Abstract: The results revealed that 42 and 40 percent feed samples contained labelled amount of vitamin A and D respectively, while 34 and 26 percent samples contained lesser amount and 26 and 32 percent samples contained excess amount of vitamin A and D in the poultry feeds.
Introduction
Vitamins are organic compounds essential for the normal functioning of the body, required in minute quantities. Vitamins regulate metabolic reactions. All vitamins are highly specific in their function. Vitamin A (Retinol) and vitamin D (Ergocalciferol vit. D2 and Cholecalciferol vit. D3) are fat-soluble vitamins. The principal commercial form in use is vitamin A (Retinal) and (cholecalciferol). Vitamin A is utilized promotion of growth (Raza et al., 1997) maintenance of epithelial cells and vision. Vitamin D thus helps to ensure that the body has sufficient calcium and phosphorus in the blood for the normal calcification of bones (Rowland et al., 1988). Vitamin A and D are important nutritional factors, which play an essential role in fulfilling the nutritional requirements of all animals particularly in the poultry, where it improves the quality of eggs (Konno et al., 1984; Hart et al., 1986). Vitamin A and D improves the body weight and egg laying performance, thereby, demanding an extra supplement of vitamin A and D in the rations of egg laying hens (Stevens and Blair, 1987). The present research project was undertaken to assure the quality of vitamin A and D in poultry feeds.
Materials and Methods
Fifty different feed samples of twenty feed mills were collected and extraction was carried out for three hours using chloroform as solvent at 80°C. Feed extracts were purified by column chromatography using aluminum oxide as adsorbent. An 18 percent solution of antimony trichloricie (carr-price reagent) was prepared. The sample of standard vitamin A acetate (500,000 IU/g), a light yellow crystalline mass prepared by "BASF" Germany was obtained from local market and the sample of standard vitamin D3, 40 M IU/g crystalline powder prepared by "Roche" company was obtained from Army Welfare Food Industry Faisalabad. Vitamin A and D in feed preparations was determined by using carr-price method (Hodata and Hawada, 1985). Vitamin A and D gave blue and yellow orange colour with carr-price reagent. The intensity of the colour was measured at 620 nm and 500 nm for vitamin A and D respectively.
Results and Discussion
Each feed sample was analyzed at least in triplicate. The mean absorbance values for each sample was recorded and the concentration of vitamin A and D in different feeds was calculated and converted to μg/kg of feed. An international level and in Pakistan the concentration of vitamin A and D in feed preparations is expressed in international units (lU). For vitamin A (1 lU = 0.344 μg) and for vitamin D3 (1 lU = 0.025 μg), The concentration of vitamin A and D in μg/kg of feed is converted to IU/kg of feed and shown in (Table 1).
The recommended concentration of vitamin A and D is (8000 IU/kg to 15000 IU/g) and (1500 IU/g to 3000 IU/g) of feed respectively (Roche Switzerland). Out of 50 samples 40 and 42 percent samples contained labelled amount of vitamin A and D to fulfill the nutritional requirement of poultry birds, 34 and 26 percent samples contained insufficient amount of vitamin A and D, 26 and 32 percent samples contained excessive amount of vitamin A and D respectively (Table 2).
Vitamin A and are an important nutritional factor, which plays an essential role in fulfilling nutritional requirements of all animals in particular the poultry, where it develops immunity against various diseases (Sijtsma et al., 1989; Shinki et al., 1989).
In the absence of an adequate take of vitamin A and D, a number of abnormalities and deficiency diseases appear in the poultry birds. In chicken's vitamin A deficiency causes reduced appetite, growth inhibition, weight loss, rough hair or plumage, raised cerebra spinal pressure and formation of spongy bone tissue. Deficiency of vitamin A causes Newcastle disease virus (NDV) in poultry birds. (Lessard et al., 1997). Vitamin A fluorescence weaker the kupffer cells, oesophageal gland cells, oesophageal mucosa, periesteum and vascular walls of various tissues (Friedman et al., 1991). The maximal immune response in poults may be achieved at dietary intake of vitamin A against NDV at or higher than those recommended by NRC (Sklan et al., 1995). Vitamin D deficiency causes weight loss decreased in egg production thin-shelled eggs and reduced hatchability and soft-shelled eggs were laid. Deficiency of vitamin ID in laying hens decrease thickness of the shell abruptly and numerous thin shell and soft-shelled eggs are laid (Narbaitz et al., 1987). Efficiency of vitamin D compounds prevented the tibial dyschondroplasia in broiler chicken (Edwards, 1990; Elliot and Edwards, 1994). Influence of vitamin D on eggshell quality, tibia strength and various production parameters in laying hens (Frost et al., 1990). The quantitative requirements of cholecalciferol are more in the absence of ultraviolet light (Edwards et al., 1994). The content of inorganic phosphorus in the blood are however higher for chickens given Ekonomix D (Schleicher et al., 1994). Vitamin D is very useful in the treatment of different diseases in poultry farms (Saxena and Chandna, 1996).
| Table 1: | Showing the concentration of vitamin A and D in lU/kg of poultry feed |
| Table 2: | Showing the percentage and number of vitamin A and D of each group in poultry feed |
Vitamin A and D should be provided only in suitable amounts. Over dosage of vitamin A and D results in a number of manifestation and toxicity. Excessive vitamin A intake decreases osteoblastic activity and inhibits bone formation in chick tibia. (Kannan et al., 1998), impaired skeletal formation (Saleh et al., 1995).
Poultry birds fed substandard feeds for long periods are bound to suffer from different diseases, it may be due to the addition of lesser amounts of vitamin mineral into the feed during its formulation or it may be due to the subsequent destruction of the vitamin on storage. Due to above facts, special attention should be given towards the storage conditions of poultry preparations. During storage proper temperature should be maintained and arrangements should be done to protect the feed preparations from light, moisture and other environmental condition.