REGAL
SINGLE-STAGE
Managing
the Embryo for
Performance
Managing Incubation
An improvement in the rate of gain of
broilers during the past *0 year has made the incubation period a
larger percentage of the overall growth period for commercial
poultry and has played a larger role in improving growth
efficiency.
Hatchery managers have observed
concomitant decreases in hatchability and chick performance,
whereas temperature profiles in the setters and hatchers have not
changed appreciably. Therefore, these decreases in hatchability,
first week livability, hatch time, and overall chick quality have
precipitated the need for a change in the way we manage our
hatcheries.
The use of single-stage incubation
has increased, because research has shown this system more
precisely meets the developmental demands of the
embryos.
Therefore, research has focused on
multi- and single-stage hatcheries to determine the proper hatch
conditions necessary to optimize embryonic development, chick
quality, and their effects on post hatch performance. Studies have
shown how increases in shell temperature, independent of machine
temperature, can result in increases in embryonic mortality,
decreased heart weight as a percentage of chick weight, decreased
yolk-free BW, and increased yolk weight. Factors that have
contributed to the increase in heat stress on developing embryos
include egg size, air flow, age of the embryo, and breeder flock
fertility. Other studies have shown that the variation in chick
performance can be explained by heat stress in the
hatchery.
Embryonic temperature during
incubation is now considered to be the most important physical
factor for successful commercial poultry incubation.
Selection of the optimum incubation
temperature profile is important to achieve the greatest
hatchability. Field work has demonstrated that embryos frequently
become overheated during incubation, even when the incubator is
operating correctly.
The difference between late embryonic
temperature and incubator air temperature is dependent upon thermal
conductivity, which in turn is mostly influenced by the air
velocity over the eggs. Significant production of metabolic heat
from the embryo starts at around day 4. By day 9, embryo
temperatures are greater than incubator air temperature. Therefore,
removal of heat from the embryo, rather than just distribution of
the air within the incubator, becomes a critical factor influencing
hatchability. The uniformity of the air velocity within the
incubator will depend on the ease at which the air is able to pass
over the surface of the egg shells to dissipate heat. The number
and size of shell pores and shell thickness are factors that
influence conductance, and the ability of the egg to dissipate heat
is directly related to egg size. As egg mass increases, thermal
conductance does not increase proportionally. Therefore, larger
eggs have greater difficulty dissipating metabolic heat produced by
the embryo. Physical conditions or design of the incubator can also
influence thermal conductivity. For example, failure to properly
fasten air-directing curtains in a multistage incubator, incomplete
turning, or design of egg trays may result in air passing around
the egg mass rather than through them.
Overheated embryos either in the
setter or hatcher characteristically show reduced yolk-free chick
weight, decreased heart size, and heart as a percentage of chick
weight when compared with controls. Other lesions observed in hatch
residue analysis for overheated chickens, turkeys, or both, have
been red, bruised hocks; enlarged yolk masses; unhealed navels;
increased late dead embryos; malpositions of late dead embryos with
head over the top of the wing or with head in the small end; and
others.
Regal Single-Stage incubator
designoptimized
embryonic development, chick quality, and their effects on post
hatch performance. Regal single-stage incubator improved the
temperature environment around the egg shell, which resulted in
decreasing in embryonic mortality, decreasing heart weight as a
percentage of chick weight, decreasing yolk-free BW, and increasing
the yolk weight.
Regal Single-Stage full line of
product will be welcomed by many customers because of their perfect
stability of controlling system, strong energy saving and the
flexibility of operations, and raise the subversive technical
innovation.
