In the hatchery, there is never a direct reason to apply antibiotics, since the chicks do not stay there for any great length of time, according to Gerd de Lange, senior poultry specialist with the Pas Reform Academy.
If antibiotics are applied (in ovo or by injection after hatch), this is done preventively to avoid disease problems or for potential benefits at the farm where the day-old chicks will be delivered, he explained. Furthermore, on the farm itself, antibiotics can be administered by feed or drinking water as a preventive measure or as a growth promotor (depending on regulations).
This way of using antibiotics is coming under increasing criticism, because it leads to antimicrobial resistance (AMR), which means that bacteria might eventually become resistant to antibiotics, de Lange said. In the long run, this causes problems for the treatment of diseases in people and animals. Many modern poultry companies now aim to produce without using antibiotics or at least to limit their use to therapeutic purposes only, he said.
Some countries have introduced legislation outlawing the use of antibiotics as both a preventive measure and as a growth promotor, while in other countries, companies are responding to consumer demands for "safe and clean" food, de Lange said.
The question now is what role hatcheries could play in eliminating the preventive use of antibiotics and reducing the need for therapeutic use. De Lange explained that poultry, such as a broiler flock, will stay healthy if the following two conditions are met:
1. High disease resistance, so the animals are robust and have a high level of immunity, and
2. Low disease pressure, so pathogens (e.g., bacteria and viruses) are absent or present only at very low concentrations.
Under these conditions, he said there is no need to apply antibiotics, and the broiler flock will potentially perform very well.
However, if disease resistance is low and/or disease pressure is high, problems are likely to occur on the broiler farm, de Lange added. In this case, it is tempting to use antibiotics preventively, since otherwise it is more likely that they will have to be used therapeutically in the event of problems such as increased mortality.
De Lange said day-old-chicks should be delivered with high disease resistance by applying good management practices on the breeder farm and in the hatchery. These include:
- Provide optimal incubation conditions to ensure strong and vital day-old chicks (with a well-closed navel and well-absorbed yolk sac).
- Apply a good vaccination program on the breeder or broiler farm and in the hatchery to ensure a high level of immunity.
- Avoid stress factors for embryos and chicks, such as overheating, chilling, dehydration and delayed feed access.
He said to take the following steps to keep disease pressure in the hatchery low through good hygiene practices:
- Implement biosecurity measures to prevent pathogens from entering the hatchery; this includes good egg hygiene.
- Avoid cross-contamination to prevent transport of pathogens within the hatchery.
- Clean and disinfect regularly to prevent further development of pathogens in the hatchery.