A PASrrURE HANDBOOK 49 



would be required for maintenance, which would leave but little to 

 be applied to the production of meat or milk. 



As pasture plants mature the percentages of protein and minerals 

 decrease. Au'-dried bromegrass in North Dakota cut on Alay 10 

 contained 18.5 percent of crude protein, whereas that cut on July 25 

 contained only 9.2 percent. Within the same time the ash content 

 decreased from 11.9 to 5.7 percent. 



Samples of Nevada bluegrass, violet wheatgrass, and Letterman 

 needlegi-ass from Utah contained in the dry matter 25 percent of pro- 

 tein on June 24, 11 percent on August 9, 10 percent on August 29, 

 6 percent on September 18, and 5 percent on October 7. If such 

 forage is cut about the time the seed matures, the plants contain only 

 about 40 percent of water. With so much greater growth and lower 

 moisture content, the gi-azing animals can readily get not only enough 

 dry matter for maintenance but also plenty for fattening. Forty 

 pounds of such forage would contain 24 pounds of dry matter, which 

 is practically a full feed for a 1,000-pound animal. If the same forage 

 is cut twice during the season, the water content of the fresh forage 

 would be about 54 percent. When cut four times a season the average 

 water content is about 79 percent. 



Mature forages lose a considerable part of then nutritive value by ex- 

 posure to wet weather. As the more soluble and digestible nutrients 

 are leached out by rain, the less valuable part for feedmg therefore 

 remains. There may be a loss in soluble mmeral matter or salt which 

 sometimes may exceed 60 percent. Consequently it is very miportant 

 that a mineral supplement be supplied to livestock fed chiefly on 

 leached roughage. 



The effect of the leaching action of rain, accompanied by the loss 

 of leaves, is illustrated by bur-clover in California. When it is ripe 

 cattle prefer it to the green feed that is available and fatten rapidly. 

 But if much rain faUs on the ripe clover it loses its leaves and the feed- 

 ing value is not even sufficient for maintenance m many cases. 



Exposure to rain and sun also leads to loss of carotene in hay. 

 Such hay, especially if left in storage for a year, may be seriously 

 deficient in carotene. 



In the arid and semiarid sections of the West, where the pasture and 

 range grasses cm-e in their natural state with little or no loss of leaves, 

 these grasses have nearly the same feeding value as hay made from the 

 same plants and ordinarily carry cattle, horses, and sheep through the 

 winter in good condition, if a plentiful supply is available. However, 

 they may be low in carotene. 



MINERAL CONTENT OF PASTURAGE 



Green, immature grasses consist largely of leaves and hence are 

 much better sources of mmerals than hay or mature plants from the 

 same land. Immature grass is generally about twice as rich in 

 phosphates as mature freshly cured gi-ass, and may be from 4 to 5 

 times as rich in them as grass that has matured and been exposed to 

 the weather for several months. The dry matter of miniature grass 

 contains practically 4 times as much mineral as the average cereal 

 grain, and as much as the average legume hay. Furthermore, pas- 

 turage produced on fertile land contains more of the important min- 

 erals than that produced on poor soil. 



Although pasturage is ordinarily the best source of minerals, there 

 are important mstances of mmeral deficiencies hi the grazing of live- 



710433°- -46 • 



