GENERAL PROBLEMS IN SHEEP HUSBANDRY 539 



ability to exist in great flocks and thrive under the most ordinary con- 

 ditions of care and keep. In the grazing districts of the West thousands 

 of sheep carrying more or less Merino blood are held in single bands 

 where the range furnishes sufficient feed, and tens of thousands may 

 be successfully fed together, as is still done with range sheep which are 

 brought to feeding points in the western states and in the Mississippi 

 valley. 



In the humid regions, however, 200 sheep of the mutton breeds are 

 as many as can usually be successfully managed in one flock, for when 

 the farm is heavily stocked with sheep, the troubles from stomach worms 

 and other parasites are much greater. The beginner had best begin 

 with a flock of 25, increasing the number as experience grows. 



826. Breed tests. The experiments which have been carried on to 

 compare the various breeds of sheep have not yet been extensive enough 

 to warrant definite conclusions concerning any differences in economy 

 of production. Two trials by Wilson and Curtiss at the Iowa Station 2 

 furnish the most complete data yet available. Wethers of various 

 breeds were fed the same rations for periods of 90 and 105 days, respec- 

 tively. Nine breeds were compared in these tests Merinos, Dorsets, 

 Oxfords, Shropshires, Southdowns, and Suffolks among the medium- 

 wooled breeds; and Cotswolds, Leicesters, and Lincolns among the long- 

 wooled breeds. The "Merinos" (which were Delaine-Merinos in the 

 first trial and Rambouillets in the second one) made the smallest daily 

 gains and required the largest amount of feed per 100 Ibs. gain, due 

 to the fact that they are slow-maturing and are not primarily mutton 

 sheep. The long-wools made somewhat the largest gains and yielded the 

 heaviest fleeces. Considering the relatively small numbers of each breed 

 included in the trials, there were no significant differences among the 

 mutton breeds in the amounts of feed required for 100 Ibs. gain. 



827. Cross breeding for the western ranges. In earlier years the sheep 

 on the western ranges were of Merino blood, for wool was the product 

 sought. When the demand for lamb and mutton increased, rams of the 

 mutton breeds were used on the range ewes to improve the mutton 

 qualities of the offspring. It has been found, however, that the in- 

 troduction of mutton blood can not go beyond a certain degree in the 

 range flocks of breeding ewes, or they will lose both their hardiness and 

 their Merino herding instinct, and will scatter on the range so that many 

 are lost or fall prey to wild animals. A rather troublesome system of 

 crossbreeding must accordingly be followed in range flocks, in order to 

 produce lambs of good mutton conformation and yet retain sufficient 

 Merino blood in the breeding ewes. 



To avoid this, the Corriedale breed was developed in New Zealand by 

 crossing Lincoln and to a lesser extent Leicester rams on Merino ewes, 

 mating the hybrids together, and selecting the offspring with the de- 

 sired qualities. The value of this breed for American range conditions 



3 Iowa Buls. 33, 35. 



