Identification of N6-Methyladenosine-Related Factors and the Prediction of the Regulatory Mechanism of Hair Follicle Development in Rex and Hycole Rabbits

Hair follicle development directly affects the development of the rabbit fur industry. The growth and development of a hair follicle is modified and regulated by many genes and mechanisms. M6A is an important RNA modification. However, there are few studies on the effects of the regulation of m6A on hair follicle growth and development. In this study, hematoxylin-eosin (HE) staining was used to explore the difference in hair follicle development between Rex rabbits and Hycole rabbits, and we performed m6A sequencing to identify the key genes with m6A modification in hair follicle growth. The results showed that the hair length, coarse hair percentage, primary hair follicle ratio, and skin thickness of Hycole rabbits were significantly higher than those of Rex rabbits. However, the proportion of secondary hair follicles in Hycole rabbits was significantly lower than that in Rex rabbits. In addition, we found five differential methylases, 20 differential genes, and 24 differential signaling pathways related to hair growth and development. The results of the Sankey diagram showed that 12 genes were related to 13 signal pathways. Finally, we found that five methylases regulated the development of hair follicles through differential genes/signal pathways. These findings laid a molecular foundation for the function of m6A modification in hair development.

The Effect of the Season, the Maintenance System and the Addition of Polyunsaturated Fatty Acids on Selected Biological and Physicochemical Features of Rabbit Fur

Simple Summary

Rabbit furs are a valuable material used in the fur industry. Many studies show beneficial effects of omega-3 acids supplementation on the skin and coat of animals. The aim of the study was to show the impact of environmental conditions and dietary supplementation with ethyl esters of linseed oil on the quality of the rabbit hair coat. The experiment was carried out in four stages: laboratory (summer and winter) and outdoor (summer and winter). The experimental rabbits were given an addition of ethyl linseed oil to their feed (during 2 months). To assess biological and physico-mechanical properties of the coat samples and to determine fatty acid profile and histological evaluation, the hair samples were collected three times: before the study, after two months of treatment, and after two months from the end of supplementation. The obtained results show that the environmental conditions have a major impact on the quality of the rabbit coat. The best results of hair heat protection were obtained from animals kept outdoors. Administration of linseed oil ethyl esters had a positive effect on the hair fatty acid profile.

Abstract

The aim of the study was to show the impact of environmental conditions and dietary supplementation with ethyl esters of linseed oil on the quality of the rabbit hair coat. The research was divided into 4 stages: laboratory (summer and winter) and outdoor (summer and winter). In each stage of the research, animals were divided into control and experimental groups. The animals were fed in accordance with the feeding standards of reproductive rabbits during the period of sexual dormancy. The rabbits from the experimental groups during the first two months were given an addition of ethyl linseed oil to the feed. In the experiment, linseed oil was cold-pressed directly in the laboratory. Three samples of hair were collected: before the study, after two months of treatment, and after two months from the end of supplementation. The hair coat biological properties, such as share of individual hair fractions (%), heat transfer index (HTI), hair diameter (μm), as well as physico-mechanical properties such as breaking force (N), breaking stress (kg/cm²) and elongation (%) were performed. Moreover, the histological structure of hair and histological hair evaluation were performed. The fatty acid profile was determined in the hair as well. The obtained results of the content of individual fatty acids were grouped into saturated fatty acids and unsaturated fatty acids. In addition, omega-3 and omega-6 were distinguished from the group of unsaturated acids. The environmental conditions have a major impact on the quality of the rabbit coat. The best results of hair thickness and their heat protection were obtained from animals kept outdoors. The studies did not show an influence of the administered preparation on the quality of the rabbit coat. The hair became thinner, but more flexible and tear-resistant. Administration of linseed oil ethyl esters had significant, beneficial changes in the fatty acid profile in hair and hair sebum were observed. There was a significant increase in omega-3 acids, and a significant decrease in the ratio of omega-6 to omega-3 acids.

Seasonal variations in furs of Gabaly and New Zealand white rabbits and their crossbred under Egyptian semi-arid conditions

The effect of breed and season on rabbits’ fur characteristics under Egyptian semi-arid conditions was studied in this research. Fifty-nine male rabbits aged 3-3.5 mo of Gabaly (GB, n=21) and New Zealand White (NZW, n=27) breeds and their crossbred (NZW×GB, n=11) were studied during two subsequent seasons; summer (n=31) and winter (n=28). Skin samples were taken pre-slaughtering to determine the histological parameters, skin layer thicknesses and physical traits of fur fibres. After slaughter, rabbits’ furs were chrome tanned to determine physical and chemical properties. Results showed that all histological parameters of follicle dimensions were affected (<em>P</em>&lt;0.01) by season, breed and their interaction. In summer, primary follicles had larger follicle dimensions and produced coarser fibres than in winter, whereas opposite results were observed for the secondary follicles. Additionally, the uniformity of fibre diameter distribution and hair length of furs were higher (<em>P</em>&lt;0.01) in summer than in winter. Results indicated the role of the seasonal variations in body coat to accommodate the climatic changes. NZW rabbits were superior (<em>P</em>&lt;0.01) in most histological parameters of follicle dimensions, followed by NZW×GB crossbred and finally GB rabbits, while NZW×GB crossbred produced finer (<em>P</em>&lt;0.01) fur fibre than NZW and GB rabbits. Otherwise, influence of season and breed were negligible on the skin layer thickness values and the physical and chemical fur properties. Consequently, the study concluded that tanned rabbit furs are suitable for manufacturing leather garments when used alone, while reinforcing the fur with textile padding may increase their utility for other leather manufacturing purposes.