Factors Affecting Composition Of Milk

FACTORS AFFECTING COMPOSTION OF MILK

Dr. Mohammad Ashraf Paul Faculty of veterinary Sciences, Alusteng, Kashmir

Milk differs widely in composition  All milks contains the same kinds of constituents but in varying amounts  Milk from individual cows shows greater variation than mixed herd milk.  The variation is always greater in small herds than in larger ones 

In general, milk fat shows the greatest daily variation , then comes protein followed by ash and sugar The factors affecting milk composition may be either Genetic or Environmental Genetic 1. Species: Each sps. yields milk of a characteristic composition 

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Breed: In general, breeds producing more milk, yield milk of a lower fat content and vice-versa Individuality: Each cow tends to yield milk of a composition that is characteristic of that individual. ENVIRONMENTAL Interval of milking A longer interval is associated with more milk with a lower fat content

Morning-evening-interval shorter -more variation in fat.  Evening-morning-interval larger-lesser variation  12-hour interval-equal-least variation  SNF not affected much 

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Completeness of milking Fore milk-low in fat Stripping-higher fat Complete milking-fat test normal Incomplete milking-lower fat test. Frequency of milking No greater effect

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Irregular milking: Frequent changes in time and interval of milking-lower fat. Day-to-day milking May show variations for the individual cow Disease and abnormal conditions Tends to alter the composition of milk

especially when they result in a fall in yield. o Both fat & SNF are reduced eg. mastitis 7) Portion of milking o Fore milk low in fat o Stripping highest o Other milk constituents only slightly affected on fat free basis.

Stage of lactation o First secretion after calving ( colostrums) - different from milk in composition and general properties. o Gradual change from colostrums to milk. 9) Yield: o For an individual cow-there is a tendency for increased yields to be accompanied with lower fat test & vice-versa 8)

10 Feeding: o Underfeeding- lower SNF; lower fat o Low energy diet- lower SNF o Fat content and fat composition both influenced by roughage (fiber) intake. o Green pasture promotes high content of USFA (Oleic) o Concentrates such as sunflower ,linseed cake give soft fat (more USFA)

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Coconut and palm oil cakes-hard fat Effect of season on iodine value (measure of oleic acid in fat) Month Iodine value January 27 February 27.2 March 27.5 April 28.0 May 29.0

June July August September October November December

35.0 38.0 38.5 39.0 35.0 31.0 28.0

11) Season o

Both fat & SNF show slight but well defined variation during the course of the year.

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

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

0.02 percentage units per lactation) o The fall in SNF is more greater 13) Condition of cow at calving o Good physical condition-fat/SNF higher o Poor physical condition – low fat/SNF 14) Excitement o Transient fluctuations during periods of excitement both in yield as well as composition

15) Administration of drugs and

hormones o Certain drugs elicit temporary change in fat. o Injection/feeding of hormones-increase yield and fast content 16) Exercise: o Moderate- no ill effects o Extensive-adverse effects.