PSXV-19 Informative value of study of mineral composition of the mane hair to assess quality of stallions’ sperm

The research aim was to study the effect of the elemental status of stallions detected by concentration of chemical elements in the mane hair on the quality indicators of sperm. The research was done on stallions of Arabian breed (n = 54) aged from 5 to 15 years. Hair samples were taken from plot of the mane in the area of projection of the first cervical vertebra (not less 0.24g). The elemental composition of biosubstrates was explored for 5 toxic elements (Al, Cd, Pb, Sn, Sr) by atomic emission and mass spectrometry (AES-ICP and MS-ICP). Spearman rank correlation was calculated at the first stage of the experiment that demonstrated negative correlation of Sr in the hair with volume of ejaculate (r=-0.55; P < 0.05) and total number of progressive motile spermatozoa (r=-0.31; P < 0.05). The entire research sample was divided into three groups: I - concentration of Sr in the hair below 1.88 mcg/g; II – within 1.89 – 3.89 mcg/g; III – above 3.9 mcg/g. Comparative analysis showed that stallions with Sr levels below 1.88 mcg/g (group I) exceed stallions from group II by ejaculate volume by 18.2%; sperm survival in hypothermic sperm preservation after cryopreservation by 24.1% (P < 0.05); total spermatozoa number by 14.6% (P < 0.05); total number of progressive motile spermatozoa by 15.0% (P < 0.05). Difference in the value of the studied parameters between the animals of groups I and III was even more pronounced and was at the level of 38.2% (P < 0.01); 34.7 (P < 0.05); 23.7 (P < 0.05); 26.7% (P < 0.05), respectively. The research was carried out with the support of Russian Science Foundation (project №. 17-16-01109 P).

Characteristics of the microscopic hair structure of domestic mammals from Equidae family

Hair is an indispensable component of the animal body. Having structural features of the structure, it allows you likely to identify the type and age of animals, conditions of keeping animals, feeding and even sex. Paleontologist's findings prove, the hairline stores the undisputed information on its “owner” for thousands of years. According to the results of the conducted research it is established, that the hair coat of the studied animal species – Equinus asinus and Equus caballus – has significant differences in the structure of the brain substance and superficial drawing of the cuticle. Microscopic examination of discolored samples of animal hair well-recognizes the structure of the brain substance, which makes it possible to differentiate the species of animal. The brain substance in the donkey mane hair occupies most of the hair, is represented by densely grouped cells, sometimes interrupted, whereas in the horse mane hair, it has the appearance of grouped rounded cells with small intervals between sections of 6–10 cells. The brain substance of the donkey covering hair is represented by cells of different size and shape, which disappear from the middle of the hair to the peripheral end. This tendency is also typical for the brain substance of the horse covering hair, but unlike donkey hair – cells of the same size, begin with a continuous cord at a distance of 1–1.5 mm from the root of the hair, towards the peripheral end of the hair the gaps between them increase to the complete disappearance of cells. Ultramicroscopic examination of the cuticle superficial drawing of hair samples allowed to establish the peculiarities of two species of the same animal genus. The donkey and horse mane hair had almost the same thickness, the number of scales (waves) per 100 μm of hair length and the size of the scales (wavelength), however, the overall drawing was significantly different. Superficial drawing of hair cuticle from horse mane represented by irregular waves with sharp pointed edges of scales, instead, the donkey has fringed edges of scales. The horse's covering hair was thicker than the donkey's hair and had differences in the location and shape of the scales. Superficial drawing of covering hair cuticle of donkey represented by a regular wave of scales with clear and even edges, while the scales on the surface of the covering hair of the horse have indistinct torn edges and collected in intermittent (irregular) waves.

Characteristics of the microscopic hair structure of domestic mammals from Equidae family

Hair is an indispensable component of the animal body. Having structural features of the structure, it allows you likely to identify the type and age of animals, conditions of keeping animals, feeding and even sex. Paleontologist's findings prove, the hairline stores the undisputed information on its “owner” for thousands of years. According to the results of the conducted research it is established, that the hair coat of the studied animal species – Equinus asinus and Equus caballus – has significant differences in the structure of the brain substance and superficial drawing of the cuticle. Microscopic examination of discolored samples of animal hair well-recognizes the structure of the brain substance, which makes it possible to differentiate the species of animal. The brain substance in the donkey mane hair occupies most of the hair, is represented by densely grouped cells, sometimes interrupted, whereas in the horse mane hair, it has the appearance of grouped rounded cells with small intervals between sections of 6–10 cells. The brain substance of the donkey covering hair is represented by cells of different size and shape, which disappear from the middle of the hair to the peripheral end. This tendency is also typical for the brain substance of the horse covering hair, but unlike donkey hair – cells of the same size, begin with a continuous cord at a distance of 1–1.5 mm from the root of the hair, towards the peripheral end of the hair the gaps between them increase to the complete disappearance of cells. Ultramicroscopic examination of the cuticle superficial drawing of hair samples allowed to establish the peculiarities of two species of the same animal genus. The donkey and horse mane hair had almost the same thickness, the number of scales (waves) per 100 μm of hair length and the size of the scales (wavelength), however, the overall drawing was significantly different. Superficial drawing of hair cuticle from horse mane represented by irregular waves with sharp pointed edges of scales, instead, the donkey has fringed edges of scales. The horse's covering hair was thicker than the donkey's hair and had differences in the location and shape of the scales. Superficial drawing of covering hair cuticle of donkey represented by a regular wave of scales with clear and even edges, while the scales on the surface of the covering hair of the horse have indistinct torn edges and collected in intermittent (irregular) waves.