In a herd environment, mares are only fertile when the length of daylight hours exceeds the length of hours of darkness.

Spring Equinox, is March for the Northern Hemisphere and 21st September  for the southern hemisphere.

Pedigrees are really only a written record of the ancestry, of the horse and DO NOT, in any way, guarantee quality or soundness, of any horse. Horses, with what could be regarded as excellent pedigrees, have been seen with faults and conditions, which render them useless, for any horse activity. In fact it may well be that the horse, without the pedigree, may well be an animal with more desirable features, than the horse with a pedigree. Pedigrees are of value in designing breeding programmes but one should look further than the pedigree, of the two animals, to be mated. Conformation, temperament, ability and performance of full sisters and brothers, half sisters and brothers, sons, daughters, grandparents and great grandparents and possible other relatives should all be assessed when devising a mating strategy.  The more constant and repetitive any character, or characters, are exhibited in the available relatives of any horse , the more HOMOZYGOUS (pure and repetitive) that feature is likely to be. in that animal, and the greater is the chance that such character, or characters, either desirable or undesirable, will be passed on to any resultant progeny. In the evaluation of stallions for the desired characters, one has to carefully consider the quality of the mares previously served by that stallion. It could well be that for a variety of reasons, the mares put to a stallion, in the past, may not have been the quality, or breed type. which allowed the stallion to fully express potential.

Phenotypic SELECTION this is the term used to describe the selection, of a horse, by visual appraisal, ignoring anything to do with pedigrees, bloodlines and or relations, which is commonly called Genotypic Selection. This is a assessment of the horse on conformation and or performance and or temperament, alone, as in any led in, or in hand, class at the local show. Opinions vary tremendously as to what constitutes in a led in class, the results is after all only one judges opinion and as some, who have exhibited consistently in led in classes with the same horse, will testify a first prize winner one week may not even get a ribbon the next week.

REMEMBER THAT GENE COMBINATION, AT CONCEPTION, OCCURS SIMPLY BY CHANCE AND THE MOST UNDESIRABLE CHARACTERS MAY COME FROM THE MATING OF TWO "IDEAL" HORSES.

Dominance: where a particular gene is able to overpower, or override, any action of its partners gene.