DHI Notes...

October 2006 | Code Swedish Reds as Breed “A” in PCDART | Bennet Cassell

State DHI averages for important management areas in September 2006

Management area	September 2006	Change from last year
Rolling herd average milk	21727	+566 lbs.
Peak yield in heifers	76	1 lbs.
Days to first breeding	95	+1 days
Days open	166	+6 days
Net Merit of proven service sires	$286	*
Herd turnover less dairy sales (%)	29%	0%
Monthly average SCS	3.4	+0.1
Feed cost per cwt. (milking cows)	$5.65	-$0.04
Milk blend price	$13.31	-$2.35

*Net Merit changed in August 2006 and averages are not comparable.

This month, I want to write about a topic unrelated to the averages in the table. For some time, many Virginia dairy farmers have been experimenting with a little – or maybe a lot - of crossbreeding. We are conducting a crossbreeding experiment in the Virginia Tech herd. We have run into a problem correctly recording services performed to Swedish Red bulls because there is no unique Swedish Red breed code that is recognized at this time in our DHI system. I talked with John Clay at DRMS Raleigh about this problem and received the following instructions. Code services to Swedish Red bulls by the bull’s five-digit registration number, which begins with a “9”. Code the breed of the bull as “A”. Yes, I know he’s not an Ayrshire, but the computer system will figure it out. For example, we have used B Jurist, 91011 and Peterslund, 91213 in the Virginia Tech herd. We have coded services to them every way from Sunday, but are now going back and recording breed of sire as “A” and bull number as 91011 or 91213. John tells me that this system will be in place for the immediate future but that they hope to eventually be able to enter something that looks more like an NAAB bull code such as “249SR91011”. The 249 represents the bull stud Svensk Avel, SR is for Swedish Red, and 91011 identifies B Jurist. Until we hear differently, we all are to use breed “A” and the correct sire ID number starting with “9”. Why does this matter on a crossbred calf? Researchers – like me - need good pedigree information on crossbred animals on DHI test to be able to evaluate performance of different breed mixes under commercial conditions. If you use a US dairy breed bull like a Jersey on a Holstein heifer, use the standard NAAB code number to record breedings and be sure the dam is correctly identified by sire and breed. The sire ID for the dam has always been important, but is especially critical if the dam herself is breed X, a crossbred. We use the ID of the sire and maternal grandsire to determine the breed “mix” of a calf born to a breed X dam – or to a purebred dam for that matter. Please consider crossbred animal identification to be just as important as ID’s on purebreds in your farm records. The only way research can ever tell dairy producers which crosses work is if dairy farmers themselves report accurate pedigree information on crossbred cows.

Bennet Cassell
Genetics and Management