Chemical composition and sanitary value of cow and sheep milk
1997
Tietze, M. | Majewski, T. (University od Agriculture, Lublin (Poland). Dept. of Animal and Environment Hygiene)
Cow milk samples (440 units) of black and white breed with an admixture of Holstein-Friesian blood were collected four times at the time of lactation (300 days). The milk of 600 sheep of fertile and woolly as well as meat breeds and their hybrids was sampled on 15th, 45th and 75th day of lactation. The sanitary value was established in total milk. On average, the composition of cow milk was 3.26-3.85 per cent protein, 3.20-3.60 per cent fat, 4.20-4.60 per cent lactose, 0.68-0.78 per cent mineral salts, and about 87-88 per cent water at the average annual efficiency equal to about 6000 kg milk. Sheep milk showed a differentiated chemical composition: 5.26-6.59 per cent protein, 5.50 per cent lactose, and 4.31 per cent fat in the first stage of lactation. On the 45th day, protein reached the highest value of 7.61 per cent, just as in the last stage. The level of fat and lactose did not differ significantly throughout a lactation period, yet it did within breeds only, and was the highest for meat breeds, and the lowest (4.15-4.54 per cent) in Oikuska hybrids. The sanitary value of cow milk demonstrated some mesophilic and psychotrophic bacteria impurities (1000000 and 10000, respectively) at 0.1 coli titre. In sheep milk mesophilic impurities reached 1000, whereas psychotrophic were 100 at 0.1 coli titre. It was found that a total protein content in cow milk was significantly higher (p more than 0.01) at the beginning of lactation time. Sheep milk showed some changes in chemical composition both with lactation period and within breeds. Bacterial contamination of cow milk was higher compared with sheep milk.
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