464 



FARMER'S CYCLOPEDIA OF LIVE STOCK 



changes in the protein or fat content 

 of the rations did not produce noticeable 

 changes in the composition of the milk. 

 With some cows it was found that a 

 considerable percentage of the milk fat 

 must come from the carbohydrates in 

 the feed. On the whole, it appeared 

 that more than 40 per cent of the avail- 

 able energy in the rations was necessary 

 for maintaining the cow, while slightly 

 more than 30 per cent was transformed 

 into milk. This leaves a balance of 

 about one-fifth of the ration, which is 

 presumably used up in the work of 

 milk secretion. 



Wing and Ford made some interest- 

 ing experiments in increasing the fat 

 content of milk by means of liberal 

 feeding. The experiment was under- 

 taken after having observed that, in 

 many instances, dairymen were feeding 

 their cows rations which were appar- 

 ently deficient in nutrients and energy. 

 It was found that in a herd of poorly 

 fed cows a liberal ration of easily di- 

 gestible feed, rather nitrogenous in 

 character, and conducted for a period of 

 two years, resulted in an increase of ^4 

 of 1 per cent in the fat content of the 

 milk. This increase was accompanied by 

 an increase of about 50 per cent in the 

 total amount of milk and fat produced 

 and was obtained economically in so far 

 as the cost of feeding was concerned. 

 This result indicates clearly the great 

 capacity of good dairy cows to give prof- 

 itable returns from liberal feeding. 



Relation of the size of the ration 

 to economy of production — With dairy 

 cows, as with other animals, it is gen- 

 erally true that the more feed which they 

 can utilize, the greater the profit. As a 

 rule, cows which eat the most feed pro- 

 duce the most milk and butter and most 

 economically. This proposition has been 

 clearly demonstrated in New York, 

 Pennsylvania and elsewhere, as well as 

 in the official test made at the world's 

 fair in Chicago. The feeding power of 

 cows is therefore an important matter 

 to consider in selecting or building up a 

 dairy herd. It is necessary, however, 

 to make sure, in any case, of a cow 

 which will consume large quantities of 

 feed, and that this feed is utilized for 

 milk production and not in laying on 

 body fat. 



The period of lactation as related to 

 milk yield — J n numerous experiments 

 carried on in New York, Ohio, Wis- 

 consin and elsewhere, it has been found 



that the greatest production of milk 

 fat takes place soon after calving, say 

 in the second and third weeks, and 

 that the milk flow gradually diminishes 

 after this period. In a careful test car- 

 ried on in New York, it appeared that 

 the milk yield for each month was about 



9 per cent less than that of the preced- 

 ing month. It is a matter of some im- 

 portance to know at what time in the 

 period of lactation the cow will make 

 her best record. Some of the dairy as- 

 sociations require the production of 

 milk and butter at a certain rate in order 

 to admit cows to advance registration. 

 Haecker made a study of this matter in 

 Nebraska and in looking over herd rec- 

 ords found that considerable variation 

 existed in the best week of lactation. It 

 appeared than nine-tenths of the cows 

 make their best record during the first 



10 weeks of lactation and that with more 

 than one-half of cases this occurs dur- 

 ing the first month. On the whole, the 

 second and third weeks were found to 

 include the time of greatest production. 

 The cow reaches her highest production 

 of butter fat somewhat earlier than she 

 does the greatest flow. 



Age of cows as related to their 

 productivity — According to the observa- 

 tions of Carlyle and Woll, the quality 

 of the milk deteriorates somewhat as the 

 cows advance in age, the average fat con- 

 tent being 4.49 per cent during the first 

 year of lactation; 4.4 per cent in the 

 second year; 4.29 per cent in the third 

 year, and 4.17 per cent in the fourth 

 year. Dairymen have commonly ob- 

 served that the milk yield increases up 

 to about seven years of age, after which 

 it remains nearly constant until about 

 the twelfth year, when it begins to de- 

 crease more rapidly. The average dairy 

 cow is therefore at her best between the 

 ages of seven and 10, and there is us- 

 ually a slow and gradual decline in the 

 milk yield after the seventh year of life, 

 until the twelfth year. From this time 

 on the cow is likely to be less profitable 

 than the heifer. In New York, it was 

 found that the cost of milk was greatest 

 in two-year old heifers and decreased up 

 to the age of four years, after which jt 

 remained nearly constant. The gain 

 in the amount of milk between the ages 

 of two and three years was 5 per cent; 

 between three and four years, 18 per 

 cent, and between four years and the age 

 of greatest production, 15 per cent. Like- 

 wise in Ohio, it has been shown that the 



