather Effects disappeared when hot weather DMI were adjusted for cool weather treatment effects West et al., JDS Suppl 78(1)

18 Goal #1 Maintain Nutrient Intake Carbs Mixed Fats P< Energy Balance, kj/kg MBW 38 a 103 b 76 ab 0.01 Milk yield, kg/d Milk fat, % 3.86 a 4.10 ab 4.16 b <0.01 Milk Protein, % BHBA, mmol/l 0.63 a 0.73 b 0.76 b 0.01 SCC x a 3.67 a 4.25 b 0.01 Addition of carbohydrates reduced NEB and BHBA concentration Also reduced milk fat Limit fat to 5-7% of diet DM Van Knegsal, et al., 2007

19 Goal #1 Maintain Nutrient Intake Treatment Shaded Evaporative Cooled Effect LQ HQ LQ HQ DMI, lb/d C 3.5% FCM, lb/d P, C Rectal Temp Resp Rate High quality protein can also improve milk yields during heat stress Chen, et al., 1993

20 Electrolytes/Minerals/Probiotics Most commonly added to water trough Boss cows? Late coming out of parlor? New products designed to be added to feed Electrolyte plus combination of probiotcs

21 Bovine Bluelyte (TechMix) Electrolytes/Minerals Treatment Control Bovine BlueLite SEm P< Milk Yield, kg/d Fat, % Protein, % Lactose, % SNF, % SCS, % No change in MY or components or SCC Did improve heat stress Reduced resp rate and rectal temp Improved MY in first 5 days of lactation

22 Goal #2 Encourage Water Intake

23 Goal #2 Encourage Water Intake Mean Minimum Temperature ( F) MY (lb/d) DMI (lb/d) Gallons per day

24 Goal #2 Encourage Water Intake Lower temperature of water? Conflicted research Chilled water can increase DMI and MY Clean and adequate access is most important During hot months clean tanks 1x per week Keep shaded if in pasture

25 Goal #2 Encourage Water Intake Easy access and plenty of space In return alleys 2 ft per cow In housing 2 waters per group 4in linear water space per cow <50 ft distance Locate near housing and out of direct sunlight Reduce algae growth

26 SQMI Farm Data Type of ration fed Frequency of feeding/ push up

27 SQMI Farm Data Type of ration fed had significant effect on SCC Ration Type Ration Type TMR GRS

28 SQMI Farm Data Feeding frequency did not have an effect (P <0.15) Number of times feed pushed up per day did not have an effect Feeding Frequency Feeding Frequency 1x/d 2x/d 3+

29 SQMI Farm Data Fresh feed available after milking did reduce SCC Feed Availability Feed Availability YES NO

30 Take Homes TMR- decreases sorting, reduces impact of HS and improved SCC Offer fresh feed- increased DMI, offering after milking reduced SCC Reduce fiber in ration leads to greater DMI Cannot sacrifice fiber needed for health rumen or milk fat Balance minerals- adding electrolytes can offset loss through increased respiration Use nutrition to work beyond what mechanical heat abatement cannot do

31 Would Not BePossible Without This project is supported by Agriculture & Food Research Initiative Competitive Grant no from USDA National Institute of Food & Agriculture

32 2017 Annual Meeting Sponsors Platinum Diamond V Gold Dairy Farmers of America Silver Elanco VA State Dairymen s Association Zoetis Thanks for your support!

33

34 Grazing Supplement timing Grazing under pivot (last slide- lead in to Amanda)

35 Grazing Farm Data

36 Enzymes/DG

37 Enzymes/DG