A Broiler House Losing Money at Four Weeks
A farmer has 200 day-old broiler chicks in a 4 m × 3 m house. At 28 days, 16 chicks have died and 184 remain. The litter is wet and caked, especially near the drinkers, which are open troughs filled from a leaking tap. Ammonia stings the eyes at head height, and ventilation is one open window. Feed used is 360 kg, and average live weight is 0.90 kg; the target for this strain is 1.1 kg with a feed conversion ratio of 1.7. Feed costs $0.45/kg, each chick cost $0.60, and the expected selling price is $2.20 per bird at about 2.2 kg. The farmer wants to buy a coccidiostat and an antibiotic and continue to 42 days.
1. Calculate the current feed conversion ratio and the cost of the feed inefficiency. Show your working.
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Live weight gain: 184 birds × 0.90 kg = 165.6 kg.
FCR: feed used ÷ live weight gain = 360 ÷ 165.6 = 2.17.
Target feed use: at FCR 1.7, the same gain would need 165.6 × 1.7 = 281.5 kg.
Excess feed: 360 − 281.5 = 78.5 kg.
Cost of excess: 78.5 × $0.45 = $35.33.
That is the direct feed penalty so far, roughly $0.19 per surviving bird. It understates the total loss because the 16 dead chicks cost 16 × $0.60 = $9.60, they also ate feed, and the survivors are 0.2 kg behind target, which delays sale and extends overhead costs.
The FCR is not a diagnosis on its own: it tells us the flock is converting feed badly, and the house conditions explain why. The number matters because it converts a vague complaint into a measurable loss that can be compared with the cost of fixing ventilation, drinkers and density.
2. Rank the likely causes of the poor performance and justify the order. Then say whether the proposed medication is the right first step.
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Ranking:
Wet litter from leaking drinkers. This is the root cause and the cheapest to fix. Wet litter generates ammonia, which damages the respiratory tract, reduces feed intake and growth and increases susceptibility to disease.
Ventilation. One open window cannot remove moisture and ammonia from 184 growing birds. Ammonia at eye-stinging concentration is already above a healthy level.
Stocking density. 184 ÷ 12 m² = 15.3 birds/m², well above the 10–12 birds/m² normally recommended at this age. Overcrowding worsens litter wetness, heat stress and competition for feeders.
Possible coccidiosis or bacterial infection. Wet litter favours coccidiosis, but this should be confirmed by checking droppings and post-mortem findings rather than assumed.
On medication: buying a coccidiostat and antibiotic first is the wrong order. Medication treats a consequence while the environment keeps producing new cases, and unnecessary antibiotic use is poor practice. Repair the drinkers, remove caked litter, add dry bedding, improve ventilation and reduce density first. If bloody droppings or a diagnosed infection appear, treat under veterinary advice.
3. Should the farmer sell at 28 days or continue to 42 days? Reason with the figures and state one condition that would change your advice.
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Continuing is only worthwhile if the house conditions are corrected at the same time.
If nothing changes: the flock is already 0.2 kg behind at 28 days with an FCR of 2.17. At that efficiency, reaching 2.2 kg would consume far more feed than the $2.20 sale price can justify, and mortality and ammonia damage are likely to rise. Selling earlier at a lower weight reduces feed cost and risk.
If conditions are fixed: the birds have compensatory growth potential. Removing the ammonia burden, drying the litter, cutting density to around 12 birds/m² and ensuring clean water can pull the FCR back towards 1.9 and improve daily gain. The decision then depends on the projected margin: feed to add roughly 1.3 kg per bird at about 2.0 FCR costs 2.6 kg × $0.45 = $1.17, against the price gain from 0.9 kg to 2.2 kg. That is clearly profitable if the price holds.
Condition that changes the advice: if ammonia remains high, mortality accelerates or a disease is confirmed, sell the flock early rather than feed a losing flock.