FEEDING AND CARE OF DAIRY COWS 261 



The first 2 rules apply only when abundant roughage of good 

 quality is supplied. Heavy producers require a narrower nutritive 

 ratio than ordinary animals, and hence it may be advisable to alter 

 the character of the concentrate mixture for them. It is also wise 

 to feed a more nitrogenous concentrate allowance to cows showing a 

 tendency to fatten, while those losing flesh should receive a larger 

 proportion of the carbonaceous concentrates, such as the farm-grown 

 grains. Since heifers in milk are still growing in addition to giving 

 milk, they should be fed more liberally than mature cows yielding 

 the same amount of milk. 



Feeding concentrates on pasture. — The economy of feeding con- 

 centrates to cows on good pasture depends on tbe relative cost of 

 pasturage and concentrates, the price secured for dairy products, 

 and the productive capacity of the cows. While the animal giving 

 only an average quantity of milk may not pay for such addition, the 

 heavy-yielding cow can not long continue her high production with- 

 out some concentrates, unless the pasture be unusually luxuriant. 

 Eckles ^^ concludes that a Jersey giving 20 lbs. or a Holstein yielding 

 25 lbs. of milk or more daily, should be fed some concentrates on 

 pasture, the amount being left to the business judgment of the dairy- 

 man. Feeding a moderate amount of concentrates on pasture is 

 often advisable, even when it does not increase the yield enough to 

 return an immediate profit, for the cows are kept in better condition 

 and will yield more the following months. This is especially true 

 with heifers which are still growing and require liberal feed in order 

 to reach full development. 



Supplementing short pasture. — It is of great importance that ad- 

 ditional feed be given daiiy cows when pastures become parched and 

 scant in midsummer. Otherwise, the milk flow will surely decrease, 

 and even should the pastures improve later, the cows can not be 

 brought back to their normal flow of milk. Corn or sorghum silage 

 usually furnishes the cheapest feed for this purpose, but where this 

 is not available soiling crops should be specially grown. 



The ration should be properly balanced. — Because milk is rich in 

 protein and mineral matter, especially lime and phosphorus, the 

 ration of the dairy cow should contain an ample supply of these 

 nutrients. (See Chapter VI.) Fortunately, legume hay is rich in 

 all these constituents, which explains its high value for milk produc- 

 tion. As pointed out in Chapter VIII, the amount of protein it will 

 pay to feed depends on the relative prices of protein-rich and car- 

 bonaceous feeds. Even when the former are high in price, the pro- 

 tein allowance should not fall far below the minimum shown in 



13 Dairy Cattle and Milk Production, p. 256. 



