The rejective behaviour of mares to their foals occurs relatively rare in breeding. According to the available literature, there is the evidence of this behaviour between 2 to 5 % of cases. In practice, it complicates the life of the foal, mare and breeder. According to available records, there are several forms of rejecting behavior. They have a different ways of preventing and resolving the situation. As a result of the mare's rejective behavior can be the need of human assistance with a care of the foal. In extreme cases, the behavior of the mare can result in orphanshood of the foal. Within the informations from breeders in Czech Republic, the rejective behaviour was manifested in 15 of 344 (4,36 %) of mares. This group was consisted of mares of different ages and breeds. In total these mares gave birth to 48 foals. Twenty of these foals were partly rejected by their mothers. Only 1 foal died. Two foals were not accepted by their mothers after the assistance of breeder which was necessary and these foals had to be bred by human. The most frequent manifestations is unwillingness of nursing the foal. This behaviour occurred in 13 mares. The mare normally tries to protect her foal from various environmental influences. However, in two mares this behavior was not observed. Other form of rejective behaviour is the fearfulness of mare caused by the presence of the foal. This behaviour was manifested in 20 % of them. Two mares were trying to avoid the contact with their foals. In 46,67 % of cases were demonstrated vocalization of mares to their foals. There was the evidence of 3 cases of chasing foals by their mothers. Threat manifestations are made by effort of biting (7) and kicking (4). Two mares did not sniff their foals, another mare did not show interest in licking of the foal. Both of these activities are very important in forming of social bond between mare and foal. Mares rejected the most often their foals at the age of 4 years. The rejection occurred in both primarous and also multiparous mares. Despite the fact that multiparous mares already have an experiences of parturition and maternity care of offspring.

In this work I focused on the Czech warmblood breed, its history and combustibility characteristics. The aim of the thesis is to compare the performance parameters stallions, their daughters and description of the performance tests of the Czech warmblood. The basis for database was selected stallions stallions list, with permission for bree-ding in the Czech Republic in 2015. The work was focused on the performance parame-ters of sires and their daughters, while I conducted an evaluation of whether stallions are worse or innovators. The data were processed using Excel and Statistics 12, in which I-selected stallions ranked alphabetically. Then I developed a table, where they are evaluated and compared the average value of the relevant class mares with stallions (father).

The objective is to determine the composition of mare´s milk at different stages of lactation and changes in its content that occurs during lactation. Variability of constituents in the milk contents between mares and possible link in the content of individual components of milk was also examined. Average values of contents were found during the five months of lactation: Fat 1.5%, protein 1.62%, lactose 6.55% and dry matter 9.78%. It was found that during lactation fat content decreases from 1.7% to 1.3% and protein content decreases from 1.75% to 1.48%. Lactose and dry matter content is unchanged. A higher coefficient of variation was found in fat and protein (between 16 -17%), lower in lactose and dry matter content (5-6%). Relation was found between protein and fat. On the contrary, no evidence of correlation between protein and lactose content, nor between the fat and lactose content was found.