A respected authority on the beef cattle industry in his home county of South Africa, Dr. Cas Marce gave a detailed presentation on functional efficiency at the 1985 TLBAA National Convention (a videotape of the seminar is available from the TLBAA). An associate of veteran Longhorn breeder Waller Scott, Maree has had the opportunity to study several Longhorn herds. Based on those observations, discussions with Longhorn breeders and his extensive experience with many cattle breeds, Dr. Maree has made the following report to TLBAA members.
By Dr. Cas Maree
Department of Livestock Science
University of Pretoria
The selection of cattle for functional efficiency is frequently not promoted by judging standards along traditional lines in terms of breed characteristics. All conformational features and subjective traits should at least represent some function or improve some biological feature of benefit to the animal(s) concerned. Otherwise, breed standards become meaningless and may indeed be disadvantageous to the breed.
Features under Column A determine functional attributes, while features under Column B determine the more traditional breed standards. There is fair overlapping, but it is essential that the promotion of any feature in Column B shall not in any way be detrimental to features (functions) under A.
A. Features related to functional efficiency
2) Growth ability
3) Calving ease
5) Carcass quality
6) Physical fitness (freedom from all defects)
B. Features related to conformational standards
1) Breed/breed type
4) Muscling/carcass type
5) Head, neck, back and hindquarters
6) Legs and feet
7) Heritable defects
8) Trade marks
The following observations are relevant to the Texas Longhorn:
Requirements for a high level of herd fertility are the following:
In females-Early sexual maturity and conception, ease of calving, regular and easy reconception and a long, productive life span.
The Texas Longhorn has an excellent rating for female fertility.
In males-Early sexual maturity, well developed and normal conformation of testicles, good semen quality in addition to a high level of libido and total physical fitness are prerequisites for fertility in bulls.
Growth Ability in Females:
In females, ease of birth, a strong and vigorous calf, and a good weaning index and early conception are the essential features of growth ability. There is a close interaction between growth ability and fertility and also adaptability.
Fertility is a sensitive and reliable indicator of growth ability. Poor doers will not conceive. Unadapted females will do poorly.
Many breeders concentrate on size in females, but fertility is what counts, not size. Females that do not breed regularly are big and fleshy. Selecting big females inevitably leads to the selection of sub fertile females.
Growth Ability in Male:
Growth parameters in beef bulls are the weaning index, post-weaning growth (ADGADA) and 12-month, 18-month, mature weight, etc.
Again, it easily happens that the most growthy bulls are not highly fertile. That is why they grow tall and such bulls are inclined to be leggy and flat.
Fertility is a much higher priority in breed improvement (or economics) than growth ability. Body weight gain is directly related to selling price and beef yield. Therefore, a safe balance is to be maintained between fertility on the one hand and size (weight) on the other hand.
Selection for growth (weaning weight, adult weight, efficiency of gain) increases birth weight and adult size.