Producers often ask why some flocks perform exceptionally well, while others do not, under the same conditions.
A well-known quotation goes: “You are the master of your own destiny”. If applied to broiler farmers, this implies that, with correct management and a suitable vaccination programme, broiler performance will be as expected.
There are various breeder diseases that can affect broiler production. Broiler chicks derived from breeder flocks that are chicken anaemia virus (CAV) and reovirus won’t have maternal antibodies to fight these diseases, so if they’re exposed to them, they’ll be affected and runting will occur.
- Nutrient deficiencies in breeder rations can affect chick vitality. Vitamin B12 shortage and poor energy levels are common and could have a negative impact on young broiler chicks. Deficiencies can be addressed by supplying chicks with soluble vitamins in their drinking water. Talk to feeding companies for advice or add brown sugar to the drinking water of chicks to address low energy levels – 20g of sugar per 2 litres of water.
- Egg hygiene and egg handling affects broilers – dirty eggs result in an increase in the incidence of “mushy chick” and cracked eggs could result in Aspergillus being a problem in the hatchery.
- The following conditions can be controlled by applying suitable vaccination programmes effectively and monitoring the health status of breeder flocks.
MANAGING BREEDER DISEASES
The following conditions can be controlled by applying suitable vaccine programmes effectively and monitoring the health status of breeder flocks.
- Infectious bursal disease (IBD) – The maternal antibody titre level of young broiler chicks will determine the vaccination programme needed to control this disease. The vaccination applied to the breeder flocks will determine the maternal antibody level.
- Newcastle disease (ND) and infectious bronchitis (IB) – If the parent flocks are exposed to field challenges which affect their performance, the vitality of the broiler chicks derived from these parents could be negatively affected.
- Ornithobacterium rhinotracheale – If the parents are affected, the disease can spread to broilers and cause respiratory problems, and result in an increased rate of condemnation in the processing plant.
- Micoplasma gallisepticom (Mg) and Micoplasma synoviae (Ms) – These diseases can be carried-over from the ovaries of the hen via the egg into the chick (this is called vertical transmission). Broilers born from infected breeder flocks are more prone to respiratory problems.
- Salmonella enteritis can also be transmitted vertically to the broilers resulting in poor body weight gains and increased chick mortality.
The hatchery is an important part of the production process. Good hygiene and management procedures must be applied at all times. A well-managed hatchery not only ensures good hatchability, but also gives the broiler farmer a healthy, viable chick which will perform to recognised breed standards.
MASTERING THE BASICS
The following are important factors to consider:
- first week brooding;
- feed quality and availability;
- water quality – water contaminated with bacteria such as faecal E. coli will impact on chick growth. Ensure that the water is tested regularly and is potable(fit to drink).
- air temperature and quality – low humidity will affect the respiratory system negatively. High dust or ammonia levels will also do so and often result in secondary E. coli infections; and
- litter contaminated with Aspergillus can result in high mortality rates. Some chicks will eventually die from Ascites caused by lung damage resulting from Aspergillus.
ALWAYS ENSURE THAT:
- Chicks are purchased from a reputable supplier and that information is provided on the health status of the parent flocks, as well as a suggested broiler vaccination programme. Monitor the health status of the broiler flocks by testing for Newcastle disease (ND), infectious bronchitis (IB), infectious bursal disease (IBD), and Micoplasma gallisepticom (Mg), using blood collected at slaughter.
- A suitable vaccination programme is applied to the broilers, in order to provide sufficient protection against ND, IB and IBD.
- The health status of the parent flock is provided, so that suitable measures can be taken to control vertically transmitted diseases such as Mg, if present. Here, good communication with the hatchery is important.
- Discuss the nutritional requirement of the broilers with a nutritionist and always ensure that enough attention is paid to the basic details of management.
MORE MANAGEMENT TIPS
- Egg handling and storage are important links in the chick production chain. As mentioned before, poor hygiene can result in an increase in “mushy chick” or an outbreak of Aspergillus.
- The management of setters and incubators is important as incorrect temperature or humidity settings affect the hatch period and chick vitality. Chicks which hatch early will spend an extended period in the hatcher, and this could result in a
decrease in vitality.
- Formaldehyde – The use of “trickle fumigation” is accepted hatchery practice, but if mismanaged, the formaldehyde will damage the respiratory mucosa. Exposing chicks to formaldehyde in the hatchery will damage their respiratory system and they could become more susceptible to vaccine reactions.
- Vaccine applications in the hatchery can easily cause severe reactions if the application methods are incorrect. Contamination of the vaccines or equipment with bacteria such as Pseudomonas will increase mortality.
- Prolonged storage or transport of day-old chicks if temperature fluctuations are extreme will affect chick vitality and could aggravate reactions to vaccines.
- This article was first published in the book: Guide to poultry production, published by Landbouweekblad