@conference {40197,
	title = {Exploiting the physiology of growth},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {50},
	year = {1990},
	month = {Jan},
	pages = {59-72},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The response of ram lambs from the Massey university backfat   selection lines to a urea load were measured in order to ascertain   whether there were line effects on urea space and to evaluate   relationships between urea space and empty body water content. Thirty-   six 6-8 month-old ram lambs held in metabolism crates and fed lucerne   chaff at 1.3 maintenance, were given 120mg urea/kg through jugular   catheters. Plasma urea levels were measured in samples taken before and   after the urea load. All animals were slaughtered within 7d of the urea   challenge and total body water was determined. In contrast to previous   studies, baseline plasma urea levels were not significantly higher in the   high-backfat-line animals and were not related to carcass fat or water   content. The increases in urea levels following the urea load were   greater for the high backfat line at 15min, but not at subsequent   sampling times. Clearance rates following the load did not differ   between the lines. Correlations between empty body water and estimates   of urea space were low, suggesting that this is not a useful means of   obtaining body composition information for live sheep at this stage.   Urea space estimated in several ways was significantly higher for the   low backfat line group.    },
	issn = {1176-5283},
	author = {Buttery PJ and Dawson JM and Harper JMM}
}
