FEED CONVERSION 



Trend and Seasonal Variation in Feed Conversion 



The development and improvement of high-energy broiler rations, the 

 breeding of improved broiler strains, and better management of broilers 

 have had a profound effect on the trend of feed conversion ratios. Fig- 

 ure 1 illustrates this trend over the 3-year period 1956-1958 during which 



Figure 1. Feed Conversion Ratios of 672? Broiler Flocks 

 Averaged by Month of Sale, 1956-1938 



the amount of feed required to produce a pound of meat decreased by 

 0.612 pounds or approximately 20 percent. Statistical tests indicate that 

 the conversion ratios of flocks sold during December, January, February, 

 March, and April during the 3-year period differed significantly from 

 those sold during July and August. 4 



Breeds and Feed Conversion 



Feed conversion ability is commonly used as a basis for evaluating 

 the meat-producing efficiency of the various broiler breeds. Two statisti- 

 cal tests were made to determine whether breeds might differ in this 

 respect. 



The first test consisted of comparing the feed conversion ratios of 

 flocks of two breeds sold over a 15-month period by growers of an inte- 

 grated firm. No significant difference was found. 5 



The second test consisted of comparing feed conversion ratios of seven 

 breeds entered in three broiler trials. The broilers in each trial were 

 subject to the same management conditions, which was not the situa- 

 tion in the first test. Thus, the differences in the ratios in the trials were 

 more reliable for indicating differences in feed conversion ability. How- 

 ever, in this test also no statistically significant difference was found. 7 

 Thus it was concluded that the breeds tested did not differ in feed con- 

 version ability. 



4 See Appendix Table 1. 



5 See Appendix Table 2. 



6 The 1958 New Hampshire Broiler Trials, Department of Poultry Science, Universi- 

 ty of New Hampshire. 



7 See Appendix Table 3. 



6 



