20 Carotenoids in Aviculture
527
vitamin E concentrations in the liver and plasma were significantly elevated as a
result of maternal diet supplementation with CX. In fact, α-tocopherol concentration
in the chick liver decreased more than 10-times in the first week. In such an extreme
situation, increased CX concentration in the chick liver slowed down the depletion
of vitamin E from the liver, which could be explained by the same mechanisms of
CX/vitamin E interactions.
As a result of enrichment of the chick liver with CX and vitamin E due to the
maternal dietary supplementation, tissue susceptibility to lipid peroxidation significantly decreased in 1-d-old and 7-d-old chicks. The protective effect CX against
lipid peroxidation may be mediated via its effect on antioxidant enzymes (Palozza
et al. 2000). The enhancement of the antioxidant system in the developing chick as
a result of supplementing the maternal diet presents great opportunities for poultry
producers. Postnatal development of the chicken is a crucial time for the maturation
of major physiological systems, including the immune system, as well as a time of
high risk of peroxidation (Surai 2002). Therefore, increased supplementation of the
maternal diet with carotenoids, in particular CX, could help maintain antioxidant
system efficiency and increase chick viability.
The idea of exploiting the beneficial effects of dietary CX supplementation in
breeder diets was further developed by Zhang et al. (2011a, b). In this study,
270 Chinese Three-Yellow breeder hens were randomly divided into two groups
consisting of 135 birds each (five replicates of 27). The breeder hens were fed either
a basal diet or one supplemented with 6 mg of CX/kg for 24 weeks. At the end of
the experiment, all hatching eggs laid over five consecutive days from each group
were collected and incubated. For each breeder group, 100 newly hatched chicks
(five replicates of 20) were reared under environmentally controlled conditions for
21 d. The results from this trial showed that CX supplementation gave a significant
increase in the yolk colorimetric score on the Roche Yolk Color Scale (P < 0.001),
confirming an effective CX transfer from the diet to the egg yolk. Egg yolk enrichment with CX was associated with a significant improvement of the antioxidant
status of the egg yolk (P < 0.05), whereby malondialdehyde (MDA) content of the
egg yolk decreased from 139.83 nmol/g down to 86.92 nmol/g (P = 0.023). At the
same time total antioxidant capacity (TAC) of the egg yolk increased from 1.87 U/g
up to 3.16 U/g (P < 0.001). These important improvements in the antioxidant status
of yolk could be due to CX transfer or improvements of vitamin E status (Surai et al.
2003). One important finding was the improvement of the serum TAC in the breeder
hen (P < 0.029). This could be an important element in an improvement of protection of laying birds from commercially relevant stresses, including fluctuations in
temperature and feed quality (Surai 2002).
The chicks that hatched from eggs laid by breeder hens fed the CX diet demonstrated a higher pigmentation colorimetric score of their shank skin (P < 0.05),
ascribed to CX accumulation (Surai et al. 2003) and the antioxidant capacity of the
newly hatched chicks was significantly increased (P < 0.05). There was a significant
decrease in MDA (from 4.28 down to 2.61 nmol/ml, P < 0.001) in the plasma of
day-old chicks, thought to be a result of increased CX and vitamin E concentration
in plasma (Surai et al. 2003). It is of great importance to see increased SOD activity
527
vitamin E concentrations in the liver and plasma were significantly elevated as a
result of maternal diet supplementation with CX. In fact, α-tocopherol concentration
in the chick liver decreased more than 10-times in the first week. In such an extreme
situation, increased CX concentration in the chick liver slowed down the depletion
of vitamin E from the liver, which could be explained by the same mechanisms of
CX/vitamin E interactions.
As a result of enrichment of the chick liver with CX and vitamin E due to the
maternal dietary supplementation, tissue susceptibility to lipid peroxidation significantly decreased in 1-d-old and 7-d-old chicks. The protective effect CX against
lipid peroxidation may be mediated via its effect on antioxidant enzymes (Palozza
et al. 2000). The enhancement of the antioxidant system in the developing chick as
a result of supplementing the maternal diet presents great opportunities for poultry
producers. Postnatal development of the chicken is a crucial time for the maturation
of major physiological systems, including the immune system, as well as a time of
high risk of peroxidation (Surai 2002). Therefore, increased supplementation of the
maternal diet with carotenoids, in particular CX, could help maintain antioxidant
system efficiency and increase chick viability.
The idea of exploiting the beneficial effects of dietary CX supplementation in
breeder diets was further developed by Zhang et al. (2011a, b). In this study,
270 Chinese Three-Yellow breeder hens were randomly divided into two groups
consisting of 135 birds each (five replicates of 27). The breeder hens were fed either
a basal diet or one supplemented with 6 mg of CX/kg for 24 weeks. At the end of
the experiment, all hatching eggs laid over five consecutive days from each group
were collected and incubated. For each breeder group, 100 newly hatched chicks
(five replicates of 20) were reared under environmentally controlled conditions for
21 d. The results from this trial showed that CX supplementation gave a significant
increase in the yolk colorimetric score on the Roche Yolk Color Scale (P < 0.001),
confirming an effective CX transfer from the diet to the egg yolk. Egg yolk enrichment with CX was associated with a significant improvement of the antioxidant
status of the egg yolk (P < 0.05), whereby malondialdehyde (MDA) content of the
egg yolk decreased from 139.83 nmol/g down to 86.92 nmol/g (P = 0.023). At the
same time total antioxidant capacity (TAC) of the egg yolk increased from 1.87 U/g
up to 3.16 U/g (P < 0.001). These important improvements in the antioxidant status
of yolk could be due to CX transfer or improvements of vitamin E status (Surai et al.
2003). One important finding was the improvement of the serum TAC in the breeder
hen (P < 0.029). This could be an important element in an improvement of protection of laying birds from commercially relevant stresses, including fluctuations in
temperature and feed quality (Surai 2002).
The chicks that hatched from eggs laid by breeder hens fed the CX diet demonstrated a higher pigmentation colorimetric score of their shank skin (P < 0.05),
ascribed to CX accumulation (Surai et al. 2003) and the antioxidant capacity of the
newly hatched chicks was significantly increased (P < 0.05). There was a significant
decrease in MDA (from 4.28 down to 2.61 nmol/ml, P < 0.001) in the plasma of
day-old chicks, thought to be a result of increased CX and vitamin E concentration
in plasma (Surai et al. 2003). It is of great importance to see increased SOD activity