Determination of maternal pedigree and ewe–lamb spatial relationships by application of Bluetooth technology in extensive farming systems

Abstract

The objectives of this study were to validate the application of Bluetooth technology to determine maternal pedigree and to determine ewe-lamb spatial relationships in extensive farming systems. A total of 35 first-cross Merino ewes (Merino × Border Leicester and East Friesian) and 23 of their lambs aged 1 to 3 wk were fitted with activity monitors equipped with Bluetooth (BT) technology (ActiGraph wGT3X-BT) by means of halters and collars, respectively. The BT devices on lambs were programmed to receive wireless signals once every minute from nearby BT units on ewes, which were programmed as beacons sending BT signals 4 times every second. Ewes and lambs fitted with sensors were dispatched into the paddocks, and after 10 d, the sensor units were retrieved and the BT signals received by lambs were downloaded using the ActiGraph software. The maternal pedigree of the lambs was determined as the ewe from which the lamb received the most BT signals. The distance between the lamb receiving the signal and the ewe sending the signal was estimated from the strength of BT signal received. The pedigree determined by BT was compared with the pedigree determined by DNA profiling and verification. The results showed that the accuracy of maternal pedigree determined by BT signals reached 100% within the first 15 min of returning animals to pasture of ewes and lambs fitted with sensors. Maternal signals (counts/d) received by 1-, 2-, and 3-wk-old lambs were 617 ± 102, 603 ± 54, and 498 ± 36, respectively, and the corresponding nonmaternal signals received were 140 ± 27, 106 ± 30, and 155 ± 39, respectively. Maternal signals received during the dark period were significantly higher than the maternal signals received during the light period ( < 0.05). Maternal signals received during the light period by 3-wk-old lambs were significantly lower when compared with those received by 1- and 2-wk-old lambs. Over 90% of the BT signals received from within 2 m of the lamb were from its mother. The maternal BT signals expressed as a portion of total BT signals decreased with increasing distance from the lamb. The results show that BT wireless networking is a fast and reliable method for the determination of maternal pedigree of lambs in extensive farming systems. In addition, wireless BT technology is also useful in determining mother-offspring spatial relationships.

Facial action units, activity and time spent with dam are effective measures of pain in response to mulesing of Merino lambs

“…Of all lambs, 95% were reunited with their dam within the first hour post-marking. This was more than the 15 min to reunite that was previously reported by Sohi et al 14 , but still a relatively short period. Both results are probably due to the small mob size and area grazed the ewes and lambs.…”

“…Any movement of the lamb was captured by the activity monitors, including lying, standing, walking and grazing, and, as such, was recorded as overall activity with no specific unit. The activity monitors fitted to the ewes were programmed as a beacon, and those fitted to the lambs were programmed as a receiver as described by Sohi et al 14 The activity monitors on the lamb received a ‘hit’ via Bluetooth when in proximity of a beacon. The ewe and lamb were pedigree matched as the ewe from which the lamb received the most hits as described by Sohi et al 14 A hit occurred every 60 s, and these ‘hits’ were accumulated over time, thus enabling the time the lamb and dam spent together to be determined.…”

Validation of Real-Time Kinematic (RTK) Devices on Sheep to Detect Grazing Movement Leaders and Social Networks in Merino Ewes

“…The threshold distances in this study were smaller threshold distances than those tested by Haddadi et al [ 36 ], 2–3 m] and those typically set for proximity logger detection of social interactions in groups of sheep (e.g., 1–1.5 m [ 10 , 48 ]). The precision of the RTK rovers may be beneficial or necessary for specific close contact situations such as ewe-lamb relationships [ 25 ].…”

“…The data from these sensors can provide new insights into how individuals in a group interact and/or influence each other, including affiliative and/or agonistic relationships between group members [ 19 , 20 ], network structure [ 19 ], and resource-use patterns [ 21 ]. Commercially, sensor technologies that allow quantification of social interactions may, for example, enable understanding of how animals learn new technologies such as virtual fencing [ 22 ], detect male-female interactions to determine oestrus [ 23 ] and mating [ 24 ], allow maternal pedigree detection through ewe-lamb contact [ 25 ], or could monitor grazing behaviour [ 26 ]. Thus, the potential for the application of sensors to detect social interactions, leaders and networks is fast developing and can provide new insights into the social behaviour of livestock animals.…”

Technologies for the automated collection of heat stress data in sheep

“…Unlike standard accelerometers, ActiGraphs include a Bluetooth function for measuring proximity and have been used to on ewes and rams during joining to indicate the birth date of lambs [109]. In addition, this Bluetooth technology has been used to determine maternal pedigree and ewe-lamb spatial relationships in extensive farming systems [110]. These flagship activity monitors are a discrete way of measuring mating behaviour and could be used to monitor the effects of hot conditions on ewe-ram interactions throughout the joining period.…”