Genetic Change in Alpacas: Rules and Tools, Introduction

Julio Barreda worked with ancient Peruvian alpaca stock, always striving to improve it. In North America, many breeders are fortunate to be working with animals that have already been improved. However, there is much more work to do. How shall we go about advancing to create the alpacas of our dreams?

We start by knowing which breed standards we want to achieve, developing a breeding plan or program to achieve that end and, finally, by consistently applying our plan. I will address all of these ideas on Peru Unplugged.

Alpaca breeders cannot change Mendel’s laws, alter the number of genes that make an alpaca, or affect the genes’ interrelationship. They cannot change the expression of dominance or the negative effects of some recessive genes.

That leaves only two ways for alpaca breeders to control the heredity of their animals. First, they select the alpacas that make up their herd. Second, they decide which alpaca will mate with each of the alpacas in the herd, and how many offspring each parent will have. This process must also involve culling. Julio Barreda culled 10% of his herd every year.

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The second group of decisions they make — whom to breed to whom and how often — is every bit as important as the breeder’s initial selection decision. A breeding program integrates your selection system — how you choose the traits to breed for, and how you choose the animals you will breed: by pedigree, phenotype, or progeny testing (EPD’s) — and your mating system — choosing which animals to mate to which.

Today, most breeders practice some form of selection when they purchase and breed their alpacas. However, many of them substitute their concept of selection for their breeding program. But a breeding program must include both careful selection and careful attention to the four keys of genetic change.

An alpaca has high breeding value when it breeds true or produces offspring which resemble itself. This

ability is dependent on the alpaca’s genotype being homozygous for a variety of positive traits.

While this genotype will be reflected in the animal’s phenotype, or appearance, the opposite may not be true:

An excellent phenotype does not necessarily indicate a superior genotype.

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The four keys to making genetic change in an alpaca herd are:

  1. Selection accuracy
  2. Selection intensity
  3. Genetic variation
  4. Generation interval

We will discuss each of these concepts in the four upcoming four parts of this series. I would like to leave you with one thought. Julio Barreda, the world’s greatest alpaca breeder, said,

When selecting your breeding stock and determining who to mate with whom, you cannot use your eye for a microscope and your arm for a scale.

EPDs Supercharge Genetic Gain

Simply put, Gregory Mendel created the rules and EPDs to provide a tool. The breeder must also use a breed standard as a tool or template to guide his eye in the initial culling of all breeding stock for conformation flaws and unproductive physical traits.

Part one of this series will examine the first rule of genetic gain: selection accuracy.