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NUTRIENT DEFICIENCIES AND DIETARY EXCESSES Most diets of U.S. and Canadian swine are composed of one or more grains, together with soybean meal or other protein sources that complement the indispensable amino acids lacking in the grains. These major ingre- dients of the diet should be supplemented with vitamins and essential mineral elements to provide all the known nutrient requirements. Diets formulated in this manner should prevent the appearance of any signs of nutrient deficiencies or excesses when fed to swine reared under suitable environmental conditions and free from infec- tious diseases. Clinical signs (outwardly apparent) and subclinical signs (determinable only by clinical method- ology) of nutrient deficiencies are presented in Table 1. Dietary excesses, with readily recognizable clinical signs, seldom occur. They are nevertheless a potential problem, particularly with micronutrients such as the trace minerals and some nonnutrients. A toxicity of cop- per would not likely occur unless copper were added at a high level (250 ppm, or more), and with low dietary iron or zinc or high levels of calcium. Iron toxicity is less likely unless there is a vitamin E-selenium deficiency. Sodium chloride toxicity is avoided if adequate water is provided. Fluorosis is seldom seen unless all supplemental phos- phorus is from a nondefluorinated raw rock phosphate source, but high levels of fluoride will reduce rate and efficiency of gain. Because of an interference with zinc absorption, an excess of calcium may be manifested by the skin condition, parakeratosis. Thus, signs of dietary excess are commonly conditioned by the interrelation- ship of two or more factors. Signs of these and other dietary excesses are presented in Table 2. The toxic dietary levels listed are those which experimentally pro- duced the signs indicated and are not necessarily minimum toxic or maximum tolerant levels. TABLE 1 Signs of Nutrient Deficiencies Signs of Nutrient Deficiency Nutrient Clinical Subclinical Energy Weakness, low body temperature, loss of weight, coma, and death Protein: Amino acid Impaired growth Unthriftiness Reduced resistance to bacterial infec- tion Fat: Linoleic acid Vitamin A Scaly dermatitis may appear Incoordination Lordosis Paralysis of rear limbs Night blindness Congenital defects Hypoglycemia Loss of subcutaneous fat Elevated hematocrit and serum cholesterol Reduced blood glucose, calcium, and sodium Kwashiorkor-like signs in baby pigs, including reduced serum pro- tein and serum albumin, anemia, gross edema, and increased lipid liver concentration Small gallbladder Elevated triene/tetraene in tissue lipids Retarded bone growth Increase in cerebrospinal fluid pressure Degeneration of sciatic and femoral nerves Minimal visual purple Atrophy of epithelial layers of genital tract 14
Nutrient Requirements of Swine 15 TABLE 1 Continued Nutrient Signs of Nutrient Deficiency Clinical Subclinical Vitamin D Rickets Osteomalacia Low calcium tetany Vitamin E-Selenium Edema Sudden death Vitamin K Pale newborn pigs with loss of blood from umbilical cord Sudden death following dicoumarin intake Thiamin Poor appetite Poor growth Sudden death Riboflavin Slow growth Seborrhea Impaired sow reproductivity Niacin Poor appetite Poor growth Severe diarrhea Dermatitis Pantothenic acid Poor appetite Poor growth Diarrhea Unusual gait (goose-stepping) Impaired sow reproductivity Vitamin Be Poor growth Epileptic seizures Vitamin B,2 Depressed growth Hypersensitivity Reduced sow reproductivity Choline Slow growth Reduced litter size Biotin Dermatosis Spasticity of hind legs Folacin Poor growth Weakness Calcium Rickets Osteomalacia Low calcium tetany Phosphorus Poor growth Rickets Osteomalacia Lack of bone calcification and proliferation of epiphyseal cartilage Rib and vertebra fracture Low plasma calcium, magnesium, and inorganic phosphorus levels Elevated serum alkaline phosphatase levels Generalized edema Liver necrosis (hepatosis dietetica) Microangiopathy Cardiac muscle degeneration (mulberry heart) Pale, dystrophic muscle Increased prothrombin time Increased blood-clotting time Internal hemorrhage Anemia due to blood loss Cardiac hypertrophy Bradycardia First and second degree auriculoventricular block Elevated plasma pyruvate Lens cataracts Increase in neutrophilic leukocytes Birth of weak pigs with skeletal anomalies Necrotic lesions of intestine Inflammation of colon Degeneration of sciatic and peripheral nerves Reduced blood pantothenic acid level Reduced free pantothenic acid level in milk Microcytic hypochromic anemia Elevated serum iron Fatty infiltration of liver Elevated urinary xanthurenic acid Elevated gamma globulin-like blood protein fraction Reduced serum and tissue H,: levels Fatty infiltration of liver Reduced conception rate Reduced urinary biotin excretion Normocytic anemia Lack of bone calcification Bones easily fractured Low plasma calcium level Elevated serum inorganic phosphorus and alkaline phosphatase Lack of bone calcification Bones easily fractured Low serum inorganic phosphorus level Elevated serum calcium and alkaline phosphatase Enlarged costochondral junction (beading)
16 Nutrient Requirements of Swine TABLE 1 Continued Nutrient Signs of Nutrient Deficiency Clinical Subclinical Magnesium Potassium Sodium Chlorine Iron Copper Zinc Iodine Manganese Water Poor growth Stepping syndrome Weakened carpo-metacarpo-phalangeal and tarso-metatarso-phalangeal joints Tetany Anorexia Rough hair coat Emaciation Ataxia Poor appetite Low water consumption Unthriftiness Poor growth Poor growth Rough hair coat Pallor Anoxia Leg weakness Ataxia Poor growth Poor appetite Parakeratosis Goiter Myxedema Sows farrow weak, hairless pigs Lameness in growing pigs Increased fat deposition in pregnant gilts with birth of weak pigs with poor sense of balance Poor appetite Dehydration Loss of body weight Possible salt poisoning Death Low serum magnesium and calcium Reduced bone magnesium Reduced heart rate Increased PR, QRS, and QT intervals on electrocardiogram Reduced serum potassium Negative sodium balance Elevated serum potassium Elevated plasma urea nitrogen Reduced chlorine retention Reduced plasma chlorine Reduced sodium and potassium retention Hypochromic microcytic anemia Enlarged heart and spleen Enlarged fatty liver Ascites Clumping of erythroblastic cells in bone marrow Reduced serum iron and percent transferrin saturation Microcytic hypochromic anemia Reduced serum copper and ceruloplasmin Aortic rupture Cardiac hypertrophy Reduced serum, tissue, and milk zinc Reduced serum albumin-globulin ratio Reduced serum alkaline phosphatase Reduced thymus weight Retarded testicular development Impaired reproductivity of sows Enlarged hemorrhagic thyroid Hyperplasia of follicular epithelium of thyroid Reduced plasma protein-bound iodine Replacement of cancellous bone with fibrous tissue Early closure of distal epiphyseal plate Low serum manganese and alkaline phosphatase Negative manganese balance Elevated hematocrit Elevated plasma electrolytes Loss of temperature regulation Tissue dehydration
Nutrient Requirements of Swine 17 TABLE 2 Signs of Dietary Excesses Nutrient Toxic Dietary Level" Age Signs of Dietary Excess Calcium Copper 300-500 mgi levels of d Iodine 800 mg/kg Iron 5,000 mg/kg Manganese 4,000 mg/kg Selenium 5-8 mg/kg' 1% (with limited zinc) Immature 1% (with adequate zinc and limited Immature phosphorus) 300-500 mg/kg (in absence of higher Immature Immature Immature Immature Immature Breeding (sows) 10 mg/kg Sodium chloride and 1-8% (with severe water restriction) All ages other sodium salts Zinc Arsenic Cadmium Cobalt 2,000 mg/kg 990 mg/kg 50 mg/kg 150 mg/kg 450 mg/kg 400 mg/kg Fluorine: Soluble fluorides 100 mg/kg Rock phosphate F 200 mg/kg Immature Immature Immature Immature Immature Immature Mature Mature Depressed appetite, reduced rate of gain, parakeratosis Reduced rate of gain and reduced bone strength Reduced growth, lower hemoglobin, icterus, and death' Depressed feed intake and rate of gain, lowered hemo- globin,1' and eye lesions Depressed feed intake and rate of gain, reduced serum inorganic phosphorus and femur ash, rickets1' Depressed feed intake, reduced growth rate, stiffness, and stilted gait Anorexia, hair loss, separation of hoof and skin .it coronary band, degenerative changes in liver and kidney Reduced conception; pigs small, weak or dead at birth Nervousness, weakness, staggering, epileptic seizures, paralysis and death Growth depression, arthritis, hemorrhage in axillary spaces, gastritis and enteritis Poor growth, erythema, ataxia, posterior paralysis, quadraplegia and blindness; myelin degenera- tion of optic and peripheral nerves Reduced gain and hematocrit Severe depression of gain and hematocrit Severe depression of gain and hematocrit and ap- pearance of dermatitis Anorexia, growth depression, stiff-legged, humped back, incoordination and muscle tremors, anemia" Mottled enamel, enamel hypoplasia, softening of teeth, osteomalacia, excessive loss of weight by lactating Gossypol* Lead Mercury Nitrate Nitrite 200 mg/kg 660 mg/kg Single oral dose of 5 to 15 mg methyl Immature mercury dicyandiamide per kilo- gram of body weight 1,800 mg NO,/kg 400 mg NO,/kg Immature Muscular weakness, dyspnea, generalized edema, death; myocarditis, hepatitis, and nephritis Immature Squealing as if in pain, diarrhea, salivation, grinding of teeth, depressed appetite, reduced growth rate, muscular tremors, ataxia, increased respiratory rate, decreased heart rate, enlarged carpal joints, impaired vision, clonic seizures, death Anorexia, bodyweight loss, central nervous system depression, weakness, gagging, vomiting, diarrhea, ataxia, cyanosis, muscular tremors, postural and gait abnormalities, polyuria Immature Growth depression, dyspnea and cyanosis, elevated Immature methemoglobin, lymphocytosis, reduced serum vitamin A and E levels
18 Nutrient Requirements of Swine TABLE 2 Continued Nutrient Toxic Dietary Level' Age Signs of Dietary Excess Urea 2.5% Immature Reduced feed intake and growth rate; increased plasma urea nitrogen level â¢ The toxic dietary levels listed are those that have experimentally produced the signs indicated and are not necessarily minimum toxic or maximum tolerant levels. "Inn few instances, a dietary level of 250 mg/kg has resulted in signs of excess. r In some instances, 500 mg/kg of copper has been fed without icterus or death occurring. "Anemia of iodine toxicity alleviated with supplemental iron. ' Rickets from excessive dietary iron alleviated by increasing dietary phosphorus. 'Selenium toxicity partially alleviated with arsenic. â¢ Cobalt toxicity alleviated by supplemental methionine, iron, zinc, and manganese. â¢ Gossypol toxicity alleviated by increasing dietary iron toequal the weight of free gossypol.