03193nam a2200193Ia 4500999001700000003000400017005001700021008004100038082001600079100001800095245007600113260009200189502000900281520250000290700002402790856005702814942001202871952011602883  c25051d25051OSt20210730144753.0140128s9999    xx            000 0 und d  a637bSIM/CH  aSimon Daniel   aChemical constituents affecting cosmolality of milk in crossbred cattle  aMannuthybDepartment of Dairy Science, College of Veterinary and Animal Sciences c1981  bMVSc3 aA study was planned to ascertain the behaviour of osmotically active components in normal milk, milk collected from animals induced to lactate and milk collected from infected udder. An exhaustive review on the literature available on the topic was made.

The samples of milk were collected from three groups of crossbred cows which were in three phases of lactation namely, early, middle and late. Milk samples were also collected from two infertile animals which were induced to lactate with the administration of steroid hormones and from four cows affected with mastitis. All the samples were analysed for lactose, chloride, sodium and potassium by standard methods described.

The lactose and potassium contents of the milk low in colostrum. The lactose attained the normal level by seventh day of calving and potassium by 15th day. The mean lactose content was 4.54% in mid-lactation and 4.33% in the late phase. Potassium showed the similar trend and decreased to 1290.36 ppm from a mid-lactation value of 1367.86 ppm. The lactose and potassium were positively correlated in all the three phases of lactation.

The sodium and chloride content varied in the milk in an opposite manner than that of lactose and potassium. The sodium contents were 546 ppm in early, 547.86 ppm in middle and 626.86 ppm in late phases of lactation. Colostrum contained 857.5 ppm of sodium. Chloride was also higher in colostrum and decreased to an average early phase chloride of 0.147% from 0.209%. Middle phase had a chloride content of 0.141% and in late phase it was 0.165%.





All the components behaved in the similar manner to that of milk in the milk from induced lactation. But the chloride and sodium were high. Mastitis lowered the lactose and potassium to 2.14% and 1147.92 ppm respectively while sodium and chloride increased to 1023.33 ppm and 0.223%.

The chloride-lactose ratio was 6.36 in colostrum, 3.21 in early phase, 3.09 in middle phase and 3.87 in late phase of lactation. Potassium-sodium ratio was amounted to 2.44, 2.49 and 2.06 respectively for early, middle and late phase of lactation. The ratio was 1.36 in colostrum. Mastitis lowered the potassium-sodium ratio while increased the chloride lactose ratio.

The correlation between lactose and chloride, lactose and sodium and potassium were negative while positive correlations were observed between sodium and chloride and lactose and potassium. 

These observations were discussed with reference to other reported values.   
  aPavithran K (Guide)  u http://krishikosh.egranth.ac.in/handle/1/5810139673  2ddccTH  00102ddc4070aKAUCLVbKAUCLVcTHESESd2014-03-18l0o637 SIM/CHp170095r2014-03-18 00:00:00w2014-03-18yTH