@conference {41121,
	title = {Can Beta-hydroxybutyrate levels predict postpartum anoestrous interval of dairy cows?},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {205-207},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Concentrations of  b-hydroxybutyrate in plasma (pBOH) and milk (mBOH) were measured post-partum (pp). Mean pBOH
levels were highest in Weeks 3\&4 pp (1.1 {\textpm} 0.1 mmol/L). Cows were grouped for length of post-partum anoestrous interval (PPAI) for the statistical analyses. Of those cows which required hormonal treatment because they were anoestrous at the planned start of mating, 77\% had pBOH >1 mmol/L during Weeks 1\&2 pp, compared to 52\% of other cows (P < 0.1). Levels of pBOH alone could not predict the length of the PPAI (r2  = 2\%). Logistic regression analyses confirmed age, calving live-weight and calving condition score as risk factors for prolonged PPAI. When these factors were considered with pBOH at Weeks 5\&6 pp, a predictive relationship was found (P < 0.05). Levels of mBOH and pBOH were related (r2  = 0.68; P < 0.001).  These results support negative energy balance in early lactation as a risk factor for prolonged PPAI, along with age and live-weight and body condition score at calving.},
	issn = {1176-5283},
	author = {Verkerk GA and Guiney JC}
}
