@conference {3672,
	title = {Supply curves for yields of dairy products from first-lactation Holstein Friesian, Jersey and Holstein Friesian-Jersey crossbred cows accounting for seasonality of milk composition and production.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {76},
	year = {2016},
	month = {07/2016},
	pages = {139-143},
	address = {Adelaide},
	abstract = {The economic efficiency of a milk-processing system is influenced by seasonality of the milk supply, and changes to milk
composition, influences the product potential of that milk. Lactation curves for milk yield and composition for seasonal calving
first-lactation Holstein Friesian (F), Jersey (J) and Holstein Friesian-Jersey crossbred (FxJ) cows were used as inputs in a
deterministic simulation model to produce seasonal curves for daily yields of dairy products. The dairy products were whole milk
powder, skim milk powder, cheese, or butter. Dairy product potential was estimated for each animal from a population of 4333
mixed-breed, first-lactation cows. Lactation lengths differed (P<0.0001), among F, FxJ, and J, which averaged 219, 222 and 221
days respectively. Total-lactation milk yield was different (P<0.0001) among breeds and averaged 3257, 3092 and 2902 litres for
F, FxJ and J cows, respectively. Whole-milk powder potential (yield per 1000 L of milk) was greatest at the start of the season
and least at the end of the season, whereas cheese-production potential (yield per 1000 L of milk) followed the opposite pattern.
Total-lactation whole-milk powder yield was different among breeds (P<0.0001) at 366, 338 and 312 kg of whole-milk powder for
F, FxJ and J cows, respectively. Total-lactation cheese yield was also different among breeds (P<0.0001), and was 371, 375 and
361 kg for F, FxJ and J cows, respectively. The supply curves indicate that milk is best processed into whole or skim milk powder
during peak season, and cheese and butter at the end of lactation. However, seasonal production of specific products would limit
the use of by-product lactose from cheese manufacture in the production of milk powders, and thus negate the efficiency gains
from changes to processing priorities.},
	issn = {1176-5283},
	author = {Sneddon NW and Lopez-Villalobos N and Davis SR and Hickson RE and Shalloo L and Garrick DJ}
}
@conference {3672,
	title = {Estimation of crossbreeding effects on yields of dairy products and value of milk processed in different product portfo},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {48-53},
	address = {Dunedin},
	abstract = { The international market requires milk products to meet specified minimum standards that define acceptable composition. This
study used a deterministic simulation model to estimate milk products yields of individual cows for different export markets. Four
milk product portfolios were analysed which included 100\% of the milk to either whole-milk powder (WMP), skim-milk powder,
cheese, or butter. Milk product potential was estimated for 4310 mixed-breed heifers from LIC Sire Proving Scheme herds based
on total lactation production. Lactation lengths were 212, 214 and 213 days for Holstein Friesian (HF), Holstein Friesian-Jersey
crossbreds (HFxJ), and Jerseys (J) respectively. Milk yields were significantly different between breeds averaging 3121 for HF,
2947 for HFxJ, and 2751 litres for J cows. Holstein Friesians had the lowest fat, protein and lactose concentrations, whereas J had
the highest. Holstein Friesian had the greatest yields of WMP per 1000 litres of milk, whereas J had the least. For all scenarios, J
milk was most valuable per litre. Crossbred cows provided greater total milk income for all scenarios except 100\% butter. Positive
heterosis effects were estimated for first-cross HFxJ animals for milk production and product yields. Crossbreeding produces cows
with milk better suited to the processing requirements of the New Zealand dairy industry and returning greater value to the New
Zealand dairy farmer.},
	issn = {1176-5283},
	author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L and Garrick DJ}
}
@conference {3678,
	title = {Supply and demand for lactose in the New Zealand dairy industry},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {74},
	year = {2014},
	month = {06/2014},
	pages = {215-219},
	address = {Napier},
	abstract = {Global milk product demand has been rapidly growing in the past decade, which is reflected in an increased demand for milk powders. The New Zealand dairy industry is capitalising on this by shifting its product portfolio towards milk powders. However, current international product specifications in combination with New Zealand milk composition and an industry objective to maximise farm profitability makes the industry deficient in milk lactose. This study aimed to determine how lactose deficit or surplus is influenced by changes in the product portfolio. In order to quantify this lactose balance, a computer simulation model was used (Moorepark Processing Sector Model). The 2012 New Zealand milk production (19.129 billion litres, milkfat concentration (4.99\%), protein concentration (3.82\%) and lactose concentration (4.70\%, anhydrate)) was used within the analysis. Four manufacturing portfolio scenarios were investigated with different proportions of milk diverted to whole milk powder production (80\%, 60\% (current proportion), 30\% and 10\%). The model simulated the total production of whole milk powder, skim milk powder, casein, whey powder, buttermilk powder, butter and cheese. Whole milk powder production varied from 2,292,000 tonnes for the 80\% scenario to 286,000 tonnes for the 10\% scenario. Lactose mass balance varied from 214,000 tonnes in deficit for the 80\% scenario to 510,000 tonnes in surplus for the 10\% scenario. These analyses indicate that as more whole milk powder is produced, milk from current New Zealand cows results in an increased deficit of milk lactose. The national breeding objective could be adjusted to reflect changes in the future product portfolios to better align the composition of milk with the likely product mix.},
	issn = {1176-5283},
	author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L and Garrick DJ and Geary U}
}
@conference {89263,
	title = {Review of milk payment systems to identify the component value of lactose},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {73},
	year = {2013},
	month = {Jan},
	pages = {33-36},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {<p>New Zealand{\textquoteright}s export dairy product mix has shifted towards the production of whole milk powder. This has resulted in a deficit in milk lactose to meet international standardisation requirements for whole milk powder. Currently, the deficit in lactose is filled using imported lactose with an estimated cost of New Zealand dollars 300 million annually. This study compares payment systems from America, Europe, Australia and New Zealand, and outlines possible strategies for payment for lactose to New Zealand dairy farmers. The prominent milk payment system in New Zealand is the {\textquoteleft}A+B-C{\textquoteright} multiple component pricing system, where A and B are the monetary values per kilogram of fat and protein and C is the penalty per litre of milk volume. An alternative payment system that may encourage farmers to increase the supply of lactose could be {\textquoteleft}F+P+L-V{\textquoteright} where F, P and L are the monetary values of fat, protein and lactose respectively and V is the penalty per litre of milk volume. This payment system is currently in operation at one small New Zealand dairy processor. This study has shown that the {\textquoteleft}F+P+L-V{\textquoteright} payment system results in smaller deviation from the true value of the milk for differing breeds, milk compositions and product mixes than the current {\textquoteleft}A+B-C{\textquoteright} system of milk payment.</p>
},
	issn = {1176-5283},
	author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L}
}
@conference {78991,
	title = {Genetic parameters for lactose and its relationship with concentrations and ratios of other milk components},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {76-80},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {<p>The objective of this study was to estimate genetic parameters for milk yields, milk concentrations and ratios of milk components. Herd-test records from 268 Jersey cows from a Waikato dairy farm were obtained along with pedigree information. Genetic and phenotypic (co)variances for daily yields of milk (MY), fat (FY), protein (PY), milksolids (MSY; FY + PY) and lactose (LY), percentages of fat, protein, and lactose, and ratios of protein to fat (P:F) and protein to protein plus lactose (P:PL), and somatic cell score, were obtained with single trait and bivariate animal models using a restricted maximum likelihood methodology. The models included the fixed effects of month of calving and days in milk, modelled using an exponential curve, lactation number and the random effects of animal and cow permanent environment effects were also included in the model. Heritability estimates were 0.50 {\textpm} 0.12 (standard error) for MY, 0.25 {\textpm} 0.10 for FY, 0.30 {\textpm} 0.12 for PY, 0.27 {\textpm} 0.11 for MSY, 0.50 {\textpm} 0.12 for LY, 0.24 {\textpm} 0.04 for P:F ratio and 0.53 {\textpm} 0.04 for P:PL ratio. The genetic correlations for daily yields were high and positive. The genetic correlation between MSY and P:F ratio was -0.35 indicating that increases in MSY under the current breeding objective will decrease the P:F ratio, thus departing from an optimal ratio for whole milk powder processing.</p>
},
	issn = {1176-5283},
	author = {Sneddon NW and Lopez-Villalobos N and Hickson RE and Shalloo L}
}
@conference {42051,
	title = {Genetics of residual energy intake in Irish grazing dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {88-91},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {The objective of this study was to investigate the genetics of residual net energy intake (RNEI) in grazing Holstein-Friesian cows. RNEI was defined as net energy intake minus predicted net energy requirements using the unit{\'e} fourrag{\`e}re lait (UFL) system. Net energy intake from grass and concentrate was estimated up to four times per lactation on 1,111 lactations from 463 cows on an experimental farm in Southern Ireland. Grass dry matter intake was estimated using the n-alkane technique. Lactation curves for milk, fat, protein, lactose and live weight were modelled with splines using weekly measures. A random regression was used to estimate residual, additive genetic and permanent environmental variances for RNEI and breeding values at Day 60 for each cow. Heritability for RNEI across lactation varied from 0.05 at 30 days in milk to 0.38 at 296 days in milk. Genetic parameters for RNEI obtained in this study are in agreement with those obtained under indoor conditions. Comparative performance between cows of low and high RNEI breeding value at Day 60 agrees with results obtained in beef cattle selected for high or low residual feed intake showing similar productivity but higher feed conversion efficiency in cows selected for low residual feed intake.},
	issn = {1176-5283},
	author = {Lopez-Villalobos N and Berry DP and Horan B and Buckley F and Kennedy J and O{\textquoteright}Donovan M and Shalloo L and Dillon P}
}
