[ Uo ] 



XIIL— ON THE COMPOSITION OF THE MILK OF FORTY- 

 TWO COWS, BY CHARLES A. CAMERON, m.d., Fellow 

 AND Professor of Chemistry, Royal College of Surgeons, 

 Ireland. 



[Read, March 21st, 1881.] 



During the winter quarter of 1880, analyses were made of the 

 milk of forty-two cows kept at the Government Agricultural 

 Institution, Glasnevin, County of Dublin. 



The morning's milk and the evening's milk of each cow were 

 each analysed once ; and an examination of the mixed milk of 

 the forty-two cows was also made on the 11th December, 1880. 



The results of these anal3^ses are given in the following table. 

 The cows, it may be mentioned, were good animals; they had 

 from one to three crosses of the shorthorn breed. They were in 

 the house during the period of the experiments. Their food 

 consisted of a daily allowance, of from eight to ten stones of 

 pulped mangels and turnips, and exhausted grain from the 

 brewery, together with from half to one and a half stones of hay. 

 They were, therefore liberally fed. 



The figures given in the table are sufficiently numerous to 

 warrant some conclusions being deduced from them, in reference 

 to the average composition of cow's milk, and the limits of 

 variability in the proportions of the difi*erent ingredients. Some 

 conclusions may also be drawn, but with greater reserve, from 

 them, as to the influence of age and period of lactation upon 

 the composition of the milk. 



Influence of Age upon the Quality of the Milk. 



Tlie ages of the cows ranged from four years to nine years, 

 inclusive. If we take the two groups (1st) those aged four 

 years and five years, and (2nd) those aged eight years and nine 

 years, we shall find a great difierence in favour of the milk of the 

 latter, both in quantity and quality. 



The eighteen cows composing the first group, were on the 

 average, giving milk during three months; the average yield 

 from each cow, was nine three-fourth quarts ; their morning's 

 milk contained on the average, 12-97 per cent, of solid matter, 

 and their evening's milk, 13-58 per cent, of solid matter. On the 



SciEN. Proc, R.D.S. Vol. hi., Pt. hi. L 



