@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 {41307,
	title = {Monitoring onset of puberty in three genetic strains of Holstein-Friesian dairy cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {30-33},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {Live weight and age at puberty were determined in three strains of Holstein-Friesian dairy cattle in each of two consecutive years. The strains were overseas-origin high-breeding-worth genetics (OS), New Zealand-origin high-breeding-worth genetics (NZH), and New Zealand-origin low-breeding-worth genetics (NZL), similar to the New Zealand dairy cow of the 1970s. Onset of puberty was monitored by weekly measurement of progesterone in a total of 271 heifers. Animals were considered to have attained puberty when plasma progesterone concentrations were greater than 2ng/ml in two out of three consecutive samples. Live weight at puberty differed between the strains (OS > NZH > NZL; P<0.05) but not between years. Age at puberty was affected by strain in Year 1 (OS > NZH > NZL; P<0.01), but not in Year 2. The greater live weight required to attain puberty in OS genotype animals must be recognized in target live weights for rearing of heifers. },
	issn = {1176-5283},
	author = {McNaughton LR and Morgan SR and Gore P and Verkerk GA and Holmes CW and Parkinson TJ}
}
@conference {41282,
	title = {Postpartum anoestrous interval and metabolic changes in heifers supplemented with pasture prepartum},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {188-191},
	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 whether supplementation with pasture from 6 weeks before calving would alter the postpartum anoestrous interval (PPAI) in heifers calving with low body condition score (BCS). Metabolic hormones and metabolites were measured during the pre- and postpartum period. Forty Friesian heifers were managed during the last five months of gestation to achieve a BCS (1-10) of 4.0 (restricted; R; n=27) or 5.0 (fully fed; FF; n=13) by 6 weeks prepartum. One group with low BCS then received pasture ad libitum until calving (restricted + fully fed; R+FF; n=12). Live weight (LW) and BCS were assessed weekly. Blood samples were collected weekly from 10 weeks prepartum to 10 weeks postpartum to measure glucose, urea, non-esterified fatty acids (NEFA), betahydroxybutyrate (BOH) and cholesterol content. The patterns of metabolites measured differed between groups at different times, future work to investigate the relationship these profiles and PPAI would be of value. The percentage of cows cycling as measured by an elevated milk progesterone concentration was 69\%, 75\% and 8\% for FF, R+FF and R groups, respectively. Fully feeding heifers, with low condition score, 6 weeks before calving decreased PPAI when compared to heifers receiving restricted feeding. },
	issn = {1176-5283},
	author = {Chagas LM and Morgan SR and Gore PJS and Clark BA and Verkerk GA}
}
@conference {40995,
	title = {Manipulating patterns of ovarian follicle development in cattle with progesterone and gonadotrophin releasing hormone to produce oestrous cycles with two or three follicle waves},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {58},
	year = {1998},
	month = {Jan},
	pages = {85-87},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {This study tested the hypothesis that oestrous cycles with two follicle waves created using progesterone, could be converted to oestrous cycles with three follicle waves using gonadotrophin releasing hormone (GnRH). Oestrus (Day 0) was synchronised in 24 Friesian cows. On Day 2, a progesterone containing device (CIDR) was inserted into the vagina of 16 cows for 10 days. Eight of these animals received 8{\textmu}g of buserelin (GnRH) at device removal. Eight untreated animals formed the Control group. Daily transrectal ultrasonography showed that the oestrous cycles of the cows treated only with a CIDR device had two ovarian follicle waves compared to 1/8 in CIDR+GnRH and 3/8 in Control groups (p<0.01). The average length of the oestrous cycle was shorter in the CIDR-only group (19.3 {\textpm} 0.5 days), compared to the CIDR+GnRH (20.9 {\textpm} 0.2 days) and Control (22.3 {\textpm} 1.1 days) groups (p<0.05). These results demonstrate that strategic administration of GnRH can convert progesterone induced two-wave oestrous cycles into a three-wave pattern. },
	issn = {1176-5283},
	author = {Clark BA and Rhodes FM and Burke CR and Morgan SR and Macmillan KL}
}
