@conference {41287,
	title = {Feed intake capacity in Holstein-Friesian cows which differed genetically for body weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {207-209},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The feed intake capacity (FIC) of pregnant, non-lactating Holstein-Friesian cows, selected for either high (H) or low (L) breeding values for live weight (LW), was measured when fed to appetite on hay (7.5 MJ ME/kg DM in 1998) and on pasture (11.1 MJ ME/kg DM in 1999). The H cows were heavier than the L cows in both years (546 v 482 kg; 540 v 464 kg in years 1 and 2 respectively), and the H cows ate significantly (P<0.01) more feed than the L cows in both years (12.5 v 11.1 kg hay DM, and 13.1 v 11.6 kg pasture DM per day in years 1 and 2 respectively. Regression analysis showed that for each 100-kg increase in LW, daily DMI per cow increased by 1.43 and 1.81 kg respectively in 1998, and 1999. Regression analysis of the data after conversion into log10 , showed that DMI was proportional to LW0.66 and LW0.65 in 1998 and 1999 respectively. These results indicate that the genetically heavier cows ate more DM than the genetically lighter cows. Nevertheless, the difference between maintenance costs and FIC (or "net" FIC) may be similar for both strains, so that the smaller intake of the lighter cows does not disadvantage their productive capacity. },
	issn = {1176-5283},
	author = {Caicedo-Caldas A and Lemus-Ramirez V and Holmes CW and Lopez-Villalobos N}
}
@conference {41291,
	title = {Intake, live weight and feed-conversion efficiency of lactating Holstein-Friesian dairy cows which differ genetically in live weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {221-223},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The objective of this study was to measure during mid lactation the effect of live weight on the metabolisable energy intake by cows in two lines of Holstein-Friesians selected for heavy or light mature live weight. Yields of milksolids and intakes of dry matter were estimated during two 3-day faeces collection periods. Live weights were measured once in each period. Intakes of pasture dry matter by individual cows were estimated using the alkane technique. Least-square means for live weight, daily yield of milksolids, intakes of dry matter, intakes of metabolisable energy and feed-conversion efficiency for the heavy and the light line were obtained. Linear regression coefficients of metabolisable energy intake on metabolic live weight and yield of milksolids were obtained. Mean values were 15.0 vs. 15.3 kg of dry matter eaten/cow daily, 532 and 488 kg live weight, 1.58 and 1.55 kg milksolids/cow daily, and 108 and 106 g milksolids/kg of dry matter eaten, for the heavy and the light line respectively. The partial regression coefficient of metabolisable energy intake on metabolic live weight was 0.65 MJME/kg LW 0.75 for both lines, similar to commonly reported values. Both lines had similar feed-conversion efficiencies. These data, from 73 grazing cows, generally support other data, and show that live weight does affect maintenance requirements as expected for cows in the heavy and light live weight lines. But they disagree with previous data because the heavy cows did not have higher intakes.},
	issn = {1176-5283},
	author = {Tolosa MX and Caicedo-Caldas A and Holmes CW and Lopez-Villalobos N}
}
