Peak milk is not only the highest point in the lactation curve, but it is also a direct result of your dedication to proper prefresh and fresh cow management.
Your herd should maximize peak milk while maintaining dry matter intake (DMI), bypassing costly metabolic disorders and improving profitability.
Peak milk production sets the pace for the whole lactation, defining both the lactation curve and total milk production. For every 1 pound improvement in peak milk, producers can expect 200 to 225 additional pounds produced during the lactation, says Dr. Michael Hutjens, dairy extension specialist with the University of Illinois. You should expect cows to hit peak milk 45 to 70 days after calving, he adds, but how high that peak goes depends heavily on your feeding program and management throughout the transition period.
Start in the close-up pen
Cows are only in the milking string one to two months before reaching peak milk, which means precalving nutrition has a direct effect on how high peak milk can rise. If cows transition poorly they may not reach their milk production potential.
According to Hutjens, herds with a rolling herd average of 29,000 pounds, should see first-calf heifers peak around 90 pounds. Second lactation peaks should hit 118 pounds, while third- and later-lactation cows should reach 128 pounds.
To meet and exceed these peaks, Hutjens focuses on the prefresh diet. For your fresh cows to succeed in the milking string, DMI should be front-and-center starting before they calve, he says.
DMI is so critical because a drop in intake in the prefresh pen may only be the beginning of what’s to come after calving. If a cow eats less dry matter, a negative energy balance can result, leading to higher incidence of metabolic disorders, poor production performance and a costly sick pen stay. Once sick cows rejoin the milking herd, they often produce well below their potential and struggle to regain normal production levels.
To maintain DMI and bypass expensive metabolic disorders, achieving a proper dietary cation-anion difference (DCAD) is essential, says Hutjens. A negative DCAD in the prefresh ration increases cows’ ability to mobilize calcium from bones and improve efficiency of calcium absorption and utilization. Lowering DCAD in the close-up group to between -8 to -12 meq per 100 grams of ration dry matter can facilitate optimal DMI, while reducing the risk of metabolic disorders.
Over the lactation
A smooth entry into the milking herd can make it easier for cows to reach their peak milk potential. Focus on three areas after calving to achieve maximum peak yields:
1) feeding to reach proper DCAD levels
2) feeding the right nutrients
3) minimizing stress
To meet all three goals, Hutjens again focuses on DMI as the key indicator of success. The sooner fresh cows improve intake, the earlier they will reach a positive energy balance. That means energy from feed will be used for milk production rather than for daily maintenance, resulting in higher milk yields.
To boost DMI after calving, add feed-grade potassium carbonate to the ration. Raising DCAD levels to the optimal range of +35 to +45 meq per 100 grams of ration dry matter through the help of potassium carbonate has many beneficial results, including:
• Improving DMI
High DMI after calving is hard to achieve, especially as fresh cows are undergoing so many changes, says Hutjens. It’s important to provide your herd with a ration they can’t refuse, and research is showing that potassium helps do this. One research study found that raising DCAD levels to +45 meq per 100 grams of ration dry matter with potassium carbonate improved DMI by 7.4 percent, which resulted in a 17.3 percent improvement in fat-corrected milk production.
• Replacing potassium lost in milk
As much as 13 percent of the potassium in a cow’s body is used for milk, so it’s no surprise that university research done in Texas found a direct link between milk production and the amount of potassium in cows’ diets. With higher milk production, especially during times of peak milk yields, more potassium is pulled to the milk, lowering the levels in the blood, and making it even more important to supplement these high-producing cows.
• Improving early lactation production
University research reported the addition of potassium carbonate to the ration not only raised DCAD levels to support the potassium needs of high-producing cows, but also improved DMI, increased fat-corrected milk production by 3.2 pounds and boosted component levels.
• Fighting heat stress
Potassium is also a great tool to help fight heat stress. Heat stress causes cows to perspire and urinate potassium more quickly, creating a greater potassium deficit. This results in lowered DMI, rumination and saliva production.
Work with your nutritionist to add the right levels of potassium carbonate to the ration to alleviate some of the negative effects of heat-stressed conditions.
Manage for optimal peak yields
Hutjens notes that although nutrition plays a major role in peak milk production, management on the dairy can make or break peak performance. Here are a few management tips that can influence your herd’s ability to perform to their potential.
• Persistency after peak
After peak milk is achieved, maintaining milk production, or persistency, can lead to more milk throughout the lactation. Hutjens notes lactation persistency is often associated with ration energy. If cows are peaking high but quickly drop production, work with your nutritionist to evaluate energy in post-peak and late-lactation rations.
• Make comfort a top priority
Fresh cows should have very low stress as they move from the close-up pen to the milking string. Hutjens notes comfort plays a large role in environment adaptation and, ultimately, peak milk performance. Provide cows with a cool and comfortable environment that promotes high DMI.
• Group fresh cows together
Monitor fresh cows especially closely, which may mean grouping them separately from the rest of the herd. Make sure fresh cow pens are not crowded and encourage high DMI.
• Allocate forages properly
Early lactation cows should be given the best forages to achieve proper rumen function. In the first few weeks after calving, poor-quality feeds can negatively impact how well cows perform in the coming months. Utilize lower-quality feeds as part of the dry cow, heifer and late-lactation rations.
By paying extra attention to your prefresh and fresh cow pens, you can reap the benefits of higher peak milk and the additional milk that follows throughout lactation. With the right nutrition and management, your herd will be ready to perform to their maximum potential. PD
References omitted but are available upon request at editor@progressivedairy.com
Elliot Block
ARM & HAMMER
Animal Nutrition
elliot.block@churchdwight.com
