@conference {40990,
	title = {Growth curves and productivity of Holstein-Friesian cows bred for heavy or light mature live weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {68-72},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {This paper presents data for live weights (LW) from birth to maturity, and for yields of milk and milksolids (MSY) per lactation, from two lines of Holstein-Friesian cows bred for heavy (H) or light (L) mature LW. Compared with the Brody, Gompertz and Logistic functions, the Von Bertalanffy function provided the best fit to the LW data, and prediction from this function has been used in the following analyses. The breeding values (BV) for LW of the sires (H: 86.3 kg; L: 31.0 kg) and maternal grandsires (MGS) (H: 55 kg; L: 38 kg) used to develop the H and L LW lines were higher (P<0.001) for the H line than for the L line, and they were significantly associated with the actual birth weight (H: 41 kg; L: 35 kg) and mature live weight (H: 520 kg; L: 467 kg) of the cows. The heavy sires also had significantly higher BV for yield of milk (H: 1037 l; L: 737 l), milkfat (H: 33.0 kg; L: 27.5 kg), and milk protein (H: 31 kg; L: 22 kg), and the H cows produced more milk (H: 4708 l; L: 4323 l), and MSY (H: 364 kg; L: 348 kg) than the L cows. However, L sires had slightly higher (P = 0.07) value for Breeding Worth than the H sires (H:37; L:46), and there were only small differences in yields of milk or MSY between the two lines when these were expressed per kg of LW, per kg of LW0.75 or per tonne of dry matter required (H: 84 kg MSY/tonne DM; L: 87 kg MSY/tonne DM). The results indicate that the extra MSY by the H cows (+ 16 kg) almost compensated for the effect of their extra LW (+ 46 kg), so that the H cows were only slightly less efficient than the L cows, as predicted by their respective sire{\textquoteright}s Breeding Worth. },
	issn = {1176-5283},
	author = {Garcia-Muniz JG and Holmes CW and Garrick DJ and Lopez-Villalobos N and Wickham BW and Wilson G and Brookes IM and Purchas RW}
}
