@conference {89232,
	title = {Effect of heifer live weight on calving pattern and milk production},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {73},
	year = {2013},
	month = {Jan},
	pages = {103-107},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {<p>Many heifers on New Zealand dairy farms fail to reach their target live weight. This failure leads to lost milk production and poorer reproductive performance. This study investigated effects of breed and region on heifer live weight and also effects of pre-calving heifer live weight (18{\textendash}21 months) on milk production. Less Friesian heifers reached their target live weight than Jerseys, or Crossbreds (85.3 versus 89.3 versus 88.1\%; P \&lt;0.001). Heifers born in Otago (91.9\%) and Taranaki (91.8\%) were the closest to achieving their target live weight, whilst those born on the West Coast (85.6\%) and Northland (86.0\%) had the greatest number of heifers not reaching their target. Heifers that had only one calving recorded on the database were a significantly lower percentage of target live weight than those heifers that had two calvings recorded (83.5\% versus 87.1\%; P \&lt;0.001). In heifers with a live weight record between 18 and 21 months of age, every 1\% increase in the percentage of target live weight attainedwas associated with an increase in milk volume of 23 {\textpm} 0.6 litres in the first lactation and 24 {\textpm} 0.9 litres inthe second lactation. Further work is required on the economics of feeding heifers to achieve their target live weight.</p>
},
	issn = {1176-5283},
	author = {McNaughton LR and Lopdell T}
}
@conference {75925,
	title = {Effect of sub-clinical uterine infection on plasma amino acid concentrations in early lactation dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {291-295},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {This study examined the effect of sub-clinical endometritis (scEndo) in early lactation on plasma amino acid (AA) concentrations of dairy cattle (n = 46). On D21 and D42 postpartum cows were classified as having scEndo or Clean based on uterine cytology; >18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with a large proportion of scEndo cows having self-resolved the infection by D42. Plasma serine concentrations were higher (P <0.03) in scEndo compared to Clean cows irrespective of day postpartum. Independent of uterine status, three AA altered (P <0.05) in concentration between D21 and D42. The effect of change in uterine status from D21 to D42 resulted in decreased (P =0.05) concentrations of three AA in cows that resolved infection. The use of a lower cut-off to define scEndo (4\% vs 18\%PMN) identified four AA, instead of three AA at 18\% that differed over time. Thus, during the early postpartum period, the concentrations of a number of AA change (P <0.05) irrespective of uterine health. However, scEndo is associated with an increase in plasma serine and a decrease in the concentration of several AA when a uterine infection is resolved.},
	issn = {1176-5283},
	author = {Lopdell T and Berg MC and Green MP and Back PJ}
}
@conference {75926,
	title = {Sub-clinical uterine infection is associated with altered amino acid concentrations of follicular fluid in early lactation dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {296-300},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {The effect of sub-clinical endometritis (scEndo) in early lactation on follicular amino acid (AA) concentrations was determined. On D21 and D42 postpartum cows were classified as having scEndo or Clean based on uterine cytology; >18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with a large proportion of scEndo cows having self-resolved the infection by D42. Follicular histidine (P = 0.04), as well as alanine, aspartate and serine concentrations (P <0.1) were higher in scEndo compared with Clean cows. The effect of change in uterine status from D21 to D42 resulted in increased (P <0.1) follicular glutamate, ornithine and valine concentrations in cows that resolved infection. Correlation coefficients were determined to test the relationship between plasma and follicular AA concentrations. A greater number of AA in Resolved cows showed no relationship between plasma and follicular concentrations compared to Clean cows. Thus, scEndo is associated with an increase in follicular histidine and an increase in the concentration of several AA when a uterine infection is resolved. This study demonstrates that scEndo may be responsible for long-term alterations in follicular AA concentrations that could potentially result in altered oocyte viability.},
	issn = {1176-5283},
	author = {Back PJ and Lopdell T and Berg MC and Green MP}
}
