@conference {40406,
	title = {Effect of sire, breed and age on plasma FSH concentrations in FecB FecB and Fec+ Fec+ Booroola rams before and after castration},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {52},
	year = {1992},
	month = {Jan},
	pages = {175-178},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Feed intake and wool production data on unmated, single- and  twin-bearing/rearing ewes from a year-long field trial were incorporated  into feed budget models of a hill country farm. Increasing the basal  liveweight of an unmated ewe from an average of 45 to 55 kg increased  greasy wool production from 4.15 to 5.10 kg/ewe. Relative to the annual  feed requirements (614 kg DM/y) of a typical breeding ewe (1 sheep stock  unit (ssu) on the case farm the annual feed requirements of unmated 45,  50 and 55 kg ewes were estimated to be 0.58, 0.66 and 0.72 ssu. At 1991  costs and prices the gross margins (GM) were $15.50/ssu for breeding  ewes (100\% lambs weaned) and, depending on liveweight, from $7.12 to  $8.11/ssu for the all-wool options. The breeding ewe policy remained  more profitable even if low lamb prices or a poor lambing percentage  were achieved.  },
	issn = {1176-5283},
	author = {Isaacs KL and McNatty KP and McLeod BJ and Condell L and Littlejohn RP}
}
