Clear oestrus symptoms in cows are important for insemination management and for the fertility of a herd. The strength of oestrus symptoms are closely linked to insemination success. A clear activity increase is an important pre-requisite to good fertility results and a sign of healthy and fit cows. This was discovered by Canadian researchers in several studies.
However, farmers often complain that their cows do not show the signals clearly enough. This should be understood as a warning signal that something isn’t quite right. Various cow-related or external factors can have a positive or negative influence on the cow’s oestrus signals. Clear oestrus is always a sign of the cow’s well-being, on the other hand cows which are weak or in silent oestrus show that there are deficiencies (mainly) in husbandry and/or fodder.
Our Oestrus strength checklist (pdf) gives you a fast overview of the external and cow-related influence factors. It can be downloaded immediately.
Instructions for correct oestrus observation
Many farms know the problem: The less time spent, the worse the oestrus detection, because as we are constantly sliding from one workload peak to another, oestrus observation can fall by the wayside. The consequence: cows, whose oestrus you never see or cows that you inseminate at the wrong time leading therefore to poor results. Therefore the first principle has to be: “Take the necessary time – and observe calmly”.
Observe the animals for a quarter of an hour three times, or even better four times a day. This is what the experts recommend – but not during milking or feeding times, because at those times the cows are often more concerned with other issues than manifesting signs of oestrus. Therefore, oestrus detection has the best chances of success when someone takes the time every day to observe the animals in pasture, in the yard and also when they are resting in the shed.
Three times 15 minutes
Therefore your oestrus observation is a central aspect in the fertility occurrences in the herd. For many years now experts have been recommending that cows be observed three times a day for fifteen minutes to ensure a good oestrus detection. But who can still afford the time for this in an era of ever larger farms and increasing working hours? Often this problem ends in a mediocre fertility situation in the herd. Is this the case for you?
Distraction during milking
Cows are distracted from their oestrus behavior during milking, feeding or when moving out to pasture. This is why it is recommended to look for cows in oestrus three times a day outside of the main shed periods (ideally also once at night or at least very early in the morning).
Silent oestrus (anoestrus)
These cows do not show any signs.
The external oestrus signals of silent oestrus cows are only weak or impossible to detect although an oestrus cycle is running on the ovaries and in the uterus. Oestrus follicles mature from which a corpus luteum develops. Sometimes a cow can be seen bleeding without having previously shown other oestrus signals.