This study investigated the impact of metabolic disorders (milk fever and ketosis) and mastitis on dairy cow reproduction. The researchers found that milk fever was associated with increases in days to first service, services per conception, and a decrease in conception risk. Ketosis was linked to increases in days open and culling rates. Mastitis reduced pregnancy rates and increased abortion risk. The mechanisms by which these diseases negatively influence fertility include alterations in uterine function, ovarian blood flow, gastrointestinal motility, dry matter intake, and calcium absorption as well as increased inflammation.

1. Impact of Metabolic Disorders and
Mastitis on Reproduction
Amin Ahmadzadeh*, Joseph C. Dalton
Animal and Veterinary Science Department
University of Idaho

2. Introduction
 Reproductive disorders such as dystocia,
retained placenta, ovarian cysts and
metritis can decrease reproductive
performance of dairy cows
 The effects of other diseases, such as
metabolic disorders and mastitis, on dairy
cow fertility have not been quantified

3. Introduction
 The studies that have investigated the
relationship between metabolic
disorders, mastitis, and reproduction,
have only established associations and
were unable to infer causality
 Milk Fever
 Ketosis
 Mastitis

4. Hypocalcemia
 5.9% of U.S. Cows  Subclinically
(NAHMS, 1996)
present in up to 50-
65% of fresh cows
 Ketosis: 23.6 X
  Smooth Muscle
 Dystocia: 3 to7 X function
 Release of cortisol
 Retains: 4 X
accompanies (
 Mastitis: 5 to 8 X immune function)
 K and Na alkalinize
 DA: 2 to 4 X blood and alter Ca
Associate costs to producer ~$300

5. Milk Fever and Reproduction
Fourichon et al., (2000):
Days to 1st Service ↑ 5 days
Services per Conception ↑ 0.3 services
Days open & conception to AI No Change
Chebel et al., (2004):
Risk of Conception ↓ 2.25 X

6. Mechanism(s) of Action
 Alteration in uterine muscle function
 Slower uterine involution
 Reduced blood flow to the ovaries
 Indirect effects:
 dystocia
 retained placenta
 endometritis
reviewed in Mulligan et al., (2006)

7. Plan of Action
 Feed a balanced ration, especially during
the close-up period (3 to 4 weeks before
calving)
 Feed a balanced ration balanced for
dietary cation-anion difference (DCAD)
 Feed dietary potassium at recommended
levels
 Feeding anionic salts may be considered.

8. Ketosis
 Prevalence:
 12 to 14% in North American dairy cows
 7 to 32% worldwide (reviewed in Cook et al., 2001)
 Etiology:
 marked glucose insufficiency
 increased fat mobilization
 Increase in blood ketone bodies

9. Decrease in feed intake
(2 wks before and 3 wks after calving)
Mobilization of body fat
Increase in blood fatty acids
1) - EB & 2) Stress of calving
Liver overload and inhibition of FA oxidation
Accumulation of triglycerides within hepatocytes
Increased conversion of acetyl-CoA to
acetoacetate and -hydroxybutyrate

10. Ketosis and Reproduction
Fourichon et al., (2000):
 Days to 1st Service ↑ 2.5 days
 Days open ↑ 6 days
 Conception to 1st service ↓ ~ 4%
 Hazard ratio of
conception (56 to 120
days postpartum)
↓ 13.5 %
The effects of clinical ketosis on reproduction are
limited and show large variation in different
production systems.

11. Ketosis and Reproduction
Cook et al., (2001):
 Days open ↑ 54 days
 Increased Culling rate
Walsh et al., (2007):
Increased BHBA
↓ 50% likelihood
of pregnancy to
(1st-2nd wk postpartum)
1st AI

12. Health Problems in the First 60 DIM and
Pregnancy in Dairy Cows
Pregnant,
Health status Adjusted OR (95% CI) P
%
Healthy 51.4 1.00
Type of health problem
Calving problem 40.3 0.75 (0.63 – 0.88) < 0.001
Metritis 37.8 0.66 (0.56 – 0.78) < 0.001
Clinical endometritis 38.7 0.62 (0.52 – 0.74) < 0.001
Fever postpartum 39.8 0.60 (0.48 – 0.65) < 0.001
Mastitis 39.4 0.84 (0.64 – 1.10) 0.20
Clinical ketosis 28.8 0.50 (0.36 – 0.68) < 0.001
Lameness 33.3 0.57 (0.41 – 0.78) < 0.001
Pneumonia 32.4 0.63 (0.32 – 1.27) 0.20
Digestive problem 36.7 0.78 (0.46 – 1.34) 0.38
5,719 postpartum dairy cows evaluated daily for health disorders in seven dairy farms in the US

13. Health Problems and Pregnancy Loss in the First
60 d of Gestation in Dairy Cows
Health status Loss, % Adjusted OR (95% CI) P
Healthy 8.9 1.00 ---
Type of health problem
Calving problem 15.9 1.67 (1.16 – 2.40) < 0.01
Metritis 11.3 1.01 (0.71 – 1.60) 0.76
Clinical endometritis 15.1 1.55 (1.04 – 2.32) 0.03
Fever postpartum 18.0 2.00 (1.24 – 3.14) < 0.01
Mastitis 19.8 2.62 (1.48 – 4.64) < 0.001
Clinical ketosis 14.6 1.64 (0.75 – 3.59) 0.22
Lameness 26.4 2.67 (1.38 – 5.12) < 0.01
Pneumonia 16.7 1.87 (0.40 – 8.69) 0.42
Digestive problem 15.8 1.81 (0.52 – 6.32) 0.35
5,719 postpartum dairy cows evaluated daily for health disorders in seven dairy farms in the US.

14. Plan of Action
 Provide adequate dietary energy
 Minimize the reduction of dry matter intake
during the last 3 weeks prepartum
 Maximize dry matter intake after calving
 Avoid overcrowding cows, especially in fresh
cow pen
 Feeding additives such as niacin, calcium
propionate, propylene glycol, and rumen-
protected fat or choline, may be considered

16. Milk Fever Ketosis
Muscle Function Ovarian Blood GI Motility
Flow
Uterine Motility
DMI and Ca2+ Absorption
Dystocia Retained Placenta
(−)
BHBA
Uterine Infection
(−)
[ Fatty Liver
− EB
Inflammation
Cytokines
(−) (−)
(TNFα, IL’s., etc.)
(−)
Oocyte maturations, embryo
(−) Fertility
fertilization and development
Figure 1. Potential mechanisms by which milk fever and ketosis affect fertility.

17. Mastitis
Definition:
 Inflammation of the mammary gland
• trauma and (or) injury to the udder,
• infection due to microorganisms or chemical
irritation
Symptoms:
• decreased milk production
• alterations in milk composition and
appearance
• elevated body temperature
• swelling, redness, heat in infected quarters
and pain

18. Estimated Losses Due to Mastitis Once a Year
Item Dollar Loss per Cow
Reduced milk production $55 -121
Early cow replacement cost $30 - 40
Discarded milk $11- 35
Extra labor $1- 3
Drugs $7 - 12
Veterinary service $2 - 3
Total $106 - 214
Source: Winning the Fight Against Mastitis
Loss due to reproductive inefficiency

19. Percentage of cows by producer-
identified health problems
Health problem Incidence rate
(% of cows)
Clinical mastitis 16.5
Lameness 14.0
Retained placenta 7.8
Dystocia, metritis 3.8
Milk fever 4.9
Displaced abomasum 3.5
Ketosis* 3.7
 NAHMS, 2007 *From Jordan and Fourdraine, 1993

20. Change in health problems
1996 to 2007
18
16 1996
14 2002
12
Percentage
2007
10
8
6
4
2
0
Mastitis Lameness RP Dystocia Milk DA
fever

21. Does mastitis affect other physiological
functions?
 Thecost of mastitis reaches far beyond
the associated milk loss, drug and
veterinary costs, and labor
 Recent studies confirm that mastitis
has detrimental effects on reproductive
efficiency of dairy cows

22. Mastitis and Reproductive Performance
Moore et al., (1991):
 Negative correlation between clinical
mastitis and reproduction caused by
gram positive bacteria
 Cows experiencing clinical mastitis
were 1.6 times more likely to have an
altered inter-estrus interval than
healthy cows

23. Effects of Mastitis Type Before First Insemination on
DFS, DO, and S/C
Black : clinical; Gray : subclinical
Striped: subclinical to clinical Hatched: uninfected
Schrick et al. (2001)

24. Clinical Mastitis and Abortion
Risco et al., (1999):
 Infected cows within the first 45 days of
gestation were at 2.7 times more risk of
abortion as compared with uninfected
cows
Chebel et al., (2004):
 Cows having clinical mastitis between AI
and pregnancy confirmation were 2.8
times more likely to have an abortion than
those not experiencing mastitis

25. The effect of mastitis on reproductive performance in dairy cows
Source Reproductive Parameters Mastitis Uninfected
Barker et al. (1998a) Days open 114  10 92  4.6
S/C 1.6  0.3 1.7  0.1
Barker et al. (1998b) Days open 136  11 92  4.6
S/C 2.9  0.3 1.7  0.1
Schrick et al. (2001) Days open 110  6.9 85.4  5.8
S/C 2.1  0.2 1.6  0.2
Conception rate 48% 63%
Kelton et al. (2001) Conception rate 38% 46%
Santos et al. (2003a) Days open 165  5.7 140  3.7
S/C 2.6  0.1 2.6  0.1
Conception rate at 1st AI 22% 29%
Santos et al. (2003b) Days open 189  7.2 140  3.7
S/C 3  0.2 2.6  0.1
Conception rate at 1st AI 10% 29%

26. The effect of mastitis on reproductive performance in dairy cows
Source Reproductive Mastitis Uninfected
Parameters
Nava-Trujillo et al.
(2010 c)
Days open 187  8.6 144  7.5
S/C 2.35  0.2 2.21  0.2
Conception rate at 1st AI 49% 56%
Hertle et al. (2010) Gram negative infection: 80%
reduction in probability of
conception, if infection occurred
in the week after AI
Probability of conception Gram positive infection: 47%
reduction in probability of
conception, if infection occurred
in the week after AI
c. dual purpose breed under tropical condition

27. The Effect Of Mastitis on
Reproductive Performance in Dairy
Cows
Reproductive Mastitis Uninfected
Parameters
Days open 160 days 126 days
S/C 2.4 2.1
Conception rate 10 – 49 % 29 – 63 %

28. Health Problems in the First 60 DIM and
Pregnancy in Dairy Cows
Pregnant,
Health status Adjusted OR (95% CI) P
%
Healthy 51.4 1.00
Type of health problem
Calving problem 40.3 0.75 (0.63 – 0.88) < 0.001
Metritis 37.8 0.66 (0.56 – 0.78) < 0.001
Clinical endometritis 38.7 0.62 (0.52 – 0.74) < 0.001
Fever postpartum 39.8 0.60 (0.48 – 0.65) < 0.001
Mastitis 39.4 0.84 (0.64 – 1.10) 0.20
Clinical ketosis 28.8 0.50 (0.36 – 0.68) < 0.001
Lameness 33.3 0.57 (0.41 – 0.78) < 0.001
Pneumonia 32.4 0.63 (0.32 – 1.27) 0.20
Digestive problem 36.7 0.78 (0.46 – 1.34) 0.38
5,719 postpartum dairy cows evaluated daily for health disorders in seven dairy farms in the US

29. Health Problems and Pregnancy Loss in the First
60 d of Gestation in Dairy Cows
Health status Loss, % Adjusted OR (95% CI) P
Healthy 8.9 1.00 ---
Type of health problem
Calving problem 15.9 1.67 (1.16 – 2.40) < 0.01
Metritis 11.3 1.01 (0.71 – 1.60) 0.76
Clinical endometritis 15.1 1.55 (1.04 – 2.32) 0.03
Fever postpartum 18.0 2.00 (1.24 – 3.14) < 0.01
Mastitis 19.8 2.62 (1.48 – 4.64) < 0.001
Clinical ketosis 14.6 1.64 (0.75 – 3.59) 0.22
Lameness 26.4 2.67 (1.38 – 5.12) < 0.01
Pneumonia 16.7 1.87 (0.40 – 8.69) 0.42
Digestive problem 15.8 1.81 (0.52 – 6.32) 0.35
5,719 postpartum dairy cows evaluated daily for health disorders in seven dairy farms in the US.

30. Limitations
Previous field trial:
 None of the mentioned studies provides
information on whether cows with mastitis
also experienced other diseases
 Meta-analyses showed problems such as
RP, ovarian cysts, and metabolic disorders
negatively affected reproduction, but
mastitis had no effect on reproductive
performance Fourichon et al., (2000)
.

31. Study in Idaho
Objectives
To evaluate the effect of clinical mastitis and
(or) other diseases on reproductive
performance, and to test the effect of time of
clinical mastitis occurrence on reproductive
performance in Holstein cows

32. Materials and Methods
 Records from 963 lactating Holstein cows
(commercial dairy farm in Southern Idaho)
Groups:
Group 1 (n=50): cows with clinical mastitis and diseases
Group 2 (n=154): cows with clinical mastitis only
Group 3 (n=187): cows with diseases other than mastitis
Group 4 (n=572): healthy cows

33. Effect of Group on Days Open
180 a
160 a
140 155
Days Open
120 140 b
100 b
80 97
88
60
40
20
0
Mastitis + Mastitis Diseases Healthy
Diseases
Groups
a,b Bars with different letters differ (P < 0.05).

34. Effect of Group on Services/Conception
a
3
Services/Conception
2.9 b
bc
2 c
2.1
1.9
1.6
1
0
Mastitis + Mastitis Diseases Healthy
Diseases
Groups
a,b,c Bars with different letters differ (P ≤ 0.05).

35. Effect of Group on Days in Milk at 1st Service
Days in Milk 1st Service
80
72
60 72 67
65
40
20
0
Mastitis + Mastitis Diseases Healthy
Diseases
Groups

36. Non-linear Regression for the Effect of Mastitis and Diseases
on the Proportion of Non-pregnant Cows by 224 DIM
100 MD
M
90
Predicted Proportion nonpregnant (%)
D
80 C
70
60
50
Healthy vs. MD and M
40
*Slope = P < 0.01
30 Asymptote = P < 0.01
20
10
0
56 77 98 119 140 161 182 203 224
Days in Milk Mast vs. Mast & Dis
Slope = P < 0.05
Asymptote = P > 0.5

37. Effect of Time of Clinical Mastitis
Occurrence on Days Open
200 *
180
175
*
140
150 *
Days Open
122
125
100 88
75
50
25
0
Mastitis < 60 d Mastitis 60-100 d Mastitis > 100 Healthy
Days Post-partum
* Different from healthy P < 0.01

38. Effect of Time of Clinical Mastitis
Occurrence on Services/Conception
*
Services/Conception
3
* 3.0
†
2 2.4
1.9
1.6
1
0
Mastitis < 60 d Mastitis 60-100 d Mastitis > 100 d Healthy
Days Post-partum
† Different from healthy P = 0.06
* Different from healthy P < 0.01

39. Probability of
Scenario Conception
3rd lactation cow, winter, 21%
after second AI
gram+ mastitis1 wk 11%
before 2nd AI
gram-negative mastitis 5%
in the wk after AI
Hertle et al. (2010)

40.  The value of this difference in conception for
a given situation can easily be weighed
against the cost of resources including
semen cost (especially if sexed semen is
used) and labor as well as other management
considerations including stage of lactation,
milk yield, and number of AI.

41. How does mastitis affect reproductive
performance on dairy cattle?

42. Mastitis Pathogens
Fever
Endotoxin
PGE
Cortisol Inflammation
(−)
FSH Cytokines
Estradiol LH (TNFα, IL’s., etc.)
(−)
LHr
Follicle (−)
Fever PGF2 (−) Nitric Oxide
CL
(−) (−) (−)
Progesterone
Oocyte maturation, embryo
fertilization and
development
Embryonic loss, Abortion
Figure 3. Potential mechanisms by which mastitis affects fertility.

43. Bottom Line
 Clinical mastitis alone affects reproductive
performance and these effects are more
evident when cows experience both mastitis
and diseases
 While producers should manage mastitis at all
times, extra attention should be taken when
clinical mastitis occurs during AI period and
pregnancy establishment

44. Take Home Message
 The e disorders can increase the risk of other
metabolic disorders as well as several
reproductive maladies such as dystocia, retained
placenta, and metritis
 Disease prevention is the key to success.
Producers, veterinarians, nutritionists and farm
consultants should not only focus on disease
outcomes, but also review 'up-stream' factors
such as management practices, nutritional
regimens and health status, especially during the
transition period

45. Be Aggressive in Systematic
Breeding Protocol
Initiation of the
Set up injection protocol 1st Breeding
~ 50 days ~ 75 days
in milk ~ 65 days, VWP in milk

46. Extra Attention to
Completion of Milking and Mastitis
Breeding Protocol
and AI
Management
Post-AI Until Pregnancy conformation
(~ 45 days)