Understanding Swine Growth Performance
Average Daily Gain (ADG) and Feed Conversion Ratio (FCR) are the two most important production metrics in commercial swine operations. Together they determine the biological and economic efficiency of converting feed into marketable pork.
Growth phases and typical ADG:
- Nursery (12–50 lbs): 0.7–1.2 lbs/day
- Grower (50–130 lbs): 1.5–2.0 lbs/day
- Finisher (130–280 lbs): 1.8–2.3 lbs/day
ADG is influenced by genetics, nutrition, health, and environment. Modern lean-type genetics (PIC, Topigs Norsvin) routinely achieve finishing ADG above 2.0 lbs/day under optimal conditions. Poor ADG often signals subclinical disease (e.g., PRRS, PED, Ileitis) before clinical signs appear.
Feed Efficiency and Economic Impact
Feed represents 60–70% of the total cost of pork production. Even small improvements in FCR have outsized economic impact — a 0.1-point FCR improvement across 1,000 finishing pigs saves approximately 2,000 lbs of feed per closeout.
Key drivers of FCR:
- Diet formulation: Phase-feeding matched to nutrient requirements (NRC 2012) minimizes waste. Pelleted feed improves FCR by 5–7% vs. meal.
- Feeder management: Improperly adjusted feeders can waste 5–15% of feed. Target 40–50% pan coverage.
- Environment: Pigs below their lower critical temperature (~60°F for finishers) increase feed intake without proportional gain.
- Health: PRRS-positive herds typically show 0.3–0.5 higher FCR than negative herds.
- Water access: Inadequate water flow (<1 cup/min for finishers) directly depresses feed intake and ADG.
Track FCR by barn and closeout to identify trends and set improvement targets.
