Response of barrows to space allocation and ractopamine

Area of Science:

• Animal Science
• Swine Nutrition
• Agricultural Engineering

Background:

• Space allocation and feed additives are critical factors influencing pig growth and carcass quality.
• Ractopamine is a widely used feed additive to enhance lean meat production in pigs.

Purpose of the Study:

• To investigate the interactive effects of space allowance and dietary ractopamine supplementation on the performance and carcass characteristics of crossbred barrows.
• To determine if space restriction impacts the efficacy of ractopamine in pigs.

Main Methods:

• A 2x2 factorial experiment was conducted with 264 crossbred barrows.
• Treatments included two space allocations (0.55 or 0.74 m²/pig) and two ractopamine levels (0 or 10 ppm).
• Pigs were fed from approximately 30 kg to 108 kg body weight, with ractopamine administered for the final 28 days.

Main Results:

• Reduced space allowance (0.55 m²/pig) resulted in lower average daily gain, average daily feed intake, backfat depth, and loin muscle depth.
• Dietary ractopamine supplementation (10 ppm) decreased feed intake but improved feed conversion efficiency and increased carcass lean percentage.
• No significant interaction was observed between space allocation and ractopamine, indicating similar responses to ractopamine under both crowded and uncrowded conditions.

Conclusions:

• Space allowance significantly impacts pig growth performance and carcass traits, with more space generally leading to better outcomes.
• Ractopamine effectively improves feed efficiency and carcass leanness in pigs, regardless of the space allowance within the tested range.
• Optimizing space allocation and considering ractopamine supplementation are key strategies for enhancing swine production efficiency.