INVESTIGATION IN ANIMAL NUTRITION 

 BEEF-PRODUCTION 



By T. L. HAECKER 



INTRODUCTION 



During our investigations in feed requirements in milk-production, 

 covering a period of fifteen years ending in the spring of 1909, much 

 new and valuable information was obtained in regard to feed and 

 nutrient requirements under fairly normal conditions and rational 

 methods of feeding for milk-production. The practical application of 

 the data secured in these investigations was published in popular form 

 in Bulletin 130, and the details of the work were set forth in Bulletin 

 140. The demand for Bulletin 130 has required the issue of 100,000 

 copies. When definite and authentic information on milk-production 

 meets with such universal favor by owners of milk cows, it is reason- 

 able to assume that similar information bearing on rearing and fatten- 

 ing of steers for beef-production will meet with favor. 



The plan of investigation is the same as the plan of the investigation 

 of feed and nutrient requirements for milk-production. 



The results will be discussed first from the standpoint of total feed 

 requirements and the general feed-cost of production ; second, from the 

 standpoint of the dry matter and available nutrients required in the 

 various stages of growth and fattening, and the relation of these nutri- 

 ents to the tissues in the body. 



The data under Feed Requirements give new and definite informa- 

 tion that has been needed for many years, and are of permanent value, 

 as the feed or nutriment required to produce a given product is now 

 what it was a decade ago and will be the same a decade hence. The 

 data under Feed-Cost of Production, on the other hand, give only gen- 

 eral, not definite, information, because prices of feed-stuffs vary and 

 price levels change. 



I. FEED REQUIREMENTS 



Beginning in the autumn of 1891, seven calves were used for study- 

 ing the feed and nutrient requirements in the growing and fattening 

 of steers in comparison with like requirements for cows for milk- 

 production. In the experiments in feeding dairy cows to determine the 

 nutriment required in milk-production, it was found that certain cows 



