One cow at a time adds up to a herd

In the April issue of Graze we made an attempt to stimulate some discussion about the optimal cow in a “no grain” grass fed grazing dairy.    In the summary paragraph I mentioned that “we can only breed one cow to one bull at a time”.    Lots of feedback was received for this article, asking for specifics on the ideal grass cow physique and how to breed that, but no one mentioned this statement.

e transforming data into trait indexes and composite ranking, it is the conclusion of geneticists that your best selection strategy is simple: breed all your cows to that bull who ranks highest.    (Oh, you worry about inbreeding?  Then use the second highest bull as well.)

Your conclusion: variation in my cows doesn’t matter.  Breed the group, not the individual.

So let’s consider how we provide data.    You are a grazier who participates in DHIA testing and keep track of sire and dam ID.    That qualifies your data for genetic evaluations.    Heifer “x” calves along-side a couple dozen other heifers.  They get to walk across the pastures every day.  Unlike the others, however, “x” does not walk gracefully, she gimps and limps.    She brings up the rear at every milking.

As soon as she is out from milking, she lays down.    Over the next few weeks, she milks off her body and then production declines.   She is not breeding back.   You clean and trim her feet, but nothing you do appears to improve her mobility.    Eventually you mark her “DNB” and at the point her production falls below your cutoff, you send her to town.

Once a month that DHIA tester comes back.   He notes this cow has no milk weight.  He needs to code a reason for this: did you sell her for dairy? (no)  Dry her up early? (no)  Did she die? (yes, but no, not here)  Was she shipped as a cull? (yes)    What caused you to ship her??      

The biggest issue with accurate genetic mating is that you must determine between Causality and more simplistic Associative relationship.    The cause of “x” being a cull was mediocre feet.   The associated reason for culling was she had fallen below minimum production requirement (as a result of a chronic negative energy state, reducing appetite, caused by feet incapable of sustained grazing).          

As for the accuracy of DHI data for genetic purposes, we have already heard that on average, 15% of all cows on test are misidentified by sire.   I would propose that there is even more error in the coding of any discretionary question that has a multiple choice answer (“why did you sell this cow?”).    Most DHI systems are now owned by AI studs, and they favor the herds that maximize production per cow, as the genetic evaluation ranking systems are based on pounds.    Large percentages of graziers do not use DHI testing because you get tired of being put on the bottom of the DHI herd ranking publications.

They got the test %… they got the modern udders… with longevity as a bonus.

Sir Inka May had eighteen years of breeding service!!     Today we would aAa him as 5-1-3-6-4-2 (so a near-perfect match with their linebred Segis bulls offering 2-4-6).     His parents both lived into teenage so his longevity was inherited; but his physique also had the sturdiness of legs, the moderate frame size and the openness of rib with adequate blending of parts to express that latent longevity.   He modernized the Carnation cattle away from their extreme size and weight that held back their production in herds of less capability to feed them to their capacity or house them in typical commercial stalls of that period.

In other words, he was a high type and component % sire with good health traits under today’s sire definitions, rather than a high milk and early maturity (fast aging, less fertility) bull typical of decades of sire selection in the AI era.

In my opinion, Red Holsteins persisted because these original “seedstock” were superior for sound type, will to live, longevity (--and you cannot achieve “longevity” without first having good “fertility”)  with high butterfat % as a bonus that helped Holstein dairymen enter premium milk markets.    Even today, forty years after Holstein USA allowed Red Holsteins into registry, Red and Whites persist in AI popularity in spite of rarely being ranked near the top of any production-driven selection index.

Worldwide, Red & White cattle are preferred where selection is multiple-trait oriented (milk + fat % + protein % + fertility + moderate size + easy body condition), as in the semi-tropics where heat resistance is important, and in Europe where dairy is more grass-based and cheese yields set the milk price.

On the type front, three sires who set records for combinations of type and longevity—ABC Reflection Sovereign *RC, Amcana Dictator Model-Twin *RC, and Rosafe Citation R *RC—were all descended from Sir Inka May.    An additional sire who was more revered for mature production was Elmer Brook Aristocrat *RC.     All of these sires were active in Holstein AI breeding circles during the eras prior to Holstein USA opening up for Red registry.    As soon as their Red calves could be registered, the values of their semen sought the stratosphere.     Purebred breeders of our fathers’ generation valued type and longevity combinations as being the best route to realizing genetic progress: without a surplus of cows and heifers to sort for your future herd, you cannot harvest genetic progress in reality, no matter what the pedigrees and sire stacks indicate on paper.    You have to be able to voluntarily cull to keep the best you have produced, and you have to have sound enough animals kept to also reproduce.   Longevity will lead to a second income stream from replacement cows and service bulls desired by local dairymen. 

FACT:   All modern Red Holsteins descend from (in fact are linebred to) Sir Inka May.

While there are lesser contemporaneous sources of Red factor to Sir Inka May (the Winterthur herd and the Stewart and Maytag herds come to mind), they basically were the mates that allowed “Red” to shine through once exposed to descendants of Sir Inka May.     The famous ABC Reflection Sovereign *RC (sire of the equally revered Rosafe Citation R *RC) had “Inka” in both sire’s and dam’s pedigree.   

The influence of “Inka” is not limited to his “Red” descendants, given Pawnee Farm Arlinda Chief  has multiple crosses to “ABC” and his sire Montvic Rag Apple Sovereign *RC.     His contemporary Round Oak Rag Apple Elevation has some crosses to “Inka” on the maternal side of his pedigree.   ALL the high production AI sires of the modern day combine these two seminal 1960s sires in their ancestry.                

Today, combinations of polled heads and other desired traits are easier to find in Red Holsteins.

This is part of why we seek out the Red and *RC sires in all the programs we represent.

Recessive Red color can teach us a lesson in the Genomic selection era

Historical fact: for eighty years, Holstein USA denied registration to Holstein calves born Red instead of the ubiquitous Black.    Thousands of such calves were killed at birth and buried so the neighbors would not see your breeding stock was “polluted” by the Red recessive gene.    In the first thirty years of the AI industry, studs were “encouraged” to cull sires who produced Red calves.

Yet Red & White calves persisted in being born.    Eventually in the early 1960s the Red & White Dairy Cattle Association was formed among dairymen who were collecting up Red Holstein calves from better herds and forming Red herds, sometimes crossing them to add milk to Ayrshires and Shorthorns.   Soon as frozen semen allowed semen exports into Europe (where Red cattle were prized over Black) Holstein USA “saw the [green] light” and allowed registration of Reds, to facilitate profits from European exports of not only semen but live cattle and then embryos, which continues today.

How does a recessive gene receiving 80 years of discrimination survive in a cow population?

We all now understand that because it takes both parents to carry the Red gene for simple recessive gene pairing to produce a Red calf, when only one parent has the gene, he/she can pass it to offspring without detection.     Major breeding herds (Winterthur, Carnation, Maytag, among others using their bulls) early on decided that as Red was not a lethal recessive, just a hair color gene, they did not cull carriers; mostly just tried to avoid mating two carriers together.    So a few breeders with views contrary to the Holstein USA position conspired to retain better animals that were suspected or known Red carriers.

During the AI era, when Red carrier sires were routinely culled, the high profile of Canada’s Rag Apple bloodline created the misimpression that Red originated in Canada.   Actually the foundational Canadian cattle were not Red carriers: “Red” entered Canada when Mount Victoria Farms in Quebec (the original “Rag Apple” herd, linebred to Johanna Rag Apple Pabst) purchased an “outcross” sire from Wimbledon Farms in Maryland, and renamed him Emperor of Mount Victoria.    This bull was a son of Carnation Emperor, a son of Governor of Carnation that was in turn sired by Carnation’s first outcross herd sire, Sir Inka May…   a bull bred in Minnesota they purchased in 1925 after his dam had set a national milk record…  a bull who remained physically sound and virile and lived to 20 years of age (1943).

His first major son at Carnation, Governor of Carnation, was born in 1930 and lived 15 years, to 1945.   Many of his sons were in the first AI cooperatives as those systems began to form in the 1940s.   Once a few of his descendants from the “Montvic Rag Apples” also entered early AI, the red calves showed up, and of course were mostly blamed on the “Rag Apples” (rather than the Carnation “Inka-Madcaps”).

So what is my point?    (And I do have one)

Carnation Farms like most high profile Holstein breeders of the 1920-1940 era were linebreeders.

The descendants of their breeding were called the “Carnation Homestead” bloodline.     The original super cows of the Carnation Farm were sired by a bull named King Segis 10^th who sired strong framed, sharp uddered, round rear-ended cows (today we would say aAa 4-2-6).    These cows milked volumes at rather low butterfat % levels.   After a few generations of this linebreeding, Carnation sought for an outcross that would raise the butterfat % and modernize the udders to make them adaptable to machines. Sir Inka May was chosen for his high butterfat% inheritance and his mother’s relatively modern udder with smaller teats.     (Typical of that era, he was not a “cold” outcross, because he had some ancestry related to old King Segis 10^th.)

Matrix selection helps to avoid inbreeding effects

Bet you never heard that before.    But it is a statistical fact that pedigree inbreeding coefficients and AI selection by “one size fits all” index ranking go hand in hand.

Why?   Because a composite index establishes an “ideal genotype” (a process that is much accelerated by Genomics, which is 60% based on “ideal” marker gene possession).   If you insist on the highest affordable level of “ranking” you will be breeding “like to likes” at the level that will express inbreeding depression in some form by third or fourth generation.

Under “matrix” selection you monitor each generation for its results, and change the traits on which you can see the emerging needs before they get out of hand.   In this way, genotypes over multiple generations remain heterozygous (as in more capable of hybrid vigor than we see from homozygous genotype selection defined by a sire ranking index).   

Mating to balance the physique improves adaptability of your replacements

Many dairymen utilizing “matrix” sire selection also utilize “aAa” concepts for the choice of matching cows in the herd to sires found through the matrix screening.   The idea here is that most of our involuntary culling losses come from physiques that had extreme characteristics leading to structural failure of the udder, the legs and/or feet, or major body organic systems (circulation, respiration, spinal nerve signals, pelvic calving dimensions, energy metabolism)

A major review of the impact of “aAa” concepts on the performance and longevity of 1980s purebred Holsteins (utilizing data provided by Holstein USA) indicated a 5000 pounds per lactation difference between “getting it right” and “breeding likes to likes” according to how aAa perceives those differences in cattle physiques.

Nothing developed as a result of Genomic technology (including the very interesting work being done by Zoetis on “wellness” trait correlations) has changed any aspect of breeding that is beyond the limited “reductionist” focus of trait and composite indexes.   Thus either “index selection” or “matrix selection” results can still be improved by adding the physical mating selection to the genetic trait selection, especially on the side of “cost control”.

Ranking indexes keep changing

CDCI will soon incorporate the “Livability” trait at a 1% level into Net Merit.   AJCA has announced a major revamp of Jersey Performance Index.    All this tinkering with indexes that are the basis for AI studs’ young sire selection is evidence that “one size fits all” does not fit anyone very well.    Just as cows have unique genotypes, herds have unique genetic trait bundles.    The job of the breeding industry is not to tell you what to use, it is to help you find what best fits your current needs, and to recognize when needs change before our herds suffer declining economic competitiveness and physical adaptability.

Genetic selection is important; compensatory mating is equally important; when these work together you insure your future herd can deal with changing economic and environmental conditions.   Breeding should be under your hands-on control, not left to the theorizing of mathematicians who fail to see the tremendous random variability that exists in biology at levels they are not factoring into their equations.   

“Custom Indexes” or what we used to call “Matrix Selection”

The previous generation of dairy geneticists who gifted the world with the “selection index” must be rolling in their graves.    These were the fellows who actually told us “just breed on Net Merit ranking and all your other problems will go away.”    At that time “Net Merit” was based 70% on PD Milk and 30% of PD Butterfat—no protein, no type, no fertility, no health trait measurements.  All those things were added after the cow population began to suffer in all of those areas (some of which those same geneticists tried to claim were “management” traits rather than heritable behavior, as we now know them to be).

Consistent through all the formulation and recalculation and creation of new measurements (some of which are quite arcane, perhaps less than 5% heritable) – the advice was always, “don’t focus on some specific list of traits, just let the selection index do the job”.    Indexes were promoted as “more efficient” than a dairyman making his own list of desired traits and setting minimum levels of trait expression he would accept—a practice known as “matrix” selection.    

For the 55% of dairymen who still use a “matrix” approach, the latest advice – “calculate your own index” (according to the needs of your current herd) – is a vindication.   So as not to offend their old college profs, these new geneticists just avoid the word “matrix”.   But in fact they are now telling us, “composite index selection is obsolete” (even though these are the basis for all sire selection being done under Genomics, which are calculated purely to the various national index formulas).    

Just ask Nate Elzinga of Zeeland, MI, one of Michigan’s most milk productive dairymen, how he chooses his sires.   His office computer is programmed to recalculate the data from every sire AI offers him, to the weighting of traits he devised matched the heritable traits he wished to address in his herd of cows.   Or ask Josh DeHaan of Wayland, MI, how much he was able to accomplish in improving all fertility characteristics of their expanding herd by a focus on health and fertility traits alongside matings to create balanced physiques.   Many of your neighbors may be requiring plus bf% and pr% traits who wish to raise their milk price and find they are $2.00 per cwt above their breed average after only two generations.

The famous Wally Lindskoog of Arlinda Farms, Turlock, CA shortly before his passing told an interviewer that he could see the future of AI developing many specialty AI companies, whose sire selection would not be based on an ”index” but on the genetic preferences of like- minded dairymen of similar geography or facility design and milk market.    We have seen this process occurring ever since Alta Genetics purchased Landmark Genetics.

How do you design your own herd index?

First, you look at your own economic and management data.    What elements of cow care and management are costing you the most?   Focus on whatever heritable measures may have an impact on those issues.    For example, if conception rates are an issue, then establish a minimum trait value for daughter pregnancy rate (not semen conception rates, which have no impact on your cows’ natural fertility capability).    If you lose too many calves at birth look at stillbirth rate; if you lose too many heifers to hard calvings, look at both sire direct and daughter calving ease.    Establishing dollar values for each of these types of financial loss helps to put all of your herd data in perspective of where genetic change could help.

Facing facts about fertility

AI systems today sell twice as many straws per calf born as they did in the 1970s, in spite of all the advances in technologies and near-universal adoption of “production medicine” approaches by veterinarians.    For many dairymen the cost of each cow pregnancy has grown to several hundred dollars (ultrasounding, pre synch shots, Ov Synch, multiple services per cow, sexed semen on heifers) as traditional fertility management (breeding on observed natural heats) has gone out the window for these operations.

What role did decades of ignoring genetic fertility play in this development?   We think the answer is simple—it is Darwinian to assume that “genes not exercised in the current environment will be lost to future generations”.    If we ignore fertility genes, they do not stay the same—selection for anything else (especially if negatively correlated to fertility) will result in a declining “genetic base’ for that gene expression.

Want to improve the fertility in your herd by genetics?    Use the tools already available; health and fitness traits, maternal pedigree screening for longevity, physical balancing of matings from the “aAa” breeding guide.     Your progress will be measurable. 

What does the statistical “heritability” of each PTA trait really mean?

Dairymen have a right to be confused about the so-called “health and fitness” traits, which faced a great deal of resistance from breeders and AI stud personnel who were trained to believe “genetics” was about PRODUCTION and TYPE.     Select for PTA milk and you get more milk: Select for PTA type and you get sounder type.     PTA Milk would make milk checks, and PTA Type would lower the herd turnover rates, reducing replacement costs.     Then along came “management traits” (so called by nay-sayers) to confuse the genetic selection and the index ranking calculations.    

The statistical measures of “heritability” indicate how powerful a selection response you get from each trait.     Traits are not equal:   “h2” for milk, butterfat and protein yield (pounds) is estimated 25%- 30%.

“h2” for butterfat % and protein % (density) is estimated 55%- 60% (twice that of yield volume).    You can feed for “more milk” but you have to breed for a “higher milk price” from bf% and pr%  selection.

In other words, the higher the “h2” [heritability%] of the trait, the less you can effect change by feeding and cow comfort and better milking procedures.      Linear type traits have a similar pattern of as high as 40% h2 for stature, 25%  to 35% on udder traits, generally 10% to 20% on feet and legs and frame traits.   

By comparison, the “health” and “fitness” traits (SCS = Somatic Cell score, DPR = daughter Pregnancy rate, PL = Productive life, LIV = livability, plus the calving ease and stillbirth PTAs) began life with a lower scale of “heritability” (5% to 20%).    Thus, in the opinion of those pedigree/type and index/milk breeders, these should remain secondary considerations.

Heritabilities vary with the calculation and the geography

Our experience with New Zealand genetics among grazing-based dairymen indicates that “heritability”  is not fixed in stone: it is an accumulation of the consistency of selection within a cow population.   In a seasonal breeding system, “fertility” is the key genetic trait, and multiple generations of selection in its favor appears to improve the heritability (NZ genetics sets “h2” of calving interval at twice the level we have observed in the USA).    

The data from our friends’ herd would certainly suggest a clear linear result between DPR selection and resulting days open—and it should, as this is the basis of the DPR calculation anyway.     We were told for decades that, if cows are to milk more, we must expect conception rates to be lower:  however, once dairymen quit accepting that line, and forced geneticists to study the data closer, they found some cattle are just a bit more fertile than others, and this could be tracked by family lines.

Body condition ability:  a key “environmental” variant in the search for fertility

Inside the dairy genetics mainstream, “body condition” is something for nutritionists to manage.   It has not been considered “genetic”, except as the linear type system (devised in the 1970s to identify young cows who would respond to more grain fed with more milk produced) actually preferred the cow that would delay body conditioning.     In other words, to 1960-70s geneticists, cows who gained weight if fed more grain were undesirable cows.  Today, with higher forage utilization, these genes are needed.

In the “aAa” (Weeks Analysis) system, we recognize what all other biologists recognize, that ability to maintain healthy body condition (a key indicator of positive nutrient energy utilization) is heritable.   It is not hard to figure out that always mating cows to be more angular will inhibit expression of + DPR.