Optimize your feeding

program to maximize

milk quality

John K. Bernard, Ph.D., P.A.S., Dipl. ACAN

Animal & Dairy Science Department

University of Georgia – Tifton Campus

The relationship of nutrition and milk quality

has been recognized for a long time.

Curtis et al. 1985. J. Dairy Sci. 68:2347-2360.

Feeding and Milk Quality

Nutrition affects milk quality primarily through it role in maintaining an optimized immune system and the prevention of metabolic disease (stress).

This relationship is not limited to ration formulation, but includes management factors related to the day-to-day feeding and management of animals which may have as much impact as any other factor related to nutrition!

Feeding and Milk Quality

To optimize immune function and optimize milk quality (as well as production and reproduction), we must strive for consistency to deliver a balanced nutrition diet and have a proactive nutritional management program!

Feeding and Milk Quality

There are no magic ingredients, additives,

or supplements that will completely

prevent or cure milk quality issues!

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NUTRITION

Feeding and Milk Quality

There are nutrients and additives that

have been shown to improve immune

function and lower SCC or reduce the rate

of new intramammary infections.

Feeding and Milk Quality

It is also important to avoid self inflicted

problems by overfeeding select nutrients or

depending on select additives.

NRC Recommendations

Nutrient Units Early dry Close-up Lactation

Copper PPM 12 13 11

Iron PPM 13 13 17

Manganese PPM 16 18 13

Zinc PPM 21 22 52

Selenium PPM 0.3 0.3 0.3

Vitamin A IU/d 80,300 82,610 75,000

Vitamin D IU/d 21,900 21,530 21,000

Vitamin E IU/d 1,168 1,202 545

Feeding and Milk Quality

Supplementation that reduces oxidative

stress and supports a viable immune

system has a greater potential for reducing

the risk of mastitis and lowering somatic

cell counts in milk.

Antioxidant role of trace minerals

and vitamins

Nutrient Component Function

Vitamin A β-carotenePrevents fatty acid peroxidation chain

reactions

Vitamin C Ascorbic acid Radical scavenger

Vitamin E α-tocopherolDisrupts fatty acid peroxidation chain

reactions

Selenium Thioredoxin reductaseRedox signaling and reduces reative

oxygen species

Selenium Glutathione peroxidaseRedox signaling and reduces reative

oxygen species

Copper Ceruloplasmin Oxidase activity; peroxyl radical scavenger

Copper, Zinc,

ManganeseSuperoxide dismutase Converts superoxide to hydrogen peroxide

Iron CatalaseEnzyme that converts hydrogen peroxide

to water

Selenium and Vitamin E supplementation

and incidence of mastitis

0

5

10

15

20

25

30

30 60 90 150 210 305

Days in milk

Cu

mu

lative

No

. o

f clin

ica

l ca

se

s Control Supplemented

Smith et al. 1984. J. Dairy Sci. 67:1293-1300.

Selenium and Vitamin E

Increased concentrations of one does not substitute for a deficiency of the other. Both must be supplemented to meet minimum NRC requirements.

Availability of Se from organic selenium sources is higher

Amount of Vitamin E required is proportions to oxidative potential of rations (and water)

Other Supplements

• There are a number of supplements that

have research to support their use.

• Be sure to evaluate the research and the

conditions in which they worked.

Effect of supplemental Zinc

Item Control ZM SE P

Milk, kg/d 30.5 31.8 1.63 0.0001

ECM, kg/d 30.4 31.7 1.5 0.003

Fat, % 3.47 3.48 0.12 0.90

Fat, kg/d 1.06 1.10 0.05 0.03

Protein, % 3.14 3.11 0.02 0.17

Protein, kg/d 0.96 0.99 0.05 0.003

SCC, x103/mL 294 196 41 0.001

Summary of 10 trials with 180 to 400 mg Zn/d per head of Zn methionine complex.

Kellogg et al. 2004. Prof. Anim. Sci. 20:295-3010.

Immune modulatorItem Control IM P

DMI, kg/d 21.1 20.9 NS

Milk, kg/d 42.5 41.6 NS

Fat, % 3.73 3.80 NS

Protein, % 2.57 2.61 NS

SCC,

1,000 cells/mL 360 91 0.05

Bernard et al. 2015. unpublished.

Effect of different feeding rates of

enzymatically hydrolyzed yeast on SCC

Yuan et al. 2015. J. Dairy Sci. 98:3236-3246.

Supplements do not always work!

Results of research trials examining the role of supplemental trace minerals and/or vitamins do not always support improvements in milk quality.

Reasons for the lack of response may be related to factors associated with management, environment, or other nutritional deficiencies.

Transition Period

Cows that experience numerous pen changes (social stress) often have reduced immunity (reduced intake). When coupled with high nutrient demand to support milk production after calving (negative energy balance) lead to increased risk of mastitis!

How well the cows immune system adapts to all of these stressors and challenges determines how well she can fight any potential infection in the mammary gland!

Feeding and Milk Quality

Feeding management or diets that result

in greater risk of metabolic disease also

increase the risk of reduce milk quality.

Increased BHBA and NEFA as a result of

excess body weight/condition loss

Excess protein, salt, etc. which increases the

severity of udder edema

Stress associated with pen moves during

transition

Transition Cow Nutrition

The days just before and after calving are

the most challenging to the cow.

Maintaining nutrient intake is essential to

minimize any decrease in immune function

and avoid metabolic disease. This is

especially true during periods of heat

stress.

Effect of corn silage source beginning 3

wk prepartum through 3 wk postpartum

20

25

30

35

40

45

50

55

60

65

-3 -2 -1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Week pre- and postpartum

DM

I, l

b/d

Normal BMR

Stone et al. 2012. J. Dairy Sci. 95:6665-6676.

Treatments

Fed the same diet

Effect of corn silage source on health

disorders

Item Normal BMR P

Retained placenta 5 1 NS

Metritis 3 0 NS

Ketosis 1 0 NS

Ketosis with diarrhea 0 2 NS

Mastitis

wk 1-6

wk 7-15

3

7

2

4

Total, wk 1-6 12 5 0.009Stone et al. 2012. J. Dairy Sci. 95:6665-6676.

Transition Cow Nutrition

There are several approaches that are used to maintain intake and decrease metabolic disease postpartum:• Feeding a fully or partially acidified diet (negative

DCAD) prepartum

• Goldilocks diets (straw)

• Post-calving Ca supplementation

Key is to minimize the reduction in intake which leads to excess body weight loss and reduced immunity.

Feeding Management

Keys to providing a consistent diet and optimizing milk quality.

Quality forages

Work with nutritionist to design nutritional program that to optimize nutrition for your dairy

Good daily feeding management • Monitoring and adjusting DM content of ingredients

• Properly mixing and feeding

• Feed bunk management

• Monitoring cows and adjusting diets to avoid under/over body condition

• Regrouping of animals that minimizes stress

Summary

Nutrition does impact milk quality and

producers should work with their

nutritionist to develop and deliver a

consistent, balanced ration that will

optimize milk quality.

There are no supplements or additives

that will correct poor milk quality!

Summary

Feeding management programs that

maintains intake in the close-up dry cow

and transition cow will sustain the immune

system which should minimize milk quality

issues.

Questions