Besides protein, carbohydrates, fats, and vitamins, many other elements form a part of the quail’s nutritional requirements. Minerals can be divided into macrominerals and microminerals. Macrominerals are required in large amounts, and are often struct ured parts or acid-base elements. These are: calcium, phosphorus, potassium, magnesium, sulfur and salt (NaCl). The microminerals are associated in activation or integrated parts of enzymes. These include: cobalt, copper, iodine, iron, manganese, selenium and zinc. Minerals make up 3 to 5% of the quail’s body. Since minerals cannot be synthesized, they must be provided by the diet.
Calcium and phosphorus. The main function of these two minerals is in the make-up of the bones of the body. Calcium is also essential for the deposition of egg shell. It is not only that calcium and phosphorus are required in sufficient quantity but also in the correct proportions. For the young growing quail the ratio should be 1:1 to 2:1. The young quail needs a minimum of 0.8 per cent of the diet as calcium and 0.45 per cent as available phosphorus, whilst the laying quail needs about 2.5% to 3% of calcium since this is the main constituent of the egg shell.
HAF observed no difference in body weight or bone ash of quail up to 6 weeks of age as long as the diets contained 0.58% to 1.18% total phosphorus and 0.44% to 2.3% calcium. Lee and Shim (1971) found that 0.5% calcium was adequate for the growing quail and a level of 4.9% calcium retarded growth. HAF observed that growing as well as laying quail were in positive calcium balance as long as the diets contained 0.8%, 1.5%, 2.6% or 3.5% calcium. A level of 3.5% dietary calcium reduced hatchability.
Minerals are present in many of the ingredients in the diet. Fish meal, meat and bone meal, milk products are good supplemental sources of calcium and phosphorus. Oystershell, limestone, tricalcium phosphate or calcium carbonate are usually added to the feed to supplement these elements.
Magnesium. Magnesium is an essential constituent of tissues and body fluids. Its ions serve as activators of important enzymes involved in intermediary metabolism. When it is absent from the diets, quails grow slowly, exhibit convulsions and may eventually die. Deficiencies in laying rations produce a rapid drop in egg production. The magnesium requirement was recommended to be 300 mg/kg diet. In our research, magnesium requirement for survival and growth was met by supple menting 150 mg magnesium per kg diet, or 50 mg magnesium per liter drinking water. We found no detrimental effects from feeding 1,000 mg magnesium per kg purified diet.
Natural feedstuffs contain adequate amount of magnesium. Some limestone (the dolomites) contain a high percentage of magnesium and are to be avoided because excess magnesium is laxative and interferes with calcium usage.
Manganese. The main function of manganese is to prevent perosis, a condition where the Achilles’s tendon slips off its groove behind the hock joint, pulling sideways and backwards. It is also required for normal growth, egg shell deposition, egg production and good hatchability. It is supplemented in the diet in the form of manganese sulphate.
Iron, Copper and Cobalt. These trace elements are essential for the formation of haemoglobin. Nutritional anemia occurs when there are deficiencies of these minerals. The red blood cells contain iron. Copper is necessary for iron utilization when haemoglobin is formed. Harl and et al. (1973) reported the iron requirement of growing Japanese quail as 90-120 mg/kg, and of copper as 5 mg/kg diet based on EDTA extracted isolated soybean protein.
Cobalt is the integrated part of vitamin B12 which involves in haemoglobin formation. The amount of these elements in the diet is quite specific; excesses may be toxic. Usually, only small amounts are added in the feed. We studied the effect of supplementary 50, 100, 250 and 500 mg cobalt sulphate per kg diet on vitamin B12 concentration in liver and caeca. The concentration was highest with 1200 mg cobalt sulphate/kg diet.
Selenium. Selenium is an essential element for growing quail even in presence of vitamin E. Diets consisting of amino acids and 100 mg d-alpha-tocopheryl acetate/kg needed to be supplemented with 0.1 mg selenium as selenite for proper survival of quail.
Impaired reproduction was observed in Japanese quail fed a diet low in selenium and vitamin E from hatching to maturity. Oviposition rate and fertility were not affected, but the hatchability of fertile eggs, viability of male and female adults and newly hatched chicks were reduced. Dietary supplementation with either 1 mg selenium or 30 I.U. vitamin E/kg diet prevented the impaired reproduction. Selenium supplementation of the diet at 0.2 mg/kg diet prevented nutritional pancreatic atrophy and resulted in significant elevation in SeGSHpx activity.
Zinc. Japanese quail are quite sensitive to a dietary deficiency of zinc. Zinc deficiency in quail chicks was characterized by slow growth, abnormal feathering, labored respiration and an in coordinated gait, low tibia ash, and a low concentration of zinc in liver and tibias. The zinc requirement for normal growth, feathering, tibia length and conformation was 25 mg/kg diet. HAF studied the protective effect of a high prior zinc intake for rapidly growing quail to a subsequently fed low zinc diet. The birds fed an initial level of 75 mg zinc/kg grew significantly better than those fed initially 25 mg zinc/kg. Bone might store zinc and it might be mobilized during zinc deprivation. A reduction in zinc absorption in adult quail by high levels of calcium.
Salt (Sodium chloride). This is needed for protein digestion and these elements are also involved with acid-base equilibrium in the body. The growing Japanese quail fed a purified type of diet containing 0.042-0.051% sodium had poor growth , high mortality, adrenal enlargement, elevated haematocrit, and depressed plasma sodium suggestive of an aberration in fluid and electrolyte haemostasis. A dietary sodium level of 0.1% overcame these difficulties.
Natural feedstuffs usually require supplemental feeding of salt (NaCl) to satisfy the quail’s requirement for sodium and chloride and this is normally added to the feed at amounts of 0.25 to 0.35 per cent. Too much salt produces a laxative effect and results in wet droppings and also wet litter.