FACTORS AFFECTING FACTORS AFFECTING COMPOSTION COMPOSTION

OF MILKOF MILK

Dr. Mohammad Ashraf Paul Dr. Mohammad Ashraf Paul

Faculty of veterinary Sciences, Faculty of veterinary Sciences, Alusteng, KashmirAlusteng, Kashmir

Milk differs widely in compositionMilk differs widely in composition All milks contains the same kinds of All milks contains the same kinds of

constituents but in varying amountsconstituents but in varying amounts Milk from individual cows shows Milk from individual cows shows

greater variation than mixed herd greater variation than mixed herd milk.milk.

The variation is always greater in small The variation is always greater in small herds than in larger onesherds than in larger ones

In general, milk fat shows the greatest In general, milk fat shows the greatest daily variation , then comes protein daily variation , then comes protein followed by ash and sugarfollowed by ash and sugar

The factors affecting milk composition The factors affecting milk composition may be either may be either

Genetic or EnvironmentalGenetic or Environmental

GeneticGenetic

1.1. Species: Each sps. yields milk of a Species: Each sps. yields milk of a characteristic compositioncharacteristic composition

2.2. Breed: In general, breeds producing Breed: In general, breeds producing more milk, yield milk of a lower fat more milk, yield milk of a lower fat content and content and vice-versavice-versa

3.3. Individuality: Each cow tends to yield Individuality: Each cow tends to yield milk of a composition that is milk of a composition that is characteristic of that individual.characteristic of that individual.

ENVIRONMENTALENVIRONMENTAL1.1. Interval of milkingInterval of milking• A longer interval is associated with A longer interval is associated with

more milk with a lower fat contentmore milk with a lower fat content

Morning-evening-interval Morning-evening-interval shorter -more variation in shorter -more variation in fat.fat.

Evening-morning-interval Evening-morning-interval larger-lesser variationlarger-lesser variation

12-hour interval-equal-least 12-hour interval-equal-least variationvariation

SNF not affected muchSNF not affected much

2. Completeness of milking2. Completeness of milking Fore milk-low in fatFore milk-low in fat Stripping-higher fatStripping-higher fat Complete milking-fat test Complete milking-fat test

normalnormal Incomplete milking-lower Incomplete milking-lower

fat test.fat test.3.3. Frequency of milkingFrequency of milking No greater effectNo greater effect

4)4) Irregular milking:Irregular milking: Frequent changes in time and interval Frequent changes in time and interval

of milking-lower fat.of milking-lower fat.

5)5) Day-to-day milkingDay-to-day milking May show variations for the May show variations for the

individual cowindividual cow

6)6) Disease and abnormal conditionsDisease and abnormal conditionso Tends to alter the composition of milkTends to alter the composition of milk

especially when they result in a fall in especially when they result in a fall in yield.yield.

o Both fat & SNF are reduced eg. Both fat & SNF are reduced eg. mastitismastitis

7)7) Portion of milkingPortion of milkingo Fore milk low in fatFore milk low in fato Stripping highestStripping highesto Other milk constituents only slightly Other milk constituents only slightly

affected on fat free basis.affected on fat free basis.

8)8) Stage of lactationStage of lactationo First secretion after calvingFirst secretion after calving

( colostrums) - different from milk in ( colostrums) - different from milk in composition and general properties.composition and general properties.

o Gradual change from colostrums to milk.Gradual change from colostrums to milk.

9)9) Yield:Yield:o For an individual cow-there is a tendency For an individual cow-there is a tendency

for increased yields to be accompanied with for increased yields to be accompanied with lower fat testlower fat test & & vice-versa vice-versa

10 Feeding:10 Feeding:o Underfeeding- lower SNF; lower fatUnderfeeding- lower SNF; lower fato Low energy diet- lower SNFLow energy diet- lower SNFo Fat content and fat composition both Fat content and fat composition both

influenced by roughage (fiber) intake.influenced by roughage (fiber) intake.o Green pasture promotes high content of Green pasture promotes high content of

USFA (Oleic)USFA (Oleic)o Concentrates such as sunflower ,linseed Concentrates such as sunflower ,linseed

cake give soft fat (more USFA)cake give soft fat (more USFA)

o Coconut and palm oil cakes-hard fatCoconut and palm oil cakes-hard fat

Effect of season on iodine valueEffect of season on iodine value

(measure of oleic acid in fat)(measure of oleic acid in fat)MonthMonth Iodine valueIodine value

JanuaryJanuary 2727

FebruaryFebruary 27.227.2

MarchMarch 27.527.5

AprilApril 28.028.0

MayMay 29.029.0

JuneJune 35.035.0

JulyJuly 38.038.0

AugustAugust 38.538.5

SeptemberSeptember 39.039.0

OctoberOctober 35.035.0

NovemberNovember 31.031.0

DecemberDecember 28.028.0

11)11) SeasonSeasono Both fat & SNF show slight but well Both fat & SNF show slight but well

defined variation during the course of defined variation during the course of the year.the year.

Effect of season on Iodine valueEffect of season on Iodine value (Measure of Oleic Acid in fat)(Measure of Oleic Acid in fat)

12)12) AgeAgeo Fat content declines with Age (@ Fat content declines with Age (@ ~ ~

0.02 percentage units per lactation)0.02 percentage units per lactation)o The fall in SNF is more greaterThe fall in SNF is more greater13)13) Condition of cow at calvingCondition of cow at calvingo Good physical condition-fat/SNF Good physical condition-fat/SNF

higherhighero Poor physical condition – low fat/SNFPoor physical condition – low fat/SNF14)14) ExcitementExcitemento Transient fluctuations during periods of Transient fluctuations during periods of

excitement both in yield as well as excitement both in yield as well as compositioncomposition

15)15) Administration of drugs and Administration of drugs and hormoneshormones

o Certain drugs elicit temporary change in Certain drugs elicit temporary change in fat.fat.

o Injection/feeding of hormones-increase Injection/feeding of hormones-increase yield and fast contentyield and fast content

16)16) Exercise:Exercise:o Moderate- no ill effectsModerate- no ill effectso Extensive-adverse effects.Extensive-adverse effects.