1474 CATTLE 



given a heav3^ ration from birth to first calving, the second a hght ration. 

 The heav3^ ration consisted of whole milk during the first six months, on 

 an average i6 lbs. per head per day, and all the grain (corn two parts, 

 oats one part) and hay the animals would consume up to the first calving. 

 During the summer a number of these animals were kept grazing and re- 

 ceived in addition the grain ration, others were not put on pasture but re- 

 ceived the hay and grain all through the year. After calving all the cows 

 had alfalfa, hay, silage and a grain mixture of four parts of corn, two of 

 bran and one of oilmeal, administered proportionally to the milk pro- 

 duction of the animal. The light fed group received the mother's milk 

 during the first fortnight, this was then gradually replaced with skim milk, 

 fed warm and sweet immediately after separation, until the end of six 

 months. Alfalfa hay was given as soon as the animals would consume it. 

 Grain was only given from the time when milk production commenced. 

 In the summer a number of the animals was put on pasture, while the re- 

 mainder received only hay and a little green soiling crops. After calving 

 all the cows of the second group received the same ration as those of the 

 first. 



The factor of age at first calving was introduced by taking care that 

 half the cows of each group calved at an early age for the breed, and the 

 other half about a year later. 



Influence of ration upon rate of growth. — The weight and skeleton mea- 

 surements were determined everj'- month. The effect of the heavy feeding 

 was a more rapid development of the skeleton especialh^ during the period 

 when growth is most rapid. lyater it produced a much greater fattening. 

 The animals which were hghtly fed grew less rapidly but for a longer time ; 

 nevertheless they never attained a size equal to that of the first group- 

 The difference between heavy feeding and light feeding for the young ani. 

 mals shows more strongh^ upon the weight than upon the rate of skeleton 

 growth. One cause of the existence of small cows in commercial herds is 

 the character of the ration during the growing period. 



Influence of the age at first calving on the size. — This factor has a mark- 

 ed effect on the size of cows. Milk production imposes a heavy tax on the 

 cow and checks the grov\^h in a very decided way. On the other hand ges- 

 tation does not sensibly hinder its development. The most important 

 factors which tend to hmit the size of cows are scanty feeding during the 

 growing period and early breeding. 



Sexual maturity. — The ration exercises a considerable influence on 

 the time of sexual maturity. Animals fed heavily mature sexualh' when 

 two to four m.onths younger than animals fed lightly. 



Relation of ration to dairy qualities. — The heifers heavily fed during 

 growth were slightly inferior in milk production, to those fed lightl5^ The 

 employment of heavy grain rations seems to have had some detrimental 

 effect on the milking functions. But, within the limits ordinarily existing 

 in practice, this factor probably has no appreciable influence. vSome high- 

 producing cows were found in each group, and also some medium and some 

 inferior. The data indicate that the hereditarv factors such as the influence 



