On the Other Hand

Genetics are the point of the arrow when it comes to the livestock industry. Although genetics are of equal importance to disciplines such as herd management, nutrition, animal health, marketing, forages, record keeping and Human Resources, genetics remain the prime mover.

As the last link in the value chain, the consumer being the first link, genetics determine how the rest of the value chain flourishes or fails.

It is the duty of the seedstock producer to act as a scientist with their ranch or farm being their laboratory. By adapting their genetics to the particular environment, resources and objectives they’re dealing with, the seedstock producer experiments, invents and proves or disproves genetics.

There are an abundance of selection tools available to cattle breeders. These tools vary from traditional to cutting edge and are all used to differing degrees within both the beef and dairy industries.

The selection tools I’ll discuss in this article include phenotype, pedigree, inherd indexes, Production Based Culling, EBVs/EPDs, and Genomics/Genomic enhanced EPDs. All of these tools can be useful when making breeding decisions provided that they are used in context and with a non-biased and balanced approach.

The first objective to be considered is whether the animal you’re wanting to breed is destined to be utilized in a maternal breeding program or as a terminal animal for beef. The selection criteria for these two options is vastly different and I’ll go into more details in paragraphs to come.

A premise to consider is that there are two types of traits in a maternal breeding program. Profit traits which include adaptability, functional efficiency, fertility and longevity. Turnover traits which include growth, muscle, milk and marbling. Turnover traits are very important, but are meaningless if profit traits are not used to lay the initial foundation.

Every breeding decision needs to be made according to objectives, resources and environment. Without matching these decisions to these three factors, there’s a good chance of missing your target. The animal’s Pedigree is extremely valuable when making selections.

Understanding or remembering pedigrees is fast becoming a lost art in the age of genomics, however, pedigree is the motherlode from whence all these technologies have sprung. Traits such as mothering ability, libido, temperament/ aggression, wellbeing and hardiness are immeasurable in any accurate form by any technology. The knowledge of the ability for certain bloodlines and cow families to work together is where the art of breeding comes to fruition. A lot of selection criteria is too nuanced for scientific method.

Phenotype is extremely useful, and I’d say essential,when making breeding decisions. A lot of what data or EBVs/EPDs are telling you can be seen in the animal itself. The analogy that I like to use is that when you are told that it is raining outside, one can simply open the curtains and take a look instead of checking the weather application on one’s smartphone. Growth, Fat, Muscle, Milk, Calving

Ease and a host of other traits are as easily observed with the human eye as they are read off of a chart. When doing phenotypic selections, one needs to first consider if the animals are maternal or terminal.

In maternal animals, cattle need to be able to eat, walk and reproduce. Focussing on the Profit Traits (adaptability, functional efficiency, fertility and longevity) is first and foremost. Balance is essential. This includes physiological and endocrinological balance, carcass balance (muscle/fat ratio), skeletal balance and hormonal balance. High inherent body condition (easy fleshing ability/doability/ constitution) plus hormonal balance equals fertility.

In terminal animals, the fundamental traits remain vital. In animals bred for a high yielding carcass, factors to focus on are a high growth rate and large ribeye area. Dimension is essential too, as three dimensional animals produce heavy carcasses. Carcass balance is essential still as fat cover is needed for good grading and fleshing ability whilst muscle is required for yield. Structural soundness is essential in terminal animals too. Structurally unsound animals tend to founder and go lame when in the feedlot. These animals lose their appetite and don’t gain appropriately. Also, steers have sisters and mothers out grazing on pasture their entire lives, so ignoring structure in terminally bred cattle is dangerous.

In terminal animals bred for high quality eating experiences like the Japanese and South Korean breeds, the logic remains similar in terms of structural integrity. Carcass balance leans further towards marbling traits with muscle being necessary but not pinnacle. Waxy horns, a sharp poll (or a fine ridge between the horns), oily skin, silky hair coat, flat and fine bone with small joints and a flatter muscle-shape all augur well for high-marbling carcasses.

Production Based Culling is a term I use where replacement females and breeding bulls are selected based on the fact that their dams, grand-dams and great-grand-dams have simply jumped over every hurdle the breeder has placed in front of them regarding criteria to remain in the herd. These include reasonable nutritional supplementation, age at first calving, inter-calving-period, short breeding seasons, cow/calf ratio at weaning, minimum weaning weights, unassisted births etc. This is a fast way of building a profitable, consistent, adapted and uniform herd.

In-herd Indexes were the primary arithmetic used for cattle selection prior to the arrival of EBVs and EPDs. These in-herd indexes remain a vital tool when customers purchase animals from a reliable seed-stock breeder or when the seed-stock breeder is presenting their product to the market. They give context to how animals have performed in their given environment and herd. It is important to remember that not all herds are the same. A 100 index in a progressive herd is superior to a 100 index in a less progressive herd. However, if one is familiar with and utilizes a registered herd for their seed-stock needs, using in-herd indexes for selection purposes is very valuable.

EBVs/EPDs/Breed Population Indexes are widely used worldwide by animal producers. These numbers are based on the in-herd ratios of the animal itself as well as the in-herd-indexes of its ancestors, siblings, relatives and offspring.

EBVs (Expected Breeding Values)/EPDs (Expected Progeny Differences) can be extremely useful if used in context and with matching them to objectives, resources and environment. As a breeder, one needs to decide whether one trusts these numbers being published by their specific breed society/association. If the breeder believes that they are relevant and that most breeders are measuring everything, all the time, accurately, honestly, in large numbers and in the same environment then it is important to remember that the number being produced is an objective one. Therefore, no EPD/EBV can be good or bad. It depends on one’s objectives, resources and environment.

In maternal breeding programs, it is essential to remember that the sex hormones only start when the growth hormones stop. Therefore, if one selects for high growth numbers, one is directly selecting against fertility. Selecting for fertility starts with high inherent body condition and hormonal balance. On an EBV/EPD chart that would mean higher BACK/RUMP FAT numbers and higher SCROTAL CIRCUMFERENCE at a year of age. Selecting for the Top 5% Weaning and Yearling Weight continuously will create higher birth weights, leaner, later maturing, and less fertile cattle with higher energy requirements. Selecting for high inherent body condition and early sexual maturity will produce cattle with high relative (reaching mature size early) growth rates, low energy requirements, and high fertility. If one feels that the average animal in one’s breed is big enough, it makes no sense to require anything more than the breed average EPD/EBV Yearling Weight or Mature Cow Size. Similar logic works with all traits.

You’ll notice that herds that have focused heavily on growth and carcass traits for some time will have a lack of sexual dimorphism in their cattle. There won’t be much difference in size and shape between the bulls and females. This sexual monomorphism is an expression of hormonal imbalance and subfertility. The bulls tend to be less masculine, and the females less feminine. Sexual dimorphism occurs when selection for high inherent body condition and hormonal balance is practiced. These animals are earlier maturing and are more fertile. The bulls are significantly larger and shaped and colored differently from the females.

Publishing trait leaders is counter-intuitive, in my opinion. For example, why is less fat better than more fat when publishing a FAT trait leaders list? Doesn’t it depend on the objectives, resources, and environment of the breeding program? Big, lean, late-maturing cattle are great for feedlots and processors but devastatingly expensive to keep for cow-calf operators. What good is giving the tools of a Top 1% for a trait like milk to marketing companies to run with? The top 1% for milk doesn’t even make a profitable dairy cow, never mind how destructive it proves to be for beef cow operators.

In terminal breeding programs, traits such as Weaning Weight, Yearling Weight, Ribeye Area, and Intramuscular Fat become important. Managing birth weight to where its functional is important. Genomic Enhanced EBVs/EPDs are based on the same premise as EBVs/EPDs.

However, the actual genetics of the animal are taken into consideration, and not just the average EBVs/EPDs of sire and dam at birth are considered. GE-EPDs/ GE-EBVs increase the accuracy of an EPD/EBV for an animal with no offspring to have the same accuracy as that same animal if it had had up to a dozen offspring. If the premise of EPD’s and EBV’s make sense to the breeder, then GE-EPDS/GEEBVs will work for them.

If, however, a breeder does not agree that the data being used to create GE-EPDs/ GE-EBVs is measured entirely, honestly, accurately, in large numbers, all the time, eliminating environmental influence by most breeders, then it is probably better to revert to the other tools in the selection toolbox. These being Phenotype, Pedigree, In-herd Indexes, and Production Based Culling.

Cattle breeding is as much an art as it is a science. Artists and scientists alike are passionate and obsessive about their work. Context and nuance is key.