1017] ANIMAL PRODUCTION. 867 



let ; lot 2, Shropshire ; lot 3, Hampshire ; lot 4, Southdown ; lot 5, Lincoln ; and 

 lot 6, half-blood Karakule-Lincoln. The resulting lambs numbered 120, all of 

 which were hardy and thrifty from birth. The highest average birth weight 

 was shown by the Hampshire-Rambouillet cross, and they also made the great- 

 est total gain and seemed to finish in a shorter period. The cost of feed per 

 pound of gain in the experiment was, from October 13 to January 5, 3.32 cts., 

 and from January 6 to 17, 5.03 cts. 



Six of the best lambs were taken "from each lot and fed from January 6 to 

 March 8 for the National Feeders' and Breeders' Show, The cost of feed per 

 pound of gain during this period was 6.32 cts. Pens of these lambs in compe- 

 tition at the show were ranked as follows: Lincoln-Rambouillet, Hampshire- 

 Rambouillet, Southdown-Rambouillet, Rambouillet, Karakule-Rambouillet, and 

 Shropshire-Rambouillet. 



A novel salt trough used during the experiment, and which seemed to be 

 effective, was made to apply pine tar to the lambs to keep the gadfly away from 

 the nasal cavities. The trough, 4 in. by 6 in. by 4 ft., had a board 3J in. wide 

 placed 3 in. from the bottom. A strip of sheepskin, with the wool side out, was 

 tacked to the edge of this board and smeared with pine tar every evening just 

 before bringing the sheep into the lot. 



Oestrus and ovulation in swine, G. W. Coener and A. E. Amsbaugh {Abs. in 

 Anat. Rec, 11 (1917), No. 6, p. 5^5).— The authors found that animals killed 

 during the period of heat usually show ruptured Graafian follicles, and in such 

 animals the ova were recovered by washing out the Fallopian tubes. Rupture 

 of the follicle is spontaneous, occurring even in the absence of the boar. Sows 

 killed on the third day of heat showed regularly that ovulation had taken place. 

 The unfertilized ripe ovum of the sow, as found in the tube, measures from 155 

 to 165 /M in diameter. The zona pellucida is from 7 to 8 m thick, inclosing a yolk 

 heavily laden with fat globules, obscuring the nucleus. The polar bodies are 

 often clearly seen in the fresh ovum. Study of a small series of ova which 

 have been cut into serial sections seems to show no deviation from the stages 

 reported in other mammals. The first polar body is formed within the follicle 

 just before rupture, the second in the tube. Entrance of the spermatozoon and 

 fusion of the pronuclei occur in the tube. 



Cost of keeping farm horses and cost of horse labor, M. R. Cooper {U. S. 

 Dept. Agr. Bui. 560 (1917), pp. 22, figs. 5).— Results are given of a study of 

 cost accounting records for 154 horses on ten farms in Illinois, 72 horses on 

 seven farms in Ohio, and 90 horses on ten farms in New York. The purpose of 

 the bulletin is to show how the annual cost of keeping a farm work horse and 

 the cost per hour worked may be determined, and to point out that the cost per 

 hour worked is the true measure of the profitableness of a horse to its owner. 



The several items of cost and credit which make up the annual average cost 

 per horse are analyzed in detail and tabulated. It was found that the annual 

 net cost for keeping a horse was $100.65 in Illinois, $120.37 in Ohio, and $145.02 

 in New York. A study of the relation of work performed to the total feed cost 

 shows that on an average on the farms studied there was a fairly uniform 

 difference between the average feed cost and the total cost per hour of horse 

 labor, showing that the number of hours worked and the feed cost per horse are 

 the controlling factors in the total cost per hour of horse labor. Or. the Illinois 

 farms the horses worked an average of 1,053 hours per year at an average cost 

 of 9.56 cts. per hour, on the Ohio farms an average of 866 hours per year at an 

 average cost of 13.9 cts. per hour, and on the New York farms an average of 

 1,020 hours at an average cost of 14.22 cts. per hour. 



It was found that the large farms permit of a more efficient use of horse 

 labor than do the small farms. On the large farms in Illinois there were 22.2 



