Last week we listed the possible abnormalities which could emerge from injudicious (incorrect) breeding of animals destined to be pets in loving and caring households.
TODAY, we’ll look at a very special method of breeding animals with the hope of capitalizing on specific assets of related parents. This is called Line Breeding. Actually, it is practised quite often here in Guyana, but not consciously and objectively. It happens more by accident or because of the laziness of the “breeder” to ascertain whether the two prospective parents are related. Perhaps it is carried out quite purposefully, because the “breeder” cannot be bothered about the damage being done when siblings are mated, or when mother and son or father and daughter are brought together to produce “cute” puppies which can be sold to kind-hearted, but inexperienced Guyanese.
LINE BREEDING AND INBREEDING
Broadly speaking, any litter which has the same dog on each side of the pedigree is an inbred one. However, this term is usually applied only to those matings which are in the order of parent to offspring, or brother to sister. Inbreeding is something we should not do haphazardly. Interbreeding among dogs further removed is called Linebreeding.
Linebreeding is the safest and best method to preserve type and conformation, provided that the foundation dogs are well chosen and one has the judgment and experience to pick the best puppies. Conscious Inbreeding, on the other hand, requires a genetically clean stock, knowledge of the faults and virtues of all the common dogs in the pedigrees for at least three generations, and the willingness to cull ruthlessly when it becomes necessary.
I should mention in passing that a common misconception is that inbreeding causes high-strung, nervous and aggressive dogs. Because two individuals are closely related does not mean that their offspring will necessarily be unsound. It is the genetic potential in the background of the pair which determines the outcome. A fundamentally sound strain remains fundamentally sound. One which has some unstable dogs in its inbreeding programme is likely to have problems later on.
After having linebred for three or four generations, most breeders have found from experience that it is wise to bring in new blood. The use of a stud from a totally different bloodline may be considered. This produces an outcrossed litter and “reshuffles” the genes that have tended to become fixed, in a more or less predictable manner, through previous linebreeding. Many times, particularly with an overly refined bitch, an outcross will give surprisingly good results. An improvement in health and vigour of the resulting puppies is apparent from the time they are born. The process is known as “nicking”. While the litter will sometimes lack uniformity, nevertheless, some really good show dogs have been produced in this manner.
When two strains have “nicked” successfully, other crosses between them may work as well. Puppies from matings usually are bred back into one of the two strains, thereby providing a basis for a new line.
One final breeding method is to mate a dog and a bitch who are both of mixed ancestry. Neither has a linebred background. When using this approach, it is essential that one has a definite objective in mind. One dog may carry an attribute or quality totally lacking in the other. However, the method of breeding strengths to weakness, in the hope that the strengths will win out, may sometimes be disappointing. Too often weaknesses win out, producing puppies of inferior quality. Because of the infinite possibilities when we are dealing with genes and chromosomes and with biological entities in general, the science of genetics is not as exact as one would wish it to be, which was alluded to at the very outset.
Much of what has been written was designed for and directed to those who are “breeding” dogs (hardly ever cats) for sale, We, nevertheless, recommend that those of you desirous of acquiring a pet, seek answers from breeders on the issues raised in these columns.
