480 EXPERIMENT STATION RECORD. [Vol.35 



New Jersey Experiment Stations two pens of 100 White Leghorn pullets each 

 were fed the regulation ration, pen 1 receiving in addition an unlimited amount 

 of sour skim milk. 



Pen 1 laid during the first 12 months 12,044 eggs, or an average production of 

 34.4 per cent. The value of these eggs on the wholesale market was $375.04. 

 The food cost, including skim milk, was $116.37, leaving a net profit above all 

 food consumed of $258.67. Pen 2 laid during the first 12 months 8,382 eggs, or 

 an average percentage production of 25.76, with a resulting value of eggs pro- 

 duced of $256.14. The cost of all food consumed in this pen was $99.21, leaving 

 a resulting profit, above food, of $156.93. 



In addition to this study four other tests with younger and older birds and 

 with birds of different breeds were run simultaneously. The results of all 

 these studies verify the differences shown in this particular instance, although 

 in no case was the difference quite so pronounced. The conclusion reached from 

 a careful analysis of these and other records of similar nature are as follows : 



Sour skim milk has a very definite place in the nutrition of laying hens, being 

 a splendid source of protein food, the element so necessary for the production 

 of eggs. Tlie returns measured in number of surplus eggs produced indicate 

 that the sour skim milk has nearly five times the value paid for it. The feeding 

 of sour milk kept the birds in better physical condition, lowering mortality and 

 keeping them practically free from disease. It slightly increased the consump- 

 tion of other parts of the ration, probably because the skim milk kept the diges- 

 tive organs in splendid running order so that they were able to handle larger 

 amounts, and it is thought that on a commercial basis this factor would appear 

 more strongly than it did in this somewhat limited experiment. Egg producers 

 can afford to pay from 40 to 80 cts. per 100 lbs. for skim milk. It can be fed in 

 open pans, thus necessitating very little labor. 



External characters as indications of egg production, O. B. Kent {Jour. 

 Amer. Assoc. Instr. and Invest. Poultry Hush., 2 (1916), No, S, pp. 63. 6^). — A 

 study of the theory that late layers are late molters and that late molters molt 

 rapidly gave a correlation of over 0.5 with a probable error of ± 0.02. The re- 

 lation held true regardless of whether it was the first, second, third, or fourth 

 year of production. None of the birds that were more than half way through 

 their molt about October 1 were high producers and only a few late molters 

 were low producers. Contrary to popular opinion the late molters molt rapidly 

 and begin to lay as soon or sooner than the early molters. The medium molters 

 begin to lay slightly ahead of the late or early molters. A very sightly better 

 correlation was found between color of shank and egg production than between 

 molting and egg production. This degree of pigmentation elsewhere is also an 

 indication. 



The health of the bird, as shown by the condition of the comb, is deemed a 

 fair indication of egg production. When the comb is full-sized, red, pliable, and 

 somewhat slippery the bird is usually laying The comb shrinks, becomes hard, 

 light-colored, and rough as the bird stops laying. A series of observations made 

 between pliability of comb and egg production gave a correlation of over 0.3 

 with a probable error slightly greater than it 0.02. The pliability of the comb 

 indicates whether the bird is laying at the time. Late laying tends to give high 

 egg production. 



The smoothness, pliability, and oiliness of the skin are also indications of egg 

 production. A laying bird has a softer, smoother feeling than a nonlaying one. 



The abdomen is a very good indicator of egg production. A bird, due to the 

 yolks developing in the ovary and the increase in size of the oviduct, swells out 

 its abdomen in preparation for a laying period. It makes little difference 

 whether the distance between the pelvic arches, from the keel bone to the pelvic 



