HEREDITY OR ENVIRONMENT?
THE EFFECT OF EACH IN NATURAL BREEDING
During a recent conversation with a customer who purchased several TENNESSEE MEAT GOAT™ bucks and does from Onion Creek Ranch during 1997, he remarked to me that his area of the country now had all the Tennessee Meat Goats™ that they would ever need! Curious, I asked him how, knowing that this improved myotonic goat was originated and developed here at Onion Creek Ranch and that I had not sold additional fullblood Tennessee Meat Goats™ to him or anyone else in his immediate vicinity recently. He responded that he had bred and flushed embryos from the TENNESSEE MEAT GOAT™ does, and he now has fullblood TMG'S all over the area.
I had to stifle a laugh, because this man neither understands how genetics works nor does he know what he purchased from me. I use this incident as an example from which we all can learn. His name shall not be mentioned; it is not my desire to embarrass him.
Genetics is a game of numbers. .. . or to put it less politely, a crap shoot. Regardless of breed or species, superior quality offspring will never result from every single breeding.
Visualize the outline of a bell as seen from its side. In genetics, this is called The Bell Curve. With each breeding, a few exceptional animals will fall at the top (the smallest part) of The Bell Curve. Exceptional means precisely what it says . . . these animals are the exception, not the rule. Lots of average animals will fall on the ascending side of the Bell, while lousy ones will make up the descending side of the Curve. In other words, with every breeding cycle, lots of animals must be culled to achieve quality stock.
One the biggest fallacies inherent in flushing embryos and raising the offspring in the womb of surrogate mothers flows from The Bell Curve of Genetics. The quality of the kids born from the embryos is largely indeterminable until they are born and begin to grow and mature, even though a grading system for quality of embryos exists.
Just as importantly, the influence of the surrogate mother on that kid both while in utero and while she is raising it is often discounted by breeders. Quantity of milk produced by the surrogate mother is usually the only factor taken into serious consideration. However, many factors make up mothering ability and directly impact how that kid will grow out.
Although it is true that goats rely on instinct to a significant degree, any serious observer of a dam and her kid soon realizes that each mother teaches her offspring many things that it needs to know in order to survive and thrive. How does a breeder know which characteristics, good or bad, came from the biological mother (donor doe) and which derived from the surrogate (recipient doe)?
For example, Nubian dairy does handle newborns much differently from TENNESSEE MEAT GOAT™ mothers. Producers know how leisurely that dairy offspring get on their feet to nurse their mothers when first born and cleaned up. Days pass before dairy kids really get up and move around on their long, somewhat unsteady legs. Tennessee Meat Goats™ mothers, on the other hand, give birth, clean the kids, feed them colostrum, and move the newborns hundreds of yards to safety in approximately one hour. . . ever wary of predators who might be stalking their newborns for a tasty meal. Observe how a dam handles her newborn kid if she was taken from her mother at birth and bottle raised. The difference is profound. I am convinced that these behaviors and traits transfer to the kids and surface when they are old enough to become mothers. I have seen it occur. (Note: These statements are not meant as any sort of criticism of dairy goats . . . just observations of actual events which I believe impact on the offspring.)
A kid born of an embryo flushed from its biological mother but raised by a surrogate dam will retain qualities from each female involved in its life. To state unequivocally that an embryo kid is as "good" or is of the same "quality" as a kid born of its natural mother is both simplistic and untrue. It is humankind's wishful thinking that we can rush the natural process and not in some way interfere with or alter "Mother Nature." The kid may turn out "inferior" or it may be "superior," but it is certainly not identical to the offspring that would have been produced had the biological mother carried it to term and raised it to weaning age.
My second point addresses the definition of TENNESSEE MEAT GOATS.™ TENNESSEE MEAT GOATS™ are the result of highly selective breeding and heavy culling of large-framed, heavily-muscled myotonic (stiff-leg) goats. Only those animals who develop the body characteristics that we at Onion Creek Ranch consider good enough will ever be called TENNESSEE MEAT GOATS™. All of the culls (and we cull a large percentage, though the number declines each year as we perfect our animals) are ordinary stiff-legs.
As we improve our genetics with each kidding season, our group of quality animals increases. However, the physical laws of genetics . . . that "numbers game" that is displayed upon The Bell Curve . . . dictate that there will always be culls in any breed. The man who believes that he has lots of Tennessee Meat Goats™ running around simply misunderstands what they are. He may have a few TMG's from his embryo flush, but unless he culled heavily, he mainly possesses lots of ordinary stiff-legs.
Perhaps a better analogy might be that while there are good Boers and there are poor Boers, among myotonic goats there are Tennessee Meat Goats™ and then there are stiff-legs . . . and the TENNESSEE MEAT GOATS™ are a small, select percentage of elite animals within this breed.
Let us now observe how genetics works in crossbred animals. At Onion Creek Ranch, we are working towards developing the ultimate slaughter goat by crossing fullblood Tennessee Meat Goats™ with Boers. We are combining the muscling of the fullblood TENNESSEE MEAT GOAT™ with the quicker growth rate of the Boer. We now have an F4 which appears to be the seed stock of the production animal which we are seeking. Males and females from different genetic lines will be bred to each other to try to develop offspring that will breed "true."
Because crossbred animals have multiple genetics, the number of combinations available in resulting offspring is greatly increased. In other words, it is much easier to breed "true to breed" when mating fullbloods. So it will take years of breeding and heavy culling to determine if we can obtain offspring which emulate their parents. Refer to the history of the development of beef cattle crossbreds for a better understanding of the work involved and the time it takes to produce a consistent product. Many years passed before the King Ranch brought the Santa Gertrudis to market.
Until breeders begin to understand the way genetics works, there will be much wasted effort. TIME . . . LOTS OF TIME . . . is needed to develop a superior breed of animals. Let us all learn from each other's successes . . . and failures . . . so that we waste as little of that precious commodity as possible. The goal towards which we are striving . . . a superior slaughter goat . . . is certainly worth it.
Important! Please Read This Notice!
All information provided in these articles is based either on personal experience or information provided by others whose treatments and practices have been discussed fully with a vet for accuracy and effectiveness before passing them on to readers.
In all cases, it is your responsibility to obtain veterinary services and advice before using any of the information provided in these articles. Suzanne Gasparotto is not a veterinarian.Neither tennesseemeatgoats.com nor any of the contributors to this website will be held responsible for the use of any information contained herein.
The author, Suzanne Gasparotto, hereby grants to local goat publications and club newsletters, permission to reprint articles published on the Onion Creek Ranch website under these conditions: THE ARTICLE MUST BE REPRODUCED IN ITS ENTIRETY AND THE AUTHOR'S NAME, ADDRESS, AND CONTACT INFORMATION MUST BE INCLUDED AT THE BEGINNING OF THE REPRINT. We would appreciate notification from any clubs or publications when the articles are used. (A copy of the newsletter or publication would also be a welcome addition to our growing library of goat related information!)
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