598 Summary of Agricultural Experiments, [oct., 



the Lancashire County Council have now carried on tests for three 

 m years — in 1908 on fourteen farms, in 1909 on twelve farms, and in 19 10 

 on twelve farms. Each herd was tested, as regards the yield and com- 

 position of the milk, once every three weeks, this having been found to 

 give results sufficiently correct for practical purposes. The total yield 

 for the three weeks was obtained by multiplying the yield on the day 

 of testing by io'5, and the estimated yield half-way between two 

 testings by 10*5, and adding the two results. A number of points 

 elucidated by the records obtained are discussed in this report. 



Farmers generally believe that heifers yield richer milk than older 

 cows. This is supported by the figures obtained. In the case of cows 

 two years old the average percentage of fat was 3 71, and of total 

 solids 12 71. These percentages decrease gradually but regularly with 

 older cows, until with cows of seven and eight years the composition is 

 3'6o per cent, of fat and 12*34 per cent, of total solids. The yield, how- 

 ever, improves until the cows reach at least seven or eight years of age, 

 and it would therefore appear advisable to keep the animals until they 

 have had at least four calves. 



The usual great differences were found in the capacity of individual 

 cows. Taking the two best and the two worst cows at various ages 

 (twelve good and twelve bad cows in all), the average yield of milk of 

 the best cows was found to be nearly double that of the worst. It is 

 estimated that in the case of the former, after paying for the cost of 

 keep, a gross profit of £10 per annum per cow is left, but with the 

 latter a loss of 35. Sd. per cow. It may be assumed, therefore, that the 

 smaller-yielding cows in the herds tested gave little or no profit to the 

 owner. 



The opinion is often held that the milk of high-yielding cows is 

 poorer than that of cows with a lower yield, and that consequently 

 when a herd is kept for butter- or cheese-making the difference noted 

 above is largely compensated for. The records obtained showed that 

 this was not the case. At all ages the milk of cows giving from 4,000 

 to 6,000 lb. per annum on the average differed little in composition 

 from, that of cows giving from 2,000 to 4,000 lb. — sometimes the per- 

 centage of solid was a little greater, sometimes a little less— and there- 

 fore, owing to the heavier yield, the former cows gave a much greater 

 total quantity of solids. 



The records of seven of the herds have now been kept for three 

 years, and nearly all of these show a distinct improvement in yield and 

 composition of milk, which it is considered is at any rate partly due to 

 the help afforded by the records in eliminating unsatisfactory animals 

 and improving the herd. 



Churnability of Cream (Jour. Roy. Agric. Soc, Vol. 71, 1910).— This 

 paper contains an account of investigations carried on at the Royal 

 Agricultural Society's Show at Liverpool, and in the Cooper Research 1 

 Laboratory, with the object of finding an explanation of the peculiar j 

 variation in the churnability of creams from different breeds of cows. 1 

 It has been suggested, particularly by D'Hont, that the churnability of 

 cream depends upon the size of the fat globules present. In order 

 to discover the predominant sizes of fat globules in different milks. , 

 microphotographs were taken, and the number of fat globules 

 of different sizes shown in the photographs counted. In this way six j 



