| Heat resistance is an important factor that would be considered in southern beef cattle production.Jinjiang cattle is a kind of zebu with heat resistance and coarse feeding.In this study,the thickness of skin and epidermis,and the morphological parameters of sweat gland and sebaceous gland in six region of Jinjiang cattle and its hybrid F1 with simmental and further backcross F2 with Jinjiang cattle cow in summer and autumn to reveal the reason of skin’ heat resistance of Jinjiang cattle and its genetic characteristics of backcross F2.This experiment is divided into three parts as follows:1 The Characteristics of Skin and Sweat Gland of Jinjiang cattle and Its Hybrid with SimmentalThe purpose of this study was to compare the morphological characteristics of sweat glands of Jinjiang cattle and its hybrid with Simmental,and to explore whether the strong heat resistance and sweating ability of Jinjiang cattle could be extended to its hybrid with Simmental.A total of 8 healthy adult Jinjiang cattle and its hybrid with simmental(weight 380±10 kg,all slaughtered at the end of November 2018)were selected for this experiment.The skin samples of neck,shoulder,back,abdomen,buttocks and leg were taken to measure the skin thickness,and the HE,PAS and AB-PAS staining were used to observe the morphological characteristics of sweat gland and sebaceous gland,and also measure the epidermis thickness.The secretions of sweat glands and sebaceous glands of Jinjiang cattle and its hybrid with simmental were neutral and acid mixture,and there was no glycogen in the cytoplasm of glandular cells.The sweat glands of Jinjiang cattle and its hybrid with simmental were apocrine and bursiform glands,and the sebaceous glands were grape-like and vesicular glands,which belonged to whole pulp-secreting glands.And the secretion was a mixture of neutral and acidic,and there was no glycogen in the cytoplasm.Breed×Region showed a interaction in the epidermis thickness and skin thickness(P<0.01).The abdomen of Jinjiang cattle’s hybrid with simmental and the back of Jinjiang cattle was from the epidermis thickness significantly thicker than other region,and had a significant difference with neck and legs(P<0.05).The skin thickness of neck and buttocks of Jinjiang cattle was significantly difference with other regions(P<0.05),and that of legs in Jinjiang cattle and its hybrid with simmental was thinner than other regions(P<0.05).Breed×Region showed a interaction in the density and the morphological characteristics of sweat gland and sebaceous gland(P<0.01),but there was no significant difference in the of depth of sweat gland and sebaceous gland(P>0.05).The skin’s characteristics of Jinjiang cattle similar to zebu is also reflected in its hybrid with simmental,and further show hybrid advantage.2 Effects of Summer and Autumn Seasons on The Morphological Characteristics Of Sweat Glands And Sebaceous Glands And Skin Thickness of Jinjiang CattleIn order to explore the reasons for the heat resistance of Jinjiang cattle’ skin,a total of 8 healthy adult Jinjiang cattle(4 in summer and 4 in autumn;weight 380±10 kg)were selected for this experiment.After slaughter and bloodlet,skin samples were taken from the neck,shoulders,back,abdomen,buttocks and legs to measure the skin thickness.The morphological characteristics of sweat glands and sebaceous glands,and the epidermis thickness were observed and measured by HE,Periodic Acid-Schiff stain(PAS)and Alcian blue-periodic acid sthiff(AB-PAS)staining.The results showed that:(1)the sweat glands of Jinjiang cattle were apocrine and bursiform glands,and the sebaceous glands were grape-like and vesicular glands,which belonged to whole pulp-secreting glands,and the secretion was a mixture of neutral and acidic,and there was no glycogen in the cytoplasm.(2)Region×season showed an interaction in the skin thickness,epidermis thickness and the morphological parameters of sweat gland and sebaceous gland(P<0.01).The skin thickness of neck and buttocks of Jinjiang cattle was significantly thicker than that of other regions(P<0.05),and that of all regions in autumn was significantly thicker than that in summer(P<0.05).Except the back and legs,the skin thickness in summer was significantly thicker than that in autumn.In summer,the density of sweat glands in buttocks was significantly higher than that in other regions(P<0.05),and there were significant differences in summer and autumn in other regions besides the neck and abdomen(P<0.05).In summer,the sweat glands’s depth in the buttocks was lower than that in other regions,and that of back was higher than that in other regions.In summer,the sweat glands’ volume in back was significantly larger than other regions(P<0.05),and in autumn,the buttocks’ volume was significantly larger than that in other regions(P<0.05).In summer and autumn,the sweat glands’ volume in shoulder,back and buttocks was significantly different(P<0.05).In summer,the density of sebaceous glands in the buttocks was significantly higher than that in other regions(P<0.05),and the sebaceous glands’ density in other regions in summer and autumn was significantly lower than that in other regions besides the neck(P<0.05).The depth of sebaceous glands in the buttocks in summer and autumn was significantly lower than that in other regions(P<0.05).In conclusion,the study demonstrated that the morphological characteristics of sweat glands,sebaceous glands and the thickness of epidermis and skin associated with regional and seasonal changes in thermal environment,were closely related to heat resistance of Jinjiang cattle.3 Effects of Summer and Autumn Seasons on Skin Cell Apoptosis,Antioxidant Capacity and Related Gene Expression in Jinjiang CattleThe purpose of this study was to explore the influence of summer and autumn on the heat tolerance related indexes of Jinjiang cattle’s skin.Test design as before.Apoptosis staining was carried out on the shoulder,back and buttocks,and the indexes of skin antioxidant capacity,the relative expression of FGA,TYPR1,DCT and the melanin content were measured.The results showed that:(1)the SOD activity of shoulder,back and buttocks in summer was higher than that in autumn,and the MDA content of skin in summer was significantly lower than that in autumn(P<0.05),and there was a significant difference in the MDA content of all regions in each season(P<0.05).The apoptosis degree of Jinjiang cattle in back was higher than that of shoulder and buttocks,and the apoptosis degree of Jinjiang cattle’s back,shoulder and buttocks in summer was higher than that in autumn.(2)There was an interaction between region and season on the level of relative expression of gene FGA(P<0.01),and the level of gene FGA of shoulder in autumn was significantly higher than that of back and buttocks in summer and autumn(P<0.05),and that of shoulder and buttocks in summer was greater than that of shoulder and buttocks in autumn(P<0.05).The level of relative expression of TYPR1 of the back was significantly different in summer and autumn(P<0.05),and that of TYRP1 on the shoulder and back was significantly greater than that of the buttocks in summer(P<0.05),while the level of DCT on the back and buttocks was significantly less than that of shoulders in summer(P<0.05).(3)The content of melanin in the shoulder in autumn was significantly higher than that in the back and buttocks in summer and autumn(P<0.05),and the content in the back was lower than that in the shoulder and buttocks(P>0.05).In conclusion,under high temperature and humidity in summer,Jinjiang cattle would improve the skin antioxidant capacity,the degree of cell apoptosis,the subcutaneous blood flow and melanin content,and further maintain the skin tissue renewal and heat resistance. |
PDF Full Text Request