What is pregnancy toxemia in dairy cows and how to prevent it?

Dairy cow is a kind of cattle bred for dairy products. It is an excellent breed after highly breeding. The dairy cows in China are mainly black and white cows. This breed was introduced from the cattle and sheep breeding base of Shandong Province Animal Husbandry Bureau in 1980. It has strong adaptability, wide distribution, high milk yield and tolerance to coarse feeding. Black-and-white cows are also called Chinese Holstein cows. Chinese Holstein cows have a history of more than 100 years and their breeding process is very complicated. In short, it is a long-term selection of high-generation hybrids between purebred Dutch cattle and native cows. Cow breeding disease prevention is very important, so what should cows do if they have pregnancy toxemia?

What is Cow Pregnancy Toxemia?

Dairy cow pregnancy toxemia is a kind of excessive obesity caused by energy metabolism disorder during pregnancy. Clinically, it is a nutritional metabolic disease characterized by loss of appetite, weakness, preference for lying, rapid heart rate, coma, severe ketonemia and high mortality.

Causes of Pregnancy Toxemia in Dairy Cows

Unreasonable feeding management, such as single feed variety, too much concentrate, lack of coarse feed, insufficient exercise, etc., caused the cow to be overweight in the late pregnancy. Mixed group feeding, diet is not adjusted according to different physiological stages, so that cows in dry period due to excessive energy caused by digestion, metabolism, reproduction and other functional disorders. Feeding high-energy feed in late lactation or dry period, such as feeding too much grain or silage corn; or premature withdrawal time before delivery; or prolonged dry period; or excessive feed supply in early pregnancy, etc., makes energy intake excessive, resulting in excessive obesity of cows in late pregnancy, which is easy to occur under stress conditions such as delivery, lactation, sudden change of climate or sharp decrease of feed intake. In addition, pregnant with twins or large fetuses of cows, milk production of high dairy cows, dietary protein deficiency or calcium deficiency can lead to the occurrence of this disease.

Symptoms of Pregnancy Toxemia in Dairy Cows

Cows are abnormally obese, have no appetite within a few days after delivery, milk production decreases, fall to the ground, present severe ketosis symptoms, and take measures to treat ketosis is ineffective. The affected cow gradually weakens and usually dies on the ground after 7 to 10 days. Some sick cattle have neurological symptoms, prolonged gaze, head elevation, head and neck muscle tremors, and finally coma, heart rate increase, most of the sick cattle died. Temperature, pulse and respiration were normal throughout the course of the disease. If fatty liver occurs 2 months before delivery, the sick cow often refuses food for 10 ~14 days, is depressed, lies down, assumes chest lying posture, breathes rapidly, the nasal mirror cracks, the nasal secretion increases, has the clear water sample nasal fluid; to the later stage discharges the rotten yellow loose stool, the coma, dies in the quiet state. The mortality rate of this disease is high, and the course of disease is 10 ~14 days. According to its symptoms, it can be divided into acute and subacute types:

Acute type acute type with childbirth and onset. Loss of appetite, lack of milk or no milk, cyanosis of visible mucosa, yellow staining, temperature increased to 39.5℃~40℃, strong gait, dull eyes, weak response to the outside world. With diarrhea, yellow foul smell loose stool, no reaction to drugs, in 2 to 3 days of death or lying on the ground do not rise.

Subacute type Subacute type more than 3 days after delivery onset, the main manifestations of ketosis, sick cattle appetite decreased or waste, milk production decreased, feces less and dry, urine with ketone taste, ketone body reaction positive, accompanied by mastitis, placenta, uterine atony, birth canal product more brown rancid lochia, drug treatment ineffective, lying on the ground, moaning, grinding teeth.

Diagnosis of Pregnancy Toxemia in Dairy Cows

According to abnormal obesity, postpartum sudden refusal, lying and other characteristics, should be suspected of this disease. Cow obesity syndrome must be distinguished from left displacement of abomasum occurring postpartum. The left displacement of abomasum can be combined with auscultation and percussion to produce steel pipe sound. The feeding of high concentrate diet and the body condition of excessive obesity are helpful to distinguish this disease from other diseases such as birth paralysis and falling down syndrome.

Treatment of Pregnancy Toxemia in Dairy Cattle

The effect of treatment will not be satisfactory, most of the cows who refuse to eat completely will die; for those who can still maintain appetite, there is hope of cure with treatment. Drug therapy, the purpose is to inhibit fat decomposition, reduce fatty acid accumulation in the liver, accelerate the use of fat, prevent complications ketosis. Its principle is detoxify, protect liver, fill candy. The following treatments are available: 50% glucose solution 500 ml ~1000 ml, intravenous injection.

50% dextran 1500 ml iv for the first time, then 500 ml iv, 2 to 3 times a day.

Niacin 12g ~ 15g, once orally taken for 3 ~5 days. Its actions are antilipolytic and inhibition of ketone production.

Cobalt chloride or cobalt sulfate 100 grams per day, oral administration.

Propylene glycol 170g ~ 342g, twice a day orally, continuous service for 10 days, intravenous injection of 50% dextran 500ml before feeding, the effect is better. Choline chloride 50 grams, once orally, twice a day.

To prevent secondary infection, broad-spectrum antibiotics, aureomycin or tetracycline, 2 million to 2.5 million international units, once intravenously, twice daily, can be used.

Prevention of Pregnancy Toxemia in Dairy Cows

Strengthen feeding management to keep feed stable and avoid sudden changes. Dry cows should limit concentrate and increase hay feed. Each cow was fed 3 kg to 4 kg mixture and 15 kg silage per day, hay ad libitum.

Group management. According to different physiological stages, adjust the nutritional ratio at any time, dry cows and lactating cows are fed separately.

Ensure that dry cows have 1 hour to 1 and a half hours of exercise every day.

Strengthen health examination and establish monitoring system to detect sick cattle early. Urine ketone and pH value should be measured every other day from the week before delivery, and sick cattle should be treated immediately.

Regular sugar and calcium supplements. For old, high-yielding cows with poor appetite and history of ketones, intravenous injection of 20% glucose solution and 20% calcium gluconate 500 ml each was given to each cow one week before birth, totally 1 ~3 times.

4 g ~8 g nicotinic acid (dosage per cow, the same below) for prevention and treatment of puerperal ketosis, once a day for 7 days before delivery.

Propylene glycol 200 ml or sodium propionate 125~250 g, 8 days before delivery, once a day, continuous service for 15 ~30 days.

Timely breeding does not miss oestrus cattle, improve conception rate, prevent cows from drying too long and lead to excessive fat.