@conference {41655,
	title = {An economic evaluation of automatic milking systems for New Zealand dairy farms},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {263-269},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {An economic analysis for automatic milking for a medium sized farm set up to milk 450 cows and installing either a 40-bail rotary dairy with automated cup removal and drafting or a 5-unit Greenfield system is evaluated. The analysis used a model that incorporated findings from the previous 5 years of research and development at the Greenfield automatic milking project and used physical and financial data collected in Dexcel{\textquoteright}s 2003/04 Economic Farm Survey for the conventional milking system comparison. The model assumed a payout of $4.25/kg milk solids (MS) and used current cost of technology. Once cows were established into the Greenfield System, the cost of producing 1 kg MS was 27\% higher than for the conventional rotary system. This was due to higher interest, depreciation and service contract costs, despite the lower labour, cow health and dairy costs. Sensitivity analysis showed that when other factors were held constant a 70\% decrease in capital cost or a more than two-fold increase in cow throughput was required for the Greenfield System to be as economic as the rotary system. Alternatively combining future improvements in AMS technology and farm system development including improved throughput to 112 cows/AMS, a 25\% decrease in milk harvesting system capital cost, equivalent production and a 10\% increase in the cost of labour produce a similar economic performance for the two systems. },
	issn = {1176-5283},
	author = {Jago JG and Davis KL and Newman M and Woolford MW}
}
@conference {41905,
	title = {Mastitis in cows milked in an automated or conventional milking system in New Zealand},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {252-257},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {The viability of automated milking systems (AMS) for pasture-based dairying has been studied in New Zealand in the past four years. Automatic milking differs from conventional milk harvesting systems (CMS) in a number of ways, which may impact on udder health. These include fewer machines/cow, distributed vs. batch milking, variable milking intervals, automatic udder health monitoring systems, and pre and post-milking teat sanitation procedures. Three seasons of data from two pasture-based research farms that milked cows with either a two unit AMS or a 30 bail rotary CMS were compared. Quarter milk samples were collected routinely from all cows for bacteriological analysis during the 2002-03, 2003-04 and 2004-05 seasons, with sampling occurring throughout lactation and at detection of clinical mastitis (CM) cases. The number of cows in the AMS herd ranged from 94 to 196 and in the CMS herd, from 289 to 324 across the seasons. Clinical mastitis affected 7, 11, and 15 cows/100 cows/season in the AMS herd and 24, 23 and 14 cows/100 cows/season in the CMS across the three seasons, with Streptococcus uberis isolated from approximately 50\% of CM cases from both herds. Prevalence of S. uberis post-calving averaged 8\% of cows for the AMS and 16\% for the CMS across the three seasons. We compared several indicators of udder health between an AMS and a CMS herd managed under pastoral conditions. },
	issn = {1176-5283},
	author = {Lopez-Benavides MG and Williamson JH and McGowan JE and Lacy-Hulbert SJ and Jago JG and Davis KL and Woolford MW}
}
@conference {41654,
	title = {Stage of lactation affects the milking performance and behaviour of cows in a pasture-based automated milking system},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {258-262},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {The successful implementation of automatic milking (AM) technology in pastoral dairy systems is dependent on the regular voluntary passage of cows from the grazing area to the dairy. A herd of 94 cows at the Dexcel Greenfield research farm was observed during a 31-day period to determine the effect of stage of lactation on milking performance and behaviour. Sixty-five cows were spring calved (late lactation, average 266 days in milk) and 29 were autumn calved (early lactation, average 19 days in milk). Cows were grazed as one herd in a rotational grazing management system with a fresh area of pasture available twice daily. Early lactation cows had a shorter average milking interval (14.6 vs 20.4 hours, p < 0.001) and a higher average daily production (20.0 vs 7.0 kg milk/cow/day, p < 0.001). They visited the selection units (from which they could gain access to water, fresh pasture and the raceway to the dairy housing the AM units) more often than cows late in lactation (2.8 vs 1.8 visits/cow/day, p < 0.001) and had a quicker transit time between pasture and the AM units (2.2 vs 2.7 hours/cow/milking, p = 0.026). Fewer early lactation cows needed to be manually moved from the grazing area for milking. The data indicates that stage of lactation will be a significant factor to consider when developing management systems for combining grazing with automatic milking. },
	issn = {1176-5283},
	author = {Jago JG and Davis KL and Woolford MW}
}
@conference {41569,
	title = {The drinking behaviour of dairy cows in late lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {209-214},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The drinking behaviour of grazing cows was investigated in two studies with the purpose of determining the suitability of using water intake as a motivator for voluntary movement of cows within a pasture-based automatic milking system (AMS). In the first study 100 mixed-age Jersey cows in late lactation were observed for 48 h. Cows drank on average 2.4 times/24 h (range: 1-6) and usually alone or with one or two other animals. Although every cow drank at least twice during the 48 h, 31\% of cows recorded an interval between drinks > 24 h. Less than 1\% of drinking occurred between 2000 h and 0700 h. The second study compared the drinking behaviour of Overseas (OS) and New Zealand (NZ) Holstein Friesian cows that were either grazing pasture (GRASS) or fed a Total Mixed Ration (TMR). TMR cows drank more often (5.2 times/24 h) than GRASS cows (3.5 times/24 h, P < 0.001). Feed type altered the distribution of drinking with 76.8 \% of TMR cows drinking between 2000 h and 0700 h compared with only 24.5\% for GRASS. Water intake was also higher for TMR (73.0 L/cow/day) compared with GRASS (53.7 L/cow/day) animals. The studies showed that the individual nature of drinking behaviour would be aligned with the AMS objectives of distributed rather than batch milking. However, the small number of cows drinking during darkness when grazing indicates that water intake would need to be used in combination with other motivators to ensure a continuous flow of cows to the dairy.
KEYWORDS: drinking behaviour; grazing; dairy cows; automatic milking. },
	issn = {1176-5283},
	author = {Jago JG and Roche JR and Kolver ES and Woolford MW}
}
@conference {41833,
	title = {Factors influencing milk harvesting efficiency in an automatic milking system},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {271-275},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Maximising milk harvested per robot is an important goal of pasture-based automatic milking systems (AMS). Results are presented from an analysis of 2937 cow milkings in a year-round milking system during January 2003 at the Dexcel Automatic farm (average herd size = 75 cows). Each cow milking was classified as OK (yield > 80\% of expected yield, EY), Yield Carry Over (YCO, 20\% < yield < 80\% EY), or Failed (F, yield < 20\% EY). The time and duration (from entry to exit from crate) of each cow milking was determined, as well as milk yield, and from these milk harvesting rate was calculated. There were an average of 95.8 cow milkings/day, average milking frequency was 1.13 milkings/cow/day (range 0.9 {\textendash} 1.9 milkings/cow/day). Eighty-four percent of milkings were classified as OK, 8.9\% as YCO and 7.1\% as F (after which the cow was returned to the yard for another attempt). Milking times {\textpm} SD (F = 3.76 {\textpm} 2.57, YCO = 7.63 {\textpm} 3.31, OK = 10.07 {\textpm} 4.09 minutes/event) and milk harvesting rate (F = 0.09, YCO = 0.76 and OK = 1.37 kg/minute) suggest that failed milkings were costly in terms of time. The data show potential for improving the 24 h milk harvest per AMS through cow selection, a more consistent flow of cows through the AMS and technological improvements.
KEYWORDS: milk harvesting efficiency; automatic milking systems; grazing; dairy cows. },
	issn = {1176-5283},
	author = {Davis KL and Jago JG and Wieliczko R and Copeman PJA and Bright K and Woolford MW}
}
@conference {41119,
	title = {Sealing of the bovine teat canal after dry-off.},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {198-200},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Closed teats have proven more resistant to dry period mastitis than open teats. Natural rate of keratin plug formation within closed and open teats, and consequences of bacterial colonisation of the teat canal, were examined using 67 low somatic cell count cows. Cows were dried off without antibiotic therapy and teats assessed for closure status at 5, 10, 15 and 20 d after drying off. Weight and bacteriological status of the keratin plug was determined by reaming teats with a sterile pre-weighed tapestry needle 7 d prior to drying off and on one occasion post drying off. Initially (d 5), keratin weight for all teats increased by 100\% compared to lactating teats (4.89 mg/qtr). Between d 10-20, keratin weight from open teats (29\% of teats) was 34-55\% less than for closed teats. Subclinical infections in the teat canal significantly reduced likelihood of teats closing after drying off. },
	issn = {1176-5283},
	author = {Lacy-Hulbert SJ and Williamson JH and Day AM and Woolford MW}
}
@conference {40780,
	title = {Effect of Streptococcus uberis infection on milk characteristics of individual quarters},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {65-67},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Composite 24 h milk samples were collected for detailed milk analysis  from each quarter of ten cows known to be free of intramammary infection.  Milk yield and concentration of lactose and serum albumin (BSA) were  significantly higher (P<0.001), and chloride ions significantly lower  (P<0.001), in hind compared with fore quarters. Four cows developed  clinical intramammary infection when subsequently challenged in the left  hind quarter with Streptococcus uberis. For all parameters measured, i.e.  protein, lactose, somatic cell count (SCC), BSA and immunoglobulins  (IgG), milk from the infected quarter differed significantly from the  uninfected quarters. No effect of infection was observed in quarters adjacent  to the infected quarter, except for SCC, which increased significantly  (P<0.001) in the uninfected hind quarter. Milk proteolytic activity in the  infected quarter increased significantly (P<0.001) due to increased  conversion of plasmin to plasminogen.},
	issn = {1176-5283},
	author = {Lacy-Hulbert SJ and Woolford MW and Nicholas G and Stelwagen K}
}
@conference {40831,
	title = {Reduction in SCC and colostrum levels in milk after calving},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {263-265},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Somatic cell count (SCC) and immunoglobulin G1 (IgG1) content  were determined in mammary secretions of 15 Friesian x Jersey cows and 5  heifers at each milking for 10 d following natural calving. Milk yields for  cows on d 1 were 20.2 l/d, declined sharply on d 2 to 14.4 l/d, then increased  slightly, reaching 17.9 l/d by d 10. In contrast, heifer milk yields were low  on d 1 (6.6 l/d) but increased steadily to 11.9 l/d by d 10. The SCC and IgG1  levels were extremely high on d 1 (1.50 x106 cells/ml and 24.0 g/l IgG1) but  declined rapidly within 48 h of calving. Average SCC and IgG1 reduced  below the penalty levels by d 4 for cows, and d 5 for heifers, confirming that  milk should be withheld from the bulk tank for 4 d and 5 d after calving for  cows and heifers respectively. Individual cows may exceed these levels for  short periods.},
	issn = {1176-5283},
	author = {Lacy-Hulbert SJ and Malcolm DB and Copeman PJA and Woolford MW and Franks R}
}
@conference {40651,
	title = {Influence of milking frequency and feeding level on plasmin activity and casein degradation in milk},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {9-11},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Wool samples from 28 Merino wethers, 31 Corriedale ewes, 37  Perendale ewes and 30 Coopworth ewes were examined for propensity to  develop yellow discolouration in relation to the mean fibre diameter and  its variability.    The propensity of wool to develop yellow discolourations was estimated  by two techniques, namely, an incubation technique which measures the  colour developed in the wool fibre during an incubation in the  laboratory, and the predictive technique described by Aitken et  al., 1994.    Correlations between propensity to yellow (Y-Z) and mean fibre diameter  were low in the Corriedale, Perendale and Coopworth samples, but high in  the Merinos. Correlations between propensity to yellow and standard  deviation of fibre diameter were also low in the Corriedales, Perendales  and Coopworths, but moderate in the Merinos. The correlations between Y  and Z and the fibre diameter statistics following similar trends to  those for Y-Z.    All correlations between propensity to yellow and coefficient of  variation of fibre diameter were low.    Thus while the propensity to discolour during growth is positively  related to fibre diameter in fine wool, no such relationship exists in  medium and coarser wool. This provides a further reason for Merino  breeders to produce a fine fleece type.   },
	issn = {1176-5283},
	author = {Prosser CG and Nicholas G and Stelwagen K and Lacy-Hulbert SJ and Woolford MW and McFadden TB}
}
@conference {40676,
	title = {Influence of once daily milking and restricted feeding on milk characteristics in late lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {85-87},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Ninety 1991 drop Merino wethers, thirty from each of fine, medium   and strong wool strains were randomly allocated on the basis of stratified  live   weight within strains to one of three treatment groups. The first treatment   involved grazing ample good quality natural or irrigated pasture (H)   throughout the experiment so that the sheep remained in good to excellent   condition throughout. The second involved grazing restricted amounts of   pool quality nature pasture (L) throughout the experiment so that the sheep   remained in backward store condition. As a control, a third group (C) grazed   natural pasture such that the sheep subject to seasonal variations in pasture   quality and quantity and their condition varied from store to forward store   throughout the experiment.    Intake was estimated on two occasions; in February 1994, and July 1994, by   dosing with controlled-release alkane capsules. Pasture samples were taken   at these times based on observation of sheep grazing patterns. However,   later analysis showed that the pattern of alkanes in the collected herbage was   different to the alkane pattern in faecal samples, indicating that the herbage   samples were not truly representative of the herbage consumed by the sheep,   particularly at the summer sampling.    Actual intake (AI) (expressed as kgOM/day },
	issn = {1176-5283},
	author = {Lacy-Hulbert SJ and Woolford MW and Bryant AM}
}
@conference {39714,
	title = {Physical effects within the teatcup related to intra-mammary infection},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {41},
	year = {1981},
	month = {Jan},
	pages = {76-81},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Woolford MW and Williamson JH and Phillips DSM}
}
@conference {39680,
	title = {The implications of milking management strategies involving variations of milking frequency in the immediate post-partum period},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {40},
	year = {1980},
	month = {Jan},
	pages = {166-174},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Phillips DSM and Woolford MW and Copeman PJA}
}
@conference {39672,
	title = {Laser light scattering as a probe of sperm motility},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {40},
	year = {1980},
	month = {Jan},
	pages = {124-129},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Woolford MW and Woolhouse JK and Phillips DSM and Hawley SA and Harvey JD and Shannon P and Curson B}
}
@conference {39681,
	title = {Milk production losses associated with clinical mastitis within identical-twin sets},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {40},
	year = {1980},
	month = {Jan},
	pages = {175-179},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Woolford MW and Williamson JH}
}
