@article {3672,
	title = {Investigating the potential for global positioning satellite data to provide information on ewe behaviour around the time of lambing},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {29-34},
	address = {Online},
	abstract = {Global positioning satellite (GPS) devices allow spatial-temporal data sets to be generated which can describe ewe movement around the time of lambing and can potentially be linked to traits of interest, such as the timing and location of lambing events and maternal outcomes including lamb weaning weight. Collar-mounted GPS units were fitted to 25 ewes during their anticipated lambing period. Lambing timing and site were estimated based on a minimum of twice-daily checks of the ewes. Lambing and GPS data were ultimately available for 15 ewes. From the resulting data set, several traits were calculated including the average distance deviation from the central point of the three-hour time block. During the birthing event (at a resolution of hours), the ewes changed their movement behaviour and remained close to the centralised point of the three-hour block. There were significant associations among the weaning weight of the ewes{\textquoteright} offspring (adjusted for rearing rank) and the GPS-derived traits: ewes that were comparatively inactive produced lambs with low weaning weights. Overall, this study demonstrates the potential of GPS-derived traits to be of relevance in studies investigating ewe behaviour around and after-lambing and its impact on production outcomes.


Keywords: lambing; global positioning satellites; weaning weights},
	issn = {1176-5283},
	author = {PL Johnson and Welsh A and Knowler K and Pletnykov P}
}
@article {3672,
	title = {Preliminary investigations into genetic variation in distance travelled by young sheep},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {81},
	year = {2021},
	month = {01/2022},
	pages = {63-67},
	address = {Online},
	abstract = {In pastoral grazing systems, animals need to walk to obtain nutrients (pasture) and water, however, it is also thought that the distance an animal travels is further influenced by factors including the grazing behaviour of the animal, its health status and its general motivation for moving. The purpose of this research was to investigate the repeatability and genetic variation in the trait of distance travelled for New Zealand sheep. Data were collected using global positioning satellite (GPS) collars fitted to 422 animals from three different groups of animals (Group). The animals were allowed ad libitum grazing. Progeny from 44 sires were represented in the data set. The GPS collars were fitted for up to 17 days. Given between-day variability in distance travelled depending on paddock attributes (size and feed availability) all data were scaled to a constant mean. A univariate repeated measures model was fitted to the data using ASREML, with Group fitted within the model, and day within Group fitted as the repeated measure. The heritability estimate for daily distance travelled was 0.36{\textpm}0.09, with a repeatability estimate of 0.51{\textpm}0.03. The results indicate that distance travelled is a repeatable trait at the individual animal level and is under moderate genetic control.

Keywords: sheep; GPS; distance travelled},
	issn = {1176-5283},
	author = {PL Johnson and Cullen N and Hickey SM and Knowler K and Bryson B and Hall M and Pletnykov P}
}
