528
P. F. Surai and I. I. Kochish
(from 98.4 to 144.7 U/ml, P = 0.031) in plasma, and these findings are in agreement
with previous observations indicating a stimulatory effect of CX on SOD (Palozza
et al. 2000). It is interesting to underline that maternal supplementation with CX has
a positive effect on TAC of newly hatched chicks, which increased by 33% (from
13.8 to 18.3 U/ml, P = 0.052).
In a field trial, Robert et al. (2008) studied the effect of CX in ROSS breeders on the
antioxidant status of their progeny. They observed that the antioxidant status of sera
was significantly higher and the TBARS level was significantly lower in 1-day old
chicks from hens fed 6 ppm CX in the breeder feed. According to these authors, the
results indicate that maternal supplementation with CX (6 ppm) enhances antioxidant
capability and depresses oxidative stress in chicks. Similar to finding from previous
work (Surai et al. 2003), maternal effects of CX supplementation has been seen in
postnatal chicken development. Indeed, shank pigmentation score (a reflection of
CX accumulation) and MDA in plasma were significantly lower in 7-day-old chicks
hatched from the CX-enriched eggs. The experimental chicks also showed a lower
mortality (0 vs. 4%) during the first 21 d post hatch. These findings support the
hypothesis that CX supplementation of the maternal diet enhances the protective
capacity of tissues against oxidative stress in vivo, which might be beneficial for
poultry producers.
The next step in examining the beneficial effects of CX in the maternal diet was
provided by an experiment conducted in Brazil in the Poultry Science Laboratory of
the Department of Zootechnics at the Federal University of Santa Maria (UFSM);
Rosa et al. 2012). Three hundred and sixty female pullets and 36 roosters were placed
in an open-sided house allocated into 12 pens. At 42 weeks of age, the breeder
hens and roosters were distributed into two experimental groups with similar body
weight and uniformity, and from weeks 46 to 66, one group received 6 ppm of CX,
supplemented in the diet, and the other group received the diet without addition of
CX (control diet). Those fed with CX had significantly better egg-laying rates during
certain periods, but overall there was no difference between the two treatment groups.
Two weeks after the start of the supplementation the pigmentation measured with
the colour fan was 9.33 in the control group and 14.67 in the CX group (P < 0.0001)
and this difference in yolk colouration remained stable throughout the experiment.
These results are in agreement with previous observations (Surai et al. 2003; Zhang
et al. 2011a, b). In concurrence with previous observations, a reduction of TBARS
was observed in yolks from stored hatching eggs produced by breeders fed CX. The
reduction in TBARS was observed in eggs submitted for analysis on the same day
they were produced (P = 0.0214) and in eggs stored for four (P < 0.0002), eight (P
< 0.0003) and twelve days (P < 0.0001).
The most important finding of this study was the positive effect of CX supplementation of the maternal diet on fertility, hatchability and embryonic mortality. In
fact, CX in comparison to the control improved fertility (92.1 vs. 91.0%, P < 0.02)
and hatchability (93.7 vs. 91.3%, P = 0.0003) and reduced embryonic mortality (3.7
vs. 5.5%, P < 0.003). As a result, hatching rate was significantly (86.2 vs. 83.0%, P
= 0.0001) improved. As to the different stages of embryo mortality, CX was most
efficacious for its prevention in the first 48 h (1.04 vs. 1.8%, P = 0.008) as well as
P. F. Surai and I. I. Kochish
(from 98.4 to 144.7 U/ml, P = 0.031) in plasma, and these findings are in agreement
with previous observations indicating a stimulatory effect of CX on SOD (Palozza
et al. 2000). It is interesting to underline that maternal supplementation with CX has
a positive effect on TAC of newly hatched chicks, which increased by 33% (from
13.8 to 18.3 U/ml, P = 0.052).
In a field trial, Robert et al. (2008) studied the effect of CX in ROSS breeders on the
antioxidant status of their progeny. They observed that the antioxidant status of sera
was significantly higher and the TBARS level was significantly lower in 1-day old
chicks from hens fed 6 ppm CX in the breeder feed. According to these authors, the
results indicate that maternal supplementation with CX (6 ppm) enhances antioxidant
capability and depresses oxidative stress in chicks. Similar to finding from previous
work (Surai et al. 2003), maternal effects of CX supplementation has been seen in
postnatal chicken development. Indeed, shank pigmentation score (a reflection of
CX accumulation) and MDA in plasma were significantly lower in 7-day-old chicks
hatched from the CX-enriched eggs. The experimental chicks also showed a lower
mortality (0 vs. 4%) during the first 21 d post hatch. These findings support the
hypothesis that CX supplementation of the maternal diet enhances the protective
capacity of tissues against oxidative stress in vivo, which might be beneficial for
poultry producers.
The next step in examining the beneficial effects of CX in the maternal diet was
provided by an experiment conducted in Brazil in the Poultry Science Laboratory of
the Department of Zootechnics at the Federal University of Santa Maria (UFSM);
Rosa et al. 2012). Three hundred and sixty female pullets and 36 roosters were placed
in an open-sided house allocated into 12 pens. At 42 weeks of age, the breeder
hens and roosters were distributed into two experimental groups with similar body
weight and uniformity, and from weeks 46 to 66, one group received 6 ppm of CX,
supplemented in the diet, and the other group received the diet without addition of
CX (control diet). Those fed with CX had significantly better egg-laying rates during
certain periods, but overall there was no difference between the two treatment groups.
Two weeks after the start of the supplementation the pigmentation measured with
the colour fan was 9.33 in the control group and 14.67 in the CX group (P < 0.0001)
and this difference in yolk colouration remained stable throughout the experiment.
These results are in agreement with previous observations (Surai et al. 2003; Zhang
et al. 2011a, b). In concurrence with previous observations, a reduction of TBARS
was observed in yolks from stored hatching eggs produced by breeders fed CX. The
reduction in TBARS was observed in eggs submitted for analysis on the same day
they were produced (P = 0.0214) and in eggs stored for four (P < 0.0002), eight (P
< 0.0003) and twelve days (P < 0.0001).
The most important finding of this study was the positive effect of CX supplementation of the maternal diet on fertility, hatchability and embryonic mortality. In
fact, CX in comparison to the control improved fertility (92.1 vs. 91.0%, P < 0.02)
and hatchability (93.7 vs. 91.3%, P = 0.0003) and reduced embryonic mortality (3.7
vs. 5.5%, P < 0.003). As a result, hatching rate was significantly (86.2 vs. 83.0%, P
= 0.0001) improved. As to the different stages of embryo mortality, CX was most
efficacious for its prevention in the first 48 h (1.04 vs. 1.8%, P = 0.008) as well as