Effects of different levels of dietary calcium and
supplemental Vitamin C on growth, survivability, leg abnormalities, total ash in the
tibia, serum calcium and phosphorus in 0-4 week-old chicks under tropical conditions
Bui Huu Doan
Hanoi Agricultural University, Gialam, Hanoi, Vietnam
Abstract
A 2x2 factorial experiment was carried out
to determine the effects of two levels of dietary calcium (0.85% vs.1.10%) in combination
with Vitamin C supplementation (0 vs. 150ppm) on growth, survivability, leg abnormalities,
total ash in the tibia bone, serum calcium and phosphorus in 0-4 week-old chicks. Results
showed that the experimental factors did not significantly affect the growth rate of
chicks (P>0.05). However, the diet containing 1.10% Ca supplemented with 150 ppm
Vitamin C resulted in the lowest mortality (2.4%), incidence of crooked legs (2.2%) and
serum P (but not statistically significant (P >0.05)). This diet also brought about the
highest concentration of total ash in the tibia bone. The group fed on 0.85% Ca without
supplemental Vitamin C had the highest mortality (4.3%) and incidence of crooked legs
(6.34%). It is therefore suggested that the diet containing 1.10% Ca
supplemented with 150 ppm Vitamin C is good for increased survivability and reduced leg
abnormalities.
Keywords: Chicken, calcium, vitamin C, growth, survivability, leg abnormality,
tibia, serum calcium, serum phosphorus
Introduction
According to the guidelines of the Vietnam
Poultry Corporation, the dietary Ca level for chicks ranges from 0.9 to 1.2%. The
corresponding figure recommended by NRC (1994) is 0.8-0.9%. Moreover, Vitamin C has been
known to activate enzyme 25-hydroxyl Vitamin D3-1hydroxylase, which catalyses
the reaction converting 25-(OH)D3 (in the liver) into 1,25-(OH)2D3
(in the kidneys). Therefore, Vitamin C nutrition should have influence on calcium and
phosphorus metabolism in young chicks which possess no ability to synthesize Vitamin C
(Bains 1992).
Halley et al (1987) indicated that increased
dietary Ca did not affect the body weight but considerably reduced foot diseases such as
tibial dyschondroplasia, crooked legs and increased the tibial total ash. Lebbie and
Ademosun (1988) showed that diets containing 0.8% Ca were not sufficient to support normal
growth and led to reduced Ca levels in blood and bones. Under tropical conditions, the
optimum Ca level should be greater than 1.0% but should not exceed 1.2%. The Ca/P ratio
should be in the range of 1.3-2.0/1. Huyghebaert (1977) found that the optimum Ca/P
ratio for chicks was 2.2/1 and that 1.04% Ca in the diet gave the best concentration
of tibial ash. Franchini et al. (1993) reported that supplemental Vitamin C enhanced
the mineralization of the skeleton of young poultry. McKee and Harrison (1995) found that
dietary supplementation with Vitamin C increased the growth rate by 4.5%, and improved the
tolerability to stresses and reduced the mortality by 5%.
The objective of this study was to examine the effects of Vitamin C supplementation
and dietary Ca levels for 0-4 week old chicks under the tropical conditions of North
Vietnam.
Materials and methods
The experiment was carried out on parent
breeding chicks of breed BE 88. A total of 1200 one-day-old chicks were randomly divided
into 4 groups of 3 replicates of 100 chicks each. The 4 groups were used in a 2x2
factorial arrangement to determine the effects of two levels of dietary calcium (0.85% vs.
1.10%) in combination with Vitamin C supplementation (0 vs. 150 ppm) on growth,
survivability, leg abnormalities, total ash in the tibia bone and serum calcium and
phosphorus. The study was conducted as an on-farm trial under an average temperature of 28.6oC
(ranging from 22.5 to 38.7oC). The 4 groups were given rations as in Tables 1
and 2.
| Table 2: Analisis of the experimental rations (air dry
basis) |
![]() |
|
0.85 % Ca |
1.10 % Ca |
![]() |
| Composition\Groups |
150ppm Vit. C |
0ppm Vit. C |
150ppm Vit. C |
0 ppm Vit. C |
![]() |
| Ca, % |
0.86 |
0.86 |
1.10 |
1.10 |
| Total P, % |
0.91 |
0.91 |
0.87 |
0.87 |
| Available P, % |
0.51 |
0.51 |
0.50 |
0.50 |
| Ca/P ratio |
1.68 |
1.68 |
2.20 |
2.20 |
| Crude protein., % |
23.1 |
23.1 |
23.0 |
23.0 |
| ME (kcal/kg) |
2901 |
2901 |
2902 |
2902 |
| ME/CP |
125.7 |
125.7 |
126.0 |
126.0 |
![]() |
Results and discussion
Body weight
The average body weights of the 4 groups of
chicks at the end of each week of age during the experiment are given in Table 3.
After 4 weeks, experimental chicks of group fed with 1.10% Ca and 150 ppm
Vit. C had the heaviest body weight followed by those fed with 1.10% Ca without Vit.
C. Chicks of groups fed with 0.85% Ca had the lightest body weights. However, the differences were not
statistically significant (P >0.05), indicating that the growth of the chicks was not
influenced by the different levels of dietary calcium and 150 ppm of supplemental Vitamin
C.
Mortality and incidence of crooked legs
Table 4: Effects of dietary calcium levels and
supplemental Vitamin C on mortality and crooked legs |
![]() |
Weeks
of age |
0.85
% Ca |
1.10
% Ca |
| 150
ppm Vit. C |
0
ppm Vit. C |
150
ppm Vit. C |
0
ppm Vit. C |
| Mortality (%) |
Crooked legs (%) |
Mortality (%) |
Crooked legs (%) |
Mortality (%) |
Crooked legs (%) |
Mortality (%) |
Crooked legs (%) |
![]() |
| 1 |
1.30 bc |
0.87 a |
1.96 a |
0.89 a |
1.08 c |
0.65 b |
1.52 b |
0.87 a |
| 2 |
0.88 b |
1.31 c |
1.13 a |
1.81 a |
0.88 b |
1.09 d |
1.10 ab |
1.53 b |
| 3 |
0.40 c |
0.67 b |
0.89 a |
2.33 a |
0.44 bc |
0.44 c |
0.66 b |
0.66 b |
| 4 |
0.45 a |
0.44 b |
0.41 a |
1.67 a |
0.00 b |
0.00 c |
0.44 a |
0.44 b |
| Total |
3.00 a |
3.26 b |
4.33 b |
6.34 c |
2.40 a |
2.20 a |
3.66 ab |
3.43 b |
![]() |
NB: Means in the same row bearing dissimilar superscripts are significantly
different |
From 1-4 weeks of age, the differences in
mortality between groups were significant. For the whole period, the mortality was lowest
in group fed with 1.10% Ca and 150 ppm Vitamin C, followed by the group fed with 0.85% Ca
and 150 ppm Vitamin C, the group fed with 1.10% Ca and no Vitamin C, and lastly the group
fed with 0.85% Ca and no Vitamin C. These results indicate that the different levels of
dietary calcium and supplemental Vitamin C significantly affected the mortality rate.
Similarly, the incidence of crooked legs was
lowest in chicks fed with 1.10% Ca and 150 ppm Vitamin C, followed by those fed with 0.85%
Ca and 150 ppm Vitamin C, then those fed with 1.10% Ca and no Vitamin C, and was
highest in chicks fed with 0.85% Ca and no Vitamin C.
Total ash in the tibia bone and serum Ca and P
Table 5 shows effects of the levels of
dietary calcium and supplemental Vitamin C on tibial total ash and serum Ca and P. Chicks
fed on the ration containing 1.10% Ca supplemented with 150 ppm Vitamin C had the highest
concentration of total ash in the tibia bone, followed by those fed 1.10% Ca without
Vitamin C supplementation. The chicks fed on the ration containing 0.85% Ca without
Vitamin C supplementation had the lowest ash in the tibia.
| Table 5: Effects of dietary calcium levels
and supplemental Vitamin C on tibial total ash and serum Ca and P (n = 5) |
![]() |
|
0.85 % Ca |
1.10 % Ca |
![]() |
|
150ppm
Vit. C |
0ppm
Vit. C |
150ppm
Vit. C |
0
ppm Vit. C |
![]() |
| Tibial total ash (%) |
42.5
b |
41.1
a |
44.2c |
42.7
b |
| Serum Ca (mg%) |
12.9
b |
11.9
a |
13.6c |
13.7
b |
| Serum P (mg%) |
9.12
a |
9.75
a |
8.91
a |
9.43
a |
![]() |
| NB: Means in
the same row bearing dissimilar superscripts are significantly different |
Table 5 also shows that when the level of Ca
increased from 0.85% to 1.10%, serum Ca was increased. Supplementation of the ration with
150 ppm Vitamin C also improved serum Ca (P<0.05). In both cases, serum P tended to be
reduced, although it was not statistically significant.
References
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Nutritional approaches to minimize inadequate mineralisation. Proceedings of Poultry
Science Symposium held at the University of Queensland, Gatton College, Australia
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Halley J T, Nelson T
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and mineralisation in broiler chicks. Archiv-fur-Geflugelkunde Vol 61, No 2: 53-61
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broiler chickens exposed to multiple concurrent stresses. Poultry Science Vol 74:
1772-1785
Received 23 July 1999
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