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Showing posts with label breeding. Show all posts
Showing posts with label breeding. Show all posts
Tuesday, February 19, 2008
Breeding Notes: Part I
5:17 PM | 
Posted by
Jen Pietsch |
The last couple of weeks have been filled with cleaning house and packing to move. Through it all, in the back of my mind has been a constant concern about and delight for the prospect of selecting potential breedings for the upcoming season.I have been reading and asking questions from experienced breeders, soaking in everything I can find about genetic selection methods. Keep your eyes peeled - over the next couple of posts I will fill you in on what I have learned. Today, however, I will discuss what is known as “line breeding/in-breeding” versus “out-breeding”.
Line-Breeding vs. In-breeding
“It’s line-breeding if it works… it’s in-breeding if it doesn’t.”
Strictly speaking, line-breeding is any mating in which the mated animals have a common ancestor. When first-degree (mother/son, sister/brother, etc...) pairings occur, it is often called in-breeding. Line-breeding implies more distant relationships between the pair.
The reason for line-breeding is to produce offspring that are more genetically uniform with the goal of accentuating superior traits. With line-breeding, good traits hopefully become more consistent, although it can also magnify less desirable traits by making them more consistently prevalent as well.
In-breeding, on the other hand, tends to bring recessive genes to the surface by forcing them to pair with one another. With either in-breeding or line-breeding, the genetic pool becomes drastically smaller and the general health and fitness level of the off spring may suffer. To sum it up one can use line-breeding to achieve greater predictability in their breeding program but not without risks.
Out-breeding
Out-breeding is breeding of animals that don’t have common ancestors. The predictability of outcome of this method of breeding is decreased. Out-breeding can hide recessive genes in a way that they can’t be expressed. Inferior genes or traits can therefore be more widespread than the outward appearance would have you think in advance.
So What Is One to Do?
I see the merits of both and will seek to appropriately combine both line- and out-breeding. Much of our herd has great genes that I would hate to not ignore. The fear of the consequences of a breeding gone wrong seems to be a gamble. Therefore, in order to make the gamble pay off, I will try to ensure the positive traits that I seek to compliment from our Dams are ones that I can be reasonably assured will be passed down.
To increase the odds of achieving this goal, I will also research the off spring on the ground from the selected sires. Have the traits I want to pass on and see in my cria been passed down previously? Coupling this ‘seeing-is-believing’ approach with a healthy dose of caution about line-breeding should ensure an improvement on our herd over time.
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Thursday, January 17, 2008
Growing Possibilities
The first spring seed catalogs have started rolling into my mailbox, and I am planning and dreaming of my new Orcas garden. Burpee’s glossy photographs aside, this takes some serious imagination here in the far away frozen tundra of Chicagoland! We have had the farm now for less than six months; before the next six months pass we will have, if all goes as planned, two new cria on the ground - or - as they say in the business, “dams with cria by their side.” How I love the sound of that!Matchmaker, Matchmaker
The two expected cria are by two of my girls, Wanda and Carmen, with sires from San Juan Island’s Krystal Acres Farm. The couple who operated the farm before us had bred there in the past, and the resulting cria were sound and of good conformation; the decision to breed at Krystal Acres again was E-A-S-Y. Albert Olsen and his wife Chris picked up the girls on Orcas and transported them by ferry to San Juan. Coordinating the effort was our herd manager, Janet Franklin. We we are lucky to be working with Janet; she is keeping me and the herd under her able and experienced wing until our arrival this June -- Thank You Janet!
Albert and Chris ran tests to ensure the girls were “sufficiently pregnant,” then transported them safely home where Janet has had them in the best of care since. Now is when the decisions become difficult. I have seven girls that need to be bred come this spring to ensure babies for the following spring…
The Breeder’s Eye
Many of an alpaca’s physical characteristics are influenced by multiple genes (polygenic influence). This makes predicting breeding outcomes difficult. Understanding how genetics can work for breeders is critical for herd improvement. (Which is what I want.) What worries me is the second element of the puzzle, the art of breeding. Good breeding depends greatly on the “breeder’s eye” -- being able to visualize through an intuitive sense how a given breeding will work out. This is a skill I will have to develop over time.
What is Heritable?
Heritable traits are generally thought to include: fiber density, fiber length, fiber fineness, and the animal’s growth rate. What isn’t heritable usually includes traits involving reproduction and disease resistance, according to the literature. Over the next few weeks I will be looking for a balance of good heritable traits and fair stud pricing. I will be gambling my vision, my girls, and what I have learned thus far about genetics in order to improve our herd.
Who to breed to whom will be the focus of the next batch of posts… we at Orcas Moon Alpacas are looking for a few good men -- who produce only women! Now back to my Burpee’s catalog...
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