130 THE CHEMISTRY OF THE FARM. 



when sheep are washed before shearing. In the case of 

 Merino sheep the suint may amount to more than one- 

 half the weight of the unwashed fleece ; but in the case of 

 ordinary sheep, freely exposed to weather, the quantity 

 may be 15 per cent, or less. In a washed fleece the fat 

 may vary from more than 30 per cent, to 8 per cent., or 

 less. Short fine wool contains the largest proportion of 

 fat. Pure wool-hair contains about 16 per cent, of 

 nitrogen. The quantity of nitrogen and ash constituents, 

 both in unwashed and in washed wool, has been already 

 given on page 78. 



The production of wool-hair and of wool-fat is 

 practically no greater when sheep receive a liberal fatten- 

 ing diet, than when the diet only suffices to maintain the 

 ordinary condition of the animal ; indeed, under poor 

 treatment, the carcase may lose weight to some extent 

 without the production of wool being seriously altered. 

 With starvation, however, the yield of wool is con- 

 siderably diminished. If sheep are kept on a poor diet 

 for the mere production of wool, the amount of 

 albuminoids supplied must not fall too low, wool-hair 

 being formed entirely from this part of the food. 



Production of Milk. The quantity of milk produced 

 is largely determined by the individual character of the 

 animal, and the length of time which has elapsed since 

 birth ; the quality of the milk is also affected by the 

 same conditions. Subject to these natural limitations, 

 both quantity and quality are greatly influenced by 

 the character of the food supplied. 



A liberal diet is essential for a full supply of milk. 

 Tbe milk yielded by each cow should be recorded, and 



