Livestock Research for Rural Development 12 (1) 2000

Citation of this paper

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 1: Composition of the experimental rations

0.85 % Ca 1.10 % Ca
Ingredients, %\Groups 150ppm Vit. C 0ppm Vit. C 150ppm Vit. C 0 ppm Vit. C
Yellow maize meal  44.0 44.0 46.0 46.0
Rice bran  19.6 19.6 16.2 16.2
Soya bean meal  3.00 3.00 3.80 3.80
Groundnut cake  7.20 7.20 7.00 7.00
Fish meal  5.00 5.00 5.00 5.00
Soya bean cake  19.0 19.0 19.0 19.0
Lime stone meal  0.70 0.70 1.50 1.50
Dicalcium phosphate  1.00 1.00 1.00 1.00
L-Lysine  0.20 0.20 0.20 0.20
DL-Methionine  0.10 0.10 0.10 0.10
Premix  0.20 0.20 0.20 0.20
Suppl. Vit. C (ppm) 150 0 150 0

 

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.

Table 3: Effects of dietary calcium levels and supplemental Vitamin C on body weight of chicks (g/head)

0.85 % Ca 1.10 % Ca
Days of age 150ppm Vit. C 0ppm Vit. C 150ppm Vit. C 0 ppm Vit. C
7 134 a 133 a 144 a 140 a
14 293 a 291 a 307 a 300 a
21 414 a 409 a 495 a 487 a
28 643 a 644 a 683 a 651 a

 NB: Means in the same row bearing dissimilar superscripts are significantly different

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

Bains B S 1992 Nutritional approaches to minimize inadequate mineralisation. Proceedings of Poultry Science Symposium held at the University of Queensland, Gatton College, Australia

Franchini A, Meluzzi A, Manfreda G and Tosarelli C 1993 Effects of Vitamin C on broiler skeleton development. Atti dell' Associazione Scientifica de Produzione Animale (Italy) Vol 10: 519-524

Halley J T, Nelson T S and Kirby L K 1987 Effect of calcium, magnesium, chloride, sulfate and phosphorus on growth and leg abnormalities in broiler chicks. Nutrition and  Reproduction International 36: 1061-1070

Huyghebaert G 1977 Effect of dietary calcium, phosphorus, Ca/P ratio and phytase on zootechnical performance and mineralisation in broiler chicks. Archiv-fur-Geflugelkunde Vol 61, No 2: 53-61

Lebbie S H B and Ademosun A A 1988 The effect of dietary calcium and phosphorus level on the performance of starter in the humid tropics. Bulletin of Animal Health and Production in Africa Vol 36, No 1: 1-13

Mc Kee J S and Harrison P C 1995 Effects of supplemental ascorbic acid on the performance of broiler chickens exposed to multiple concurrent stresses. Poultry Science Vol 74: 1772-1785

Received 23 July 1999

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