GENERAL PROBLEMS IN DAIRY HUSBANDRY 349 



557. Influence of condition at calving.- Observing dairymen have for 

 some time known that when a good dairy cow calves in a fat condition 

 she will often yield milk containing 1 to 2 per ct. more fat than normal, 

 losing markedly in weight meanwhile, a fact which was brought to pub- 

 lic attention by Woll 26 and Eckles 27 . This is due to her strong dairy 

 temperament, which impels her to withdraw fat from her body and put 

 it into her milk. The yearly yield of fat may thus be increased by having 

 cows calve in good condition. Also, when a cow calves in high condi- 

 tion, a seven-day record of fat production secured shortly after calving 

 may not be a reliable index to her ability as a long-time producer. 

 Yearly records are therefore far more reliable guides to the value of 

 dairy cows. 



The following instance given by Eckles will illustrate this effect of 

 the condition of the cow at time of calving. A mature cow was so fed as 

 to be excessively fat at calving, and thereafter was given only sufficient 

 food for a dry cow. Beginning with 21 Ibs. of milk daily, she was giving 

 19.5 Ibs. at the end of 30 days of such poor feeding, during which time 

 she lost 115 Ibs. in weight. Eckles estimates that the 43 Ibs. of fat and 

 53 Ibs. of other solids yielded in the milk during this period must have 

 been drawn from her body tissues. During this period her milk averaged 

 6.1 per ct. fat. Within 48 hours after her feed was later increased the 

 fat content fell about 1.4 per ct. 



In another trial Eckles fed one heifer liberally on rich rations from 

 birth until she calved, while another was kept poor and thin. After 

 calving, the milk of the well-fed heifer tested over 4 per ct. fat and that 

 of the thin one about 3 per ct. For several weeks after calving the fat 

 heifer declined in weight, the fat percentage remaining constant. When 

 at length her weight became stationary the percentage of fat declined 

 somewhat. The thin heifer did not lose in weight after calving, and the 

 fat in her milk did not decrease. In the end the milk of the two heifers 

 was about equally rich. 



Haecker 28 found that for the first few weeks of lactation cows of pro- 

 nounced dairy temperament usually yielded milk greatly in excess of the 

 nutrients in the feed they consumed, in some instances twice as much. 

 This continued until about the eleventh week, when an equilibrium was 

 usually reached between the nutrients consumed and the product yielded, 

 but some cows required a longer time to reach a balance. 



558. Influence of feed on yield of product. It is pointed out later in 

 this chapter that the kind and amount of feed do not materially change 

 the richness of the milk. On the other hand, the amount of milk a cow 

 will produce, and hence the total yield of fat, depends on the feed and 

 care she receives, up to the point where her full capacity for milk pro- 

 duction is reached. The typical beef cow usually has a very limited 



26 Wis. Rpts. 1902, p. 117; 1903, p. 115. 



"Hoard's Dairyman, 40, 1909, p. 696 ; Mo. Bui. 100. 



^Minn. Bui. 79. 



