The Nutritive Value of Dried Citrus Pulp 



for Dairy Cattle 



By H. A. KEENER, N. F. COLOVOS, AND R. B. ECKBERG* 



DURING recent years there has been much interest in New England in 

 the use of dried citrus pulp as a supplemental concentrate feed for 

 dairy cattle. Its use has become widespread due to its increasing availa- 

 bility, favorable price relationships, and apparent high nutritive value. 

 Because the citrus industry is still expanding very rapidly, increasing 

 quantities of dried citrus pulp will become available during the next few 

 years. For this reason it appeared that citrus pulp might be used econom- 

 ically in larger quantities under New Hamphire conditions in the place 

 of other concentrates, if the nutritive value of the ration was not lowered. 



As fresh citrus fruit production began to exceed the demand at about 

 the time of World War I, the canning industry started to process juice 

 and hearts. Disposal of the waste peel, rag, seeds, and cull fruit became 

 a problem. Studies of by-product utilization were undertaken and about 

 1920 some attempts were made to feed such materials to livestock. It 

 was found by the California and Florida experiment stations that cattle 

 could readily utilize the fresh waste and such a practice became common 

 in the citrus regions. The extent of this outlet was limited by the bulk 

 and spoilage of the fresh citrus waste. 



Occasionally dried citrus by-products were left over from other uses 

 and were fed to cattle with satisfactory results. The Florida Station 

 then conducted some feeding trials and determined that dried citrus 

 pulp had much the same use in cattle feeding as beet pulp. In 1938 

 Archibald of Massachusetts reported that dried citrus pulp could replace 

 dried beet pulp in feeding dairy cows. 



Around 1940 it was discovered that because of the high sugar content 

 of the press juice from the pulp, it could be made into a citrus molasses. 

 When cane molasses came into short supply during World War II, 

 citrus molasses found wide use in the mixed feed industry as a partial 

 replacement for it. Now it is often mixed back with the pulp after drying. 



Currently the process for making the dried citrus pulp involves the 

 addition of hydrated lime to aid the removal of bound water from the 

 fresh pulp. The pulp is pressed to remove about half the moisture and 

 then dried with artificial heat to a low moisture content. The press juice 

 is concentrated to make citrus molasses which is either added to the dried 

 pulp to make cake or is utilized separately. Such a procedure gives a wide 

 variation in composition to the dried citrus pulp. Because almost all of 

 the fat is contained in the seed, the fat content of the finished product is 

 affected markedly when the seeds are removed in the processing of the 



* Dr. Keener is Dairy Husbandman, Mr. Colovos is Animal Nutritionist, and Mr. 

 Eckberg is a former graduate research assistant, all in the New Hampshire Agricul- 

 tural Experiment Station. 



