Are farmers really getting the most out of those milk records?
Farmers spend a lot of money milk recording and scanning their cows. But do we really use this information effectively to aid making the right management decisions? When it comes to this time of year, making the right drying-off and culling decisions can make good economic sense by allowing the remaining feed -- be it pasture or supplements -- to be directed at animals that can make a good return, and by not foregoing milk production from next year by compromising body condition.
If you have a spring-calving herd and have done a milk recording in the past six weeks, now is a good time to use those reports to maximum effect. The milk recording reports available provide so much more information than just a list of the top millionaires in SCC. The farm SCC/mastitis report highlights problem cows in descending order, and can be used to make immediate decisions to either treat, dry-off or cull some of these animals.
However, I find that using the detailed milk recording report can also aid in making a few good decisions. This is often an under-used resource and many just glance over it to see which cow is producing the most milk. Just looking at the milk kilogrammes is not a fair comparison. Instead, attention should actually be given to the kilogrammes of both milk fat and protein featured at the end of the list. Go through these figures and any animal producing a daily cumulative fat and protein of less than 0.5kg (eg, 0.3kg fat + 0.2kg protein) at this time of year is generally not worth milking on.
The individual report also lists the cow's SCC of both the last recording and for the number of tests above 250,000 cells/ml. Ideally your herd should have a bulk milk sample test of 150,000-200,000, though many will struggle at this time of the year to have it less than 250,000. If it's feasible with your present cow and replacement numbers, culling animals with cell counts of above 400,000 in two lactations is a good target. If not, focus on using an appropriate dry-cow therapy.
Combining this information with your scanning results -- showing when each cow will calve -- will give you an appropriate action list for drying off and culling. Using the data from cows that have been confirmed in-calf and have had their pregnancies aged can focus your management on protecting body condition of early calving cows and heifers. However, when faced with a long list of months and days, we often don't take the next step which uses the data to indicate the month of calving. Table 1 (below left) provides a basic conversion guide, though there are other effective ways of doing this.
Having analysed all your data, the next step is to take appropriate action. If you follow table 2 (below right), and a cow or heifer qualifies for two or more of the descriptions, then it is time to dry her off. These same principles can then be revisited for animals still milking in November and December. For example, if a first-lactation heifer is calving in early to mid-February, then personally I would dry her off as they tend to have a lower condition score than the herd average. However, you could condition score such an animal to qualify whether you should milk on or not. Alternatively, if a cow is producing less than 0.6kg MS and calving in February, I would also dry her off within the next week. Basically, two or more strikes and she's dry!
Dr Mary Kinston is an independent dairy consultant based in Co Kerry. email@example.com