Calculating NHRC
NHRC is calculated by multiplying the number of cows that have left the herd in the past year by the cost of a replacement, subtracting the revenue from cull cows, and dividing the difference by the total hundredweights (cwts) of Energy Corrected
milk (ECM) sold in a year. It is essentially the difference between the cost of a replacement heifer and the value of the replaced cull cow.
((# Cows Sold + # Cows Died) x Replacement Cost)) - (# Cows Sold x Cull Cow Value) / (CWTs of ECM Sold) = NHRC
In 2021, Zoetis reported that the top third of the herds for profitability had a $1.01/cwt NHRC and produced 88.2 lbs ECM/cow/day. The bottom third of herds had a $1.88/cwt NHRC and produced 78.4 lbs ECM/cow/day. Herds should strive to lower their
NHRC and set their sights on $1.01/cwt.
Tips for Achieving Your Desired NHRC
The key to reducing your NHRC is to reduce the number of cows that involuntarily leave the herd, especially due to death, and to increase ECM. Herds with high cull rates have higher proportions of first and second lactation cows. Second lactation cows produce 15% more milk than first lactation cows, and third lactation cows produce 10% more milk than second lactation cows. Reducing involuntary culling and right-sizing heifer inventory allows for more mature cows to stay in the herd. It is also important to optimize voluntary culling and replace less productive cows with heifers of higher genetic potential.
Take this example of a 1,000-cow herd that currently has a 40% cull rate and 40% first lactation cows. The herd has an 8% death rate and ships 295,802 cwts of ECM per day. Cull cow prices are currently high, which helps lower NHRC, and their current NHRC is $1.08/cwt. In the proposed scenario, the percentage of cows sold and died is lowered to a combined 30%. Additionally, the percentage of first lactation cows is reduced from 40% to 30% allowing the herd to milk 50 more second and third-plus lactation cows adding an additional 2,934 cwts of ECM shipped. This could potentially lower the herd’s NHRC to $0.83/cwt, which is $72,000 in savings.
Herds with the lowest NHRC have minimized health events, mastitis and death rates; get cows pregnant efficiently; and maintain a high proportion of high-producing mature cows. Utilizing Select Sires’ Herd Health Profit Dollars® (HHP$®) index, genomic testing and a customized inventory strategy can create these high producing cows that will stay in the herd and reduce NHRC. 
Hone in on your NHRC by contacting your local Select Sires consultant. Together, analyze your herd’s current metrics and compare them to industry benchmarks to create a plan that drives more profit to your business.