FENCELINE WEANING AND FORAGE BARLEY TO EXTEND THE GRAZING SEASON FOR REPLACEMENT HEIFERS.

摘要: In a 3-yr study an average of 47 heifers/year were allotted to two weaning treatments in early October to evaluate fenceline weaning on pasture and forage barley as an alternative to drylot weaning. The pasture-weaned group (P) was separated from their dams and grazed grass pasture across the fence from their dams for 2 wk. Then, until early December, they grazed Robust barley that was planted into oat stubble in early August. The drylot-weaned group (DL) was transported to a drylot and received grass hay, corn and protein supplement that provided. 73 kg CP and 14.5 Mcal ME/day. All heifers were managed as one group from December to April. The impact of treatment on weight gain was dependent on year (P< 0.05). In year 1, P gained more than DL during the first 2 wk after weaning (P< 0.10). In year 2, DL out gained P at 2 and 4 wk after weaning (P< 0.05). Gain from weaning to December and April was not affected by treatment in year 1 or 2. In year 3, P gained less than DL from weaning to early December (P< 0.05). In April, P weighed 23 kg less than DL (P= 0.05). Typical weaning behavior (walking the fence and bawling) was observed for DL. The P group appeared to be less stressed. No disease symptoms were observed for either group. Response to weaning vaccination was measured by IBR and BVD type 1 and 2 titers at 2 and 4 wk after weaning. There was a year x treatment interaction (P= 0.06) for BVD type 1 titer at 2 wk. In year 2, DL had a higher mean BVD type 1 titer than P (136.9 versus 73.1; P= 0.06). Titer values were similar at 4 wk. BVD type 2 and IBR titers were not affected by treatment. The P heifers had less rib fat …