(i) Age of the animal: Butter fat in milk becomes less as an animal grows old thus young animals produce milk with higher BF than older animals.
(ii) Breed differences: Different breeds of cattle produce milk with different percentage composition e.g. Jersey produce higher BF than Friesian.
(iii)Type of food eaten by an animal: Roughage feeds produce milk with higher fats, lactose and protein compared to grains.
(iv)Disease: Diseases such as mastitis reduce the lactose composition in milk because bacteria attack milk sugars.
(v) Physiological condition of the animal, i.e Sick/extremely emaciated animals register low percentage of BF/during late pregnancy cows produce milk with low BF content
(vi)Stage of lactation: The BF content in milk is highest at the middle phase of the lactation period and lowers towards end of lactation.
(vii) Time of milking: Milk produced in the morning has lower BF than milk produced in the evening.
(viii) Season of the year: BF content increases during cold season.
(ix)Completeness of milking: The last drawn milk from the udder contains 10% total B.F.C/milk drawn last from the udder during milking contains high B.F content.
Mohaissack answered the question on October 10, 2017 at 10:44