DHI Notes...
March 07| Bennet Cassell
State DHI averages for important management areas in February 2007
Management area
February 2007
Change from last year
Rolling herd average milk
21590
+56 lbs.
Peak yield in heifers
73
-1 lbs.
Days to first breeding
94
-1 days
Days open
162
0 days
Net Merit of proven service sires
$302
*
Herd turnover less dairy sales (%)
30%
0%
Monthly average SCS
3.2
+0.1
Feed cost per cwt. (milking cows)
$5.41
$0.30
Milk blend price
$15.00
-$0.92
*Net Merit changed in August 2006 and averages are not comparable.
The last two installments of DHI Notes have suggested how to use DHI records for management of milk quality and udder health through use of SCC data and for reproductive management of the herd. This month, the focus is on genetic information. All genetic information in DHI records starts with accurate identification of the animal or of the service sire to which she is bred. In the DRMS Raleigh system, where calving records start the pedigree of the newborn, the key entry is service sire ID. Always use valid NAAB sire codes or registration numbers along with the proper breed codes for service sire. All the other information needed for genetic management of the herd will follow from these entries.
1. The identification and genetic summary block is at the top of the second page of the DHI form 202. The first check is percent of producing females identified by sire and dam (both are important). The goal, of course, is 100% ID’s, but never guess at parentage. Missing pedigree information does less damage than wrong data.
2. Average Merit $ of 1 st, 2 nd, and 3+ lactation animals should show a nice increase for first calf heifers compared to the older cows. Genetic progress in AI bulls makes better bulls available each year. Herds which use better bulls as they become available will see the results in this section of their herd summary sheets.
3. The Genetic profile of service sires gives a concise summary of the bulls used in the current breeding program. It is based on bulls used at last reported service to cows in the milking herd. Three columns are shown for proven AI bulls, young sires in AI, and “other” bulls. “Other” usually means natural service to herd bulls but could also mean that service sire ID does not cross reference to an AI bull as it should.
4. Merit of bulls used is shown in the two rows marked “average merit $” and “av. Percentile rank (net merit). The more useful of the two is the percentile rank. My recommendation is that dairy producers use bulls that rank in the top 20% of currently available bulls, which would give a rank percentile of 80% of higher. To improve this figure, buy semen on higher ranking bulls and use it immediately to breed cows in heat.
Bennet Cassell
Genetics and Management
