@conference {40349,
	title = {Selection for lean and against fat in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {401-404},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {A model quantifying outputs of carcass from pasture inputs was  used to study factors affecting biological efficiency (BE) of finishing  beef from 6 months to slaughter.   Two factors which determined biological efficiency (BE, kg carcass  gain/ha/yr) on pasture were pasture utilisation and animal conversion  efficiency. Effects of stocking rate, length of finishing period (1 v 2  years), mature size and maintenance efficiency of beasts on BE and its  components were studied.   Stocking rate was the major factor affecting utilisation rate however  more lighter (eg. 12\% more 750 kg than 900 kg mature sized) cattle need  to be run to achieve equivalent pasture utilisation. Nine percent less  cattle can be run in a 2 year system.   Average conversion efficiency was 40\% lower from finishing at 2 years  than 1 year. An increase in mature size from 750 to 900 kg increased  animal conversion by 14\%. A 20\% decrease in maintenance requirements  increased animal conversion by 10\%.   Constraints to produce specified carcass weights further favoured BE  with high mature weight beasts, particularly at intermediate carcass  weights (250 kg).   Breeding cattle for high mature size appears the best way of improving  the cattle available for finishing.  },
	issn = {1176-5283},
	author = {Clarke JN and Rae AL}
}
