HIGHLY PRODUCTIVE COWS AND TWINS
Many farmers are striving for a stable, healthy herd and highly productive cows. A healthy herd contributes to the farmer’s job satisfaction and high yielding cows provide a good yield. The transition period is a tough one forhigh-yielding cows especially.
Twin pregnancy is more common on one dairy farm than on another. The frequency of twins was estimated at around 5.6% in 2012 (Andreau-Vazequez et al, 2012). Twin pregnancy is hereditary but other factors also play an important role in having twins. Elements that may play a role include the increase in milk yield. With the increase in milk yields over the years, as a result of genetic improvements and animal husbandry, so too as the number of twin pregnancy in dairy cattle.
Ovulation in high yielding cows
Researchers of the article ‘Clinical implications of induced twin reduction in dairy cattle’ have conducted research into the ovulation of cows. Research has shown that high yielding cows, with a milk yield of more than 40 litres per day, are more likely to have twins. But why are high-yielding dairy cows more likely to have twins?
The chance of twins is linked to ovulation. High yielding cows sometimes have up to 20% more chance of a double ovulation, which makes them more likely to have twins. Wiltbank (2000) mentions the possible explanation for the increase in twins in high-yielding dairy cows: “High milk production increases the blood flow in the gastrointestinal tract and therefore there is also an increased blood flow in the liver. This increased blood flow is essential for increased uptake and digestion of nutrients in the gastrointestinal tract. The increased blood circulation in the liver results in increased steroid metabolism”.
The effects of twin pregnancy
In the case of twins, the cow generally calve down too early. As with heavy calving, twins require a lot of energy from the cow, which is why it is difficult to maintain a cow’s condition around calving. As a result of the cows weakened immune system it can cause withheld afterbirth. It is therefore important to give the cow extra support during hardercalving. Livestock farmer Siem de Boer from Warder commented on how he tackles hard calving
“I administer the AHV Cow Metri Tablet to cows when they have calved down, and especially on cows that have had twins. I do so as a preventative. The cow will then release the afterbirth – in 65-70% of cases after 12 hours.