Getting cows into calf is one of the most important performance parameters that dictates a farms profitability. It not only affects a cows milk yield post calving, but also the number of replacements you have and the rate of your genetic progress.
Nutrition plays a key role in the success of a mating program. When looking at nutrition pre-mating there are three main focus areas that farmers need to consider to help ensure cows are set up right for calving:
- Mind the gap – Reduce the Negative Energy Balance (NEB)
- Keep the Factory Healthy – Maintain a healthy rumen
- Keep the cows healthy – Support the immune system and overall cow health
Mind the gap – Reduce the Negative Energy Balance (NEB)
Negative energy balance (NEB) in dairy cows occurs when their energy output exceeds their energy intake. This is particularly common during early lactation when milk production peaks, but their dry matter intake (DMI) has not yet reached its maximum.
Therefore, for cows to bridge this energy gap they rely on body fat. As farmers and industry professionals it is highly unlikely that we will bridge this energy gap during early lactation, so a cow will almost certainly be mobilising condition over this period, but we can however control the amount of condition she mobilises. Research has shown that if a cow loses more than If a cow loses more than 1.0 BCS unit after calving, it’s likely to have adverse effects on her reproductive performance. This includes delayed onset of oestrus, reduced conception rates, and increased risk of early embryonic loss.
Here are some nutritional tips to help minimise body condition loss pre-mating:
- Balance the nutrient supply from you pastures with supplement feeds to ensure you meet your cows’ protein and energy requirements to minimize condition loss during early lactation. To be able to achieve this balance it is important that we know what nutrients a farmers pasture is providing and therefore highly recommended having pasture tests done on farm.
- Optimise feed intake. Making sure cows are nutritionally fully fed is crucial in reducing body condition loss. Therefore, stimulating intake is key.
- Molasses is a great product to not only improve the palatability of feed but it is also a energy dense feed source that helps the bugs in the rumen perform efficiently to digest fibrous feed and stimulate feed intake
- Use bypass fats. Bypass fats are very energy-dense, providing about 2.25 times more energy per gram than carbohydrates. This makes them an effective way to increase the energy intake of cows, especially high-producing dairy cows. Research has shown that bypass fats are particularly important during from calving to peak lactation when a cow’s energy requirements are the highest.
Keep the factory healthy – maintain a healthy rumen
The rumen is the nutrient factory in the cow that drives nutrient supply to the cow and ultimately milk production and reproductive health. Like any factory, the rumen must be maintained and kept healthy for it to work at its best.
Ensure the cow are receiving some physical fibre in the form of hay or straw. The fibre in hay stimulates chewing and saliva production, which helps buffer the rumen pH and prevents acidosis. The long fibre particles in hay promote rumen motility by encouraging the formation of the rumen mat, a fibrous layer that aids in the mixing and fermentation of feed. This ensures efficient digestion and absorption of nutrients.
Rumen buffers such as Acid Buff stabilises the rumen pH over long periods of time and therefore reduces the risk of acidosis. Research has also shown that specific Levucell® SC live yeast (i.e. Saccharomyces Cerevisea) is effective in improving rumen pH and reducing inflammatory compounds in the rumen.
Keep the cows healthy – support the immune system and overall cow health
A well-functioning immune system supports hormonal balance, which is critical for regular estrous cycles, ovulation, and successful conception. Inflammation or infection can disrupt hormone levels, leading to irregular cycles, anestrus, or poor-quality ova.
Micronutrients such as selenium, zinc, and vitamins A, D, and E are critical for immune function. Deficiencies in these nutrients can weaken the immune system, making cows more susceptible to infections that impair reproductive health. Other minerals such as copper, phosphorous, and iodine play a role in ovulation and cycling. Therefore, it is important to understand the mineral status of your cows pre-mating and ensure that you are meeting their mineral requirements as it not only effects the health of the follicle but also effects a cows ability to ovulate and show heat.
A negative energy balance can suppress immune function and reduce reproductive performance. Cows that are unable to meet their energy needs are more prone to infections and are less likely to resume normal reproductive cycles after calving. This reiterates the importance of reducing improving a cows energy balance during early lactation.
Stress, whether due to environmental factors, management practices, or disease, can suppress the immune system, making cows more susceptible to infections that impact reproductive health. Stress-induced immune suppression can also directly affect reproductive hormones, leading to irregular estrous cycles and reduced fertility.
Disclaimer
The information, advice, and recommendations provided by Graincorp Animal Nutrition New Zealand are intended to be general in nature and are provided for informational purposes only. As such, GrainCorp makes no warranties, expressed or implied, regarding the completeness, accuracy, or applicability of any information, advice, or recommendations provided. Please always seek advice from your nutritionist or veterinarian if you are unsure this is relevant to your situation.
