Heat Stress Abatement in Dry Cows: Does Cooling Improve Transition Success? Bruno Amaral, Ph.D. Dairy Nutritionist & Technical Services Vita Plus Corporation Award 1
Outline Introduction Effects of heat stress on dry cows Milk production and components Immunity Mammary gland cell proliferation Summary Questions Introduction Can you increase milk production in your herd without changing ingredients and cost of the ration? 2
Definition of Stress Tension resulting from factors that tend to alter an existent equilibrium It refers to the consequence of the failure of an organism human or other animal to respond adequately to mental, emotional, or physical demands, whether actual or imagined Stress 3
Stress Stress in China 4
Heat stress Introduction Heat Stress 5
Effect of Heat Stress on Lactation Adapted from Collier et al., 2006 Effects on Heat Stress Dry Cows 6
Heat Stress Dry Cows Florida studies Experiment 1 Experiment 2 Experiment 3 COOL HOT 2 PVC water line on 8 2 PVC solenoid + timer Feed alley Fan Air flow direction 2 PVC water line on 8 2 PVC solenoid + timer HOT COOL 7
Experiment 1 Calan Gates 8
Calan Gates Fans and Sprinklers On: 71 o F Sprinklers On for 2 min Every 5 min 9
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Milking Cows After calving All cows were housed in a free stall barn with cooling (fans and misters) Rectal Temperature ( C) 39.4 39.2 39.0 38.8 38.6 38.4 38.2 Heat Stress Increases Rectal Temperature of Dry Cows 101. 6 o F 101.3 o F Morning Treatment Effect; P<0.05 102. 6 o F Time a 101. 8 o F b Heat Stress Cooling Afternoon do Amaral et al., 2009 16
Calf Body Weight Heat Stress: 68.3 lbs Cooling: 97.0 lbs 28.7 lbs (42%) Dry Matter Intake 17
Cooling Cows Prepartum Improves Milk Production in the Subsequent Lactation 3.5% FCM (Lbs/d) 100 80 60 40 20 0 * * * * * * * * * * * * * * * * 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Week of lactation 20.5 lbs of 3.5% FCM do Amaral et al., 2009 Milk Components Variable Heat Stress Cooling P-Value Fat, % 3.5 3.9 0.07 Protein, % 3.2 3.0 0.62 Fat yield, lb/day Protein yield, lb/day 1.98 2.87 0.01 1.76 2.204 0.09 18
Experiment 2 Second year of experiment 1 Same set up Consecutive year Experiment 2 do Amaral et al., 2010 19
Calf Body Weight Heat Stress: 87.0 lbs Cooling: 98.0 lbs 12 lbs (12.6%) Dry Matter Intake DMI, % BW 3.5 3.0 2.5 2.0 1.5 * 1.0 0.5 0.0-42 -28-14 0 +14 +28 +42 Time relative to calving, d 20
Experiment 2 FCM 3.5% FCM,Lbs/d 100 80 60 40 20 0 10.3 lbs of 3.5% FCM 0 2 4 6 8 10 12 14 16 18 20 Week of lactation * * * * * * * * do Amaral et al., 2010 Milk Components Variable Heat Stress Cooling P-Value Fat, % 3.30 3.80 0.01 Protein, % 2.90 2.80 0.41 Fat yield, lb/day Protein yield, lb/day 2.20 2.87 0.02 1.98 2.20 0.67 do Amaral et al., 2011 21
Immunity Neutrophils: A First Line of Defense Healthy animal Stress immunosuppressed Proliferation and invasion of pathogens Sources: Burton and Erskine (2003); Forsberg (2004) 22
Neutrophil Neutrophil Phagocytosis 23
Heat Stress Reduces Neutrophil Phagocytosis Phagocytosis, % 100 80 60 40 20 0 Treatment by day interaction P = 0.02-46 -20 +2 +20 Time relative to calving, d do Amaral et al., 2011 * Oxidative burst, % 100 80 60 40 20 Heat Stress Reduces Neutrophil Oxidative Burst 0 Treatment by day interaction P = 0.02-46 -20 +2 +20 Time relative to calving, d do Amaral et al., 2011 * * 24
Lymphocyte Type of white blood cells Innate immune system Lymphocyte Proliferation do Amaral et al., 2010 25
Effect of Heat Stress on IgG Response to Ovalbumin Challenge Immunoglobulin G, OD 0.8 0.7 0.6 0.5 0.4 * * 0.3 0.2 0.1 0.0-46 -32-21 0 +7 +14 +21 +28 +35 +42 Time relative to calving, d do Amaral et al., 2011 Experiment 3 Same set up Third consecutive year Mammary gland investigation 26
Temperature and Humidity Index THI 82 80 78 76 74 Heat Stress Cooling 72 70 Time of Day (h) Rectal Temperature and Respiration Rate Vita Rectal Plus Temperature Dairy Summit ( C) 2011 39.6 39.4 39.2 39.0 38.8 38.6 38.4 38.2 Treatment effects: AM: P < 0.0001, PM: P < 0.0001 Heat Stress Cooling 38.0 AM Time PM 27
Water Intake Water Intake (gallon/day/cow) 14 12 10 8 6 4 2 0 Heat stress Cooling Calf Body Weight Heat Stress: 91.7 lbs Cooling: 102.4 lbs 10.7 lbs (11.6%) 28
Dry Matter Intake DMI (Lbs/d) 50 45 40 35 30 25 20 15 10 5 0 Treatment effects: Prepartum: P = 0.03 Postpartum: P = 0.9 Heat Stress Cooling Days Relative to Calving DMI/BW (%) 3.5 3.0 2.5 2.0 1.5 1.0 0.5 Dry Matter Intake Treatment effects: Prepartum: P = 0.86 Postpartum: P = 0.69 Heat Stress Cooling 0.0-32 -18 0 14 28 42 Days Relative to Calving 29
Milk Production Milk Production (Lbs/d) 100 80 60 40 20 11.02 lbs of milk * * ** * Treatment effect: P < 0.03 *P < 0.05, **P < 0.01 * * * * * * * * * * Heat Stress Cooling 0 1 4 7 10 13 16 19 22 25 28 31 34 37 40 Tao et al., 2011 Weeks Relative to Calving Milk Components Variable Heat Stress Cooling P-Value Fat, % 3.58 3.52 0.57 Protein, % 3.01 2.87 0.01 Fat yield, lb/day Protein yield, lb/day 2.25 2.56 0.06 1.92 2.11 0.17 Tao et al., 2011 30
Does Heat Stress Abatement in Dry Cows Improve Transition Success? Milk Production (Lbs/d) 100 80 60 40 20 * * ** * 3.5% FCM (Lbs/d) * 100 0 1 4 7 10 13 16 19 22 25 28 31 34 37 40 Weeks Relative to Calving 80 60 40 20 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Week of lactation * * * * * * * * * Heat Stress Cooling Experiment 3 Mammary Gland Development 31
Mammary Gland Biopsies Mammary Gland 32
Mammary Gland Epithelial cells Stroma cells Proliferation Rate (Ki67 Labeling) Alveolar Lumen Stroma cells Epithelium cells Heat Stress Cooling 33
Heat Stress Abatement Increased Mammary Epithelial Cell Proliferation In the Dry Period Ki67 labeling, % (% of baseline) 4.0 3.5 3.0 2.5 2.0 1.5 1.0 * -20 Day Relative to Calving ** * P < 0.05 ** P < 0.01 Heat Stress Cooling 0.5 0.0 Epithelium Stroma Total Milk Fall Slump 34
Seasonality Effects on Milk Production Milk per cow (1998-2002 NASS) York Iowa New York 51.00 49.50 50.00 49.00 48.00 47.00 46.00 45.00 1 2 3 4 2 nd Quarter- (April-June) Highest milk per cow 49.00 48.50 48.00 47.50 47.00 46.50 46.00 45.50 45.00 1 2 3 4 Minnesota Michigan Wisconsin 50.00 49.00 48.00 53.50 53.00 52.50 49.00 48.50 48.00 47.50 47.00 46.00 52.00 51.50 47.00 46.50 46.00 45.00 44.00 43.00 1 2 3 4 51.00 45.50 45.00 50.50 44.50 50.00 44.00 1 2 3 4 1 2 3 4 Seasonality Effects on Milk Production Milk per cow (1998-2002 NASS) York Iowa New York 51.00 49.50 50.00 49.00 48.00 47.00 46.00 45.00 1 2 3 4 4th Quarter- (Oct. Dec.) Lowest milk per cow 49.00 48.50 48.00 47.50 47.00 46.50 46.00 45.50 45.00 1 2 3 4 Minnesota Michigan Wisconsin 50.00 49.00 48.00 47.00 46.00 53.50 53.00 52.50 52.00 51.50 49.00 48.50 48.00 47.50 47.00 46.50 46.00 45.00 51.00 50.50 45.50 45.00 44.00 43.00 1 2 3 4 44.50 50.00 44.00 1 2 3 4 1 2 3 4 35
Milk Fall Slump 3.5% FCM (Lbs/d) 100 80 60 40 20 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Week of lactation Take Home Message Heat stress abatement in dry cows improves transition into lactation by Increasing mammary cell proliferation Milk production Immune function 36
Questions Dry cows are one of the most important group of cows at your farm. Emphasis on transition success is the key 37