The milk is the food that all young mammals should eat after birth. This food provides the necessary nutrients and immunity for the offspring of the different species. Once the lactation process is over and weaning occurs, mammals stop drinking milk. With the exception of the human being, who consumes the milk of other animals.
In this article on our site we will explain how cows produce milk and answer questions such as: How long does a cow give milk? cow? o How much milk does a cow produce per day?
Cow udder structure
Like all other female mammals, cows are able to transform nutrients acquired through the diet intomilk for her calves The cow's udder is divided into four compartments, each with a nipple that will release milk when the time comes.
Inside these compartments there are some mammary glands highly irrigated with blood vessels, the blood transports the nutrients to here, where they are transformed into milk. Specifically, the blood reaches structures called alveoli,in each of the four compartments of the udder that make up the mammary gland, leaves the nutrients to form milk and then, returns to its usual flow.
To produce a kilogram of milk, between 400 and 500 liters of blood must pass through the mammary glandsAs lactation is a critical period for females, they need an extra supply of nutrients in the diet to produce enough milk for the calf without losing its good he alth. The amount of milk a cow can produce per day will depend on many factors, such as breed, age, he alth status, diet, environmental stress, etc. But they are around 20 liters per day
Cow's milk production cycle or lactation
The lactation or milk production cycle is divided into four periods: mammogenesis, lactogenesis, galactopoiesis and involution. Each of these periods is strictly regulated by three different groups of hormones: reproductive hormones (estrogens, progesterone, lactogen-placental, prolactin and oxytocin), metabolism hormones (growth hormone, corticosteroids, thyroid hormones, and insulin) and locally produced hormones (prolactin, parathyroid-peptide, and leptin).
Mamogenesis
Begins at 35 days of fetal developmentof the cow, that is, when she has not yet been born, ends with well-differentiated nipples and ducts. At puberty, females undergo changes at the level of the glands, which become fat, linked to the estrous or heat cycle.
Later on, when the cow becomes pregnant, growth hormones, sex hormones (estrogen and progesterone), and prolactin cause the mammary glands to grow and thicken. The true tissue that will be able to generate milk develops.
Lactogenesis
During this period the epithelial cells that will produce the compounds necessary to create milk begin to differentiate. At this time, the action of two sets of hormones means that milk is not produced until the end of gestation, when colostrum or first milk begins to form thanks to prolactin.
Galactopoiesis
Galactopoiesis is the transport of milk from the alveoli, through the ducts, to the nipples. The most important hormone at this stage is oxytocin.
Involution
Involution is the gradual regression of the mammary glands once the lactation period is over In the meat industry, weaning is carried out of calves, at approximately 3 months. In the dairy industry, dairy cows do not suckle calves, after they drink colostrum or first milk, they are fed with a concentrated feed whey.
Dairy cow reproductive cycle
Have you ever wondered if cows give milk without having calves? The answer is no. For a cow to produce milk, a pregnancy and consequent calving must first have occurred. In addition, the cow does not release milk just like that, it requires a stimulus. The most natural stimulus is the sight of your calf or its sucking on your teats. In the dairy industry, this cannot be done, because the calf's saliva would rise up the ducts, contaminating it and making the milk unfit for human consumption. For this reason, it has been decided to use other less natural stimuli, such as udder massage
If the cow suffers stress during milking, she will produce adrenaline which will radically cut milk production.
As milk production only kicks in after calving and usually lasts no more than 10 weeks, it is necessary for the cow to for once a year, she begins her estrus shortly after giving birth and becomes pregnant again while she is still producing milk. For this reason, the reproductive cycles of dairy cows overlap with each other, leaving barely 2 months without milking (end of pregnancy) and for the mammary glands to prepare for the next cycle.
After calving, if the cow has had a good diet, heat may appear at 30 days, but if she becomes pregnant at this time, she can direct nutrients to the developing embryo and lower production milk. So farmers wait about 8 weeks to carry out the mating or assisted reproduction, and they will continue milking it for another 24 weeks. Leaving at the end of pregnancy a period of drying the udders so that the production and quality of the milk of the next cycle does not decrease.
In short, the cow gives birth, milking begins. At 60 days she becomes pregnant again. She milks milk for another 300 days, approximately. The udders are allowed to dry for 50 days and another calving occurs.
Dairy Cow He alth Problems
Some of the common cattle diseases are related to milk production. The good he alth of cows is essential for them to produce milk. The main diseases or ailments suffered by dairy cows usually derive from mishandling and abuse
The most common pathologies are:
- Mastitis: This is the most common problem. It usually appears in cows linked to the high production milk industry. It consists of an infectious and inflammatory process of the mammary glands and must be treated urgently. It is caused by the obstruction of a duct of the glands or by an infection.
- Lameness: Lameness in cows is a very common ailment, whether in the dairy or meat industry. It occurs when the facilities where the cows are located are not suitable, such as slippery floors. But the most common cause is the lack of rest of the animals, which do not spend the necessary hours lying down.
- Diseases related to childbirth: dystocia, retained placenta, endometritis, puerperal fever, ketosis and displaced abomasum.
