@conference {41621,
	title = {Predicting cow production based on an estimate of animal genotype within a whole farm model},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {93-97},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Body condition score (BCS) has been proposed for inclusion in the New Zealand national dairy index, Breeding Worth (BW), to account for replenishment of body tissue. Currently, the breeding objectives model positively accounts for body tissue mobilisation (through extra yield), but not the negative cost of replenishing body tissue. Two methods have been proposed: 1) Including BCS directly into BW by calculating and assigning an economic value to BCS and 2) Adjusting liveweight Breeding Values (BVs) for BCS, which would mean that liveweight BVs would beexpressed at a constant BCS (indirect method). Energy equations were used to calculate the direct economic value for BCS and included a sensitivity analysis. With an economic weight of $25, the percentage emphasis of BCS in BW would be 3.4\%. Including BCS in BW, either directly or indirectly, had little impact on sire rankings (rank correlations with and without BCS within breed were >0.99) and would only have a small impact on the economic response of BW ($0.02 net /cow/annum) and the improvement in BCS(0.006 BCS units/cow/annum). It is concluded that there would be little benefit to including BCS as an independent trait in BW. Body condition score is already included as a predictor in the genetic evaluation of fertility and breeding values for BCS will be estimated routinely from the fertility model.},
	issn = {1176-5283},
	author = {Beukes PC and Palliser CC and Lancaster J and Leydon-Davis C and Levy G and Folkers C and Macdonald K and Thorrold BS and Montgomerie B and Wastney M}
}
@conference {41610,
	title = {Using a whole farm model to explore options for feed grown on-farm to achieve 1750 kg milksolids per hectare in the Waikato},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {29-34},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Dexcel{\textquoteleft}s Whole Farm Model (WFM) is a computer model of a dairy farm that simulates individual cows and paddocks, with pasture growth driven by observed climate data and with management policies guiding decisions on a daily basis. The aim of the study was to design a farm system to produce 1750 kg milksolids (MS)/ha/yr from feed grown on-farm. An average predicted pasture growth curve was derived by initialising the WFM for a typical all-pasture Waikato farm (3 cows/ha) with "best practice" management policies and running the simulation for 29 years of Ruakura climate data. The model was then used with this average growth curve to design the high producing system. Pasture growth alone (17.3 t DM/ha) did not fulfil the feed requirement for the 1750 kg MS/ha scenario, with an overall feed deficit of 3.1 t DM pasture/ha. Improvements in ryegrass cultivars and N-fertilisers could be expected to increase pasture production by around 10\%, reducing the overall feed deficit to 1.6 t DM pasture/ha. These improvements together with irrigation at 2 mm/day over the three summer months (Dec - Feb) reduced the feed deficit to zero. Irrigation could be replaced by cropping between 11\% and 20\% of the farm in a rotation of annual ryegrass yielding 7 t DM/ha and maize yielding 22 to 28 t DM/ha respectively. },
	issn = {1176-5283},
	author = {Beukes PC and Clark CEF and Wastney ME and Palliser CC and Levy G and Folkers C and Lancaster JAS and Leydon-Davis C and Thorrold BS}
}
