Optimize dairy cow fertility through nutrition

The goal is to achieve peak milk five to six weeks after calving. A 1-pound increase in peak milk can translate to 250 pounds of milk for the cow’s entire lactation, so achieving peak milk quickly and effectively is critical.

Silvio Miranda

Poor management during this important stage can lead to reduced intakes and losses in body condition, leading to fertility issues which can have a significant impact on a dairy farm’s bottom line.

Here are three ways to optimize dairy cow fertility:

1. Close the energy gap

In early lactation, cows will inevitably be in a negative energy balance, meaning they are not able to take in as much energy as they require because their peak milk yield occurs before their peak in dry matter intake. Therefore, they will lose a certain amount of condition. Managing cows appropriately can minimize body condition loss during this critical period.

One way this can be done is by feeding a diet that will encourage intake and provide adequate energy. As a cow approaches calving, its feed intake can decrease by up to 35 percent. This intake decrease prior to calving, coupled with the dramatic increase in energy requirement when the cow begins lactating, can further drive the cow into negative energy balance.

Often in early lactation, it is always recommended to feed forages with high nutritive value with suitable sources of fibre, starch and sugars. All of these promote good feed intake and optimize rumen function.

Canadian dairy producers normally feed a balanced combination of fermented forages such as corn silage, barley silage, alfalfa silage and concentrates to achieve this goal.

2. Maximize immunity and health

Early lactation is typically a period of high stress for the cow, as there are a number of physiological and nutritional changes during this time. It is critical to ensure the cow has an optimal immune status during early lactation in order to maximize fertility.

Some cows will have a higher risk of uterine infections due to retained placenta and metritis after calving. Uterine infections and ovarian problems will inevitably have a negative effect on fertility.

Reproductive performance is highly dependent on nutritional status, with trace minerals playing a critical role. Trace minerals are involved in synthesis of reproductive hormones, reduction of inflammatory compounds, embryo implantation and fetal growth and development. Essential trace minerals, such as selenium, play a key role in maintaining a healthy immune system in the calving period.

Other essential trace minerals, such as copper, manganese and zinc, and macrominerals such as phosphorus, calcium and magnesium, play pivotal roles in ovulation and cycling; if there is a deficiency in either, the possibility of anoestrus becomes more likely.

While the amount of trace mineral supplied in an animal’s feed is important, bioavailability of trace minerals will determine absorption and utilization.

Trace minerals commonly have been fed as inorganic salts; however, research has proven feeding essential trace minerals in their organic form, such as proteinated minerals, leads to these minerals being better absorbed, stored and utilized by the animal.

Better utilization results in improved reproductive and immune status when trace minerals are fed as propionates versus salts.

3. Look after the rumen

Amongst other functions, the rumen has direct participation in the generation of the energy that drives the cow. The key to getting more from feed is to ensure the rumen is working as efficiently as possible.

Increased nutrient absorption in the gastrointestinal tract allows for more milk production and reduces the need for the cow to take these valuable nutrients from its own body reserves. This depletion of body reserves lies at the core of cow health and infertility issues.

Microbes present in the rumen are not designed for abrupt changes in the ration, so it is recommended cows are gradually transitioned from a low-energy dry cow ration to a high-energy lactation ration in late gestation and early lactation. A sudden increase in starch and sugar levels in the diet during this period will cause a decrease in the pH levels in the rumen.

An abrupt ration change may cause a rumen disturbance and reduce feed intake during a period of negative energy balance.

Proper adaptation to the lactation ration around calving will allow the rumen microbes to adapt to new substrates and digest feed efficiently, which will aid in a smooth transition into lactation.

Early lactation can be a challenging time for farmers, but implementing these management tips will give your herd the best chance of getting back in calf on the next lactation.