K McCosker1, P Letchford, J C Petherick, D Meyer, M McGowan. 1. Department of Regional Development, Primary Industry, Fisheries and Resources, Katherine Research Station, Northern Territory, Australia.
Abstract
OBJECTIVE: To determine morbidity and mortality rates in yearling heifers spayed by two methods under commercial conditions in northern Australia. DESIGN: In study 1,600 Brahman heifers were allocated to one of three treatments: physical restraint and ear-tagging (Control); physical restraint, ovariectomy by the Willis dropped ovary technique, ear-tagging and ear-marking (WDOT); or electroimmobilisation, ovariectomy via flank incision, ear-tagging and ear-marking (Flank). Heifers were monitored post spaying. Mortalities occurred at unanticipated times, so study 2 investigated their timing and cause in similar WDOT-spayed heifers (n=574). RESULTS: In study 1, morbidity on the day of spaying was 6.0% in the Flank and 2.7% in the WDOT group (not statistically different). Spayed heifers showed behaviours indicative of acute pain/discomfort in the 6 h post spaying. Body weights and gains were significantly lower in the spayed compared with control heifers at days 21 and 42, and 5% of flank wounds were not healed at day 42. Mortalities were 0%, 1.5% and 2.5%, respectively, for Control, WDOT (3 estimated to have occurred on day 11) and Flank (2 on the day after spaying and 1 on each of days 5, 11 and 22). In study 2, the mortality was 0.5%, all within 4 days of spaying. CONCLUSIONS: In yearling heifers, WDOT spaying resulted in lower morbidity and short-term mortality compared with flank spaying. Both methods compromised the health and welfare of some animals for up to 4 days and body weight gains were reduced during the 6 weeks post spaying.
OBJECTIVE: To determine morbidity and mortality rates in yearling heifers spayed by two methods under commercial conditions in northern Australia. DESIGN: In study 1,600 Brahman heifers were allocated to one of three treatments: physical restraint and ear-tagging (Control); physical restraint, ovariectomy by the Willis dropped ovary technique, ear-tagging and ear-marking (WDOT); or electroimmobilisation, ovariectomy via flank incision, ear-tagging and ear-marking (Flank). Heifers were monitored post spaying. Mortalities occurred at unanticipated times, so study 2 investigated their timing and cause in similar WDOT-spayed heifers (n=574). RESULTS: In study 1, morbidity on the day of spaying was 6.0% in the Flank and 2.7% in the WDOT group (not statistically different). Spayed heifers showed behaviours indicative of acute pain/discomfort in the 6 h post spaying. Body weights and gains were significantly lower in the spayed compared with control heifers at days 21 and 42, and 5% of flank wounds were not healed at day 42. Mortalities were 0%, 1.5% and 2.5%, respectively, for Control, WDOT (3 estimated to have occurred on day 11) and Flank (2 on the day after spaying and 1 on each of days 5, 11 and 22). In study 2, the mortality was 0.5%, all within 4 days of spaying. CONCLUSIONS: In yearling heifers, WDOT spaying resulted in lower morbidity and short-term mortality compared with flank spaying. Both methods compromised the health and welfare of some animals for up to 4 days and body weight gains were reduced during the 6 weeks post spaying.
Authors: Jean K Lauder; Sonia Marti; Karen S Schwartzkopf-Genswein; Murray D Jelinski; Eugene D Janzen Journal: J Anim Sci Date: 2020-01-01 Impact factor: 3.159
Authors: Dominique Van der Saag; Peter White; Lachlan Ingram; Jaime Manning; Peter Windsor; Peter Thomson; Sabrina Lomax Journal: Animals (Basel) Date: 2018-02-28 Impact factor: 2.752