@conference {75883,
	title = {Pasture growth and quality, and lamb growth rates in high stocking rate dryland sheep farming systems},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {103-108},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {Pasture growth and quality, and lamb growth rates were measured on a conventional grass based trial unit of 87.8 ha and a high legume unit of 85.1 ha, established to investigate climate-risk management strategies within high stocking rate dryland sheep farming systems. There was no difference between the units in total pasture production with a pasture utilization of 71.7\% and 74.3\% on the grass and legume units, respectively. Metabolisable energy values remained close to, or above, the target values throughout the growing season. Preweaning lamb growth rates averaged 304 g/day on both units. There were significant differences between singles (342 g/day), twins (300 g/day) and triplets (254 g/day) and between lambs from first cycle (294 g/day) and main mob ewes (315 g/day). There were some differences in lamb growth rates between different pastures types but these were not consistent between years. Post-weaning growth rates averaged 137 g/day with significant differences attributable to litter size, mob and year. Growth from birth to sale averaged 295 g/day, slightly less than the target of 300 g/day. Thus high lamb growth rates are possible on a range of pasture types on dryland at low pasture covers of high quality.},
	issn = {1176-5283},
	author = {Bywater AC and Logan CM and Edwards GR and Sedcole JR}
}
@conference {41530,
	title = {Development of an experimental approach to measure vitamin B12 production and utilisation in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {19-22},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Cobalt (Co) is required by ruminants to enable synthesis of vitamin B12 by rumen micro-organisms. Lack of quantitative information on the synthesis, absorption or utilisation of the vitamin has made determining nutrient requirement difficult. Two trials with sheep previously depleted of vitamin B12 and offered low Co diet (0.08 mg/kg DM) are described which attempt to overcome these problems. In the first, ewes were dosed with Co intra-ruminally at rates between 0{\textendash}1 mg Co/day. Responses in plasma vitamin B12 were proportional (P < 0.001) to the amount of Co infused. In the second trial, vitamin B12 was infused into the bloodstream via the jugular vein at rates between 0{\textendash}2500 nmol/day. Plasma vitamin B B12 plateau values were directly proportional (P < 0.001) to infusion rate. The rate of vitamin B12 infusion needed to sustain the critical plasma concentration of 370 pmol B12 /l was 5.02 nmol B12 /day, which together with estimated absorption from the basal diet gives a total requirement for absorption of 8.12 nmol B12 /day. This value is in agreement with data in the literature. The model approach, therefore, seems quantitatively robust. This approach, together with estimates of vitamin B12 flow from the rumen, will enable study of dietary factors that predispose to poor vitamin B12 production in the rumen and its absorption from the alimentary tract, and therefore to low animal vitamin B12 status.
KEYWORDS: Co/vitamin B12; infusion; sheep; rumen; modelling. },
	issn = {1176-5283},
	author = {Ludemann MR and Sedcole JR and Sykes AR}
}
@conference {41273,
	title = {Changes in plasma, milk and urinary magnesium concentrations in pasture-fed dairy cows in early lactation},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {152-155},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Estimates of magnesium (Mg) balances and plasma Mg concentrations of 51 dairy cows were obtained at 2-weekly intervals from calving during the first 3 months of lactation (late August to early December). During that period estimated 24h Mg excretion increased from 1.1 to 3.2g Mg/d (P<0.001) and varied with age. Plasma magnesium concentrations in 10\% of samples were below the threshold (0.6 mM) at which productivity is considered to be impaired. Within cow repeatability for plasma Mg was 0.70 {\textpm} 0.048. Individual cows showed unique patterns in the relationship between plasma Mg and estimated urinary Mg output. Mean milk Mg concentration was 104 {\textpm} 0.54 mg/l, almost 20\% lower than published values used in estimates of net requirements for Mg. Individual cow repeatability for milk Mg concentration was 0.67 {\textpm} 0.082 which, together with the plasma data, suggest an important genetic component in Mg homeostasis. This will need to be accounted for in models of Mg metabolism. },
	issn = {1176-5283},
	author = {Thielen M and Sedcole JR and Sykes AR}
}
@conference {40846,
	title = {Effect of wool length and season of shearing on the propensity of Romney, Coopworth and Perendale wool to yellow},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {324-327},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Propensity of wool to yellow is defined as its yellowness after  incubation for 14 days at 40 C and 100\% relative humidity. It was  determined for mid-side wool samples from Romney, Coopworth and  Perendale ewes shorn in summer and/or winter. All samples had a high propensity to yellow (mean Y-Z after challenge 13.0  SD 3.2). The breed ranking from lowest to highest was Perendale, Romney  and Coopworth (12.4, 13.1, 13.6, respectively; SED 0.2). Wool shorn in  winter was less susceptible to yellowing than wool shorn in summer (11.7 vs  14.4; SED 0.26) and short wool was less susceptible than long wool (12.0 vs  14.1; SED 0.26). There was a highly significant interaction between wool  length and time of shearing. Propensity to yellow of wool sampled at hogget shearing was not a  significant predictor of propensity to yellow of the adult fleece wool. The  measurement was repeatable between some, but not all, successive shearings  of adult ewes. This suggests that the method used may be useful in selecting  adults to reduce yellowness by breeding.},
	issn = {1176-5283},
	author = {Reid TC and Sumner RMW and Sedcole JR and Botica KJ}
}
@conference {40715,
	title = {The effect of anthelmintic treatment of ewes during pregnancy},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {211-213},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	issn = {1176-5283},
	author = {Familton AS and McAnulty RW and Thompson KF and Sedcole JR}
}
