@article {3672,
	title = {Technical note: A comparison of editing criteria for lying-behaviour data derived from three-dimensional accelerometer devices on grazing dairy cows},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {80},
	year = {2020},
	month = {09/2020},
	pages = {8-13},
	address = {Online},
	abstract = {Shorter, more-frequent lying bouts (LB) could be used to predict calving and as an indicator of animal discomfort and ill-health. In
this technical study, we reviewed the literature to describe criteria for removing false short LB, caused by minor movements, from
accelerometer data using IceRobotics technology. Using an existing dataset of grazing cows, we compared unedited with edited
accelerometer data after applying three different LB thresholds (LB <33 s, <=2 min, and <4 min were removed) within IceQube
and IceTag accelerometers. Daily lying time, LB (no./d) and LB duration were derived from either IceQube or IceTag devices
for 146 and 159 multiparous cows, respectively. Very-short LB were more common in IceTag than IceQube data. Applying a
shorter LB criterion (<33 s) to the IceQube dataset produced minimal differences between unedited (8.8{\textpm}3.6 no./d; n=64,512 lying
records) and edited data (8.3{\textpm}3.4 no./d; n=60,463). In contrast, we observed large differences between unedited (307{\textpm}293 no./d;
n=2,305,693) and edited data (8.8{\textpm}4.1 no./d; n=66,139) when a longer LB criterion (<=2 min) was applied to the IceTag dataset.
Removing short LB that are unlikely to represent true behaviour will improve the interpretation of lying behaviour data; however,
prospective studies are needed to determine the most-suitable LB criterion.

Keywords: lying behaviour; grazing cows; accelerometer},
	issn = {1176-5283},
	author = {Hendriks SJ and Phyn CVC and Turner S-A and Mueller KR and Kuhn-Sherlock B and Donaghy DJ and Huzzey JM and Roche JR}
}
@conference {3672,
	title = {Contract session: An overview of postpartum hyperketonaemia and its association with cow health and performance in pasture-based dairy systems},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {77},
	year = {2017},
	month = {06/2017},
	pages = {104-106},
	address = {Rotorua},
	abstract = {Following calving, dairy cows undergo a period of negative energy balance during which they mobilise body tissue (such as fat) to support the demands of lactation. When the negative energy balance is severe, the inability of the liver to process all the mobilised fatty acids can lead to hepatic lipidosis (i.e., fatty liver disease) and incomplete fatty acid oxidation. The latter results in the hepatic production of ketone bodies, predominantly β-hydroxybutyrate (BHB), which are released into the circulation as the product of ketogenesis. The increased concentration of ketones in blood is known as hyperketonaemia...},
	issn = {1176-5283},
	author = {Phyn CVC and Kuhn-Sherlock B and Turner S-A and Grala TM and Burke CR and Roche JR}
}
@conference {89260,
	title = {Modelling the effect of temporary once-a-day milking durinmg early lactation on dairy farm production and profitability},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {73},
	year = {2013},
	month = {Jan},
	pages = {21-25},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {<p>The DairyNZ Whole Farm Model was used to predict the effect of temporary once-a-day (OAD) milking during the calving period on milksolids (MS) production, farm profitability and herd body condition score (BCS) at dry-off. Farms from three regions and three independent seasons were modelled for: wholeseason twice-a-day (TAD) milking of all cows (Control), OAD milking of all cows for eight days immediately post-calving and TAD milking thereafter (Col OAD), OAD milking of the herd for three weeks from the planned start of calving (PSC) and TAD milking thereafter (3 wk OAD), and OAD milking of the herd for six weeks from the PSC and TAD thereafter (6 wk OAD). Model outputs indicated MS production (kg/ha) losses of 2, 1.2 and 3.7\% and profit ($/ha) losses of 6.5, 4.5 and 11.6\% for the Col OAD, 3 wk OAD and 6 wk OAD regimes, respectively. Slight improvements in dry-off BCS were predicted for the OAD milking regimes, comparedwith the control. Milking the herd OAD for three weeks from the PSC may be the prefered strategy to offer labour, lifestyle and animal health benefits with the smallest losses of MS production and farm profit.</p>
},
	issn = {1176-5283},
	author = {Khaembah EN and Rius AG and Beukes PC and Levy G and Gregorini P and Roche JR and Kay JK and Phyn CVC}
}
@conference {79001,
	title = {Once-daily milking during a feed deficit improves energy status in early lactating dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {129-133},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The aim of this study was to determine the effect of once-daily (1X) milking during a feed deficit on energy status of grazing dairy cows. Multiparous cows (n = 120), grazing to residuals of 1,600 kg DM/ha, and milked twice-daily (2X) from calving until approximately 35 days-in-milk, were allocated to one of four treatments in a 2 x 2 factorial arrangement. Cows were adequately fed (14 kg DM/cow/d) or underfed (8 kg DM/cow/d) and milked 2X or 1X for three weeks, after which all cows were milked 2X and grazed to residuals of 1,600 kg DM/ha for 20 weeks. During the three-week treatment period, plasma concentrations of glucose, insulin and insulin-like growth factor-I (IGF-I) were less in underfed compared with adequately cows, while non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA) and liver enzymes were greater. An interaction existed and the increase in liver enzymes with underfeeding only occurred in cows milked 1X. Cows milked 1X had greater plasma glucose, insulin and IGF-I and less NEFA and BHBA than those milked 2X. Data indicate that milking cows 1X during an acute feed deficit improves energy status.},
	issn = {1176-5283},
	author = {Kay JK and Phyn CVC and Rius AG and Morgan SR and Grala TM and Roche JR}
}
@conference {75869,
	title = {BRIEF COMMUNICATION: Effect of milking frequency and concentrate supplementation on milk production during an extended lactation in grazing dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {42-44},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {Extending the lactation for longer than 300 days can be used to maintain a high level of milk production, improve reproductive function, and animal welfare. Extended lactations of ~600 days in milk (DIM) in pasture-based systems could benefit the dairy industry by maintaining a relatively constant milk supply throughout the season, improving labour conditions, and reducing on-farm costs (Kolver et al., 2007). Milk production during an extended lactation is dependent... Continued},
	issn = {1176-5283},
	author = {Rius AG and Phyn CVC and Kay JK and Morgan SR and Grala TM and Roche JR}
}
@conference {75868,
	title = {Effect of milking frequency and nutrition in early lactation on milk production and body condition in grazing dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {37-41},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {Multiparous Holstein-Friesian cows (n = 120), grazing pasture and milked twice-daily (2X) from calving until ~35 days in milk, were allocated to one of four treatments. Treatments consisted of 2X or once-daily milking (1X), and UnRes (15 kg dry matter (DM)/cow/day) or Res (9 kg DM/cow/day) pasture intake for three weeks. Following treatment, all animals were milked 2X and offered pasture (residuals of 1,600kg DM/hectare) for 20 weeks. During the treatment period (Weeks 1-3), yields of milk, fat, protein and lactose decreased with reduced milking frequency and feeding level. Interactions existed for milk, protein and lactose yields and the decrease due to 1X milking was greater in the UnRes than Res cows. During the post-treatment periods (Weeks 4-12 and Weeks 13-23) no interactions were present. Restricted cows produced less milk, fat, protein and lactose compared with UnRes cows during Weeks 4-12, but no difference existed during Weeks 13-23. During Weeks 4-12, cows milked 1X produced less milk, fat, protein and lactose than those milked 2X and these differences remained during Weeks 13-23. During the treatment period, body condition score was less in Res than UnRes cows, however there was no effect of milking frequency on body condition score. Neither feeding level nor milking frequency altered post-partum anoestrus interval.},
	issn = {1176-5283},
	author = {Kay JK and Phyn CVC and Rius AG and Morgan SR and Grala TM and Roche JR}
}
@conference {75870,
	title = {Effect of temporary alterations to milking frequency during the early post-partum period on milk production and body condition score in grazing dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {45-49},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {This study investigated the immediate and long-term effects of temporary alterations to milking frequency post-partum in grazing cows. Multiparous Holstein-Friesian cows (n = 150) were assigned to one of five groups at calving: milked twice daily (2X, Control), or either once daily (1X) or thrice daily (3X) for three or six weeks, and 2X thereafter. During Weeks 1-6 post-calving, 1X for six weeks resulted in greater decreases in milk, fat, protein and lactose yields (P <0.05) relative to 2X than 1X for three weeks. Furthermore, 1X for three or six weeks reduced fat, protein and lactose yields (P <0.05), and tended to reduce milk yields (P = 0.08), for the remainder of lactation (Weeks 8-32). Body condition was greater for 1X cows at Weeks 6 and 8 (P <0.05) and tended to be greater during Weeks 8-32 (P = 0.09). Milking 3X for three or six weeks increased milk yield (P <0.05) relative to 2X during Weeks 1-6 and milk yields were numerically greater during Weeks 8-32 (P = 0.17); however, fat and protein yields were not affected. Once-daily milking for three or six weeks postcalving had lactation-long negative effects on milk production, whereas 3X increased milk yield but did not result in short- or long-term benefits in fat and protein yields.},
	issn = {1176-5283},
	author = {Phyn CVC and Kay JK and Rius AG and Morgan SR and Roach CS and Grala TM and Roche JR}
}
@conference {75861,
	title = {Temporary alterations to milking frequency, immediately post-calving, modified the expression of genes regulating milk synthesis and apoptosis in the bovine mammary gland},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {3-8},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {Temporary changes to milking frequency during early lactation can elicit lactation-long changes in milk production. This study tested whether altered milking frequency, immediately post-calving, would affect mammary gene expression during and/or following treatment. Multiparous, grazing dairy cows (n = 150) were allocated to one of five treatments post-calving: milking thrice-daily (3X) for three or six weeks, and twice-daily (2X) thereafter; milking once-daily (1X) for three or six weeks, and 2X thereafter; or milking 2X for the entire lactation. Mammary tissue was biopsied from 12 cows per treatment at three, six and nine weeks postcalving and expression of milk synthesis and apoptosis genes measured using quantitative PCR. The milk fat, lactose and protein genes were down-regulated (P <0.05) in cows milked 1X compared with cows milked 2X. At nine weeks post-calving, cows milked 1X for three weeks had reduced mRNA levels of milk synthesis genes compared with cows milked 1X for six weeks (P <0.05). The expression of apoptosis genes was up-regulated (P <0.05) in cows milked 1X relative to 2X, during and post-treatment. There were no gene expression changes during 3X milking compared with cows milked 2X. Changes in gene expression observed in cows temporarily milked 1X reflect physiological changes consistent with longer-term reductions in milksolids yield.},
	issn = {1176-5283},
	author = {Grala TM and Phyn CVC and Kay JK and Rius AG and Littlejohn MD and Snell RG and Roche JR}
}
@conference {60938,
	title = {The effect of concentrate supplementation on milk production during an extended lactation in grazing dairy cows : Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {43-45},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Extended lactation systems where cows are milked for longer than 300 days, provide an opportunity for farmers to use the lactation potential of genetically superior cows, reduce calving and mating costs, even-out labour requirements, and/or build herd size by retaining non-pregnant cows. However, depending upon cow genetic strain and nutrition, milk production can be reduced in an extended lactation system relative to a {\textquoteright}normal{\textquoteright} lactation of 260 to 300 days (Kolver et al., 2007; Grainger et al., 2009). Winter-feeding levels are potentially important... Continued},
	issn = {1176-5283},
	author = {Phyn CVC and Kay JK and Roach CG and Kolver ES}
}
@conference {60934,
	title = {The effect of feed restriction during peak lactation on milk production parameters : Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {24-26},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Adverse weather conditions that reduce pasture growth and/or quality can place the lactating dairy cow under periods of transitory nutritional stress. Previous research that has focused on the effects of feed restrictions in a pasture-based dairy system have imposed feed deficits either pre-calving (Roche, 2007), immediately post-calving for five to six weeks (Bryant \& Trigg, 1979; Roche, 2007) or up to a 23\% restriction in dry matter intake (DMI) (Bryant \& Trigg, 1979). All experiments reported an immediate reduction in milk production; however, the longer-term effects varied depending on... Continued },
	issn = {1176-5283},
	author = {Kay JK and Phyn CVC and Williams YJ and Roche JR and Burke CR and Meier S}
}
@conference {42049,
	title = {Effect of genotype and concentrate supplementation on dairy product mix and the value of milk produced by grazing dairy cows during an extended lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {79-83},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {Dairy product mix and milk value were investigated in Holstein-Friesian cows of New Zealand or overseas origin that grazed pasture and were supplemented with 0, 3 or 6 kg DM concentrate/cow/day during a 600-day extended lactation. A dairy product supply chain model was used to predict relative changes in dairy product mix and milk value during the "extended period" (300 to 600 days in milk) compared with the "normal period" (0 to 300 days in milk). Cow genotype and level of concentrate supplement affected dairy product yields, with little consistency of effect between "normal" and "extended" periods. Milk produced during the "extended period" resulted in more cheese, butter, butter milk powder, casein, and whey protein concentrate, but less whole milk powder, skim milk powder and whey milk powder compared to the "normal period". The overseas strain and those cows receiving higher levels of concentrates had less of a decline in whole milk powder yields associated with the "extended period". Milk value ($/L), was predicted to be 20.8\% higher during the "extended period" compared with the "normal period". These results indicate that extended lactations may improve the dairy product mix and milk value following processing. },
	issn = {1176-5283},
	author = {Turner S-A and Phyn CVC and Kolver ES and Aspin PW and Lopez-Villalobos N}
}
@conference {42055,
	title = {Effect of genotype and diet on feed conversion efficiency of dairy cows during a 600-day extended lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {100-104},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {This study investigated the effect of genotype and diet on the gross feed conversion efficiency (FCE) of cows milked for 600-day extended lactations (24-month season) compared with 300-day lactations (12-month season). North American (NA) and New Zealand (NZ) Holstein-Friesians (HF) grazed pasture and were supplemented with either 0, 3 or 6 kg DM concentrate/cow/day. In a normal 12-month season, gross FCE was greater for NZ HF compared with NA HF cows when fed 0 or 3 kg DM concentrate (96 and 104 vs. 90 and 99 kg milksolids (MS)/t dry matter intake (DMI), respectively), but similar when fed 6 kg DM (101 kg MS/t DMI). However, during an extended 24-month season, NZ HF cows had a lower gross FCE than NA HF when fed 6 kg DM concentrate (86 vs. 99 kg MS/t DMI, respectively) and similar FCE when fed 0 or 3 kg DM (85 and 94 vs. 86 and 99 kg MS/t DMI, respectively). Regardless of diet, gross FCE in an extended lactation was 98\% of that obtained in a normal season for NA HF cows, but only 88\% for NZ HF, indicating that NA HF are better suited to converting feed into high MS production in extended lactations. },
	issn = {1176-5283},
	author = {Phyn CVC and Clark C and Aspin PW and Kolver ES}
}
@conference {41801,
	title = {Jersey cows milked once-a-day can produce 1,200 kg milk solids per hectare},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {68},
	year = {2008},
	month = {Jan},
	pages = {96-97},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Brisbane, Australia},
	abstract = {While dairy cows are generally milked twice-a-day (TAD) in New Zealand, more farmers are adopting a once-a-day (OAD) milking routine to improve their lifestyle, reduce farm costs and improve animal welfare. Clark et al. (2006) reported that the yield of milksolids (MS) from Jersey cows was less affected (-19.9\%/cow) by OAD milking than the MS yield from Holstein-Friesian cows (-29.4\%/cow). Jersey cows milked OAD in Taranaki between 2000 and 2004 averaged 222 kg MS/cow and 979 kg MS/ha (Clark et al., 2006). In the 2006/07 season average per cow production from cows milked TAD in New Zealand was 330 kg MS ...Continued},
	issn = {1176-5283},
	author = {Dalley DE and Clough JW and Hofmann LA and Phyn CVC and Clark DA}
}
@conference {41765,
	title = {Induced physical distension of rat mammary glands accelerates the onset of apoptosis and involution compared with milk accumulation alone : Brief Communication},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {403-406},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Extended periods of milk accumulation result in reduced milk secretion, increased apoptosis and eventually, involution of mammary glands. The subsequent change in epithelial cell shape from a cuboidal to a flattened morphology as the alveoli distend with milk may initiate changes in protein and gene expression (mechanotransduction) triggering the process of involution (Davis et al., 1999).},
	issn = {1176-5283},
	author = {Phyn CVC and Dobson JM and Davis SR and Stelwagen K and Singh K}
}
@conference {41749,
	title = {Production and physiological indicators to select cows suitable for extended lactations},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {315-319},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Individual cows vary in their ability to maintain milk production for an extended lactation. Identifying production and physiological markers to indicate cows suitable for extended lactations would allow dairy farmers to make early decisions to withhold mating of individual cows or to continue milking specific nonpregnant cows through the winter months. Fifty-six genetically divergent overseas and New Zealand Holstein Friesians were allocated to three pasture-based dietary treatments (0, 3 and 6 kg concentrate DM/cow/d) and mating was withheld to target a 670-d lactation. Within each treatment there was little correlation between animal evaluation index values and milksolids (MS) production during the extended lactation period (>296 days in milk; DIM). There was a positive correlation between MS yield from the initial normal season (<296 DIM) and extended lactation MS production; and a negative correlation between body condition score (BCS) at theoretical dry off date (~296 DIM) and extended lactation MS yield. Plasma hormone and metabolite data from wk 1-10 postpartum demonstrated a positive association between nonesterified fatty acid levels and extended lactation MS production, whereas glucose,insulin, and insulin like growth factor-1 were negatively associated with extended lactation MS production. Overall, data indicate that the animal evaluation index is not a good indicator of animals suitable for extended lactation, however normal season milk production, early lactation plasmahormone and metabolite and late lactation BCS data may be useful to identify animals that will undergo a successful extended lactation.},
	issn = {1176-5283},
	author = {Kay JK and Aspin PW and Phyn CVC and Roche JR and Kolver ES}
}
