CONCEPTIONS Dairy Route Newsletter February March 2020
Healthier cows, good fertility, but a key difference is they have black pigment hooves. Lots of hoof trimming professionals believe the black hoof has less heel warts and hoof rot, requires a lot less hoof trimming. This coloring comes from the original dutch Friesian-type “Holsteins”.
The relative heritability of traits and qualities in genetic selection
An ex-dairyman friend of mine who now has a cow-calf beef herd in Alabama posted recently in an online discussion “the heritability of disposition characteristics is 45%.” He caught my eye because this is higher than nearly all linear traits (production, type, fitness) measured in “dairy” and we pay no attention to this at all in genetic selection for dairy cows.
To give you
perspective, here is a chart of the heritabilities as calculated by AIPL (USDA)
for the 14 traits that go into the “Lifetime Net Merit” (G-LMN$) ranking index:
Milk (pounds), Butterfat (pounds), Protein (pounds) estimated 20% heritable. *For Jerseys, Milk and Butterfat are 23% heritable. Somatic Cell Score estimated 12% heritable.
Body Weight Composite from stature and linear frame traits, estimated 40% heritable. *For other breeds than Holstein, more like 35% heritable.
Udder Composite 27% in Holsteins, (*20% in all other breeds).
Feet and Legs Composite 15% heritable.
Calving Assistance Composite only 7% heritable.
Daughter Pregnancy Rate only 4% heritable, while Productive Life more like 8% heritable.
Cow Conception Rate 2% heritable, twice as much as Heifer Conception Rate 1% heritable.
Health Trait Composite and Livability are both only 1% heritable.
The only linear measurement traits higher in heritability than “disposition” are Protein % content (55%) and Butterfat % content (50%)—roughly twice their estimates in “pounds” because that much less affected by feeding management and other environmental variants.
So how can we anticipate disposition problems in case we want easier-tempered cows?
data from some areas of the world in milking speed and disposition, and here
are some examples of how sires we handle fare in these observations: (100 being
566H1231 Rev Me Up Red MS 108 DP 109 054H 552 Barbwire Red MS 97 DP 94
566H1261 Jo Dandy MS 106 DP 109 566H1180 Rollag MS 92 DP 96
566H1235 All Game MS 108 DP 108 566H1199 Cambridge MS101 DP 97
566H1246 Can Do MS 101 DP 108 566H1254 By Golly MS104 DP 97
099H0509 Perpetual MS 100 DP 107 566H1211 Blender MS 98 DP 98
Basically, comparing these “top five” disposition ratings vs the “bottom five” from International Protein Sires offerings, there seems to be a high correlation between temper and milking speed (and does that seem as logical to you as it does to me?) We observe from the “aAa” breeding guide that the more “balanced” cow is generally more even-tempered, as well as healthier and more reproductive, thus having longer “Productive Life”. Comparing studs, Intl. Protein Sires have above average temperament ratings, how much of that can relate to their preference for sires from longer-lasting cow families? Certainly that bad-tempered cow often ends up with a shorter herdlife, so again, logical selection can lead to a more easily-managed herd requiring less labor and veterinary intervention.