Small-Scale

Dairy Farming Manual

Volume 1

Technology Unit 1

Milk Composition - part 3

Lactation Period

The composition of the milk varies throughout the lactation cycle. During the first days of the laceration cycle composition of the milk varies a lot from the resting period. The milk which is secreted during the first days after calving is called colostrum; it has an increased content of protein and ash. Colostrum contains 20-30% dry matter. The variations in milk in the remaining lactation cycle is shown in Figure 3. Together with increase in fat content , the content of the protein and ash also increase mainly due to an increase in the salt content.

Figure 3: Variations in milk Composition During the Lactation Period.

Right after calving, the milk is called Colostrum milk:

	Water	Fat	Protein	Sugar	Salts
at birth after 12 hrs. after 24 hrs. after 48 hrs.	66,4 79.1 84.4 86.0	6.5 2.5 3.6 3.7	23.7 13.7 7.1 4.9	2.1 3.5 4.2 4.4	1.4 1.1 1.0 0.9

Colostrum milk cannot be delivered to the milk factory. About 3-5 days after calving the milk will have reached its normal composition.

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What affects milk composition ?

Lactation Period

47 Right after calving,

your cow gives colostum milk.

You cannot deliver this to the milk collecting centre.

48 After 4-5 days

the composition is normal

and you can deliver your milk.

49 Compare the differences in milk

- at birth and

- after five days.

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Time of Milking

Cows are normally milked twice a day: early morning and late afternoon. Milk obtained at the morning milking is much lower in fat (e.g. 3 percent) than at the afternoon milking (e.g. 5 percent).

This is not because fat secretion is reduced in the longer night interval but because there is a net carryover of residual milk rich in fat from the night to the day interval.

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Time of Milking

50 Morning milk has

lower fat content (about 3 parts in 100 )

than evening milk (about 5 parts in 100 ).

Type of Milk
51 There are many types of milk.
Three major types are:

	Fat Content	Energy	Vitamin A and D
Whole Milk		High	High
Low fat Milk		Medium	Medium
Skim Milk		Low	Low

All three kinds contain almost the same amount of protein.

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Type of Animal

Table 2 gives representative values for the main constituents of nutritional importance of the milk of humans and the milch animals. The composition of milk not only differs from species to species but varies widely within any one species and even within breeds or races of one species. Many factors determine composition: physiological variability of the individual, nutrition, stage of lactation, age, season of the year, amount of milk produced - to name only a few. It is clear, therefore, that the values given in the tables can only serve as a general guide and departures from them will be found in quite normal individual animals or herds. The main milch animals have been bred for centuries to produce quantities of milk far in excess of the amounts needed by their young. The milk of these domesticated and highly specialized animals retains the main characteristics of that of the wild stock. As a rule, however, the milk given in much smaller quantity by the wild or less domesticated animals is "richer" in that it contains more nonfatty solids and often more fat. The cow is more generally used throughout the world than any other milch animal and more is known about its milk, hence the examples quoted for it in the tables are likely to be more accurate.

Species

Fat

Solids
(nonfat)

Protein
(Nx6.38)

Lactose
(Anhydrous)

Calcium

Physiological
energy

g / 100 g

Calories/100g

Human

Cow:
Friesian
Guernsey

Buffalo:
Indian

Goat
Ewe
Mare
Ass
Camel
Yak
Llama
Reindeer

4.62

3.50
4.65

7.45

4.50
7.50
1.60
1.50
4.20
7.00
3.20
22.50

8.97

8.65
9.10

9.32

8.70
10.90
8.50
8.60
8.70
10.90
10.30
14.20

1.23

3.25
3.65

3.78

3.30
5.60
2.20
2.10
3.70
5.20
3.90
10.30

6.94

4.60
4.70

4.90

4.40
4.40
6.00
6.20
4.10
4.60
5.30
2.40

0.03

0.115
0.13

0.19

0.13
0.20
0.09
0.08
-¹
-
-
-

62
75

100

71
105
47
46
70
100
65
250

Table 1: Representative values for some major constituents of
good quality milk of different species

¹ In the table a dash (-) denotes lack of information or unreliable information.

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Type of Animal

52 Milk from different animals has different compositions ( g/100g ).

	Fat Content	Solids-not-fat	Note
Human	4.6	9.0
Pure breed cow	3.5-5.0	8.5-9.0	Rich in vitamin A poor in vitamin B
Zebu cow	5.0-5.5	8.5-9.0	Higher fat content Lower yield
Goat	4.5	8.7	Smell unpleasant, boil soon after milking
Ewe	7.5	10.9	Curdles sooner than cow's milk, cheese matures slower
Mare Ass Camel Yak Llama Reindeer	1.6 1.5 4.2 7.0 3.2 22.5	8.5 8.6 8.7 10.9 10.3 14.2

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Other Factors
The following also affets the composition of milk.

53 Breeding

54 Feeding

55 Hygiene

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56 Health

Age

57 Temperature

58 Handling

Ask your extension worker for advice about these factors.

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What do you know about milk composition ?

Reasons for drinking milk

1. Energy	( 5)
2. Health	(6-7)

Preparation of milk

1. Liquid at room temperature	( 9 )
2. Yellowish-white colour and sweetish smell	( 10 )
3. Freezes at slightly lower temperature than water	( 11 )
4. Slightly heavier than water	( 12 )

Composition

1. Fats	(14-21)
2. Proteins	(22-27)
3. Enzymes	(28-31)
4. Lactose	(32-35)
5. Vitamins	(36-38)
6. Minerals	(39-40)
7. White corpuscles	(41-42)
8. Bacteria	(43-46)

Factors affecting milk composition

1. Lactation period	(47-49)
2. Time of milking	(50)
3. Type of milk	(51)
4. Type of animal	(52)
5. Other factors	(53-58)

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