posted on 2023-07-21, 06:25authored byDonald Menzies
The northern Australian beef industry is dominated by cow-calf operations where reproductive efficiency has a major effect on profitability, particularly related to extended post-partum anoestrus intervals and high perinatal losses. Recording the post-partum anoestrus interval (PPAI) and distinguishing causes of perinatal loss requires the date and location of calving to be accurately known, both of which are traditionally laborious and costly. The original contribution to knowledge of this research is through the use of autonomous data collection systems to enable the recording of date and location of calving and assigning maternal parentage. The thesis firstly investigates the precision of an automated radio location device in a static array.
Secondly, the device is further researched for its ability to derive date and location of calving when used in an intravaginal apparatus. The third experiment investigates the use of Walk-over-Weighing (WoW) technology to derive maternal parentage based on the temporal sequence with which cows and calves had their identity recorded. The final experiment investigates the use of WoW to derive the date of calving based on the weight loss associated with parturition.