393
Performance Comparisons of Finishing Systems for Yearling Heifers
A 2-yr study compared performance and carcass characteristics between traditional and alternative yearling finishing systems. Heifers were weighed and randomly assigned to one of two groups: Control or Self-fed. Data were analyzed as a completely randomized design with treatment as a fixed effect, year as a random variable, and pasture being the experimental unit. Heifers grazed upland sandhills range for 129 d followed by feedlot finishing for 103 d (CON, n = 24/yr). In the alternative system, heifers grazed upland sandhills range for 138 d with ad libitum access to a self-fed dried distillers grains based supplement (SF, n = 24/yr). The SF heifers had a one-third greater stocking rate compared to CON, because the supplement (4.63 kg DM/heifer/d) replaced grazed forage. Residual forage was similar (P = 0.66) between treatments. Heifers were harvested when twelfth rib backfat was visually estimated to be 1.27 cm, but backfat at harvest was different so data were adjusted to a 28% empty body fat. The SF heifers had greater ADG (P < 0.01) and ending BW (P < 0.01) on pasture, but CON heifers had greater HCW (P < 0.01) and greater final BW (P < 0.01). There was greater G:F ratio on grass( P < 0.01) and during the feedlot phase (P = 0.04) for SF heifers. Marbling score and LM area were greater (P < 0.01) for CON heifers. However, SF heifers reached market weight in 94 fewer d than CON heifers while having similar performance. This alternative production system may provide a viable option for marketing heifers in a cow/calf or yearling enterprise.
Table 1. Performance and carcass characteristics of control (CON) and self-fed (SF) heifers
|
Adjusted1 |
|
|
|
Item |
Control |
Self-Fed |
SEM |
P-value |
Initial BW, kg |
312 |
307 |
8.99 |
0.33 |
Off Grass BW, kg |
412 |
520 |
5.91 |
<0.01 |
ADG On Grass, kg |
0.79 |
1.54 |
0.04 |
<0.01 |
Days on Grass |
129 |
138 |
8.14 |
0.17 |
Days in Feedlot |
103 |
--- |
--- |
--- |
HCW, kg |
357 |
323 |
8.42 |
<0.01 |
Final BW, kg |
567 |
520 |
13.59 |
<0.01 |
System ADG, kg2 |
1.14 |
1.54 |
0.04 |
<0.01 |
Feedlot ADG, kg3 |
1.59 |
1.54 |
0.09 |
0.46 |
G:F Grass |
0.09 |
0.16 |
0.004 |
<0.01 |
G:F Feedlot |
0.15 |
0.16 |
0.008 |
0.04 |
% EBF |
28 |
28 |
--- |
--- |
1Data adjusted to 28% empty body fat (Guiroy et al. 2001)
2Using days in system: (CON: May-December; SF: May-October)
3Using days in system: (CON: September-December; SF: May-October)
Keywords: Heifer, Distiller Grains, System