013 Sand Mountain Elite Heifer Development Program II: Heifer Performance

Abstract The Sand Mountain Elite Heifer Development program was established to demonstrate to northeast Alabama commercial cattle producers recommended methods for replacement heifer development. In Autumn 2015, 16.2 ha of novel endophyte tall fescue (Schedonorus phoenix) ,rye (Secale cereale L.) and ryegrass (Lolium perenne L.) were established or stockpiled. Heifers (n = 48) were delivered in early January. Heifers were weighed (initial weight = 280.3 ± 37.2 kg) and measured for height (118.1 ± 5.3 cm) at delivery and divided into 3 groups. Weights and heights were taken every 28 d from January through April and when heifers were checked for pregnancy in June. Heifers gained 0.85 kg/d from January to June. Weight per day of age was 0.83 kg/d with and average frame score of 5.6. A repeated mixed model analysis was used for ADG, gain, WDA, and frame score with independent variables of group, time (28, 58, 90 and 154 d on grazing), sire breed and interaction of group and time. Heifer was considered random. There was a significant group by time interaction for ADG, gain and WDA. Cumulative average daily gains of heifers in group 3 significantly (P < 0.05) outgained heifers in groups 1 and 2 throughout the development program. Average daily gains for heifers in groups 1 and 2 did improve after d 28, but were never able to recover from an initial poor start. Even with the poor ADG performance of groups 1 and 2 during the first 28 days, WDA of heifers in groups 1 and 2 were very close to their final ADG. This indicates they were on a fairly steady or even growth pattern from birth. Heifers in group 3 had a significantly lower (P < 0.05) WDA than the other 2 heifer groups until they had been in the development program for 90 days. Perhaps some of the continued differences in growth were due to compensatory gain. However, no significant differences existed between groups for final weight. Table 013. Cumulative ADG(kg/d) and WDA (kg/d) of Sand Mountain Elite Heifers Day 28 Day 58 Day 90 Day 154 Group ADG WDA ADG WDA ADG WDA ADG WDA 1 0.28a 0.79a 0.77a 0.82a 0.87a 0.83a 0.83a 0.83 2 0.34a 0.79a 0.80a 0.82a 0.86a 0.82ab 0.79a 0.80 3 0.99b 0.73b 1.03b 0.74b 1.10b 0.77b 0.98b 0.77 Values within a column with different subscripts are significantly different from one another P