Research Bulletin - University of Missouri, College of Agriculture, Agricultural Experiment Station Volume 28-35 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 Excerpt: ...did the early calving group during the period which the latter were in milk. After the first parturition by the late calving group the curve of gain is much the same as for the early calving group. It will also be seen that the lead in weight made by the late calving group was still maintained altho not with so wide a variation after the second parturition which coincides with the third for the early calving group. A study of the data presented leads to the conclusion that lactation is a severe tax upon the growth of a dairy heifer even when the PlC 13.--The influence of lactation upon growth as represented by weight. The solid line represents a group that calved first at an average age of 22.7 months, the dotted line represents a group that calved for the first time at an average age of 34.9 months, which was practically the same age at which the early calving group dropped their second calves. Note gestation rather increased than decreased the gain in weight but lactation was a decided check. The early calving group weighed 670 pounds after the second parturition and the late calving group 750 after their first. The early calving group regained part of this loss between the second and third parturition but never reached the weights of the late calving group ration received is ample. Even under favorable conditions of feed and environment the heifer that comes into milk while still considerably short of maturity will not attain as large a size as the animal which is more mature before lactation begins. The cause of the pronounced effect of lactation upon growth is undoubtedly to be found in the large amount of solids produced in the form of milk by the dairy cow. Even a mediocre heifer which gives no more than 20 pounds of milk daily with a total solid per...