@conference {4180,
	title = {BRIEF COMMUNICATION: Whole-herd extended lactations in a pasture-based system: year one of a farmlet study},
	booktitle = {Hamilton},
	volume = {85},
	year = {2025},
	pages = {9-12},
	address = {Hamilton},
	abstract = {<p>Extended lactations (EL) can potentially improve labour efficiency, reduce numbers of non-replacement calves, and reduce cow attrition. A 2023-24 farmlet study compared an EL system whereby half of the cows calved each spring with approximately 24-month calving intervals versus a Control system where all cows calved each spring with approximately 12-month intervals. The EL system produced more milksolids (MS) than Control (1,231 versus 1,182 kg/ha, respectively) from more days in milk (average of 308 across the two herds versus 251 days per cow, respectively) while consuming more supplementary feed (818 versus 621 kg DM/cow, respectively). Cows in EL produced on average 370 kg MS/cow over 304 days of lactation during the season, from a total of 855 kg MS/cow produced over a 600-day lactation. This study has shown the potential viability of this EL system and the data can be used to evaluate impacts on profitability and the environment.</p>
},
	keywords = {dairy cattle, extended lactation, New Zealand},
	author = {L.J. Farrell and J.P. Edwards and C.B. Glassey and Y. Lopez-Moreno and E Rauhala and C.R. Burke}
}
