The set of events that will allow the calf to be born is called calving. It then triggers the start of lactation in the mother, who will feed the young cattle.
Insemination doses: The straws
In lactating breeding (breeding intended for the production of meat), natural service is favored for practical reasons. Indeed, during the reproduction period, which is in spring, the cows are in the meadows, and both the detection of heat and the handling of the cows for insemination are more delicate. However, between 10 and 40% of females of meat breeds are fertilized by artificial insemination.
Artificial insemination has several advantages:
- health (limiting the spread of sexually transmitted diseases and brucellosis),
- genetic (choice of bulls),
- even of an economic nature (no maintenance of bulls on the farm).But artificial insemination also has drawbacks:
- more important handling of animals,
- the need for additional staff,
- lower pregnancy results than natural mating.
The gestation of the cow and the consequences on the organism
The gestation of the cow lasts a total of 9 months. But throughout this time, the fetus does not grow at the same rate: most of its growth takes place during the last three months (from day 190 to day 282). The weight of the future calf then drops on average from 4 kg (weight that it took 6 months to reach) to about 40 kg.
Throughout gestation, the food needs of the cow increase. And during the last third of gestation, the body of the cow carrying a calf must permanently maintain two somewhat contradictory objectives:
Its diet must be able to provide enough building material to the fetus so that it can gain 35 kg in 3 months,
But as it grows in the uterus, the calf pushes the cow’s stomach forward. This slightly reduces the volume of this stomach and increases the pressure in the belly of the cow, both on the digestive system, on the bladder… and increases the total volume of the abdomen.
The cow must therefore eat more with a more compressed stomach. It therefore becomes particularly sensitive to food problems, but also to health incidents (infections, stress, etc.) that could occur during this period.
The warning signs of calving
To predict when the start of labor will take place, several criteria can be observed:
If the cow is going to have her first calf, the udder enlarges, swells (edema). On older cows, the flow of milk begins very shortly before calving.
The ligaments in the cow’s pelvis relax: they stretch, which will allow the calf to pass through the pelvis during birth. This relaxation causes the base of the tail to descend between the tips of the cow’s buttocks, if viewed from behind. The tip of the tail is also often “very soft”. Without this physiological separation, the calf could not be expelled.
A translucent discharge of mucus appears at the vulva of the cow: it is the plug of mucus which blocked the uterus during the whole gestation which liquefies during the days preceding the birth.
Credit : la-viande.fr https://www.la-viande.fr/animal-elevage/boeuf/reproduction-bovins