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Broiler Breeder Performance
Research has shown that feeding complexed trace minerals
to broiler breeders has helped to increase egg production, enhance immunity,
reduce mortality, improve fertility, improve eggshell quality, increase
livability, and increase the quality and number of saleable chicks produced
from the breeder flock. We will review data supporting the use of complexed
trace minerals in each aspect of broiler production.
Complexed trace minerals have shown positive effects
on egg production of broiler breeder and laying hens. Egg size, eggshell
quality and egg production have all been improved:
| A. |
Egg Size and Uniformity - Egg weight is directly
related to the quality of chick produced. A general rule demonstrates
the effect of egg weight on the finished broiler; for every 1-gram
change in egg weight you will see 7 to 10 grams change in the weight
of the 42-day-old broiler. Wide variation in egg size will produce
a wide variation in chick size at hatching and affect broiler performance.
Large eggs produce large chicks, which will be dominant over smaller
chicks. Research on broiler breeders fed complexed zinc and manganese
resulted in more large eggs produced compared to hens fed the control
diet (Figure 2). |
| B. |
Eggshell Quality - Zinc, manganese and copper
play roles in the formation of the eggshell. Zinc is a component of
keratinase enzyme, which is necessary for the formation of the eggshell
membrane. Zinc is also required for carbonic anhydrase enzyme activation,
which is required for formation of the calcium carbonate shell. Manganese
affects collagen metabolism and the formation of a strong shell matrix.
Copper is necessary for eggshell membrane formation via the copper
containing enzyme lysyl oxidase. Research feeding complexed zinc and
manganese to layers demonstrated an improvement in eggshell weight
(P<0.05), eggshell thickness (P<0.05) and specific gravity (P<0.05;
19), indicators of eggshell strength. |
Figure 2. Effect of Complexed Zinc and Manganesea
on Broiler Breederb Egg Size
| C. |
Total Eggs Produced - Research conducted in the
USA demonstrated an increase of 8 eggs (243 vs. 235) produced per
hen through sixty-five weeks of age when complexed zinc was added
to the basal diet (18). Additional research has shown that complexed
zinc and manganese also increased egg production when fed to laying
hens (19, 20). A broiler breeder trial using complexed zinc and manganese
in the breeder diet from one-day of age to 65 weeks of age increased
the number of eggs per hen by 7 eggs (P<0.10; 21). Results are
shown in Figure 3.
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Figure 3. Effect of Complexed
Zinc and Manganesea on Broiler Breederb Egg Production
Minerals play an important role in developing a strong
immune defense system. Research on specific areas of the immune system
affected by complexed trace minerals are outlined below:
| A. |
Epithelial Tissue Epithelial tissue
is the first line of defense. Skin and the lining of the digestive
system are the most important epithelial tissues concerning immunity.
These are the first line of cells to interact with foreign organisms
and disease. One of the roles of epithelial tissue is to prevent foreign
organisms from entering the cells where they grow and cause disease.
Zinc and manganese play major roles in the development, repair and
maintenance of epithelial tissue. By providing adequate zinc, manganese
and copper status we assure the strength of this defense system. |
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i. |
Skin - Zinc and manganese play an important
role in healing process, skin repair and epithelial tissue growth.
Research from Parc Institute reported a reduction (P<0.05) in skin
tears (6) when broilers were fed complexed zinc. Downs and coworkers
(29), found a decrease (P<0.10) of cellulitis incidence and severity
when complexed zinc was fed to broilers.
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ii. |
Footpads - Footpad lesions or burns
are caused by ammonia accumulating in the litter. Slats or wire cages
also can cause foot lesions and joint swelling. Work at Auburn University
demonstrated a significant reduction in lesions on footpads of poultry
fed complexed zinc (Table 1). Research indicates that feeding poultry
complexed zinc will decrease footpad lesions 25 to 30% (7, 24). |
Table 1. Effect of Feeding Various Forms
of Complexed Zinc to Female Broilers
Zinpro Corporation |
| Treatment |
Footpad Lesion Scorea |
|
| Controlb |
1.70y |
| ZnMetc |
1.26z |
| ZnLysd |
1.24z |
| ZnMet/ZnLyse |
1.30z |
|
| a |
Score: 0 = no lesion, 1
= lesions of <7.5mm,
2 = lesions of >7.5mm in diameter |
| b |
55 ppm from ZnO |
| c |
Control + 40 ppm Zn from
ZINPRO® zinc methionine |
| d |
Control + 40 ppm Zn from
LyZin® zinc lysine |
| e |
Control + 20 ppm Zn from
ZnMet and 20 ppm Zn form ZnLys |
| yz |
Means lacking a common
superscript letter differ (P<0.05) |
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Hess et al., J Appl. Anim.
Res. 19:49-60, 2001 |
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iii. |
Digestion Track - The
epithelial tissue lining the digestive track is affected by the use
of complexed zinc in the diet of animals. Researchers at Alberta,
Canada, fed high levels of complexed zinc to the sow and found a significant
increase in development of gut tissue and gut immune cells in the
progeny (25). Disease organisms enter the small intestine and attach
themselves to the epithelial lining of the intestinal cell wall. If
they penetrate this defense, an infection may occur. Research was
conducted at Colorado Quality Research on feeding complexed zinc to
broilers and challenging them with coccidiosis. Trial results showed
a reduction (P<0.05) of coccidiosis lesions in the treatment groups
fed complexed zinc (8).
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| B. |
Cellular Immunity - Cellular
immunity is directed by T- cells. A common test for cellular immunity
is cutaneous basophil hypersensitivity (CBH) test. The size of toe
web swelling or waddle skin swelling response is measured when phytohemagglutinin-P
is injected just under the skin. This response is a measurement of
cellular immune response. Generally, the greater the swelling response,
the stronger the cellular immune system. The provision of supplemental
complexed zinc to broiler breeders consistently increased the phytohemagglutinin-P
response in the progeny (27). |
| C. |
Humoral Immunity - There
are two key categories of humoral immunity, Phagocytic cells and B-cells.
Both systems are essential defensive mechanisms to prevent disease
and infections. |
|
i. |
Phagocytic Cells - Macrophages are
the most prominent members of this immune defense system. Macrophages
are the next non-specific defense mechanism after epithelial tissue.
Of the three metals (zinc, manganese and copper), zinc plays a direct
role in macrophage development and activity. Young turkey poults fed
complexed zinc and manganese had statistically enhanced macrophage
activity and phagocytic response (26). |
Photo courtesy Dr. Peter Ferket, NCSU |
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ii. |
B-Cells - Several research trials have
been conducted studying the effects of feeding complexed trace minerals
to poultry and measuring titer response. Researchers in the USA and
China found increases in titer response to foreign protein (bovine
serum albumin) and Salmonella in poultry when feeding complexed trace
minerals (26, 27, 28). In a separate trial, complexed zinc and manganese
were fed to broiler breeders. Titer response was measured for infectious
bronchitis (IB), infectious bursal disease (IBD) and Newcastle disease
(ND). Breeders fed complexed trace minerals showed a higher titer
response for all three diseases (21). Titer responses are shown in
Figures 4-6 below. Internal research in broilers also have shown a
higher ND titer response when feeding complexed zinc, manganese and
copper (Figure 9). |
Figure 4. Effect of Complexed
Zinc and Manganesea on Broiler Breederb Humoral
Immune Response (antibody titers)
Figure 5. Effect of Complexed Zinc and Manganesea
on Broiler Breederb Humoral Immune Response (antibody titers)
Figure 6. Effect of Complexed Zinc and Manganesea
on Broiler Breederb Humoral Immune Response (antibody titers)
| D. |
Maternal Immunity - Immunity in the hen will be
passed on to the progeny in poultry. A common vaccination strategy
is to obtain a high level of maternal immunity so it passes on to
the chick and improves survival rate. Feeding complexed zinc to broiler
breeders increased the yolk zinc content of the eggs (28) and increased
embryonic bone zinc content (27). Researchers also found a significant
increase in the immunity (toe web swelling) of progeny when complexed
zinc was fed to the broiler breeders (27; Table 2). Researchers at
Mississippi State University showed a similar response in improved
cellular immunity of progeny when feeding the broiler breeder hen
zinc and manganese complexes (34). |
Table 2. Effect of Trace Mineral Complexes on Progeny
| Treatments |
Bone
Dry Weight (g)a |
Zinc Content
(µg/g Dry Bone)a |
Toe Web Swelling
PHAP-P (mm)b |
| Control |
0.075x |
191.31 |
0.813z |
| ZnO |
0.075x |
191.13 |
0.758z |
| Zinc complexc |
0.078w |
210.50 |
1.067y |
|
| a |
Control = 72 ppm Zn from ZnO, ZnO = Control + 80 ppm
Zn from ZnO, Zinc complex = Control + 80 ppm Zn from zinc complex |
| b |
Control = 78 ppm Zn from ZnO, ZnO = Control + 40 ppm
Zn from ZnO, Zinc complex = Control + 40 ppm Zn from zinc complex |
| c |
ZINPRO® zinc methionine |
| wx |
Within a column, means lacking a common superscript
letter differ (P<0.05) |
| yz |
Within a column, means lacking a common superscript
letter differ (P<0.0001) |
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Kidd et al. 1992 Poultry Sci.71:1201-1206; 1993 Poultry
Sci. 72:1492-1499. |
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