520 FEEDS AND FEEDING 



ment prior to dropping their first calves. The strain of milk production 

 then comes upon them and they will usually lose in weight and make 

 small growth during the first lactation period. In winter the heifers 

 should therefore be fed somewhat more liberally than is necessary for 

 steers. Plenty of protein and mineral matter should always be pro- 

 vided to ensure proper development. 



With good legume hay and corn silage for roughage, little or no grain 

 is necessary. If lower grade roughages are used, enough concentrates 

 should be added to keep them in thrifty growing condition at all times. 

 In trials at the Pennsylvania Station 33 Tomhave and Severson had good 

 results when heifers were wintered on corn silage as the only roughage, 

 with 3 Ibs. of cottonseed meal daily per 1,000 Ibs. live weight to balance 

 the ration. Rations of 20 Ibs. kafir silage, 1 Ib. wheat straw, and either 

 3 Ibs. alfalfa hay or 1 to 2 Ibs. of cottonseed meal were satisfactory for 

 wintering 630-lb. heifers in a trial by Blizzard at the Oklahoma 

 Station. 34 



Under farm conditions beef heifers are usually bred to calve when 24 

 to 30 months old. Tomhave and Severson found that when heifers drop- 

 ped their first calves prior to 30 months of age they remained perma- 

 nently stunted unless allowed 14 to 15 months between the first calving 

 and the second. 



In the range sections of the country it has been a problem for the 

 cattlemen to maintain sufficient size in their breeding herds. This is 

 due not only to animals being stunted by feed shortage in winter but also 

 to the effects of early breeding. In an extensive investigation at the 

 Hays, Kansas, Branch Station 35 by McCampbell one group of heifers 

 has been wintered on roughage alone up to the first calving, with pasture 

 in summer, while another has been wintered on a liberal ration of rough- 

 age plus grain. Half of each group was bred to calve when 2 years old, 

 and the rest at 3 years. When early calving was combined with a winter 

 ration of roughage alone, as is a common practice in this district, not 

 only did the heifers fail to reach as large size as the others, but the 

 average weight of their calves at weaning time for 3 consecutive years 

 was only 348 Ibs. 



Compared with this, the average weaning weight of the calves from the 

 heifers raised similarly, but calving as 3-year-olds, was 405 Ibs. The 

 indications were also that a considerable percentage of these heifers 

 calving as 2-year-olds and raised on roughage alone later became non- 

 breeders. Raising the heifers on a liberal allowance of grain in winter 

 largely prevented the ill-effects of early breeding, but this method was 

 expensive under range conditions. McCampbell concludes that the de- 

 velopment of heifers without grain, and breeding them to drop their 

 first calves at 3 years of age, is the most practical under range and semi- 

 range conditions. 



"Penn. Buls. 138, 150. "Okla. Rpt. 1920, p. 24. 



35 Amer. Soc. Anim. Prod., Proceedings, 1920, pp. 12-14. 



