Improve metabolic diseases in ruminants, alleviate milk fever in dairy cows, and improve production performance – calcium propionate
Calcium propionate is a synthetic organic acid salt with strong antibacterial, mold growth and bactericidal activity. Calcium propionate is in my country’s feed additive catalogue and is suitable for all farmed animals. As an organic acid salt, calcium propionate is not only used as a preservative, but also often used as an acidulant and functional nutritional additive in feed, which plays a positive role in improving animal production performance. Especially for ruminants, calcium propionate can provide propionic acid and calcium, participate in body metabolism, improve metabolic diseases of ruminants, and promote production performance.
Deficiencies of propionic acid and calcium are likely to occur in dairy cows after calving, which can easily lead to milk fever, resulting in decreased milk production and feed intake. Milk fever, also known as postpartum paralysis, is mainly caused by a large decrease in blood calcium levels in dairy cows after giving birth. It is a common nutritional metabolic disease in perinatal dairy cows. The direct cause is that due to the beginning of lactation, intestinal absorption and bone calcium mobilization cannot If the loss of blood calcium is replenished in time, a large amount of blood calcium is secreted into the milk, resulting in a decrease in the blood calcium level and causing postpartum paralysis of dairy cows. Milk fever occurs mostly in high-yielding multiparous dairy cows, and the incidence increases with the increase in parity and lactation capacity of dairy cows.
Both clinical and subclinical milk fever reduce cow productivity, increase the incidence of other postpartum diseases, reduce reproductive performance, and increase mortality. Improving bone calcium mobilization and gastrointestinal calcium absorption is an important measure to prevent milk fever through various measures from the prenatal period to before and after calving. Among them, low-calcium diets and anionic diets in the perinatal period (diets that cause acidity in blood and urine) and calcium supplementation after calving are common methods to reduce the occurrence of milk fever.
Blood calcium level monitoring is the most basic method for the diagnosis of milk fever:
When the blood calcium level is less than 2.0mmol/L, it is diagnosed as subclinical milk fever;
When the blood calcium level is less than 1.5mmol/L, the diagnosis of clinical milk fever is made.
(Note: the normal blood calcium level of dairy cows is 2.0-2.5mmol/L)
The pathogenesis of milk fever:
An adult cow contains about 10kg of calcium, more than 98% of the calcium is present in the bones, and the remaining small amount is present in the blood and other tissues. The appetite and digestive function of dairy cows before and after childbirth will be reduced, and lactation will also lead to a large loss of blood calcium in dairy cows.
The occurrence of milk fever in dairy cows is not necessarily caused by insufficient calcium supply in the diet, but may be caused by the failure of dairy cows to quickly adapt to the demand for large amounts of calcium (initiating the release of bone calcium into the blood) during calving. The main reason is that the sodium and potassium ions in the diet are too high, and the magnesium ions are insufficient. In addition, the high phosphorus content in the diet will also affect the absorption of calcium, resulting in low blood calcium, but no matter what the cause, the blood calcium is too low. , can be improved by postpartum calcium supplementation.
Symptoms and hazards of milk fever:
Milk fever is characterized by hypocalcemia, lateral recumbency, decreased consciousness, cessation of rumination, and eventual coma. Postpartum paralysis of dairy cows caused by hypocalcemia increases the risk of cows suffering from diseases such as metritis, ketosis, retained placenta, true stomach displacement and uterine prolapse, which in turn reduces milk production and service life of dairy cows, resulting in the mortality rate of dairy cows Increase rapidly.
(Liang et al.) estimated that the loss of clinical milk fever per multiparous cow was (246.23 ± 52.25) dollars, and the death loss of milk fever was among the seven major postpartum diseases of dairy cows (hypocalcemia, true gastric Lateral displacement, metritis, mastitis, lameness, ketosis, retained placenta) the most. Milk fever increases the incidence of ketosis in dairy cows, and (Rodriguez et al.) found that milk fever cows were 5.5 times more likely to develop ketosis than normal cows. In addition, milk fever can also cause a decline in the reproductive performance of dairy cows and an increase in the incidence of true stomach displacement.
The role of calcium propionate:
After calcium propionate enters the body of ruminants, it can be hydrolyzed into propionic acid and calcium ions. Propionic acid is an important volatile fatty acid in carbohydrate metabolism in ruminants. The propionic acid in the rumen is absorbed by the rumen epithelial cells, and 2% to 5% is converted into lactic acid. The main metabolic pathway of the rest of the propionic acid entering the portal vein in the liver is to generate glucose through gluconeogenesis or enter the tricarboxylic acid cycle for oxidation supply. can. Calcium propionate can not only provide energy substances – propionic acid, but also supplement calcium for dairy cows. The addition of calcium propionate to dairy cows’ diets can effectively alleviate milk fever and ketosis in dairy cows.