FARMERS' MONTHLY OF HAMPSHIRE COUNTY 



MINERALS IMPORTANT IN 



THE DAIRY RATION 



It is a well established fact that ani- 

 mals fed on rations practically freed from 

 mineral matter will die even sooner than 

 animals deprived of all feeds. From this 

 it is evident that a good ration for dairy 

 cows must supply not only the minerals 

 to be used in the milk but also those 

 necessary to assist in the proper main- 

 tenance of the body functions. The value 

 of salt in the ration has long been recog- 

 nized and any dairyman who has had the 

 experience of overlooking "salt for the 

 cows" can readily vouch for its worth. 

 The effects of a deficiency of some of the 

 other minerals are not so immediate and 

 clear-cut; nevertheless, there is little 

 doubt as to their importance. 



Our present system of economic dairy 

 management has increased the cow's need 

 for minerals. Under this system it is 

 desired that the cow freshen approxi- 

 mately once each year, produce milk for 

 ten months, and be dry for only two 

 months before the next calving. Conse- 

 quently with this practice the cow is 

 either producing milk or pregnant at all 

 times, and for a large part of the time 

 both pregnant and producing milk. For- 

 tunately, to meet these excessive demands 

 for minerals the cow is equipped by na- 

 ture with a capacity to consume large 

 amounts of roughage. If the roughage 

 part of the ration contain a legume hay, 

 it will do much to forestall a mineral 

 shortage. 



The minerals most likely to be deficient 

 in the dairy ration are lime and phos- 

 phorus. Table 1 gives the percentages of 

 these minerals present in the more com- 

 mon feeds. 



This table shows that the legume hays 

 and beet pulp are rich in lime and that 

 the protein concentrates, especially bran, 

 cottonseed meal, oil meal, and soybean 

 meal, are rich in phosphorus. The small 

 percentage of both lime and phosphorus 

 in timothy hay and corn silage is worthy 

 of note. It is evident, then, that a ration 

 should include a legume hay and at least 

 one concentrate of high-phosphorus con- 

 tent in order to supply a sufficient quanti- 

 ty of these two minerals. 



To give the exact amount of minerals 

 necessary for a certain level of milk pro- 

 duction is at this time impossible. A large 

 amount of work has been done on the 

 question, but as yet the problem is not 

 solved. 



One method of studying the mineral re- 

 quirements of the dairy cow is by means 

 of balance or digestion experiments. In 

 these experiments the mineral intake in 

 the food and drink and the outgo in the 

 milk, urine, and feces are determined and 

 the amounts compared. If the outgo of 

 minerals exceeds the intake, the animal 

 is said to be losing or taking from her 



body. On the other hand, if the intake 

 exceeds the outgo, the animal is said to 

 be storing minerals. 



By means of this method, E. B. Forbes, 

 while at the Ohio Station, showed that 

 liberally milking cows lose both lime and 

 phosphorus from their bodies. These 

 losses were larger when timothy hay was 

 fed than when alfalfa and clover hays 

 were fed. An outstanding feature of his 

 work was the fact that the ability of the 

 cow to utilize the mineral constituents of 

 the ration is much more limited than her 

 ability to utilize the fats, proteins, and 

 carbohydrates. 



Later, work by E. B. Hart of the Wis- 

 consin Station showed that the quality of 

 the roughage had an important influence 

 on the utilization of lime and phosphorus 

 by the cow. He found that feeding either 

 alfalfa hay cured under caps or green al- 

 falfa led to a storing of both lime and 

 phosphorus, even by liberally milking 

 cows. He expressed the opinion that the 

 alfalfa hays used in this work contained 

 some unknown factor which assisted in 

 the utilization of the minerals. This 

 factor is generally known as vitamin D, 

 or the anti-rachitic vitamin. The work 

 of Hart, has, in general, been verified by 

 the more recent work at the Oregon Ex- 

 periment Station. 



Professor Hart has further shown 

 within the last year that losses of min- 

 erals by milking goats could be changed 

 to storages by subjecting the goats to 

 rays from the quartz mercury vapor 

 lamp. Direct sunlight contains rays 

 similar to those given off by this lamp, 

 and, in experiments with smaller animals, 

 direct sunlight has had an effect similar 

 to the effect of light from the quartz mer- 

 cury vapor lamp. By direct sunlight is 

 meant sunlight such as an animal re- 

 ceives when out of doors, as contrasted 

 with sunlight which has passed thru win- 

 dow glass. 



The Station has conducted four balance 

 experiments in the last four years; one 



of the objects being to study the utiliza- 

 tion of minerals by dairy cows which had 

 , never been on pasture nor received any 

 ! green feed. The first two of these ex- 

 periments were conducted during the 

 summer months with the windows in the 

 barn open, allowing the sun's rays to 

 shine directly on the backs of the cows 

 during part of the day. The cows were 

 producing approximately 30 pounds of 

 milk daily. Two types of rations were 

 used — one a high protein ration contain- 

 ing as roughages 12 pounds of clover hay 

 and 2.4 pounds of timothy hay, the other 

 a low protein ration containing 5.5 

 pounds each of clover and timothy hays. 

 The difference in the lime content of the 

 two rations was not great, due to the use 

 of a large amount of beet pulp in the low 

 protein or mixed hay ration. We found 

 that the cows receiving the larger amount 

 of clover hay were storing lime, while 

 tho.se receiving timothy with the smaller 

 amount of clover hay were losing a slight 

 amount of lime. 



In the last two experiments the min- 

 eral balances of the dryfeed cows were 

 compared with those of cows taken from 

 the regular herd which had been on 

 pasture the preceding summer. These 

 experiments were made in the winter 

 with the windows closed, hence any sun- 

 light which the cows received was in- 

 direct. As in the former experiments, 

 the cows were producing approximately 

 30 pounds of milk per day. The rations 

 fed were the same in all cases, contain- 

 ing 10 Vi pounds of timothy hay, and 10 

 pounds of beet pulp in addition to a liberal 

 grain ration of corn, bran, and oats. The 

 beet pulp supplied 60 percent of the lime, 

 and the bran 52 percent of the phos- 

 phorus of the ration. Altho the intake of 

 lime was three times as great as the 

 amount contained in the milk, yet all the 

 cows were found to be taking lime from 

 their bodies. As the lime content of these 

 rations was not far below that of the ra- 

 tions used in the first experiments, it 

 could hardly be said that the lower lime 

 content of the rations was responsible for 

 the losses. We would rather explain 

 these losses as being due to the lack of a 

 legume hay with its vitamin content and 

 to the lack of direct sunlight. 



The cows that had been on pasture the 

 preceding summer were found to be tak- 

 ing twice as much lime from their bodies 

 as the dry-feed cows. This, we think, is 

 an indication of a difference in the 

 amount of lime reserves in the bodies of 

 the two groups of cows. The dry feed 

 cows were forced to utilize more of the 

 lime of the ration, because their small re- 

 serves had been largely depleted by long 

 continued feeding on winter rations. This 

 was shown by the sudden decline in milk 

 flow when increased demands for lime 

 arose, such as are experienced in the later 

 stages of pregnancy. 



Continued on page 8, column 2 



