@conference {40612,
	title = {Responses to selection for lean tissue growth in Dorset Down sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {255-260},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Responses to selection using a lean tissue growth index were estimated  
from performance data of the Lincoln University Dorset Down flock.  Data  
were available for ewes (n=922) born in the years 1984 - 1991 and rams  
(n=816) born in 1984 - 1992.  Data were from two closed lines, one control and  
the other selected for high lean tissue growth.  Initially selection was on the  
basis of an index comprising measurements of live weight and fat depth.   
Subsequently muscle depth was incorporated into the index.  Ewes and rams  
born in spring each year were run separately at pasture from weaning (late  
summer) onwards.  Performance testing was in the following autumn for ewes  
and winter for rams.  Measurements were live weight and <I>in vivo</I> ultrasonic 
fat and muscle depths.  Responses were calculated from regression of the  
difference between the line means for breeding value against time.  Breeding  
value estimates were derived by AIREML analyses. 
 
Both sexes exhibited desirable responses in all component traits: rams;  
+0.290kg/yr, +0.019mm/yr and -0.013mm/yr and ewes; +0.154kg/yr,  
+0.028mm/yr and -0.028mm/yr for live weight, muscle and fat depths  
respectively.  Increases in muscle depth occurred after it was incorporated  
into the selection index. },
	issn = {1176-5283},
	author = {Nsoso SJ and Beatson PR and Young MJ and Logan CM}
}
