Phosphorus is the most biologically functional element in all minerals. Firstly, it participates in the composition of bone and tooth structure together with calcium to ensure the integrity of bone and tooth structure.
Secondly, it participates in energy metabolism in vivo, which is an integral part of ATP and creatine phosphate.
Thirdly, it promotes the absorption of nutrient facts, phosphorus promotes the absorption of lipids and lipid-soluble vitamins in the form of phospholipids.
Fourthly, it protects energy metabolism in vivo. A phospholipid is an indispensable component of the cell membrane.
Fifth, phosphorus, as an important genetic material of life, participates in the process of life activities, such as protein synthesis and animal product production. Therefore, phosphorus is very important to the performance of dairy cows.
Although there is enough phosphorus in the feed, some diseases easily lead to a large loss of phosphorus, resulting in the imbalance of calcium and phosphorus ratio. Therefore, phosphorus supplementation is critical for some diseases in dairy cattle. There are four main diseases involved:
1. Downer cow
(1) Downer cow is a clinical syndrome characterized by "lie-down" in lactating female cows near delivery or after delivery. The incidence of high-yield cows occurring 2-3 days after calving is 2%-12%, but the mortality and elimination rate caused by this disease is quite high, accounting for 60%-70% of the number of cattle infected.
(2) After the onset of the disease, after two calcium treatment, symptoms such as high depression disappeared and then lie down. The diseased cattle had a normal appetite, body temperature, respiration, and heart rate. Some diseased cattle try to stand, kneel on their forelimbs, half-flex their hind limbs or stretch backward, and crawl in the "frog-leg" posture. Because of the long-term lying down, mastitis often occurs, and bedsore ulcers occur around the tarsal, foot and hip joints, which eventually lead to the death and elimination of the diseased cattle.
(3) Clinical use of calcium preparation, phosphorus preparation, magnesium preparation, and potassium preparation comprehensive treatment. 20% calcium gluconate 500-1000 ml, 20% potassium dihydrogen phosphate 300 ml, 10% potassium chloride 100-150 ml, added to 2000 ml 5% glucose; 25% magnesium sulfate injection 100-200 ml, one-time intravenous injection, once a day, for three days. Vitamin B1 and B12 can be injected into lumbar nerve plexus acupoints for patients with nerve injury and muscle hyperextension.
2. Production paralysis
(1) Production paralysis, also known as milk fever, is a kind of hypocalcemia that occurs suddenly in cows before and after childbirth. The disease often occurs in high-yielding cattle with 4 to 5 births, and most occurs 24 hours after delivery.
(2) Most occur 12 to 72 hours after delivery. The initial appetite and rumination stop, the standing is unstable, ataxia, the head turns to the chest, and the body temperature drops to 35 to 36 degrees Celsius. Blood calcium decreased to 3.6-7.0 mg and blood phosphorus decreased to 1.0-2.7 mg.
(3) In addition to calcium therapy and breast ventilation therapy, timely supplementation of phosphorus and magnesium should be used. 20% sodium dihydrogen phosphate 200 ml, 15% magnesium sulfate 200 ml intravenous injection. Rumen puncture should be carried out when the rumen is dry.
3. Postpartum hemoglobinuria
(1)Postpartum hemoglobinuria is a metabolic disease characterized by acute intravascular hemolysis, hemoglobinuria, anemia and hypophosphatemia in postpartum dairy cows. It mainly occurs in high-yielding dairy cows with 3-6 births from 4 days to 4 weeks postpartum and occurs more frequently in deep winter and severe cold season.
(2)Red urine is a prominent feature of the disease. During the first 1-3 days, the urine gradually changed from light red to red, dark red to purple red and brown, and then gradually disappeared. Severe illness, depression, loss of appetite, anemia, pale and yellow mucosa, blood thinning.
(3)Intravenous injection of 20% sodium dihydrogen phosphate 300-500 ml twice a day, and severe cases recovered in 2-3 days.
4. Osteomalacia
(1) Osteomalacia is chronic metabolic osteoporosis caused by inadequate calcium, phosphorus or vitamin content in feed or inappropriate ratio of calcium to phosphorus in adult cattle. Dairy cows with high lactation and improper feeding and management often suffer from this disease.
(2) Diseased cattle have abnormal appetite, often lick walls, cow pens, soil, drink urine or fecal soup; decrease of lactation and delayed oestrus mating; standing on arch back, often lying on the ground, limping on one or several limbs; swelling and deformity of limbs, displacement of tail vertebrae, swelling of costal cartilage and rib junction, rolled hoof deformity, susceptible to rotten hoof disease.
(3) Intravenous injection of 20% sodium dihydrogen phosphate 300-500 ml once a day for 5 days. At the same time, intravenous injection of 10% calcium chloride 300 ml or 20% calcium gluconate 500 ml once a day for 5 days. Also, cattle breeders should feed the diseased cattle 250 grams of bone meal every day for 5 to 7 days as a course of treatment.