Getting heifers and cows pregnant and keeping those pregnancies to terms is one of the most vital aspects of a dairy. There are a variety of issues and challenges that present themselves through a Reproductive Program, below we have listed a few tips to make sure you keep in mind.
Heat Detection – The first step is to determine when the heifer or cow is in heat. This could be done by visually observing the animal and seeing how she acts and behaves. Talk chalk or paint could also be a good indicator, when it gets rubbed off, it is obvious the cow is in estrus and is allowing others to mount. Pedometers or activity meters are a great tool to use for heat detection. Cows are more active and move around a lot more when they are in heat, so their steps or activity level can go up by almost 400% during this time.
Hormones – Sometimes hormones are utilized to synchronize a group of cows in order to make breeding easier. These are all hormones produced naturally by the cow, but given in an injection to help sync them with the rest of the herd. Using these hormones, farmers synchronize their herd with a scheduled treatment in order to improve pregnancy rates. Once started, it is important to stay on schedule with this system.
Insemination – Ovulation happens 25-32 hours after a cow or heifer begins heat. Sperm need about 6 hours in the reproductive track before they are able to fertilize the egg. Insemination, whether natural or artificial, needs to happen fairly quickly after the animal has been determined to be in heat.
Pregnancy – Determining if a cow is pregnant is another important step in the Reproductive Program. Some people choose to use the “old school” method of uterine palpitations, which occur at 35-40 days after insemination to see if the animal is pregnant. Others choose to use a Pregnancy test kit where they are able to test an animal’s blood or milk to find pregnancy hormones in their system. This is not quite as effective as Transrectal Ultrasonography, which is quickly growing in popularity among farmers. Testing can occur as quickly as 28-32 days after insemination to see if a cow is pregnant. Regardless of which method is chosen, it is best to retest in a few weeks to ensure the cow hasn’t lost the pregnancy.
“A Reproductive Update.” Hoard’s Dairyman
“Systematic Breeding Programs.” Penn State Extension