@conference {41859,
	title = {A profile of anthelmintic resistance and parasite control practices in New Zealand - results from a 2005 survey},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {66},
	year = {2006},
	month = {Jan},
	pages = {14-19},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Napier},
	abstract = {Anthelmintic (drench) resistance in New Zealand{\textquoteright}s ruminant livestock is arguably the biggest single threat to sustainable future pastoral production. Clinical and sub-clinical parasitism impacts not only on animal health, but on animal welfare, and hence the image of pastoral production systems, total production and production efficiency and has a marked impact on the economic bottom line for both farmers and the country as a whole. In 2001 it was estimated for the relatively small NZ deer industry alone (worth $311 million in export earnings) that parasitism cost $12.8 million per annum in production losses due to parasitism and parasite control (Mackintosh and Wilson, 2002).},
	issn = {1176-5283},
	author = {Rhodes AP and Leathwick DM and Pomroy WE and West DM and Jackson R and Lawrence K and Moffat J and Waghorn TS}
}
@conference {41572,
	title = {Comparing feed allowances to inferred energy intake using data from a dairy grazing farm trial},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {225-230},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The main objective of this research was to investigate whether calculating intake of dairy cows using equations to predict energy requirements provides a good alternative to conventional ways of estimating intake. The method was applied to data from the Dexcel Holstein-Friesian strain trial over three seasons. Feed intake per cow was calculated as the sum of the energy requirements for maintenance, milk production, pregnancy, growth and body tissue mobilisation using measured yields of milk, fat, protein and lactose, live weight and body condition score of cows and calf live weights. In order to compare the estimates of feed intake to the amount of feed offered, linear regressions of calculated (ME) intake (grouped by farmlet) on the amount ME offered per farmlet were performed by season. The relationship between ME intake and ME offered was weak in the first year, with a limited response to increasing the amount of feed offered. This was because all the cows were two-year-olds with lower live weights and milk yields and consequently lower feed intakes. In the subsequent two years of the trial, the relationship between ME intake calculated using the energy equations were 67\% and 72\%. The modern strains of dairy cows responded well to higher levels of feed offered, while the 1970s strain of New Zealand dairy cows failed to increase intake when offered diets of higher total ME. Our results show that energy prediction equations offer a viable and cheap alternative of estimating ME intake of lactating dairy cows.
KEYWORDS: dairy cows; energy intake; strain comparison; efficiency. },
	issn = {1176-5283},
	author = {Pryce JE and Harris BL and Montgomerie WA and Jackson R and MacDonald KA and Glassey CB and Thorrold BS and Holmes CW}
}
@conference {41539,
	title = {Economic comparison of Holstein-Friesian strains},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {68-73},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The objective of this research was to identify major determinants of net profit per cow. Data were from the Dexcel strain trial over three seasons, in which Holstein-Friesian cows were managed in groups of 12 to 20 cows in eleven farmlets. Milk returns were calculated from lactation yields of milk, fat and protein. Net profit per cow was calculated as the net return from milk sales plus sales of calves minus feed, fertility, health, shed and working expense costs. Annualised present values were derived using asset replacement theory and discounting to account for different numbers of years of data according to the year in which an animal entered the herd. Net replacement costs and average replacement returns were included where animals were replaced before the end of the trial. Partition analysis was used to identify indicators of cow profitability. Partition analysis recursively sub-divides data creating a tree of partitions. Each split is chosen to maximise the difference in profitability between branches of the split. Variables on which data could be partitioned included breeding values, Breeding Worth and traits measured in first parity. The key determinants of profitability were lactation yield of protein and fat, percentage of fat and Breeding Worth. When these variables were fitted to a multiple regression model where the response was annualised present value, the adjusted R2 was 52\%.
KEYWORDS: asset replacement model; economics; dairy cattle. },
	issn = {1176-5283},
	author = {Pryce JE and Harris BL and Glassey CB and Montgomerie WA and Jackson R and MacDonald KA and Thorrold BS and Holmes CW}
}
@conference {41372,
	title = {Computer simulation of Johne{\textquoteright}s disease in New Zealand cattle},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {62},
	year = {2002},
	month = {Jan},
	pages = {294-298},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {<p>Control options for Johne\&rsquo;s disease (JD) are explored by computer simulation because intervention trials under field conditions would be too costly. The purpose of this review is to describe a simulation model developed in The Netherlands and adapted to dairy herds in Pennsylvania (USA). The paper consequently derives what information is required for the adaptation to New Zealand dairy herds and explains the methods by which that information is currently collected. The model \&lsquo;JohneSSim\&rsquo; simulates the within herd development of JD based on time related changes. Time intervals are six months. JD is transmitted vertically through the placenta or from dam to calf around calving through direct contact, colostrum, rest milk or bulk milk, infected pasture, or through contact with adult replacement stock from other herds. Control options include test-and-cull, measures to prevent the infection of calves, vaccination, and grouping of animals by age. The simulation suggested that, in The Netherlands as well as in Pennsylvania, progressively improving calf-hygiene with little reliance on test-and-culling would decrease the prevalence considerably and was economically feasible (average benefit-costs-ratio excluding extra labor = 1.58). Test-and-cull was not economical even if a test with 80\% sensitivity was available. Contract heifer rearing, colostrum management, and seasonal calving appear to be risk factors for transmission that have specific relevance for New Zealand dairy herds.</p>},
	issn = {1176-5283},
	author = {Soons R and Heuer C and Jackson R and Groenedaal H}
}
@conference {40765,
	title = {Assessing the value of breeding technologies to dairy farmers},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {22-24},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The adoption of technologies for breeding dairy cattle requires  estimating the financial return to dairy farmers in conjunction with assessing  the financial implications to the breeding company. This paper describes a  procedure currently used by the Livestock Improvement Corporation. The net on-farm income generated as a result of the new technology is  calculated. This is discounted to a Net Present Value allowing for the cost of  the technology. A positive NPV indicates the adoption of the technology is  of benefit to the dairy farmer. The breeding company also should assess the funding implications of any  change. Typically this is expressed in terms of the increase/decrease in price  of products and services.},
	issn = {1176-5283},
	author = {Rendel J and Jackson R and Harris B and Allison T and Shannon P and Burton L and Tempero H}
}
