Examples of “heterosis” sires

In “aAa” terms, in which six major qualities relating to all the functions you expect from a cow are analyzed in your cows and in available AI sires, the vast majority of higher Genomic value sires will express these three qualities:

TALL   (aAa #2)    is the physical expression of the “growth” hormone (bovine somatotropin) in which adolescent feed intake goes to bone and internal organ growth, suppressing body energy (“fat”) deposits.   “Tall” quality heifers will mature faster, and achieve mature levels of milk production quicker.    Metabolically, they respond more to corn and oilseeds than forages.

STRONG   (aAa #4)    develops larger chests in which larger, muscled hearts pump more blood volume, building more muscle over a heavier skeletal structure.    “Strong” supports immune function and health from blood circulation of antibodies and leucocytes (infection fighters) to the extremities.    “Strong” quality heifers will become larger as mature cows.   

OPEN   (aAa #3)    The quality of “Open” aids cows to continue milking in volume after they are pregnant, thus supporting lactation persistency.    It affects elasticity of rib and width of pelvis, so supports calving ease in heifers.    It works with “Tall” to suppress diversion of energy dense grains and oilseeds into weight gain so that milk volume is maximized.

When you consider the overriding goals of Genomic indexes, you can see how they focused on these three qualities.    However, as you pursue those into multiple generations, the other half of the qualities-- #1 DAIRY   (higher natural fertility, feminine refinement)   #5 SMOOTH  (a full rumen capability to synthesize energy from forages, more even body condition, sturdier on feet) and #6 STYLE  (better blending of muscles, durability of the bone structure, less hoof trimming) are being suppressed in cows and lost from the breeding population.

These are qualities that would enable you to get a longer natural life from cows, thus get more heifers as replacements, having more cows capable of matured levels of milk yield sustainable over several lactations.   It is hard for two-lactation lifetimes to be profitable at cow prices today

 

Look at  515 HO 402  Siemers Taos PRADA   at  AI Total.    His “aAa” is 6 5 1 4 3 2, so exactly a heterosis “outcross” to the typical Genomic physique.     Now with daughters in production, his PTA values have been climbing above his original Genomic estimates.

He is unique in offering double-digit gains in butterfat % and protein %  while still +1000 milk.
He is unique having both premium Casein markers, A2A2 Beta Casein and BB Kappa Casein.
He is unique in his strong “plus” for DPR in spite of that +1000 milk rating.
He is unique as a sire that can give you longer teats, bucking the general Genomic trends.
He is unique in being +1.25 on Feet and Leg composite, avoiding a “fence post” hind leg.

We offer more “outcross” Holstein sires than anyone.   “Prada” is an example.