Switching from Starter to Grower Feed
At Day 15, it is time to transition from NovaFeed Broiler Starter Crumble to NovaFeed Broiler Grower Pellet. The Grower feed has slightly lower protein (typically 19–21%) but higher energy content to support the rapid growth phase that begins this week.
Never switch feed abruptly. Mix the old Starter and new Grower 50/50 for 1–2 days to ease the digestive transition. A sudden switch can cause stress and temporarily reduce feed intake. Add a stress pack supplement to the water during the changeover.
Feed consumption rises significantly during Week 3. Expect approximately 60–80 grams per bird per day, a sharp increase from the 30–45g of Week 2. Make sure feeders are always topped up — empty feeders during the growth phase directly reduce final market weight.
Space Expansion
By Week 3, your chicks have grown considerably and the brooder ring is now restricting their movement. It is time to remove the cardboard brooder ring and give birds access to the full house area.
Aim for 1–1.5 square feet per bird — a 20 x 20 ft house (400 sq ft) is ideal for 100 birds through to market. Overcrowding leads to poor air quality, increased pecking, and uneven growth across the flock (EntrepreneursHub).
Tip: Upgrade your equipment this week. Move from the small 4-litre chick drinkers to 12-litre drinkers, and from chick feeders to height-adjustable 14 kg feeders. Raise drinker and feeder height to the level of the birds' backs to reduce feed waste and water spillage (Shambani College).
Weighing Your Birds
At the end of Week 3, weigh a sample of 10–15 birds. Do not rely on weighing just one or two — you need a representative sample. At 21 days, well-managed Cobb 500 or Ross 308 broilers should weigh approximately 800–1,000 grams (EntrepreneursHub).
| Indicator | What to Check |
|---|---|
| Target weight at Day 21 | 800–1,000g per bird |
| Sample size | Weigh 10–15 birds from different areas of the house |
| Underweight birds? | Check feed quality, water access, stocking density, and signs of disease |
If birds are significantly below 800g at 21 days, investigate immediately. Common causes include poor-quality feed, restricted water access, overcrowding, or subclinical disease. Every day of underperformance during the growth phase is difficult to recover later.
Temperature and Vaccination
Continue reducing the brooder temperature to 26–29 degrees C this week. By now, chicks are developing better thermoregulation, but drafts and sudden cold snaps can still cause stress and reduce feed intake (EntrepreneursHub).
Gumboro second dose (Day 18–21). Administer the second dose of the Gumboro (Infectious Bursal Disease) vaccine via drinking water. This is one of the most critical vaccinations for broilers in Zimbabwe. Always confirm timing with your chick supplier or local veterinary officer (Shambani College).
Check Your Understanding
For each statement, decide if it is True or False.
1. You should switch from Starter to Grower feed suddenly, without mixing.
2. At 3 weeks, a healthy broiler should weigh around 800–1,000 grams.
3. The brooder ring should stay in place throughout the entire growing period.