Abstract

Calving date of yearling red deer hinds is, on average, two weeks later than that of adult hinds, further misaligning feed quality with nutritional requirements. The hypothesis that early joining of spiker stags with yearling red deer hinds would increase pregnancy rate and advance date of conception was studied. Yearling hinds (n = 309) were grazed in one group at least 500 m from any stags from the first week in November until 14 January when hinds were weighed, wapiti scored and randomly allocated to either an early stag joining (ES) or control (C) treatment. ES hinds were grazed as one group with 20 spiker stags and C hinds were kept in paddocks well removed from stags. On 2 March, all hinds were weighed again and 20 spiker stags joined with the C hinds. ES and C groups were grazed separately until being combined in mid-April. The stags were removed on 18 May, and hinds ultrasound pregnancy scanned on 1 June. There were no significant differences (P > 0.05) between ES and C treatments in mean wapiti score (1.8 vs 1.8, SED = 0.08), live weight (January: 79.8 vs 79.0 kg, SED = 0.86; March: 86.4 vs 85.8 kg, SED = 0.85), fetal age (48.5 vs 46.8 days, SED = 1.0) or percent hinds pregnant (85.7 vs 88.7 %, SED = 3.5). The probability of hind pregnancy increased significantly with live weight within wapiti score classes and decreased with increasing wapiti score (P<0.01), such that, with mean class live weights of 75, 81, 88 and 95 kg, the expected percentage of pregnant hinds was 95, 91, 88 and 73 % for wapiti scores of 1, 2, 3 and 4+, respectively. Fetal age increased by 0.11 (SEM 0.054) day for every 1 kg increase in January live weight (P < 0.05), but showed no significant relationship with wapiti score. These data indicate that early joining of spiker stags did not significantly improve the pregnancy rate or advance conception date of yearling red deer hinds. KEYWORDS: red deer hinds; puberty; early stag joining.

IC, Scott, JF Ward, KT O'Neill, and RP Littlejohn

Proceedings of the New Zealand Society of Animal Production, Volume 65, Christchurch, 312-315, 2005