Production performance of cows raised with different postweaning growth patterns

Area of Science:

• Animal Science
• Reproductive Biology
• Livestock Management

Background:

• Heifer development significantly influences lifetime cow productivity.
• Growth patterns established during the peri-pubertal period may have lasting effects on reproductive performance and economic returns.

Purpose of the Study:

• To investigate the long-term effects of altered heifer growth patterns on stayability, calf production, and weaning weight.
• To determine if a stair-step growth strategy improves lifetime productivity in Bos taurus cows compared to a constant growth strategy.

Main Methods:

• 685 heifers were assigned to either a control or a stair-step diet regimen from 256 days of age.
• The stair-step diet involved restricted energy intake followed by increased energy intake.
• Average daily gain (ADG), proportion of cows weaning a calf, calf weaning weight, and cumulative weight weaned were measured over six calf crops.

Main Results:

• Stair-step heifers exhibited lower ADG in Period 1 and higher ADG in Period 2 compared to controls.
• No significant differences were observed in the proportion of cows weaning a calf between treatments or breed types.
• Calves from stair-step dams had significantly heavier weaning weights (193 kg vs. 191 kg).

Conclusions:

• Altering heifer growth patterns during the peri-pubertal period did not significantly affect lifetime cow productivity or calf production across diverse Bos taurus breeds.
• While stair-step growth resulted in slightly heavier calf weaning weights, it did not improve overall stayability or cumulative weight weaned.
• The findings suggest that constant, non-obese growth patterns are as effective as stair-step patterns for lifetime productivity in Bos taurus cattle.