Chick quality is crucial in the laying-hen business, and for Ian Rubinoff, DVM, director of global technical services for Hy-Line International, the first 7 days “have an outsized importance.”
“If you’re able to make it through that first week, there is a relatively low mortality throughout the pullet period,” he said, pointing to the importance of routine hatchery testing of both healthy chicks and mortality to catch and mitigate issues early.
The importance of managing farm conditions effectively
Speaking at an American College of Poultry Veterinarians seminar, Rubinoff said farm management issues can be a cause of mortality, especially with the move to cage-free and free-range production.
“Feed, light, air and water are all very good indicators of how our management needs to be, because for the first 2 weeks of age we truly need to manage those birds well, as they are almost fully reliant on what we provide for them.”
Water access is probably the most important factor, he said, stressing that “if chicks do not have access to fresh, clean water they will not be able to eat, grow and they will likely add to our mortality numbers.”
Getting light levels right makes a big impact too, with Rubinoff suggesting producers should aim for 40 to 50 lux on feed and water in the first week.
“If we have light inside our cage, that means we have excellent light distribution for both the feed and the water automatically. As we continue to build new pullet houses, investing in lights on the inside is the best option to get chicks off to a good start.”
Humidity pivotal, but chick comfort essential
Rubinoff recommended 32° C to 33° C for leghorns and 35° C to 36° C for browns as optimal temperatures, with reductions thereafter of 1° C to 2° C per week to 21° C, but he stressed that “low humidity is really the enemy,” given its importance both for chick comfort and coccidia cycling.
“Whether we have perfect high or low temperatures, if we have really low humidity, this is always going to be a challenge for the chicks,” he added.
Regardless of the temperature and humidity achieved, observation of the chicks to make sure they are comfortable still remains key, with cameras used where necessary so as not to interfere with chick behavior.
Getting things right on the first day
To minimize stress, day-old-chick processes from sexing to vaccinations need to be managed effectively. With producers no longer able to use antibiotics for day-old chicks, more effort is required to make sure birds are disease-free, though “it absolutely can be done,” Rubinoff said.
“Overall, we have seen pretty good livability, but that requires a tremendous amount of work upstream, working with breeder flocks, working with eggs coming into the hatchery, working with the hatchery to reduce that overall bacterial load.”
Optimizing vaccination, disinfection approaches
Having the right vaccination program in place makes a difference, he said, making particular note of the importance of using Rispens-strain vaccines against Marek’s disease.
“We are hoping that with some of the new generation serotype 1 Marek’s vaccines that we’ll be able to fully treat every bird in the world, so they don’t have to worry about Marek’s.”
Spray vaccination against respiratory diseases such as infectious bronchitis and Newcastle Disease is common, but poor application can lead to reactions and early mortality. Faced with the choice of gel or water options for spraying, water can result in more chick stress in situations with inadequate ventilation, he said.
Bacterial and fungal infections are issues to look out for, Rubinoff explained, pointing to the bacterium Enterococcus and the fungus Aspergillus as notable pathogens.
With bacterial infections, mortality curves differ depending on whether infection occurred in the hatchery or farm. Hatchery-related mortalities tend to peak 3 to 6 days and fall off rapidly after 14, while with farm-related infections the peak will occur between 5 and 8 days.
In the move toward antibiotic-free hatcheries, having a lack of disinfectants will make the constant surveillance of microbiological levels ever-more important, Rubinoff said.
While producers have become good at managing bacterial issues, there remains no effective treatment for fungal spores. Current research brings hope for new “next-gen anti-fungals,” he added.
What’s in store
Looking beyond the first 7 days, Rubinoff said that while hatchery egg-storage time has a strong correlation with hatchability and chick quality, short period incubation during egg storage (SPIDES) has proved an “incredible tool” for increasing hatchability — especially for those stored beyond 10 days.
“Hatchability can be improved by almost 2% for eggs stored between 10 to 15 days and over 8% for storage over 15 days,” he said.
“Even without an increase in actual hatch, it does seem to improve the hatch window. Chicks happen to hatch much more closely together when using SPIDES.”
The role of the breeder farm
Parent flocks can have an impact on commercial chick livability, Rubinoff said, with freedom from vertically transmitted diseases such as Salmonella and Mycoplasma essential. Non-vertically transmitted respiratory viruses affect egg quality and may affect livability too.
It’s also critical that breeders get nutrition right, he added, with deficiencies in fat-soluble vitamins and B-complex vitamins impacting embryo and shell quality. Breeder environment also counts for a lot, with links between heat and cold stress and drops in chick egg quality and hatchability.
“This can be difficult to manage as you may not know how it’s going to impact until you hatch out those eggs.”